Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> |
| 3 | * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * Standard functionality for the common clock API. See Documentation/clk.txt |
| 10 | */ |
| 11 | |
| 12 | #include <linux/clk-private.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/mutex.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <linux/err.h> |
| 17 | #include <linux/list.h> |
| 18 | #include <linux/slab.h> |
Grant Likely | 766e6a4 | 2012-04-09 14:50:06 -0500 | [diff] [blame] | 19 | #include <linux/of.h> |
Stephen Boyd | 46c8773 | 2012-09-24 13:38:04 -0700 | [diff] [blame] | 20 | #include <linux/device.h> |
Prashant Gaikwad | f2f6c25 | 2013-01-04 12:30:52 +0530 | [diff] [blame] | 21 | #include <linux/init.h> |
Mike Turquette | 533ddeb | 2013-03-28 13:59:02 -0700 | [diff] [blame] | 22 | #include <linux/sched.h> |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 23 | |
| 24 | static DEFINE_SPINLOCK(enable_lock); |
| 25 | static DEFINE_MUTEX(prepare_lock); |
| 26 | |
Mike Turquette | 533ddeb | 2013-03-28 13:59:02 -0700 | [diff] [blame] | 27 | static struct task_struct *prepare_owner; |
| 28 | static struct task_struct *enable_owner; |
| 29 | |
| 30 | static int prepare_refcnt; |
| 31 | static int enable_refcnt; |
| 32 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 33 | static HLIST_HEAD(clk_root_list); |
| 34 | static HLIST_HEAD(clk_orphan_list); |
| 35 | static LIST_HEAD(clk_notifier_list); |
| 36 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 37 | /*** locking ***/ |
| 38 | static void clk_prepare_lock(void) |
| 39 | { |
Mike Turquette | 533ddeb | 2013-03-28 13:59:02 -0700 | [diff] [blame] | 40 | if (!mutex_trylock(&prepare_lock)) { |
| 41 | if (prepare_owner == current) { |
| 42 | prepare_refcnt++; |
| 43 | return; |
| 44 | } |
| 45 | mutex_lock(&prepare_lock); |
| 46 | } |
| 47 | WARN_ON_ONCE(prepare_owner != NULL); |
| 48 | WARN_ON_ONCE(prepare_refcnt != 0); |
| 49 | prepare_owner = current; |
| 50 | prepare_refcnt = 1; |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | static void clk_prepare_unlock(void) |
| 54 | { |
Mike Turquette | 533ddeb | 2013-03-28 13:59:02 -0700 | [diff] [blame] | 55 | WARN_ON_ONCE(prepare_owner != current); |
| 56 | WARN_ON_ONCE(prepare_refcnt == 0); |
| 57 | |
| 58 | if (--prepare_refcnt) |
| 59 | return; |
| 60 | prepare_owner = NULL; |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 61 | mutex_unlock(&prepare_lock); |
| 62 | } |
| 63 | |
| 64 | static unsigned long clk_enable_lock(void) |
| 65 | { |
| 66 | unsigned long flags; |
Mike Turquette | 533ddeb | 2013-03-28 13:59:02 -0700 | [diff] [blame] | 67 | |
| 68 | if (!spin_trylock_irqsave(&enable_lock, flags)) { |
| 69 | if (enable_owner == current) { |
| 70 | enable_refcnt++; |
| 71 | return flags; |
| 72 | } |
| 73 | spin_lock_irqsave(&enable_lock, flags); |
| 74 | } |
| 75 | WARN_ON_ONCE(enable_owner != NULL); |
| 76 | WARN_ON_ONCE(enable_refcnt != 0); |
| 77 | enable_owner = current; |
| 78 | enable_refcnt = 1; |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 79 | return flags; |
| 80 | } |
| 81 | |
| 82 | static void clk_enable_unlock(unsigned long flags) |
| 83 | { |
Mike Turquette | 533ddeb | 2013-03-28 13:59:02 -0700 | [diff] [blame] | 84 | WARN_ON_ONCE(enable_owner != current); |
| 85 | WARN_ON_ONCE(enable_refcnt == 0); |
| 86 | |
| 87 | if (--enable_refcnt) |
| 88 | return; |
| 89 | enable_owner = NULL; |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 90 | spin_unlock_irqrestore(&enable_lock, flags); |
| 91 | } |
| 92 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 93 | /*** debugfs support ***/ |
| 94 | |
| 95 | #ifdef CONFIG_COMMON_CLK_DEBUG |
| 96 | #include <linux/debugfs.h> |
| 97 | |
| 98 | static struct dentry *rootdir; |
| 99 | static struct dentry *orphandir; |
| 100 | static int inited = 0; |
| 101 | |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 102 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
| 103 | { |
| 104 | if (!c) |
| 105 | return; |
| 106 | |
| 107 | seq_printf(s, "%*s%-*s %-11d %-12d %-10lu", |
| 108 | level * 3 + 1, "", |
| 109 | 30 - level * 3, c->name, |
Peter De Schrijver | 670decd | 2013-06-05 18:06:35 +0300 | [diff] [blame] | 110 | c->enable_count, c->prepare_count, clk_get_rate(c)); |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 111 | seq_printf(s, "\n"); |
| 112 | } |
| 113 | |
| 114 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, |
| 115 | int level) |
| 116 | { |
| 117 | struct clk *child; |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 118 | |
| 119 | if (!c) |
| 120 | return; |
| 121 | |
| 122 | clk_summary_show_one(s, c, level); |
| 123 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 124 | hlist_for_each_entry(child, &c->children, child_node) |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 125 | clk_summary_show_subtree(s, child, level + 1); |
| 126 | } |
| 127 | |
| 128 | static int clk_summary_show(struct seq_file *s, void *data) |
| 129 | { |
| 130 | struct clk *c; |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 131 | |
| 132 | seq_printf(s, " clock enable_cnt prepare_cnt rate\n"); |
| 133 | seq_printf(s, "---------------------------------------------------------------------\n"); |
| 134 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 135 | clk_prepare_lock(); |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 136 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 137 | hlist_for_each_entry(c, &clk_root_list, child_node) |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 138 | clk_summary_show_subtree(s, c, 0); |
| 139 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 140 | hlist_for_each_entry(c, &clk_orphan_list, child_node) |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 141 | clk_summary_show_subtree(s, c, 0); |
| 142 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 143 | clk_prepare_unlock(); |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | |
| 149 | static int clk_summary_open(struct inode *inode, struct file *file) |
| 150 | { |
| 151 | return single_open(file, clk_summary_show, inode->i_private); |
| 152 | } |
| 153 | |
| 154 | static const struct file_operations clk_summary_fops = { |
| 155 | .open = clk_summary_open, |
| 156 | .read = seq_read, |
| 157 | .llseek = seq_lseek, |
| 158 | .release = single_release, |
| 159 | }; |
| 160 | |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 161 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
| 162 | { |
| 163 | if (!c) |
| 164 | return; |
| 165 | |
| 166 | seq_printf(s, "\"%s\": { ", c->name); |
| 167 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); |
| 168 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); |
Peter De Schrijver | 670decd | 2013-06-05 18:06:35 +0300 | [diff] [blame] | 169 | seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 170 | } |
| 171 | |
| 172 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) |
| 173 | { |
| 174 | struct clk *child; |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 175 | |
| 176 | if (!c) |
| 177 | return; |
| 178 | |
| 179 | clk_dump_one(s, c, level); |
| 180 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 181 | hlist_for_each_entry(child, &c->children, child_node) { |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 182 | seq_printf(s, ","); |
| 183 | clk_dump_subtree(s, child, level + 1); |
| 184 | } |
| 185 | |
| 186 | seq_printf(s, "}"); |
| 187 | } |
| 188 | |
| 189 | static int clk_dump(struct seq_file *s, void *data) |
| 190 | { |
| 191 | struct clk *c; |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 192 | bool first_node = true; |
| 193 | |
| 194 | seq_printf(s, "{"); |
| 195 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 196 | clk_prepare_lock(); |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 197 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 198 | hlist_for_each_entry(c, &clk_root_list, child_node) { |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 199 | if (!first_node) |
| 200 | seq_printf(s, ","); |
| 201 | first_node = false; |
| 202 | clk_dump_subtree(s, c, 0); |
| 203 | } |
| 204 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 205 | hlist_for_each_entry(c, &clk_orphan_list, child_node) { |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 206 | seq_printf(s, ","); |
| 207 | clk_dump_subtree(s, c, 0); |
| 208 | } |
| 209 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 210 | clk_prepare_unlock(); |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 211 | |
| 212 | seq_printf(s, "}"); |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | |
| 217 | static int clk_dump_open(struct inode *inode, struct file *file) |
| 218 | { |
| 219 | return single_open(file, clk_dump, inode->i_private); |
| 220 | } |
| 221 | |
| 222 | static const struct file_operations clk_dump_fops = { |
| 223 | .open = clk_dump_open, |
| 224 | .read = seq_read, |
| 225 | .llseek = seq_lseek, |
| 226 | .release = single_release, |
| 227 | }; |
| 228 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 229 | /* caller must hold prepare_lock */ |
| 230 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) |
| 231 | { |
| 232 | struct dentry *d; |
| 233 | int ret = -ENOMEM; |
| 234 | |
| 235 | if (!clk || !pdentry) { |
| 236 | ret = -EINVAL; |
| 237 | goto out; |
| 238 | } |
| 239 | |
| 240 | d = debugfs_create_dir(clk->name, pdentry); |
| 241 | if (!d) |
| 242 | goto out; |
| 243 | |
| 244 | clk->dentry = d; |
| 245 | |
| 246 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, |
| 247 | (u32 *)&clk->rate); |
| 248 | if (!d) |
| 249 | goto err_out; |
| 250 | |
| 251 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
| 252 | (u32 *)&clk->flags); |
| 253 | if (!d) |
| 254 | goto err_out; |
| 255 | |
| 256 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, |
| 257 | (u32 *)&clk->prepare_count); |
| 258 | if (!d) |
| 259 | goto err_out; |
| 260 | |
| 261 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, |
| 262 | (u32 *)&clk->enable_count); |
| 263 | if (!d) |
| 264 | goto err_out; |
| 265 | |
| 266 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, |
| 267 | (u32 *)&clk->notifier_count); |
| 268 | if (!d) |
| 269 | goto err_out; |
| 270 | |
| 271 | ret = 0; |
| 272 | goto out; |
| 273 | |
| 274 | err_out: |
| 275 | debugfs_remove(clk->dentry); |
| 276 | out: |
| 277 | return ret; |
| 278 | } |
| 279 | |
| 280 | /* caller must hold prepare_lock */ |
| 281 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) |
| 282 | { |
| 283 | struct clk *child; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 284 | int ret = -EINVAL;; |
| 285 | |
| 286 | if (!clk || !pdentry) |
| 287 | goto out; |
| 288 | |
| 289 | ret = clk_debug_create_one(clk, pdentry); |
| 290 | |
| 291 | if (ret) |
| 292 | goto out; |
| 293 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 294 | hlist_for_each_entry(child, &clk->children, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 295 | clk_debug_create_subtree(child, clk->dentry); |
| 296 | |
| 297 | ret = 0; |
| 298 | out: |
| 299 | return ret; |
| 300 | } |
| 301 | |
| 302 | /** |
| 303 | * clk_debug_register - add a clk node to the debugfs clk tree |
| 304 | * @clk: the clk being added to the debugfs clk tree |
| 305 | * |
| 306 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been |
| 307 | * initialized. Otherwise it bails out early since the debugfs clk tree |
| 308 | * will be created lazily by clk_debug_init as part of a late_initcall. |
| 309 | * |
| 310 | * Caller must hold prepare_lock. Only clk_init calls this function (so |
| 311 | * far) so this is taken care. |
| 312 | */ |
| 313 | static int clk_debug_register(struct clk *clk) |
| 314 | { |
| 315 | struct clk *parent; |
| 316 | struct dentry *pdentry; |
| 317 | int ret = 0; |
| 318 | |
| 319 | if (!inited) |
| 320 | goto out; |
| 321 | |
| 322 | parent = clk->parent; |
| 323 | |
| 324 | /* |
| 325 | * Check to see if a clk is a root clk. Also check that it is |
| 326 | * safe to add this clk to debugfs |
| 327 | */ |
| 328 | if (!parent) |
| 329 | if (clk->flags & CLK_IS_ROOT) |
| 330 | pdentry = rootdir; |
| 331 | else |
| 332 | pdentry = orphandir; |
| 333 | else |
| 334 | if (parent->dentry) |
| 335 | pdentry = parent->dentry; |
| 336 | else |
| 337 | goto out; |
| 338 | |
| 339 | ret = clk_debug_create_subtree(clk, pdentry); |
| 340 | |
| 341 | out: |
| 342 | return ret; |
| 343 | } |
| 344 | |
| 345 | /** |
Ulf Hansson | b33d212 | 2013-04-02 23:09:37 +0200 | [diff] [blame] | 346 | * clk_debug_reparent - reparent clk node in the debugfs clk tree |
| 347 | * @clk: the clk being reparented |
| 348 | * @new_parent: the new clk parent, may be NULL |
| 349 | * |
| 350 | * Rename clk entry in the debugfs clk tree if debugfs has been |
| 351 | * initialized. Otherwise it bails out early since the debugfs clk tree |
| 352 | * will be created lazily by clk_debug_init as part of a late_initcall. |
| 353 | * |
| 354 | * Caller must hold prepare_lock. |
| 355 | */ |
| 356 | static void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
| 357 | { |
| 358 | struct dentry *d; |
| 359 | struct dentry *new_parent_d; |
| 360 | |
| 361 | if (!inited) |
| 362 | return; |
| 363 | |
| 364 | if (new_parent) |
| 365 | new_parent_d = new_parent->dentry; |
| 366 | else |
| 367 | new_parent_d = orphandir; |
| 368 | |
| 369 | d = debugfs_rename(clk->dentry->d_parent, clk->dentry, |
| 370 | new_parent_d, clk->name); |
| 371 | if (d) |
| 372 | clk->dentry = d; |
| 373 | else |
| 374 | pr_debug("%s: failed to rename debugfs entry for %s\n", |
| 375 | __func__, clk->name); |
| 376 | } |
| 377 | |
| 378 | /** |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 379 | * clk_debug_init - lazily create the debugfs clk tree visualization |
| 380 | * |
| 381 | * clks are often initialized very early during boot before memory can |
| 382 | * be dynamically allocated and well before debugfs is setup. |
| 383 | * clk_debug_init walks the clk tree hierarchy while holding |
| 384 | * prepare_lock and creates the topology as part of a late_initcall, |
| 385 | * thus insuring that clks initialized very early will still be |
| 386 | * represented in the debugfs clk tree. This function should only be |
| 387 | * called once at boot-time, and all other clks added dynamically will |
| 388 | * be done so with clk_debug_register. |
| 389 | */ |
| 390 | static int __init clk_debug_init(void) |
| 391 | { |
| 392 | struct clk *clk; |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 393 | struct dentry *d; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 394 | |
| 395 | rootdir = debugfs_create_dir("clk", NULL); |
| 396 | |
| 397 | if (!rootdir) |
| 398 | return -ENOMEM; |
| 399 | |
Prashant Gaikwad | 1af599d | 2012-12-26 19:16:22 +0530 | [diff] [blame] | 400 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL, |
| 401 | &clk_summary_fops); |
| 402 | if (!d) |
| 403 | return -ENOMEM; |
| 404 | |
Prashant Gaikwad | bddca89 | 2012-12-26 19:16:23 +0530 | [diff] [blame] | 405 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL, |
| 406 | &clk_dump_fops); |
| 407 | if (!d) |
| 408 | return -ENOMEM; |
| 409 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 410 | orphandir = debugfs_create_dir("orphans", rootdir); |
| 411 | |
| 412 | if (!orphandir) |
| 413 | return -ENOMEM; |
| 414 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 415 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 416 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 417 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 418 | clk_debug_create_subtree(clk, rootdir); |
| 419 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 420 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 421 | clk_debug_create_subtree(clk, orphandir); |
| 422 | |
| 423 | inited = 1; |
| 424 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 425 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 426 | |
| 427 | return 0; |
| 428 | } |
| 429 | late_initcall(clk_debug_init); |
| 430 | #else |
| 431 | static inline int clk_debug_register(struct clk *clk) { return 0; } |
Ulf Hansson | b33d212 | 2013-04-02 23:09:37 +0200 | [diff] [blame] | 432 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
| 433 | { |
| 434 | } |
Mike Turquette | 70d347e | 2012-03-26 11:53:47 -0700 | [diff] [blame] | 435 | #endif |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 436 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 437 | /* caller must hold prepare_lock */ |
Ulf Hansson | 1c155b3 | 2013-03-12 20:26:03 +0100 | [diff] [blame] | 438 | static void clk_unprepare_unused_subtree(struct clk *clk) |
| 439 | { |
| 440 | struct clk *child; |
| 441 | |
| 442 | if (!clk) |
| 443 | return; |
| 444 | |
| 445 | hlist_for_each_entry(child, &clk->children, child_node) |
| 446 | clk_unprepare_unused_subtree(child); |
| 447 | |
| 448 | if (clk->prepare_count) |
| 449 | return; |
| 450 | |
| 451 | if (clk->flags & CLK_IGNORE_UNUSED) |
| 452 | return; |
| 453 | |
Ulf Hansson | 3cc8247 | 2013-03-12 20:26:04 +0100 | [diff] [blame] | 454 | if (__clk_is_prepared(clk)) { |
| 455 | if (clk->ops->unprepare_unused) |
| 456 | clk->ops->unprepare_unused(clk->hw); |
| 457 | else if (clk->ops->unprepare) |
Ulf Hansson | 1c155b3 | 2013-03-12 20:26:03 +0100 | [diff] [blame] | 458 | clk->ops->unprepare(clk->hw); |
Ulf Hansson | 3cc8247 | 2013-03-12 20:26:04 +0100 | [diff] [blame] | 459 | } |
Ulf Hansson | 1c155b3 | 2013-03-12 20:26:03 +0100 | [diff] [blame] | 460 | } |
Sebastian Hesselbarth | 496620c | 2013-04-15 08:59:46 +0200 | [diff] [blame] | 461 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
Ulf Hansson | 1c155b3 | 2013-03-12 20:26:03 +0100 | [diff] [blame] | 462 | |
| 463 | /* caller must hold prepare_lock */ |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 464 | static void clk_disable_unused_subtree(struct clk *clk) |
| 465 | { |
| 466 | struct clk *child; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 467 | unsigned long flags; |
| 468 | |
| 469 | if (!clk) |
| 470 | goto out; |
| 471 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 472 | hlist_for_each_entry(child, &clk->children, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 473 | clk_disable_unused_subtree(child); |
| 474 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 475 | flags = clk_enable_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 476 | |
| 477 | if (clk->enable_count) |
| 478 | goto unlock_out; |
| 479 | |
| 480 | if (clk->flags & CLK_IGNORE_UNUSED) |
| 481 | goto unlock_out; |
| 482 | |
Mike Turquette | 7c045a5 | 2012-12-04 11:00:35 -0800 | [diff] [blame] | 483 | /* |
| 484 | * some gate clocks have special needs during the disable-unused |
| 485 | * sequence. call .disable_unused if available, otherwise fall |
| 486 | * back to .disable |
| 487 | */ |
| 488 | if (__clk_is_enabled(clk)) { |
| 489 | if (clk->ops->disable_unused) |
| 490 | clk->ops->disable_unused(clk->hw); |
| 491 | else if (clk->ops->disable) |
| 492 | clk->ops->disable(clk->hw); |
| 493 | } |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 494 | |
| 495 | unlock_out: |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 496 | clk_enable_unlock(flags); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 497 | |
| 498 | out: |
| 499 | return; |
| 500 | } |
| 501 | |
Olof Johansson | 1e43525 | 2013-04-27 14:10:18 -0700 | [diff] [blame] | 502 | static bool clk_ignore_unused; |
| 503 | static int __init clk_ignore_unused_setup(char *__unused) |
| 504 | { |
| 505 | clk_ignore_unused = true; |
| 506 | return 1; |
| 507 | } |
| 508 | __setup("clk_ignore_unused", clk_ignore_unused_setup); |
| 509 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 510 | static int clk_disable_unused(void) |
| 511 | { |
| 512 | struct clk *clk; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 513 | |
Olof Johansson | 1e43525 | 2013-04-27 14:10:18 -0700 | [diff] [blame] | 514 | if (clk_ignore_unused) { |
| 515 | pr_warn("clk: Not disabling unused clocks\n"); |
| 516 | return 0; |
| 517 | } |
| 518 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 519 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 520 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 521 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 522 | clk_disable_unused_subtree(clk); |
| 523 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 524 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 525 | clk_disable_unused_subtree(clk); |
| 526 | |
Ulf Hansson | 1c155b3 | 2013-03-12 20:26:03 +0100 | [diff] [blame] | 527 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
| 528 | clk_unprepare_unused_subtree(clk); |
| 529 | |
| 530 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
| 531 | clk_unprepare_unused_subtree(clk); |
| 532 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 533 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 534 | |
| 535 | return 0; |
| 536 | } |
Saravana Kannan | d41d580 | 2013-05-09 11:35:01 -0700 | [diff] [blame] | 537 | late_initcall_sync(clk_disable_unused); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 538 | |
| 539 | /*** helper functions ***/ |
| 540 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 541 | const char *__clk_get_name(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 542 | { |
| 543 | return !clk ? NULL : clk->name; |
| 544 | } |
Niels de Vos | 4895084 | 2012-12-13 13:12:25 +0100 | [diff] [blame] | 545 | EXPORT_SYMBOL_GPL(__clk_get_name); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 546 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 547 | struct clk_hw *__clk_get_hw(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 548 | { |
| 549 | return !clk ? NULL : clk->hw; |
| 550 | } |
| 551 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 552 | u8 __clk_get_num_parents(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 553 | { |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 554 | return !clk ? 0 : clk->num_parents; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 555 | } |
| 556 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 557 | struct clk *__clk_get_parent(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 558 | { |
| 559 | return !clk ? NULL : clk->parent; |
| 560 | } |
| 561 | |
James Hogan | 7ef3dcc | 2013-07-29 12:24:58 +0100 | [diff] [blame] | 562 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
| 563 | { |
| 564 | if (!clk || index >= clk->num_parents) |
| 565 | return NULL; |
| 566 | else if (!clk->parents) |
| 567 | return __clk_lookup(clk->parent_names[index]); |
| 568 | else if (!clk->parents[index]) |
| 569 | return clk->parents[index] = |
| 570 | __clk_lookup(clk->parent_names[index]); |
| 571 | else |
| 572 | return clk->parents[index]; |
| 573 | } |
| 574 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 575 | unsigned int __clk_get_enable_count(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 576 | { |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 577 | return !clk ? 0 : clk->enable_count; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 578 | } |
| 579 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 580 | unsigned int __clk_get_prepare_count(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 581 | { |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 582 | return !clk ? 0 : clk->prepare_count; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 583 | } |
| 584 | |
| 585 | unsigned long __clk_get_rate(struct clk *clk) |
| 586 | { |
| 587 | unsigned long ret; |
| 588 | |
| 589 | if (!clk) { |
Rajendra Nayak | 34e44fe | 2012-03-26 19:01:48 +0530 | [diff] [blame] | 590 | ret = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 591 | goto out; |
| 592 | } |
| 593 | |
| 594 | ret = clk->rate; |
| 595 | |
| 596 | if (clk->flags & CLK_IS_ROOT) |
| 597 | goto out; |
| 598 | |
| 599 | if (!clk->parent) |
Rajendra Nayak | 34e44fe | 2012-03-26 19:01:48 +0530 | [diff] [blame] | 600 | ret = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 601 | |
| 602 | out: |
| 603 | return ret; |
| 604 | } |
| 605 | |
Russ Dill | 65800b2 | 2012-11-26 11:20:09 -0800 | [diff] [blame] | 606 | unsigned long __clk_get_flags(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 607 | { |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 608 | return !clk ? 0 : clk->flags; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 609 | } |
| 610 | |
Ulf Hansson | 3d6ee28 | 2013-03-12 20:26:02 +0100 | [diff] [blame] | 611 | bool __clk_is_prepared(struct clk *clk) |
| 612 | { |
| 613 | int ret; |
| 614 | |
| 615 | if (!clk) |
| 616 | return false; |
| 617 | |
| 618 | /* |
| 619 | * .is_prepared is optional for clocks that can prepare |
| 620 | * fall back to software usage counter if it is missing |
| 621 | */ |
| 622 | if (!clk->ops->is_prepared) { |
| 623 | ret = clk->prepare_count ? 1 : 0; |
| 624 | goto out; |
| 625 | } |
| 626 | |
| 627 | ret = clk->ops->is_prepared(clk->hw); |
| 628 | out: |
| 629 | return !!ret; |
| 630 | } |
| 631 | |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 632 | bool __clk_is_enabled(struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 633 | { |
| 634 | int ret; |
| 635 | |
| 636 | if (!clk) |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 637 | return false; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 638 | |
| 639 | /* |
| 640 | * .is_enabled is only mandatory for clocks that gate |
| 641 | * fall back to software usage counter if .is_enabled is missing |
| 642 | */ |
| 643 | if (!clk->ops->is_enabled) { |
| 644 | ret = clk->enable_count ? 1 : 0; |
| 645 | goto out; |
| 646 | } |
| 647 | |
| 648 | ret = clk->ops->is_enabled(clk->hw); |
| 649 | out: |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 650 | return !!ret; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 651 | } |
| 652 | |
| 653 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) |
| 654 | { |
| 655 | struct clk *child; |
| 656 | struct clk *ret; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 657 | |
| 658 | if (!strcmp(clk->name, name)) |
| 659 | return clk; |
| 660 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 661 | hlist_for_each_entry(child, &clk->children, child_node) { |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 662 | ret = __clk_lookup_subtree(name, child); |
| 663 | if (ret) |
| 664 | return ret; |
| 665 | } |
| 666 | |
| 667 | return NULL; |
| 668 | } |
| 669 | |
| 670 | struct clk *__clk_lookup(const char *name) |
| 671 | { |
| 672 | struct clk *root_clk; |
| 673 | struct clk *ret; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 674 | |
| 675 | if (!name) |
| 676 | return NULL; |
| 677 | |
| 678 | /* search the 'proper' clk tree first */ |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 679 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 680 | ret = __clk_lookup_subtree(name, root_clk); |
| 681 | if (ret) |
| 682 | return ret; |
| 683 | } |
| 684 | |
| 685 | /* if not found, then search the orphan tree */ |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 686 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 687 | ret = __clk_lookup_subtree(name, root_clk); |
| 688 | if (ret) |
| 689 | return ret; |
| 690 | } |
| 691 | |
| 692 | return NULL; |
| 693 | } |
| 694 | |
James Hogan | e366fdd | 2013-07-29 12:25:02 +0100 | [diff] [blame] | 695 | /* |
| 696 | * Helper for finding best parent to provide a given frequency. This can be used |
| 697 | * directly as a determine_rate callback (e.g. for a mux), or from a more |
| 698 | * complex clock that may combine a mux with other operations. |
| 699 | */ |
| 700 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, |
| 701 | unsigned long *best_parent_rate, |
| 702 | struct clk **best_parent_p) |
| 703 | { |
| 704 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; |
| 705 | int i, num_parents; |
| 706 | unsigned long parent_rate, best = 0; |
| 707 | |
| 708 | /* if NO_REPARENT flag set, pass through to current parent */ |
| 709 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { |
| 710 | parent = clk->parent; |
| 711 | if (clk->flags & CLK_SET_RATE_PARENT) |
| 712 | best = __clk_round_rate(parent, rate); |
| 713 | else if (parent) |
| 714 | best = __clk_get_rate(parent); |
| 715 | else |
| 716 | best = __clk_get_rate(clk); |
| 717 | goto out; |
| 718 | } |
| 719 | |
| 720 | /* find the parent that can provide the fastest rate <= rate */ |
| 721 | num_parents = clk->num_parents; |
| 722 | for (i = 0; i < num_parents; i++) { |
| 723 | parent = clk_get_parent_by_index(clk, i); |
| 724 | if (!parent) |
| 725 | continue; |
| 726 | if (clk->flags & CLK_SET_RATE_PARENT) |
| 727 | parent_rate = __clk_round_rate(parent, rate); |
| 728 | else |
| 729 | parent_rate = __clk_get_rate(parent); |
| 730 | if (parent_rate <= rate && parent_rate > best) { |
| 731 | best_parent = parent; |
| 732 | best = parent_rate; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | out: |
| 737 | if (best_parent) |
| 738 | *best_parent_p = best_parent; |
| 739 | *best_parent_rate = best; |
| 740 | |
| 741 | return best; |
| 742 | } |
| 743 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 744 | /*** clk api ***/ |
| 745 | |
| 746 | void __clk_unprepare(struct clk *clk) |
| 747 | { |
| 748 | if (!clk) |
| 749 | return; |
| 750 | |
| 751 | if (WARN_ON(clk->prepare_count == 0)) |
| 752 | return; |
| 753 | |
| 754 | if (--clk->prepare_count > 0) |
| 755 | return; |
| 756 | |
| 757 | WARN_ON(clk->enable_count > 0); |
| 758 | |
| 759 | if (clk->ops->unprepare) |
| 760 | clk->ops->unprepare(clk->hw); |
| 761 | |
| 762 | __clk_unprepare(clk->parent); |
| 763 | } |
| 764 | |
| 765 | /** |
| 766 | * clk_unprepare - undo preparation of a clock source |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 767 | * @clk: the clk being unprepared |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 768 | * |
| 769 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a |
| 770 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk |
| 771 | * if the operation may sleep. One example is a clk which is accessed over |
| 772 | * I2c. In the complex case a clk gate operation may require a fast and a slow |
| 773 | * part. It is this reason that clk_unprepare and clk_disable are not mutually |
| 774 | * exclusive. In fact clk_disable must be called before clk_unprepare. |
| 775 | */ |
| 776 | void clk_unprepare(struct clk *clk) |
| 777 | { |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 778 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 779 | __clk_unprepare(clk); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 780 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 781 | } |
| 782 | EXPORT_SYMBOL_GPL(clk_unprepare); |
| 783 | |
| 784 | int __clk_prepare(struct clk *clk) |
| 785 | { |
| 786 | int ret = 0; |
| 787 | |
| 788 | if (!clk) |
| 789 | return 0; |
| 790 | |
| 791 | if (clk->prepare_count == 0) { |
| 792 | ret = __clk_prepare(clk->parent); |
| 793 | if (ret) |
| 794 | return ret; |
| 795 | |
| 796 | if (clk->ops->prepare) { |
| 797 | ret = clk->ops->prepare(clk->hw); |
| 798 | if (ret) { |
| 799 | __clk_unprepare(clk->parent); |
| 800 | return ret; |
| 801 | } |
| 802 | } |
| 803 | } |
| 804 | |
| 805 | clk->prepare_count++; |
| 806 | |
| 807 | return 0; |
| 808 | } |
| 809 | |
| 810 | /** |
| 811 | * clk_prepare - prepare a clock source |
| 812 | * @clk: the clk being prepared |
| 813 | * |
| 814 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple |
| 815 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the |
| 816 | * operation may sleep. One example is a clk which is accessed over I2c. In |
| 817 | * the complex case a clk ungate operation may require a fast and a slow part. |
| 818 | * It is this reason that clk_prepare and clk_enable are not mutually |
| 819 | * exclusive. In fact clk_prepare must be called before clk_enable. |
| 820 | * Returns 0 on success, -EERROR otherwise. |
| 821 | */ |
| 822 | int clk_prepare(struct clk *clk) |
| 823 | { |
| 824 | int ret; |
| 825 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 826 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 827 | ret = __clk_prepare(clk); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 828 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 829 | |
| 830 | return ret; |
| 831 | } |
| 832 | EXPORT_SYMBOL_GPL(clk_prepare); |
| 833 | |
| 834 | static void __clk_disable(struct clk *clk) |
| 835 | { |
| 836 | if (!clk) |
| 837 | return; |
| 838 | |
Fengguang Wu | e47c6a3 | 2012-07-30 14:39:54 -0700 | [diff] [blame] | 839 | if (WARN_ON(IS_ERR(clk))) |
| 840 | return; |
| 841 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 842 | if (WARN_ON(clk->enable_count == 0)) |
| 843 | return; |
| 844 | |
| 845 | if (--clk->enable_count > 0) |
| 846 | return; |
| 847 | |
| 848 | if (clk->ops->disable) |
| 849 | clk->ops->disable(clk->hw); |
| 850 | |
| 851 | __clk_disable(clk->parent); |
| 852 | } |
| 853 | |
| 854 | /** |
| 855 | * clk_disable - gate a clock |
| 856 | * @clk: the clk being gated |
| 857 | * |
| 858 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In |
| 859 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a |
| 860 | * clk if the operation is fast and will never sleep. One example is a |
| 861 | * SoC-internal clk which is controlled via simple register writes. In the |
| 862 | * complex case a clk gate operation may require a fast and a slow part. It is |
| 863 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. |
| 864 | * In fact clk_disable must be called before clk_unprepare. |
| 865 | */ |
| 866 | void clk_disable(struct clk *clk) |
| 867 | { |
| 868 | unsigned long flags; |
| 869 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 870 | flags = clk_enable_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 871 | __clk_disable(clk); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 872 | clk_enable_unlock(flags); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 873 | } |
| 874 | EXPORT_SYMBOL_GPL(clk_disable); |
| 875 | |
| 876 | static int __clk_enable(struct clk *clk) |
| 877 | { |
| 878 | int ret = 0; |
| 879 | |
| 880 | if (!clk) |
| 881 | return 0; |
| 882 | |
| 883 | if (WARN_ON(clk->prepare_count == 0)) |
| 884 | return -ESHUTDOWN; |
| 885 | |
| 886 | if (clk->enable_count == 0) { |
| 887 | ret = __clk_enable(clk->parent); |
| 888 | |
| 889 | if (ret) |
| 890 | return ret; |
| 891 | |
| 892 | if (clk->ops->enable) { |
| 893 | ret = clk->ops->enable(clk->hw); |
| 894 | if (ret) { |
| 895 | __clk_disable(clk->parent); |
| 896 | return ret; |
| 897 | } |
| 898 | } |
| 899 | } |
| 900 | |
| 901 | clk->enable_count++; |
| 902 | return 0; |
| 903 | } |
| 904 | |
| 905 | /** |
| 906 | * clk_enable - ungate a clock |
| 907 | * @clk: the clk being ungated |
| 908 | * |
| 909 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a |
| 910 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk |
| 911 | * if the operation will never sleep. One example is a SoC-internal clk which |
| 912 | * is controlled via simple register writes. In the complex case a clk ungate |
| 913 | * operation may require a fast and a slow part. It is this reason that |
| 914 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare |
| 915 | * must be called before clk_enable. Returns 0 on success, -EERROR |
| 916 | * otherwise. |
| 917 | */ |
| 918 | int clk_enable(struct clk *clk) |
| 919 | { |
| 920 | unsigned long flags; |
| 921 | int ret; |
| 922 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 923 | flags = clk_enable_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 924 | ret = __clk_enable(clk); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 925 | clk_enable_unlock(flags); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 926 | |
| 927 | return ret; |
| 928 | } |
| 929 | EXPORT_SYMBOL_GPL(clk_enable); |
| 930 | |
| 931 | /** |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 932 | * __clk_round_rate - round the given rate for a clk |
| 933 | * @clk: round the rate of this clock |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 934 | * @rate: the rate which is to be rounded |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 935 | * |
| 936 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate |
| 937 | */ |
| 938 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) |
| 939 | { |
Shawn Guo | 81536e0 | 2012-04-12 20:50:17 +0800 | [diff] [blame] | 940 | unsigned long parent_rate = 0; |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 941 | struct clk *parent; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 942 | |
| 943 | if (!clk) |
Stephen Boyd | 2ac6b1f | 2012-10-03 23:38:55 -0700 | [diff] [blame] | 944 | return 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 945 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 946 | parent = clk->parent; |
| 947 | if (parent) |
| 948 | parent_rate = parent->rate; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 949 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 950 | if (clk->ops->determine_rate) |
| 951 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, |
| 952 | &parent); |
| 953 | else if (clk->ops->round_rate) |
| 954 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); |
| 955 | else if (clk->flags & CLK_SET_RATE_PARENT) |
| 956 | return __clk_round_rate(clk->parent, rate); |
| 957 | else |
| 958 | return clk->rate; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 959 | } |
| 960 | |
| 961 | /** |
| 962 | * clk_round_rate - round the given rate for a clk |
| 963 | * @clk: the clk for which we are rounding a rate |
| 964 | * @rate: the rate which is to be rounded |
| 965 | * |
| 966 | * Takes in a rate as input and rounds it to a rate that the clk can actually |
| 967 | * use which is then returned. If clk doesn't support round_rate operation |
| 968 | * then the parent rate is returned. |
| 969 | */ |
| 970 | long clk_round_rate(struct clk *clk, unsigned long rate) |
| 971 | { |
| 972 | unsigned long ret; |
| 973 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 974 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 975 | ret = __clk_round_rate(clk, rate); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 976 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 977 | |
| 978 | return ret; |
| 979 | } |
| 980 | EXPORT_SYMBOL_GPL(clk_round_rate); |
| 981 | |
| 982 | /** |
| 983 | * __clk_notify - call clk notifier chain |
| 984 | * @clk: struct clk * that is changing rate |
| 985 | * @msg: clk notifier type (see include/linux/clk.h) |
| 986 | * @old_rate: old clk rate |
| 987 | * @new_rate: new clk rate |
| 988 | * |
| 989 | * Triggers a notifier call chain on the clk rate-change notification |
| 990 | * for 'clk'. Passes a pointer to the struct clk and the previous |
| 991 | * and current rates to the notifier callback. Intended to be called by |
| 992 | * internal clock code only. Returns NOTIFY_DONE from the last driver |
| 993 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if |
| 994 | * a driver returns that. |
| 995 | */ |
| 996 | static int __clk_notify(struct clk *clk, unsigned long msg, |
| 997 | unsigned long old_rate, unsigned long new_rate) |
| 998 | { |
| 999 | struct clk_notifier *cn; |
| 1000 | struct clk_notifier_data cnd; |
| 1001 | int ret = NOTIFY_DONE; |
| 1002 | |
| 1003 | cnd.clk = clk; |
| 1004 | cnd.old_rate = old_rate; |
| 1005 | cnd.new_rate = new_rate; |
| 1006 | |
| 1007 | list_for_each_entry(cn, &clk_notifier_list, node) { |
| 1008 | if (cn->clk == clk) { |
| 1009 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, |
| 1010 | &cnd); |
| 1011 | break; |
| 1012 | } |
| 1013 | } |
| 1014 | |
| 1015 | return ret; |
| 1016 | } |
| 1017 | |
| 1018 | /** |
| 1019 | * __clk_recalc_rates |
| 1020 | * @clk: first clk in the subtree |
| 1021 | * @msg: notification type (see include/linux/clk.h) |
| 1022 | * |
| 1023 | * Walks the subtree of clks starting with clk and recalculates rates as it |
| 1024 | * goes. Note that if a clk does not implement the .recalc_rate callback then |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 1025 | * it is assumed that the clock will take on the rate of its parent. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1026 | * |
| 1027 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, |
| 1028 | * if necessary. |
| 1029 | * |
| 1030 | * Caller must hold prepare_lock. |
| 1031 | */ |
| 1032 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) |
| 1033 | { |
| 1034 | unsigned long old_rate; |
| 1035 | unsigned long parent_rate = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1036 | struct clk *child; |
| 1037 | |
| 1038 | old_rate = clk->rate; |
| 1039 | |
| 1040 | if (clk->parent) |
| 1041 | parent_rate = clk->parent->rate; |
| 1042 | |
| 1043 | if (clk->ops->recalc_rate) |
| 1044 | clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); |
| 1045 | else |
| 1046 | clk->rate = parent_rate; |
| 1047 | |
| 1048 | /* |
| 1049 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE |
| 1050 | * & ABORT_RATE_CHANGE notifiers |
| 1051 | */ |
| 1052 | if (clk->notifier_count && msg) |
| 1053 | __clk_notify(clk, msg, old_rate, clk->rate); |
| 1054 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1055 | hlist_for_each_entry(child, &clk->children, child_node) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1056 | __clk_recalc_rates(child, msg); |
| 1057 | } |
| 1058 | |
| 1059 | /** |
Ulf Hansson | a093bde | 2012-08-31 14:21:28 +0200 | [diff] [blame] | 1060 | * clk_get_rate - return the rate of clk |
| 1061 | * @clk: the clk whose rate is being returned |
| 1062 | * |
| 1063 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag |
| 1064 | * is set, which means a recalc_rate will be issued. |
| 1065 | * If clk is NULL then returns 0. |
| 1066 | */ |
| 1067 | unsigned long clk_get_rate(struct clk *clk) |
| 1068 | { |
| 1069 | unsigned long rate; |
| 1070 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1071 | clk_prepare_lock(); |
Ulf Hansson | a093bde | 2012-08-31 14:21:28 +0200 | [diff] [blame] | 1072 | |
| 1073 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) |
| 1074 | __clk_recalc_rates(clk, 0); |
| 1075 | |
| 1076 | rate = __clk_get_rate(clk); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1077 | clk_prepare_unlock(); |
Ulf Hansson | a093bde | 2012-08-31 14:21:28 +0200 | [diff] [blame] | 1078 | |
| 1079 | return rate; |
| 1080 | } |
| 1081 | EXPORT_SYMBOL_GPL(clk_get_rate); |
| 1082 | |
James Hogan | 4935b22 | 2013-07-29 12:24:59 +0100 | [diff] [blame] | 1083 | static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
| 1084 | { |
| 1085 | u8 i; |
| 1086 | |
| 1087 | if (!clk->parents) |
| 1088 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), |
| 1089 | GFP_KERNEL); |
| 1090 | |
| 1091 | /* |
| 1092 | * find index of new parent clock using cached parent ptrs, |
| 1093 | * or if not yet cached, use string name comparison and cache |
| 1094 | * them now to avoid future calls to __clk_lookup. |
| 1095 | */ |
| 1096 | for (i = 0; i < clk->num_parents; i++) { |
| 1097 | if (clk->parents && clk->parents[i] == parent) |
| 1098 | break; |
| 1099 | else if (!strcmp(clk->parent_names[i], parent->name)) { |
| 1100 | if (clk->parents) |
| 1101 | clk->parents[i] = __clk_lookup(parent->name); |
| 1102 | break; |
| 1103 | } |
| 1104 | } |
| 1105 | |
| 1106 | return i; |
| 1107 | } |
| 1108 | |
| 1109 | static void clk_reparent(struct clk *clk, struct clk *new_parent) |
| 1110 | { |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1111 | /* avoid duplicate POST_RATE_CHANGE notifications */ |
| 1112 | if (new_parent->new_child == clk) |
| 1113 | new_parent->new_child = NULL; |
| 1114 | |
James Hogan | 4935b22 | 2013-07-29 12:24:59 +0100 | [diff] [blame] | 1115 | hlist_del(&clk->child_node); |
| 1116 | |
| 1117 | if (new_parent) |
| 1118 | hlist_add_head(&clk->child_node, &new_parent->children); |
| 1119 | else |
| 1120 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
| 1121 | |
| 1122 | clk->parent = new_parent; |
| 1123 | } |
| 1124 | |
| 1125 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) |
| 1126 | { |
| 1127 | unsigned long flags; |
| 1128 | int ret = 0; |
| 1129 | struct clk *old_parent = clk->parent; |
| 1130 | |
| 1131 | /* |
| 1132 | * Migrate prepare state between parents and prevent race with |
| 1133 | * clk_enable(). |
| 1134 | * |
| 1135 | * If the clock is not prepared, then a race with |
| 1136 | * clk_enable/disable() is impossible since we already have the |
| 1137 | * prepare lock (future calls to clk_enable() need to be preceded by |
| 1138 | * a clk_prepare()). |
| 1139 | * |
| 1140 | * If the clock is prepared, migrate the prepared state to the new |
| 1141 | * parent and also protect against a race with clk_enable() by |
| 1142 | * forcing the clock and the new parent on. This ensures that all |
| 1143 | * future calls to clk_enable() are practically NOPs with respect to |
| 1144 | * hardware and software states. |
| 1145 | * |
| 1146 | * See also: Comment for clk_set_parent() below. |
| 1147 | */ |
| 1148 | if (clk->prepare_count) { |
| 1149 | __clk_prepare(parent); |
| 1150 | clk_enable(parent); |
| 1151 | clk_enable(clk); |
| 1152 | } |
| 1153 | |
| 1154 | /* update the clk tree topology */ |
| 1155 | flags = clk_enable_lock(); |
| 1156 | clk_reparent(clk, parent); |
| 1157 | clk_enable_unlock(flags); |
| 1158 | |
| 1159 | /* change clock input source */ |
| 1160 | if (parent && clk->ops->set_parent) |
| 1161 | ret = clk->ops->set_parent(clk->hw, p_index); |
| 1162 | |
| 1163 | if (ret) { |
| 1164 | flags = clk_enable_lock(); |
| 1165 | clk_reparent(clk, old_parent); |
| 1166 | clk_enable_unlock(flags); |
| 1167 | |
| 1168 | if (clk->prepare_count) { |
| 1169 | clk_disable(clk); |
| 1170 | clk_disable(parent); |
| 1171 | __clk_unprepare(parent); |
| 1172 | } |
| 1173 | return ret; |
| 1174 | } |
| 1175 | |
| 1176 | /* |
| 1177 | * Finish the migration of prepare state and undo the changes done |
| 1178 | * for preventing a race with clk_enable(). |
| 1179 | */ |
| 1180 | if (clk->prepare_count) { |
| 1181 | clk_disable(clk); |
| 1182 | clk_disable(old_parent); |
| 1183 | __clk_unprepare(old_parent); |
| 1184 | } |
| 1185 | |
| 1186 | /* update debugfs with new clk tree topology */ |
| 1187 | clk_debug_reparent(clk, parent); |
| 1188 | return 0; |
| 1189 | } |
| 1190 | |
Ulf Hansson | a093bde | 2012-08-31 14:21:28 +0200 | [diff] [blame] | 1191 | /** |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1192 | * __clk_speculate_rates |
| 1193 | * @clk: first clk in the subtree |
| 1194 | * @parent_rate: the "future" rate of clk's parent |
| 1195 | * |
| 1196 | * Walks the subtree of clks starting with clk, speculating rates as it |
| 1197 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. |
| 1198 | * |
| 1199 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending |
| 1200 | * pre-rate change notifications and returns early if no clks in the |
| 1201 | * subtree have subscribed to the notifications. Note that if a clk does not |
| 1202 | * implement the .recalc_rate callback then it is assumed that the clock will |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 1203 | * take on the rate of its parent. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1204 | * |
| 1205 | * Caller must hold prepare_lock. |
| 1206 | */ |
| 1207 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) |
| 1208 | { |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1209 | struct clk *child; |
| 1210 | unsigned long new_rate; |
| 1211 | int ret = NOTIFY_DONE; |
| 1212 | |
| 1213 | if (clk->ops->recalc_rate) |
| 1214 | new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); |
| 1215 | else |
| 1216 | new_rate = parent_rate; |
| 1217 | |
Soren Brinkmann | fb72a05 | 2013-04-03 12:17:12 -0700 | [diff] [blame] | 1218 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1219 | if (clk->notifier_count) |
| 1220 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); |
| 1221 | |
Soren Brinkmann | fb72a05 | 2013-04-03 12:17:12 -0700 | [diff] [blame] | 1222 | if (ret & NOTIFY_STOP_MASK) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1223 | goto out; |
| 1224 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1225 | hlist_for_each_entry(child, &clk->children, child_node) { |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1226 | ret = __clk_speculate_rates(child, new_rate); |
Soren Brinkmann | fb72a05 | 2013-04-03 12:17:12 -0700 | [diff] [blame] | 1227 | if (ret & NOTIFY_STOP_MASK) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1228 | break; |
| 1229 | } |
| 1230 | |
| 1231 | out: |
| 1232 | return ret; |
| 1233 | } |
| 1234 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1235 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
| 1236 | struct clk *new_parent, u8 p_index) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1237 | { |
| 1238 | struct clk *child; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1239 | |
| 1240 | clk->new_rate = new_rate; |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1241 | clk->new_parent = new_parent; |
| 1242 | clk->new_parent_index = p_index; |
| 1243 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ |
| 1244 | clk->new_child = NULL; |
| 1245 | if (new_parent && new_parent != clk->parent) |
| 1246 | new_parent->new_child = clk; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1247 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1248 | hlist_for_each_entry(child, &clk->children, child_node) { |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1249 | if (child->ops->recalc_rate) |
| 1250 | child->new_rate = child->ops->recalc_rate(child->hw, new_rate); |
| 1251 | else |
| 1252 | child->new_rate = new_rate; |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1253 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1254 | } |
| 1255 | } |
| 1256 | |
| 1257 | /* |
| 1258 | * calculate the new rates returning the topmost clock that has to be |
| 1259 | * changed. |
| 1260 | */ |
| 1261 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) |
| 1262 | { |
| 1263 | struct clk *top = clk; |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1264 | struct clk *old_parent, *parent; |
Shawn Guo | 81536e0 | 2012-04-12 20:50:17 +0800 | [diff] [blame] | 1265 | unsigned long best_parent_rate = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1266 | unsigned long new_rate; |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1267 | u8 p_index = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1268 | |
Mike Turquette | 7452b21 | 2012-03-26 14:45:36 -0700 | [diff] [blame] | 1269 | /* sanity */ |
| 1270 | if (IS_ERR_OR_NULL(clk)) |
| 1271 | return NULL; |
| 1272 | |
Mike Turquette | 63f5c3b | 2012-05-02 16:23:43 -0700 | [diff] [blame] | 1273 | /* save parent rate, if it exists */ |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1274 | parent = old_parent = clk->parent; |
| 1275 | if (parent) |
| 1276 | best_parent_rate = parent->rate; |
Mike Turquette | 63f5c3b | 2012-05-02 16:23:43 -0700 | [diff] [blame] | 1277 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1278 | /* find the closest rate and parent clk/rate */ |
| 1279 | if (clk->ops->determine_rate) { |
| 1280 | new_rate = clk->ops->determine_rate(clk->hw, rate, |
| 1281 | &best_parent_rate, |
| 1282 | &parent); |
| 1283 | } else if (clk->ops->round_rate) { |
| 1284 | new_rate = clk->ops->round_rate(clk->hw, rate, |
| 1285 | &best_parent_rate); |
| 1286 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { |
| 1287 | /* pass-through clock without adjustable parent */ |
| 1288 | clk->new_rate = clk->rate; |
| 1289 | return NULL; |
| 1290 | } else { |
| 1291 | /* pass-through clock with adjustable parent */ |
| 1292 | top = clk_calc_new_rates(parent, rate); |
| 1293 | new_rate = parent->new_rate; |
Mike Turquette | 63f5c3b | 2012-05-02 16:23:43 -0700 | [diff] [blame] | 1294 | goto out; |
Mike Turquette | 7452b21 | 2012-03-26 14:45:36 -0700 | [diff] [blame] | 1295 | } |
| 1296 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1297 | /* some clocks must be gated to change parent */ |
| 1298 | if (parent != old_parent && |
| 1299 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { |
| 1300 | pr_debug("%s: %s not gated but wants to reparent\n", |
| 1301 | __func__, clk->name); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1302 | return NULL; |
| 1303 | } |
| 1304 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1305 | /* try finding the new parent index */ |
| 1306 | if (parent) { |
| 1307 | p_index = clk_fetch_parent_index(clk, parent); |
| 1308 | if (p_index == clk->num_parents) { |
| 1309 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
| 1310 | __func__, parent->name, clk->name); |
| 1311 | return NULL; |
| 1312 | } |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1313 | } |
| 1314 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1315 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
| 1316 | best_parent_rate != parent->rate) |
| 1317 | top = clk_calc_new_rates(parent, best_parent_rate); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1318 | |
| 1319 | out: |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1320 | clk_calc_subtree(clk, new_rate, parent, p_index); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1321 | |
| 1322 | return top; |
| 1323 | } |
| 1324 | |
| 1325 | /* |
| 1326 | * Notify about rate changes in a subtree. Always walk down the whole tree |
| 1327 | * so that in case of an error we can walk down the whole tree again and |
| 1328 | * abort the change. |
| 1329 | */ |
| 1330 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) |
| 1331 | { |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1332 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1333 | int ret = NOTIFY_DONE; |
| 1334 | |
| 1335 | if (clk->rate == clk->new_rate) |
Sachin Kamat | 5fda685 | 2013-03-13 15:17:49 +0530 | [diff] [blame] | 1336 | return NULL; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1337 | |
| 1338 | if (clk->notifier_count) { |
| 1339 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); |
Soren Brinkmann | fb72a05 | 2013-04-03 12:17:12 -0700 | [diff] [blame] | 1340 | if (ret & NOTIFY_STOP_MASK) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1341 | fail_clk = clk; |
| 1342 | } |
| 1343 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1344 | hlist_for_each_entry(child, &clk->children, child_node) { |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1345 | /* Skip children who will be reparented to another clock */ |
| 1346 | if (child->new_parent && child->new_parent != clk) |
| 1347 | continue; |
| 1348 | tmp_clk = clk_propagate_rate_change(child, event); |
| 1349 | if (tmp_clk) |
| 1350 | fail_clk = tmp_clk; |
| 1351 | } |
| 1352 | |
| 1353 | /* handle the new child who might not be in clk->children yet */ |
| 1354 | if (clk->new_child) { |
| 1355 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); |
| 1356 | if (tmp_clk) |
| 1357 | fail_clk = tmp_clk; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1358 | } |
| 1359 | |
| 1360 | return fail_clk; |
| 1361 | } |
| 1362 | |
| 1363 | /* |
| 1364 | * walk down a subtree and set the new rates notifying the rate |
| 1365 | * change on the way |
| 1366 | */ |
| 1367 | static void clk_change_rate(struct clk *clk) |
| 1368 | { |
| 1369 | struct clk *child; |
| 1370 | unsigned long old_rate; |
Pawel Moll | bf47b4f | 2012-06-08 14:04:06 +0100 | [diff] [blame] | 1371 | unsigned long best_parent_rate = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1372 | |
| 1373 | old_rate = clk->rate; |
| 1374 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1375 | /* set parent */ |
| 1376 | if (clk->new_parent && clk->new_parent != clk->parent) |
| 1377 | __clk_set_parent(clk, clk->new_parent, clk->new_parent_index); |
| 1378 | |
Pawel Moll | bf47b4f | 2012-06-08 14:04:06 +0100 | [diff] [blame] | 1379 | if (clk->parent) |
| 1380 | best_parent_rate = clk->parent->rate; |
| 1381 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1382 | if (clk->ops->set_rate) |
Pawel Moll | bf47b4f | 2012-06-08 14:04:06 +0100 | [diff] [blame] | 1383 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1384 | |
| 1385 | if (clk->ops->recalc_rate) |
Pawel Moll | bf47b4f | 2012-06-08 14:04:06 +0100 | [diff] [blame] | 1386 | clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1387 | else |
Pawel Moll | bf47b4f | 2012-06-08 14:04:06 +0100 | [diff] [blame] | 1388 | clk->rate = best_parent_rate; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1389 | |
| 1390 | if (clk->notifier_count && old_rate != clk->rate) |
| 1391 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); |
| 1392 | |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1393 | hlist_for_each_entry(child, &clk->children, child_node) { |
| 1394 | /* Skip children who will be reparented to another clock */ |
| 1395 | if (child->new_parent && child->new_parent != clk) |
| 1396 | continue; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1397 | clk_change_rate(child); |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1398 | } |
| 1399 | |
| 1400 | /* handle the new child who might not be in clk->children yet */ |
| 1401 | if (clk->new_child) |
| 1402 | clk_change_rate(clk->new_child); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1403 | } |
| 1404 | |
| 1405 | /** |
| 1406 | * clk_set_rate - specify a new rate for clk |
| 1407 | * @clk: the clk whose rate is being changed |
| 1408 | * @rate: the new rate for clk |
| 1409 | * |
Mike Turquette | 5654dc9 | 2012-03-26 11:51:34 -0700 | [diff] [blame] | 1410 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1411 | * |
Mike Turquette | 5654dc9 | 2012-03-26 11:51:34 -0700 | [diff] [blame] | 1412 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
| 1413 | * propagate up to clk's parent; whether or not this happens depends on the |
| 1414 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged |
| 1415 | * after calling .round_rate then upstream parent propagation is ignored. If |
| 1416 | * *parent_rate comes back with a new rate for clk's parent then we propagate |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 1417 | * up to clk's parent and set its rate. Upward propagation will continue |
Mike Turquette | 5654dc9 | 2012-03-26 11:51:34 -0700 | [diff] [blame] | 1418 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
| 1419 | * .round_rate stops requesting changes to clk's parent_rate. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1420 | * |
Mike Turquette | 5654dc9 | 2012-03-26 11:51:34 -0700 | [diff] [blame] | 1421 | * Rate changes are accomplished via tree traversal that also recalculates the |
| 1422 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1423 | * |
| 1424 | * Returns 0 on success, -EERROR otherwise. |
| 1425 | */ |
| 1426 | int clk_set_rate(struct clk *clk, unsigned long rate) |
| 1427 | { |
| 1428 | struct clk *top, *fail_clk; |
| 1429 | int ret = 0; |
| 1430 | |
Mike Turquette | 89ac8d7 | 2013-08-21 23:58:09 -0700 | [diff] [blame] | 1431 | if (!clk) |
| 1432 | return 0; |
| 1433 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1434 | /* prevent racing with updates to the clock topology */ |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1435 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1436 | |
| 1437 | /* bail early if nothing to do */ |
Peter De Schrijver | 34e452a | 2013-06-05 18:06:36 +0300 | [diff] [blame] | 1438 | if (rate == clk_get_rate(clk)) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1439 | goto out; |
| 1440 | |
Saravana Kannan | 7e0fa1b | 2012-05-15 13:43:42 -0700 | [diff] [blame] | 1441 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
Viresh Kumar | 0e1c030 | 2012-04-11 16:03:42 +0530 | [diff] [blame] | 1442 | ret = -EBUSY; |
| 1443 | goto out; |
| 1444 | } |
| 1445 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1446 | /* calculate new rates and get the topmost changed clock */ |
| 1447 | top = clk_calc_new_rates(clk, rate); |
| 1448 | if (!top) { |
| 1449 | ret = -EINVAL; |
| 1450 | goto out; |
| 1451 | } |
| 1452 | |
| 1453 | /* notify that we are about to change rates */ |
| 1454 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); |
| 1455 | if (fail_clk) { |
| 1456 | pr_warn("%s: failed to set %s rate\n", __func__, |
| 1457 | fail_clk->name); |
| 1458 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); |
| 1459 | ret = -EBUSY; |
| 1460 | goto out; |
| 1461 | } |
| 1462 | |
| 1463 | /* change the rates */ |
| 1464 | clk_change_rate(top); |
| 1465 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1466 | out: |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1467 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1468 | |
| 1469 | return ret; |
| 1470 | } |
| 1471 | EXPORT_SYMBOL_GPL(clk_set_rate); |
| 1472 | |
| 1473 | /** |
| 1474 | * clk_get_parent - return the parent of a clk |
| 1475 | * @clk: the clk whose parent gets returned |
| 1476 | * |
| 1477 | * Simply returns clk->parent. Returns NULL if clk is NULL. |
| 1478 | */ |
| 1479 | struct clk *clk_get_parent(struct clk *clk) |
| 1480 | { |
| 1481 | struct clk *parent; |
| 1482 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1483 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1484 | parent = __clk_get_parent(clk); |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1485 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1486 | |
| 1487 | return parent; |
| 1488 | } |
| 1489 | EXPORT_SYMBOL_GPL(clk_get_parent); |
| 1490 | |
| 1491 | /* |
| 1492 | * .get_parent is mandatory for clocks with multiple possible parents. It is |
| 1493 | * optional for single-parent clocks. Always call .get_parent if it is |
| 1494 | * available and WARN if it is missing for multi-parent clocks. |
| 1495 | * |
| 1496 | * For single-parent clocks without .get_parent, first check to see if the |
| 1497 | * .parents array exists, and if so use it to avoid an expensive tree |
| 1498 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. |
| 1499 | */ |
| 1500 | static struct clk *__clk_init_parent(struct clk *clk) |
| 1501 | { |
| 1502 | struct clk *ret = NULL; |
| 1503 | u8 index; |
| 1504 | |
| 1505 | /* handle the trivial cases */ |
| 1506 | |
| 1507 | if (!clk->num_parents) |
| 1508 | goto out; |
| 1509 | |
| 1510 | if (clk->num_parents == 1) { |
| 1511 | if (IS_ERR_OR_NULL(clk->parent)) |
| 1512 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); |
| 1513 | ret = clk->parent; |
| 1514 | goto out; |
| 1515 | } |
| 1516 | |
| 1517 | if (!clk->ops->get_parent) { |
| 1518 | WARN(!clk->ops->get_parent, |
| 1519 | "%s: multi-parent clocks must implement .get_parent\n", |
| 1520 | __func__); |
| 1521 | goto out; |
| 1522 | }; |
| 1523 | |
| 1524 | /* |
| 1525 | * Do our best to cache parent clocks in clk->parents. This prevents |
| 1526 | * unnecessary and expensive calls to __clk_lookup. We don't set |
| 1527 | * clk->parent here; that is done by the calling function |
| 1528 | */ |
| 1529 | |
| 1530 | index = clk->ops->get_parent(clk->hw); |
| 1531 | |
| 1532 | if (!clk->parents) |
| 1533 | clk->parents = |
Rajendra Nayak | 7975059 | 2012-06-06 14:41:31 +0530 | [diff] [blame] | 1534 | kzalloc((sizeof(struct clk*) * clk->num_parents), |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1535 | GFP_KERNEL); |
| 1536 | |
James Hogan | 7ef3dcc | 2013-07-29 12:24:58 +0100 | [diff] [blame] | 1537 | ret = clk_get_parent_by_index(clk, index); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1538 | |
| 1539 | out: |
| 1540 | return ret; |
| 1541 | } |
| 1542 | |
Ulf Hansson | b33d212 | 2013-04-02 23:09:37 +0200 | [diff] [blame] | 1543 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
| 1544 | { |
| 1545 | clk_reparent(clk, new_parent); |
| 1546 | clk_debug_reparent(clk, new_parent); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1547 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
| 1548 | } |
| 1549 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1550 | /** |
| 1551 | * clk_set_parent - switch the parent of a mux clk |
| 1552 | * @clk: the mux clk whose input we are switching |
| 1553 | * @parent: the new input to clk |
| 1554 | * |
Saravana Kannan | f8aa0bd | 2013-05-15 21:07:24 -0700 | [diff] [blame] | 1555 | * Re-parent clk to use parent as its new input source. If clk is in |
| 1556 | * prepared state, the clk will get enabled for the duration of this call. If |
| 1557 | * that's not acceptable for a specific clk (Eg: the consumer can't handle |
| 1558 | * that, the reparenting is glitchy in hardware, etc), use the |
| 1559 | * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. |
| 1560 | * |
| 1561 | * After successfully changing clk's parent clk_set_parent will update the |
| 1562 | * clk topology, sysfs topology and propagate rate recalculation via |
| 1563 | * __clk_recalc_rates. |
| 1564 | * |
| 1565 | * Returns 0 on success, -EERROR otherwise. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1566 | */ |
| 1567 | int clk_set_parent(struct clk *clk, struct clk *parent) |
| 1568 | { |
| 1569 | int ret = 0; |
Ulf Hansson | 031dcc9 | 2013-04-02 23:09:38 +0200 | [diff] [blame] | 1570 | u8 p_index = 0; |
| 1571 | unsigned long p_rate = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1572 | |
Mike Turquette | 89ac8d7 | 2013-08-21 23:58:09 -0700 | [diff] [blame] | 1573 | if (!clk) |
| 1574 | return 0; |
| 1575 | |
| 1576 | if (!clk->ops) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1577 | return -EINVAL; |
| 1578 | |
Ulf Hansson | 031dcc9 | 2013-04-02 23:09:38 +0200 | [diff] [blame] | 1579 | /* verify ops for for multi-parent clks */ |
| 1580 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1581 | return -ENOSYS; |
| 1582 | |
| 1583 | /* prevent racing with updates to the clock topology */ |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1584 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1585 | |
| 1586 | if (clk->parent == parent) |
| 1587 | goto out; |
| 1588 | |
Ulf Hansson | 031dcc9 | 2013-04-02 23:09:38 +0200 | [diff] [blame] | 1589 | /* check that we are allowed to re-parent if the clock is in use */ |
| 1590 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { |
| 1591 | ret = -EBUSY; |
| 1592 | goto out; |
| 1593 | } |
| 1594 | |
| 1595 | /* try finding the new parent index */ |
| 1596 | if (parent) { |
| 1597 | p_index = clk_fetch_parent_index(clk, parent); |
| 1598 | p_rate = parent->rate; |
| 1599 | if (p_index == clk->num_parents) { |
| 1600 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
| 1601 | __func__, parent->name, clk->name); |
| 1602 | ret = -EINVAL; |
| 1603 | goto out; |
| 1604 | } |
| 1605 | } |
| 1606 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1607 | /* propagate PRE_RATE_CHANGE notifications */ |
Soren Brinkmann | f3aab5d | 2013-04-16 10:06:50 -0700 | [diff] [blame] | 1608 | ret = __clk_speculate_rates(clk, p_rate); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1609 | |
| 1610 | /* abort if a driver objects */ |
Soren Brinkmann | fb72a05 | 2013-04-03 12:17:12 -0700 | [diff] [blame] | 1611 | if (ret & NOTIFY_STOP_MASK) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1612 | goto out; |
| 1613 | |
Ulf Hansson | 031dcc9 | 2013-04-02 23:09:38 +0200 | [diff] [blame] | 1614 | /* do the re-parent */ |
| 1615 | ret = __clk_set_parent(clk, parent, p_index); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1616 | |
Ulf Hansson | a68de8e | 2013-04-02 23:09:39 +0200 | [diff] [blame] | 1617 | /* propagate rate recalculation accordingly */ |
| 1618 | if (ret) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1619 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
Ulf Hansson | a68de8e | 2013-04-02 23:09:39 +0200 | [diff] [blame] | 1620 | else |
| 1621 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1622 | |
| 1623 | out: |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1624 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1625 | |
| 1626 | return ret; |
| 1627 | } |
| 1628 | EXPORT_SYMBOL_GPL(clk_set_parent); |
| 1629 | |
| 1630 | /** |
| 1631 | * __clk_init - initialize the data structures in a struct clk |
| 1632 | * @dev: device initializing this clk, placeholder for now |
| 1633 | * @clk: clk being initialized |
| 1634 | * |
| 1635 | * Initializes the lists in struct clk, queries the hardware for the |
| 1636 | * parent and rate and sets them both. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1637 | */ |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1638 | int __clk_init(struct device *dev, struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1639 | { |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1640 | int i, ret = 0; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1641 | struct clk *orphan; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1642 | struct hlist_node *tmp2; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1643 | |
| 1644 | if (!clk) |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1645 | return -EINVAL; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1646 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1647 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1648 | |
| 1649 | /* check to see if a clock with this name is already registered */ |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1650 | if (__clk_lookup(clk->name)) { |
| 1651 | pr_debug("%s: clk %s already initialized\n", |
| 1652 | __func__, clk->name); |
| 1653 | ret = -EEXIST; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1654 | goto out; |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1655 | } |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1656 | |
Mike Turquette | d4d7e3d | 2012-03-26 16:15:52 -0700 | [diff] [blame] | 1657 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
| 1658 | if (clk->ops->set_rate && |
James Hogan | 71472c0 | 2013-07-29 12:25:00 +0100 | [diff] [blame] | 1659 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
| 1660 | clk->ops->recalc_rate)) { |
| 1661 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", |
Mike Turquette | d4d7e3d | 2012-03-26 16:15:52 -0700 | [diff] [blame] | 1662 | __func__, clk->name); |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1663 | ret = -EINVAL; |
Mike Turquette | d4d7e3d | 2012-03-26 16:15:52 -0700 | [diff] [blame] | 1664 | goto out; |
| 1665 | } |
| 1666 | |
| 1667 | if (clk->ops->set_parent && !clk->ops->get_parent) { |
| 1668 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", |
| 1669 | __func__, clk->name); |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1670 | ret = -EINVAL; |
Mike Turquette | d4d7e3d | 2012-03-26 16:15:52 -0700 | [diff] [blame] | 1671 | goto out; |
| 1672 | } |
| 1673 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1674 | /* throw a WARN if any entries in parent_names are NULL */ |
| 1675 | for (i = 0; i < clk->num_parents; i++) |
| 1676 | WARN(!clk->parent_names[i], |
| 1677 | "%s: invalid NULL in %s's .parent_names\n", |
| 1678 | __func__, clk->name); |
| 1679 | |
| 1680 | /* |
| 1681 | * Allocate an array of struct clk *'s to avoid unnecessary string |
| 1682 | * look-ups of clk's possible parents. This can fail for clocks passed |
| 1683 | * in to clk_init during early boot; thus any access to clk->parents[] |
| 1684 | * must always check for a NULL pointer and try to populate it if |
| 1685 | * necessary. |
| 1686 | * |
| 1687 | * If clk->parents is not NULL we skip this entire block. This allows |
| 1688 | * for clock drivers to statically initialize clk->parents. |
| 1689 | */ |
Rajendra Nayak | 9ca1c5a | 2012-06-06 14:41:30 +0530 | [diff] [blame] | 1690 | if (clk->num_parents > 1 && !clk->parents) { |
| 1691 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1692 | GFP_KERNEL); |
| 1693 | /* |
| 1694 | * __clk_lookup returns NULL for parents that have not been |
| 1695 | * clk_init'd; thus any access to clk->parents[] must check |
| 1696 | * for a NULL pointer. We can always perform lazy lookups for |
| 1697 | * missing parents later on. |
| 1698 | */ |
| 1699 | if (clk->parents) |
| 1700 | for (i = 0; i < clk->num_parents; i++) |
| 1701 | clk->parents[i] = |
| 1702 | __clk_lookup(clk->parent_names[i]); |
| 1703 | } |
| 1704 | |
| 1705 | clk->parent = __clk_init_parent(clk); |
| 1706 | |
| 1707 | /* |
| 1708 | * Populate clk->parent if parent has already been __clk_init'd. If |
| 1709 | * parent has not yet been __clk_init'd then place clk in the orphan |
| 1710 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root |
| 1711 | * clk list. |
| 1712 | * |
| 1713 | * Every time a new clk is clk_init'd then we walk the list of orphan |
| 1714 | * clocks and re-parent any that are children of the clock currently |
| 1715 | * being clk_init'd. |
| 1716 | */ |
| 1717 | if (clk->parent) |
| 1718 | hlist_add_head(&clk->child_node, |
| 1719 | &clk->parent->children); |
| 1720 | else if (clk->flags & CLK_IS_ROOT) |
| 1721 | hlist_add_head(&clk->child_node, &clk_root_list); |
| 1722 | else |
| 1723 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
| 1724 | |
| 1725 | /* |
| 1726 | * Set clk's rate. The preferred method is to use .recalc_rate. For |
| 1727 | * simple clocks and lazy developers the default fallback is to use the |
| 1728 | * parent's rate. If a clock doesn't have a parent (or is orphaned) |
| 1729 | * then rate is set to zero. |
| 1730 | */ |
| 1731 | if (clk->ops->recalc_rate) |
| 1732 | clk->rate = clk->ops->recalc_rate(clk->hw, |
| 1733 | __clk_get_rate(clk->parent)); |
| 1734 | else if (clk->parent) |
| 1735 | clk->rate = clk->parent->rate; |
| 1736 | else |
| 1737 | clk->rate = 0; |
| 1738 | |
| 1739 | /* |
| 1740 | * walk the list of orphan clocks and reparent any that are children of |
| 1741 | * this clock |
| 1742 | */ |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1743 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
Martin Fuzzey | 1f61e5f | 2012-11-22 20:15:05 +0100 | [diff] [blame] | 1744 | if (orphan->ops->get_parent) { |
| 1745 | i = orphan->ops->get_parent(orphan->hw); |
| 1746 | if (!strcmp(clk->name, orphan->parent_names[i])) |
| 1747 | __clk_reparent(orphan, clk); |
| 1748 | continue; |
| 1749 | } |
| 1750 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1751 | for (i = 0; i < orphan->num_parents; i++) |
| 1752 | if (!strcmp(clk->name, orphan->parent_names[i])) { |
| 1753 | __clk_reparent(orphan, clk); |
| 1754 | break; |
| 1755 | } |
Martin Fuzzey | 1f61e5f | 2012-11-22 20:15:05 +0100 | [diff] [blame] | 1756 | } |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1757 | |
| 1758 | /* |
| 1759 | * optional platform-specific magic |
| 1760 | * |
| 1761 | * The .init callback is not used by any of the basic clock types, but |
| 1762 | * exists for weird hardware that must perform initialization magic. |
| 1763 | * Please consider other ways of solving initialization problems before |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 1764 | * using this callback, as its use is discouraged. |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1765 | */ |
| 1766 | if (clk->ops->init) |
| 1767 | clk->ops->init(clk->hw); |
| 1768 | |
| 1769 | clk_debug_register(clk); |
| 1770 | |
| 1771 | out: |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 1772 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1773 | |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1774 | return ret; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1775 | } |
| 1776 | |
| 1777 | /** |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1778 | * __clk_register - register a clock and return a cookie. |
| 1779 | * |
| 1780 | * Same as clk_register, except that the .clk field inside hw shall point to a |
| 1781 | * preallocated (generally statically allocated) struct clk. None of the fields |
| 1782 | * of the struct clk need to be initialized. |
| 1783 | * |
| 1784 | * The data pointed to by .init and .clk field shall NOT be marked as init |
| 1785 | * data. |
| 1786 | * |
| 1787 | * __clk_register is only exposed via clk-private.h and is intended for use with |
| 1788 | * very large numbers of clocks that need to be statically initialized. It is |
| 1789 | * a layering violation to include clk-private.h from any code which implements |
| 1790 | * a clock's .ops; as such any statically initialized clock data MUST be in a |
Peter Meerwald | 24ee1a0 | 2013-06-29 15:14:19 +0200 | [diff] [blame] | 1791 | * separate C file from the logic that implements its operations. Returns 0 |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1792 | * on success, otherwise an error code. |
| 1793 | */ |
| 1794 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) |
| 1795 | { |
| 1796 | int ret; |
| 1797 | struct clk *clk; |
| 1798 | |
| 1799 | clk = hw->clk; |
| 1800 | clk->name = hw->init->name; |
| 1801 | clk->ops = hw->init->ops; |
| 1802 | clk->hw = hw; |
| 1803 | clk->flags = hw->init->flags; |
| 1804 | clk->parent_names = hw->init->parent_names; |
| 1805 | clk->num_parents = hw->init->num_parents; |
| 1806 | |
| 1807 | ret = __clk_init(dev, clk); |
| 1808 | if (ret) |
| 1809 | return ERR_PTR(ret); |
| 1810 | |
| 1811 | return clk; |
| 1812 | } |
| 1813 | EXPORT_SYMBOL_GPL(__clk_register); |
| 1814 | |
Stephen Boyd | 46c8773 | 2012-09-24 13:38:04 -0700 | [diff] [blame] | 1815 | static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1816 | { |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1817 | int i, ret; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1818 | |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1819 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
| 1820 | if (!clk->name) { |
| 1821 | pr_err("%s: could not allocate clk->name\n", __func__); |
| 1822 | ret = -ENOMEM; |
| 1823 | goto fail_name; |
| 1824 | } |
| 1825 | clk->ops = hw->init->ops; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1826 | clk->hw = hw; |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1827 | clk->flags = hw->init->flags; |
| 1828 | clk->num_parents = hw->init->num_parents; |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1829 | hw->clk = clk; |
| 1830 | |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1831 | /* allocate local copy in case parent_names is __initdata */ |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1832 | clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents), |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1833 | GFP_KERNEL); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1834 | |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1835 | if (!clk->parent_names) { |
| 1836 | pr_err("%s: could not allocate clk->parent_names\n", __func__); |
| 1837 | ret = -ENOMEM; |
| 1838 | goto fail_parent_names; |
| 1839 | } |
| 1840 | |
| 1841 | |
| 1842 | /* copy each string name in case parent_names is __initdata */ |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1843 | for (i = 0; i < clk->num_parents; i++) { |
| 1844 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], |
| 1845 | GFP_KERNEL); |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1846 | if (!clk->parent_names[i]) { |
| 1847 | pr_err("%s: could not copy parent_names\n", __func__); |
| 1848 | ret = -ENOMEM; |
| 1849 | goto fail_parent_names_copy; |
| 1850 | } |
| 1851 | } |
| 1852 | |
| 1853 | ret = __clk_init(dev, clk); |
| 1854 | if (!ret) |
Stephen Boyd | 46c8773 | 2012-09-24 13:38:04 -0700 | [diff] [blame] | 1855 | return 0; |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1856 | |
| 1857 | fail_parent_names_copy: |
| 1858 | while (--i >= 0) |
| 1859 | kfree(clk->parent_names[i]); |
| 1860 | kfree(clk->parent_names); |
| 1861 | fail_parent_names: |
Saravana Kannan | 0197b3e | 2012-04-25 22:58:56 -0700 | [diff] [blame] | 1862 | kfree(clk->name); |
| 1863 | fail_name: |
Stephen Boyd | 46c8773 | 2012-09-24 13:38:04 -0700 | [diff] [blame] | 1864 | return ret; |
| 1865 | } |
| 1866 | |
| 1867 | /** |
| 1868 | * clk_register - allocate a new clock, register it and return an opaque cookie |
| 1869 | * @dev: device that is registering this clock |
| 1870 | * @hw: link to hardware-specific clock data |
| 1871 | * |
| 1872 | * clk_register is the primary interface for populating the clock tree with new |
| 1873 | * clock nodes. It returns a pointer to the newly allocated struct clk which |
| 1874 | * cannot be dereferenced by driver code but may be used in conjuction with the |
| 1875 | * rest of the clock API. In the event of an error clk_register will return an |
| 1876 | * error code; drivers must test for an error code after calling clk_register. |
| 1877 | */ |
| 1878 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) |
| 1879 | { |
| 1880 | int ret; |
| 1881 | struct clk *clk; |
| 1882 | |
| 1883 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); |
| 1884 | if (!clk) { |
| 1885 | pr_err("%s: could not allocate clk\n", __func__); |
| 1886 | ret = -ENOMEM; |
| 1887 | goto fail_out; |
| 1888 | } |
| 1889 | |
| 1890 | ret = _clk_register(dev, hw, clk); |
| 1891 | if (!ret) |
| 1892 | return clk; |
| 1893 | |
Mike Turquette | d1302a3 | 2012-03-29 14:30:40 -0700 | [diff] [blame] | 1894 | kfree(clk); |
| 1895 | fail_out: |
| 1896 | return ERR_PTR(ret); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1897 | } |
| 1898 | EXPORT_SYMBOL_GPL(clk_register); |
| 1899 | |
Mark Brown | 1df5c93 | 2012-04-18 09:07:12 +0100 | [diff] [blame] | 1900 | /** |
| 1901 | * clk_unregister - unregister a currently registered clock |
| 1902 | * @clk: clock to unregister |
| 1903 | * |
| 1904 | * Currently unimplemented. |
| 1905 | */ |
| 1906 | void clk_unregister(struct clk *clk) {} |
| 1907 | EXPORT_SYMBOL_GPL(clk_unregister); |
| 1908 | |
Stephen Boyd | 46c8773 | 2012-09-24 13:38:04 -0700 | [diff] [blame] | 1909 | static void devm_clk_release(struct device *dev, void *res) |
| 1910 | { |
| 1911 | clk_unregister(res); |
| 1912 | } |
| 1913 | |
| 1914 | /** |
| 1915 | * devm_clk_register - resource managed clk_register() |
| 1916 | * @dev: device that is registering this clock |
| 1917 | * @hw: link to hardware-specific clock data |
| 1918 | * |
| 1919 | * Managed clk_register(). Clocks returned from this function are |
| 1920 | * automatically clk_unregister()ed on driver detach. See clk_register() for |
| 1921 | * more information. |
| 1922 | */ |
| 1923 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) |
| 1924 | { |
| 1925 | struct clk *clk; |
| 1926 | int ret; |
| 1927 | |
| 1928 | clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); |
| 1929 | if (!clk) |
| 1930 | return ERR_PTR(-ENOMEM); |
| 1931 | |
| 1932 | ret = _clk_register(dev, hw, clk); |
| 1933 | if (!ret) { |
| 1934 | devres_add(dev, clk); |
| 1935 | } else { |
| 1936 | devres_free(clk); |
| 1937 | clk = ERR_PTR(ret); |
| 1938 | } |
| 1939 | |
| 1940 | return clk; |
| 1941 | } |
| 1942 | EXPORT_SYMBOL_GPL(devm_clk_register); |
| 1943 | |
| 1944 | static int devm_clk_match(struct device *dev, void *res, void *data) |
| 1945 | { |
| 1946 | struct clk *c = res; |
| 1947 | if (WARN_ON(!c)) |
| 1948 | return 0; |
| 1949 | return c == data; |
| 1950 | } |
| 1951 | |
| 1952 | /** |
| 1953 | * devm_clk_unregister - resource managed clk_unregister() |
| 1954 | * @clk: clock to unregister |
| 1955 | * |
| 1956 | * Deallocate a clock allocated with devm_clk_register(). Normally |
| 1957 | * this function will not need to be called and the resource management |
| 1958 | * code will ensure that the resource is freed. |
| 1959 | */ |
| 1960 | void devm_clk_unregister(struct device *dev, struct clk *clk) |
| 1961 | { |
| 1962 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); |
| 1963 | } |
| 1964 | EXPORT_SYMBOL_GPL(devm_clk_unregister); |
| 1965 | |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 1966 | /*** clk rate change notifiers ***/ |
| 1967 | |
| 1968 | /** |
| 1969 | * clk_notifier_register - add a clk rate change notifier |
| 1970 | * @clk: struct clk * to watch |
| 1971 | * @nb: struct notifier_block * with callback info |
| 1972 | * |
| 1973 | * Request notification when clk's rate changes. This uses an SRCU |
| 1974 | * notifier because we want it to block and notifier unregistrations are |
| 1975 | * uncommon. The callbacks associated with the notifier must not |
| 1976 | * re-enter into the clk framework by calling any top-level clk APIs; |
| 1977 | * this will cause a nested prepare_lock mutex. |
| 1978 | * |
| 1979 | * Pre-change notifier callbacks will be passed the current, pre-change |
| 1980 | * rate of the clk via struct clk_notifier_data.old_rate. The new, |
| 1981 | * post-change rate of the clk is passed via struct |
| 1982 | * clk_notifier_data.new_rate. |
| 1983 | * |
| 1984 | * Post-change notifiers will pass the now-current, post-change rate of |
| 1985 | * the clk in both struct clk_notifier_data.old_rate and struct |
| 1986 | * clk_notifier_data.new_rate. |
| 1987 | * |
| 1988 | * Abort-change notifiers are effectively the opposite of pre-change |
| 1989 | * notifiers: the original pre-change clk rate is passed in via struct |
| 1990 | * clk_notifier_data.new_rate and the failed post-change rate is passed |
| 1991 | * in via struct clk_notifier_data.old_rate. |
| 1992 | * |
| 1993 | * clk_notifier_register() must be called from non-atomic context. |
| 1994 | * Returns -EINVAL if called with null arguments, -ENOMEM upon |
| 1995 | * allocation failure; otherwise, passes along the return value of |
| 1996 | * srcu_notifier_chain_register(). |
| 1997 | */ |
| 1998 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) |
| 1999 | { |
| 2000 | struct clk_notifier *cn; |
| 2001 | int ret = -ENOMEM; |
| 2002 | |
| 2003 | if (!clk || !nb) |
| 2004 | return -EINVAL; |
| 2005 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 2006 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 2007 | |
| 2008 | /* search the list of notifiers for this clk */ |
| 2009 | list_for_each_entry(cn, &clk_notifier_list, node) |
| 2010 | if (cn->clk == clk) |
| 2011 | break; |
| 2012 | |
| 2013 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ |
| 2014 | if (cn->clk != clk) { |
| 2015 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); |
| 2016 | if (!cn) |
| 2017 | goto out; |
| 2018 | |
| 2019 | cn->clk = clk; |
| 2020 | srcu_init_notifier_head(&cn->notifier_head); |
| 2021 | |
| 2022 | list_add(&cn->node, &clk_notifier_list); |
| 2023 | } |
| 2024 | |
| 2025 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); |
| 2026 | |
| 2027 | clk->notifier_count++; |
| 2028 | |
| 2029 | out: |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 2030 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 2031 | |
| 2032 | return ret; |
| 2033 | } |
| 2034 | EXPORT_SYMBOL_GPL(clk_notifier_register); |
| 2035 | |
| 2036 | /** |
| 2037 | * clk_notifier_unregister - remove a clk rate change notifier |
| 2038 | * @clk: struct clk * |
| 2039 | * @nb: struct notifier_block * with callback info |
| 2040 | * |
| 2041 | * Request no further notification for changes to 'clk' and frees memory |
| 2042 | * allocated in clk_notifier_register. |
| 2043 | * |
| 2044 | * Returns -EINVAL if called with null arguments; otherwise, passes |
| 2045 | * along the return value of srcu_notifier_chain_unregister(). |
| 2046 | */ |
| 2047 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) |
| 2048 | { |
| 2049 | struct clk_notifier *cn = NULL; |
| 2050 | int ret = -EINVAL; |
| 2051 | |
| 2052 | if (!clk || !nb) |
| 2053 | return -EINVAL; |
| 2054 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 2055 | clk_prepare_lock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 2056 | |
| 2057 | list_for_each_entry(cn, &clk_notifier_list, node) |
| 2058 | if (cn->clk == clk) |
| 2059 | break; |
| 2060 | |
| 2061 | if (cn->clk == clk) { |
| 2062 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); |
| 2063 | |
| 2064 | clk->notifier_count--; |
| 2065 | |
| 2066 | /* XXX the notifier code should handle this better */ |
| 2067 | if (!cn->notifier_head.head) { |
| 2068 | srcu_cleanup_notifier_head(&cn->notifier_head); |
Lai Jiangshan | 72b5322 | 2013-06-03 17:17:15 +0800 | [diff] [blame] | 2069 | list_del(&cn->node); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 2070 | kfree(cn); |
| 2071 | } |
| 2072 | |
| 2073 | } else { |
| 2074 | ret = -ENOENT; |
| 2075 | } |
| 2076 | |
Mike Turquette | eab89f6 | 2013-03-28 13:59:01 -0700 | [diff] [blame] | 2077 | clk_prepare_unlock(); |
Mike Turquette | b2476490 | 2012-03-15 23:11:19 -0700 | [diff] [blame] | 2078 | |
| 2079 | return ret; |
| 2080 | } |
| 2081 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); |
Grant Likely | 766e6a4 | 2012-04-09 14:50:06 -0500 | [diff] [blame] | 2082 | |
| 2083 | #ifdef CONFIG_OF |
| 2084 | /** |
| 2085 | * struct of_clk_provider - Clock provider registration structure |
| 2086 | * @link: Entry in global list of clock providers |
| 2087 | * @node: Pointer to device tree node of clock provider |
| 2088 | * @get: Get clock callback. Returns NULL or a struct clk for the |
| 2089 | * given clock specifier |
| 2090 | * @data: context pointer to be passed into @get callback |
| 2091 | */ |
| 2092 | struct of_clk_provider { |
| 2093 | struct list_head link; |
| 2094 | |
| 2095 | struct device_node *node; |
| 2096 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); |
| 2097 | void *data; |
| 2098 | }; |
| 2099 | |
Prashant Gaikwad | f2f6c25 | 2013-01-04 12:30:52 +0530 | [diff] [blame] | 2100 | extern struct of_device_id __clk_of_table[]; |
| 2101 | |
| 2102 | static const struct of_device_id __clk_of_table_sentinel |
| 2103 | __used __section(__clk_of_table_end); |
| 2104 | |
Grant Likely | 766e6a4 | 2012-04-09 14:50:06 -0500 | [diff] [blame] | 2105 | static LIST_HEAD(of_clk_providers); |
| 2106 | static DEFINE_MUTEX(of_clk_lock); |
| 2107 | |
| 2108 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, |
| 2109 | void *data) |
| 2110 | { |
| 2111 | return data; |
| 2112 | } |
| 2113 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); |
| 2114 | |
Shawn Guo | 494bfec | 2012-08-22 21:36:27 +0800 | [diff] [blame] | 2115 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
| 2116 | { |
| 2117 | struct clk_onecell_data *clk_data = data; |
| 2118 | unsigned int idx = clkspec->args[0]; |
| 2119 | |
| 2120 | if (idx >= clk_data->clk_num) { |
| 2121 | pr_err("%s: invalid clock index %d\n", __func__, idx); |
| 2122 | return ERR_PTR(-EINVAL); |
| 2123 | } |
| 2124 | |
| 2125 | return clk_data->clks[idx]; |
| 2126 | } |
| 2127 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); |
| 2128 | |
Grant Likely | 766e6a4 | 2012-04-09 14:50:06 -0500 | [diff] [blame] | 2129 | /** |
| 2130 | * of_clk_add_provider() - Register a clock provider for a node |
| 2131 | * @np: Device node pointer associated with clock provider |
| 2132 | * @clk_src_get: callback for decoding clock |
| 2133 | * @data: context pointer for @clk_src_get callback. |
| 2134 | */ |
| 2135 | int of_clk_add_provider(struct device_node *np, |
| 2136 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, |
| 2137 | void *data), |
| 2138 | void *data) |
| 2139 | { |
| 2140 | struct of_clk_provider *cp; |
| 2141 | |
| 2142 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); |
| 2143 | if (!cp) |
| 2144 | return -ENOMEM; |
| 2145 | |
| 2146 | cp->node = of_node_get(np); |
| 2147 | cp->data = data; |
| 2148 | cp->get = clk_src_get; |
| 2149 | |
| 2150 | mutex_lock(&of_clk_lock); |
| 2151 | list_add(&cp->link, &of_clk_providers); |
| 2152 | mutex_unlock(&of_clk_lock); |
| 2153 | pr_debug("Added clock from %s\n", np->full_name); |
| 2154 | |
| 2155 | return 0; |
| 2156 | } |
| 2157 | EXPORT_SYMBOL_GPL(of_clk_add_provider); |
| 2158 | |
| 2159 | /** |
| 2160 | * of_clk_del_provider() - Remove a previously registered clock provider |
| 2161 | * @np: Device node pointer associated with clock provider |
| 2162 | */ |
| 2163 | void of_clk_del_provider(struct device_node *np) |
| 2164 | { |
| 2165 | struct of_clk_provider *cp; |
| 2166 | |
| 2167 | mutex_lock(&of_clk_lock); |
| 2168 | list_for_each_entry(cp, &of_clk_providers, link) { |
| 2169 | if (cp->node == np) { |
| 2170 | list_del(&cp->link); |
| 2171 | of_node_put(cp->node); |
| 2172 | kfree(cp); |
| 2173 | break; |
| 2174 | } |
| 2175 | } |
| 2176 | mutex_unlock(&of_clk_lock); |
| 2177 | } |
| 2178 | EXPORT_SYMBOL_GPL(of_clk_del_provider); |
| 2179 | |
| 2180 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) |
| 2181 | { |
| 2182 | struct of_clk_provider *provider; |
| 2183 | struct clk *clk = ERR_PTR(-ENOENT); |
| 2184 | |
| 2185 | /* Check if we have such a provider in our array */ |
| 2186 | mutex_lock(&of_clk_lock); |
| 2187 | list_for_each_entry(provider, &of_clk_providers, link) { |
| 2188 | if (provider->node == clkspec->np) |
| 2189 | clk = provider->get(clkspec, provider->data); |
| 2190 | if (!IS_ERR(clk)) |
| 2191 | break; |
| 2192 | } |
| 2193 | mutex_unlock(&of_clk_lock); |
| 2194 | |
| 2195 | return clk; |
| 2196 | } |
| 2197 | |
| 2198 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
| 2199 | { |
| 2200 | struct of_phandle_args clkspec; |
| 2201 | const char *clk_name; |
| 2202 | int rc; |
| 2203 | |
| 2204 | if (index < 0) |
| 2205 | return NULL; |
| 2206 | |
| 2207 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, |
| 2208 | &clkspec); |
| 2209 | if (rc) |
| 2210 | return NULL; |
| 2211 | |
| 2212 | if (of_property_read_string_index(clkspec.np, "clock-output-names", |
| 2213 | clkspec.args_count ? clkspec.args[0] : 0, |
| 2214 | &clk_name) < 0) |
| 2215 | clk_name = clkspec.np->name; |
| 2216 | |
| 2217 | of_node_put(clkspec.np); |
| 2218 | return clk_name; |
| 2219 | } |
| 2220 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); |
| 2221 | |
| 2222 | /** |
| 2223 | * of_clk_init() - Scan and init clock providers from the DT |
| 2224 | * @matches: array of compatible values and init functions for providers. |
| 2225 | * |
| 2226 | * This function scans the device tree for matching clock providers and |
| 2227 | * calls their initialization functions |
| 2228 | */ |
| 2229 | void __init of_clk_init(const struct of_device_id *matches) |
| 2230 | { |
Alex Elder | 7f7ed58 | 2013-08-22 11:31:31 -0500 | [diff] [blame^] | 2231 | const struct of_device_id *match; |
Grant Likely | 766e6a4 | 2012-04-09 14:50:06 -0500 | [diff] [blame] | 2232 | struct device_node *np; |
| 2233 | |
Prashant Gaikwad | f2f6c25 | 2013-01-04 12:30:52 +0530 | [diff] [blame] | 2234 | if (!matches) |
| 2235 | matches = __clk_of_table; |
| 2236 | |
Alex Elder | 7f7ed58 | 2013-08-22 11:31:31 -0500 | [diff] [blame^] | 2237 | for_each_matching_node_and_match(np, matches, &match) { |
Grant Likely | 766e6a4 | 2012-04-09 14:50:06 -0500 | [diff] [blame] | 2238 | of_clk_init_cb_t clk_init_cb = match->data; |
| 2239 | clk_init_cb(np); |
| 2240 | } |
| 2241 | } |
| 2242 | #endif |