Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Generic pwmlib implementation |
| 3 | * |
| 4 | * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de> |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 5 | * Copyright (C) 2011-2012 Avionic Design GmbH |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2, or (at your option) |
| 10 | * any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; see the file COPYING. If not, write to |
| 19 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. |
| 20 | */ |
| 21 | |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/pwm.h> |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 24 | #include <linux/radix-tree.h> |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 25 | #include <linux/list.h> |
| 26 | #include <linux/mutex.h> |
| 27 | #include <linux/err.h> |
| 28 | #include <linux/slab.h> |
| 29 | #include <linux/device.h> |
Thierry Reding | 62099ab | 2012-03-26 09:31:48 +0200 | [diff] [blame] | 30 | #include <linux/debugfs.h> |
| 31 | #include <linux/seq_file.h> |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 32 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 33 | #define MAX_PWMS 1024 |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 34 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame^] | 35 | static DEFINE_MUTEX(pwm_lookup_lock); |
| 36 | static LIST_HEAD(pwm_lookup_list); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 37 | static DEFINE_MUTEX(pwm_lock); |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 38 | static LIST_HEAD(pwm_chips); |
| 39 | static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); |
| 40 | static RADIX_TREE(pwm_tree, GFP_KERNEL); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 41 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 42 | static struct pwm_device *pwm_to_device(unsigned int pwm) |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 43 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 44 | return radix_tree_lookup(&pwm_tree, pwm); |
| 45 | } |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 46 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 47 | static int alloc_pwms(int pwm, unsigned int count) |
| 48 | { |
| 49 | unsigned int from = 0; |
| 50 | unsigned int start; |
| 51 | |
| 52 | if (pwm >= MAX_PWMS) |
| 53 | return -EINVAL; |
| 54 | |
| 55 | if (pwm >= 0) |
| 56 | from = pwm; |
| 57 | |
| 58 | start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
| 59 | count, 0); |
| 60 | |
| 61 | if (pwm >= 0 && start != pwm) |
| 62 | return -EEXIST; |
| 63 | |
| 64 | if (start + count > MAX_PWMS) |
| 65 | return -ENOSPC; |
| 66 | |
| 67 | return start; |
| 68 | } |
| 69 | |
| 70 | static void free_pwms(struct pwm_chip *chip) |
| 71 | { |
| 72 | unsigned int i; |
| 73 | |
| 74 | for (i = 0; i < chip->npwm; i++) { |
| 75 | struct pwm_device *pwm = &chip->pwms[i]; |
| 76 | radix_tree_delete(&pwm_tree, pwm->pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 77 | } |
| 78 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 79 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
| 80 | |
| 81 | kfree(chip->pwms); |
| 82 | chip->pwms = NULL; |
| 83 | } |
| 84 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame^] | 85 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
| 86 | { |
| 87 | struct pwm_chip *chip; |
| 88 | |
| 89 | if (!name) |
| 90 | return NULL; |
| 91 | |
| 92 | mutex_lock(&pwm_lock); |
| 93 | |
| 94 | list_for_each_entry(chip, &pwm_chips, list) { |
| 95 | const char *chip_name = dev_name(chip->dev); |
| 96 | |
| 97 | if (chip_name && strcmp(chip_name, name) == 0) { |
| 98 | mutex_unlock(&pwm_lock); |
| 99 | return chip; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | mutex_unlock(&pwm_lock); |
| 104 | |
| 105 | return NULL; |
| 106 | } |
| 107 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 108 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
| 109 | { |
| 110 | int err; |
| 111 | |
| 112 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| 113 | return -EBUSY; |
| 114 | |
| 115 | if (!try_module_get(pwm->chip->ops->owner)) |
| 116 | return -ENODEV; |
| 117 | |
| 118 | if (pwm->chip->ops->request) { |
| 119 | err = pwm->chip->ops->request(pwm->chip, pwm); |
| 120 | if (err) { |
| 121 | module_put(pwm->chip->ops->owner); |
| 122 | return err; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | set_bit(PWMF_REQUESTED, &pwm->flags); |
| 127 | pwm->label = label; |
| 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * pwm_set_chip_data() - set private chip data for a PWM |
| 134 | * @pwm: PWM device |
| 135 | * @data: pointer to chip-specific data |
| 136 | */ |
| 137 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) |
| 138 | { |
| 139 | if (!pwm) |
| 140 | return -EINVAL; |
| 141 | |
| 142 | pwm->chip_data = data; |
| 143 | |
| 144 | return 0; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * pwm_get_chip_data() - get private chip data for a PWM |
| 149 | * @pwm: PWM device |
| 150 | */ |
| 151 | void *pwm_get_chip_data(struct pwm_device *pwm) |
| 152 | { |
| 153 | return pwm ? pwm->chip_data : NULL; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 154 | } |
| 155 | |
| 156 | /** |
| 157 | * pwmchip_add() - register a new PWM chip |
| 158 | * @chip: the PWM chip to add |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 159 | * |
| 160 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base |
| 161 | * will be used. |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 162 | */ |
| 163 | int pwmchip_add(struct pwm_chip *chip) |
| 164 | { |
| 165 | struct pwm_device *pwm; |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 166 | unsigned int i; |
| 167 | int ret; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 168 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 169 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
| 170 | !chip->ops->enable || !chip->ops->disable) |
| 171 | return -EINVAL; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 172 | |
| 173 | mutex_lock(&pwm_lock); |
| 174 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 175 | ret = alloc_pwms(chip->base, chip->npwm); |
| 176 | if (ret < 0) |
| 177 | goto out; |
| 178 | |
| 179 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); |
| 180 | if (!chip->pwms) { |
| 181 | ret = -ENOMEM; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 182 | goto out; |
| 183 | } |
| 184 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 185 | chip->base = ret; |
| 186 | |
| 187 | for (i = 0; i < chip->npwm; i++) { |
| 188 | pwm = &chip->pwms[i]; |
| 189 | |
| 190 | pwm->chip = chip; |
| 191 | pwm->pwm = chip->base + i; |
| 192 | pwm->hwpwm = i; |
| 193 | |
| 194 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
| 195 | } |
| 196 | |
| 197 | bitmap_set(allocated_pwms, chip->base, chip->npwm); |
| 198 | |
| 199 | INIT_LIST_HEAD(&chip->list); |
| 200 | list_add(&chip->list, &pwm_chips); |
| 201 | |
| 202 | ret = 0; |
| 203 | |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 204 | out: |
| 205 | mutex_unlock(&pwm_lock); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 206 | return ret; |
| 207 | } |
| 208 | EXPORT_SYMBOL_GPL(pwmchip_add); |
| 209 | |
| 210 | /** |
| 211 | * pwmchip_remove() - remove a PWM chip |
| 212 | * @chip: the PWM chip to remove |
| 213 | * |
| 214 | * Removes a PWM chip. This function may return busy if the PWM chip provides |
| 215 | * a PWM device that is still requested. |
| 216 | */ |
| 217 | int pwmchip_remove(struct pwm_chip *chip) |
| 218 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 219 | unsigned int i; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 220 | int ret = 0; |
| 221 | |
| 222 | mutex_lock(&pwm_lock); |
| 223 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 224 | for (i = 0; i < chip->npwm; i++) { |
| 225 | struct pwm_device *pwm = &chip->pwms[i]; |
| 226 | |
| 227 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
| 228 | ret = -EBUSY; |
| 229 | goto out; |
| 230 | } |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 231 | } |
| 232 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 233 | list_del_init(&chip->list); |
| 234 | free_pwms(chip); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 235 | |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 236 | out: |
| 237 | mutex_unlock(&pwm_lock); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 238 | return ret; |
| 239 | } |
| 240 | EXPORT_SYMBOL_GPL(pwmchip_remove); |
| 241 | |
| 242 | /** |
| 243 | * pwm_request() - request a PWM device |
| 244 | * @pwm_id: global PWM device index |
| 245 | * @label: PWM device label |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame^] | 246 | * |
| 247 | * This function is deprecated, use pwm_get() instead. |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 248 | */ |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 249 | struct pwm_device *pwm_request(int pwm, const char *label) |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 250 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 251 | struct pwm_device *dev; |
| 252 | int err; |
| 253 | |
| 254 | if (pwm < 0 || pwm >= MAX_PWMS) |
| 255 | return ERR_PTR(-EINVAL); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 256 | |
| 257 | mutex_lock(&pwm_lock); |
| 258 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 259 | dev = pwm_to_device(pwm); |
| 260 | if (!dev) { |
| 261 | dev = ERR_PTR(-EPROBE_DEFER); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 262 | goto out; |
| 263 | } |
| 264 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 265 | err = pwm_device_request(dev, label); |
| 266 | if (err < 0) |
| 267 | dev = ERR_PTR(err); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 268 | |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 269 | out: |
| 270 | mutex_unlock(&pwm_lock); |
| 271 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 272 | return dev; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 273 | } |
| 274 | EXPORT_SYMBOL_GPL(pwm_request); |
| 275 | |
| 276 | /** |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 277 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip |
| 278 | * @chip: PWM chip |
| 279 | * @index: per-chip index of the PWM to request |
| 280 | * @label: a literal description string of this PWM |
| 281 | * |
| 282 | * Returns the PWM at the given index of the given PWM chip. A negative error |
| 283 | * code is returned if the index is not valid for the specified PWM chip or |
| 284 | * if the PWM device cannot be requested. |
| 285 | */ |
| 286 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, |
| 287 | unsigned int index, |
| 288 | const char *label) |
| 289 | { |
| 290 | struct pwm_device *pwm; |
| 291 | int err; |
| 292 | |
| 293 | if (!chip || index >= chip->npwm) |
| 294 | return ERR_PTR(-EINVAL); |
| 295 | |
| 296 | mutex_lock(&pwm_lock); |
| 297 | pwm = &chip->pwms[index]; |
| 298 | |
| 299 | err = pwm_device_request(pwm, label); |
| 300 | if (err < 0) |
| 301 | pwm = ERR_PTR(err); |
| 302 | |
| 303 | mutex_unlock(&pwm_lock); |
| 304 | return pwm; |
| 305 | } |
| 306 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
| 307 | |
| 308 | /** |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 309 | * pwm_free() - free a PWM device |
| 310 | * @pwm: PWM device |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame^] | 311 | * |
| 312 | * This function is deprecated, use pwm_put() instead. |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 313 | */ |
| 314 | void pwm_free(struct pwm_device *pwm) |
| 315 | { |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame^] | 316 | pwm_put(pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 317 | } |
| 318 | EXPORT_SYMBOL_GPL(pwm_free); |
| 319 | |
| 320 | /** |
| 321 | * pwm_config() - change a PWM device configuration |
| 322 | * @pwm: PWM device |
| 323 | * @duty_ns: "on" time (in nanoseconds) |
| 324 | * @period_ns: duration (in nanoseconds) of one cycle |
| 325 | */ |
| 326 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) |
| 327 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 328 | if (!pwm || period_ns == 0 || duty_ns > period_ns) |
| 329 | return -EINVAL; |
| 330 | |
| 331 | return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 332 | } |
| 333 | EXPORT_SYMBOL_GPL(pwm_config); |
| 334 | |
| 335 | /** |
| 336 | * pwm_enable() - start a PWM output toggling |
| 337 | * @pwm: PWM device |
| 338 | */ |
| 339 | int pwm_enable(struct pwm_device *pwm) |
| 340 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 341 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
| 342 | return pwm->chip->ops->enable(pwm->chip, pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 343 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 344 | return pwm ? 0 : -EINVAL; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 345 | } |
| 346 | EXPORT_SYMBOL_GPL(pwm_enable); |
| 347 | |
| 348 | /** |
| 349 | * pwm_disable() - stop a PWM output toggling |
| 350 | * @pwm: PWM device |
| 351 | */ |
| 352 | void pwm_disable(struct pwm_device *pwm) |
| 353 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 354 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
| 355 | pwm->chip->ops->disable(pwm->chip, pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 356 | } |
| 357 | EXPORT_SYMBOL_GPL(pwm_disable); |
Thierry Reding | 62099ab | 2012-03-26 09:31:48 +0200 | [diff] [blame] | 358 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame^] | 359 | /** |
| 360 | * pwm_add_table() - register PWM device consumers |
| 361 | * @table: array of consumers to register |
| 362 | * @num: number of consumers in table |
| 363 | */ |
| 364 | void __init pwm_add_table(struct pwm_lookup *table, size_t num) |
| 365 | { |
| 366 | mutex_lock(&pwm_lookup_lock); |
| 367 | |
| 368 | while (num--) { |
| 369 | list_add_tail(&table->list, &pwm_lookup_list); |
| 370 | table++; |
| 371 | } |
| 372 | |
| 373 | mutex_unlock(&pwm_lookup_lock); |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * pwm_get() - look up and request a PWM device |
| 378 | * @dev: device for PWM consumer |
| 379 | * @con_id: consumer name |
| 380 | * |
| 381 | * Look up a PWM chip and a relative index via a table supplied by board setup |
| 382 | * code (see pwm_add_table()). |
| 383 | * |
| 384 | * Once a PWM chip has been found the specified PWM device will be requested |
| 385 | * and is ready to be used. |
| 386 | */ |
| 387 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) |
| 388 | { |
| 389 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); |
| 390 | const char *dev_id = dev ? dev_name(dev): NULL; |
| 391 | struct pwm_chip *chip = NULL; |
| 392 | unsigned int best = 0; |
| 393 | struct pwm_lookup *p; |
| 394 | unsigned int index; |
| 395 | unsigned int match; |
| 396 | |
| 397 | /* |
| 398 | * We look up the provider in the static table typically provided by |
| 399 | * board setup code. We first try to lookup the consumer device by |
| 400 | * name. If the consumer device was passed in as NULL or if no match |
| 401 | * was found, we try to find the consumer by directly looking it up |
| 402 | * by name. |
| 403 | * |
| 404 | * If a match is found, the provider PWM chip is looked up by name |
| 405 | * and a PWM device is requested using the PWM device per-chip index. |
| 406 | * |
| 407 | * The lookup algorithm was shamelessly taken from the clock |
| 408 | * framework: |
| 409 | * |
| 410 | * We do slightly fuzzy matching here: |
| 411 | * An entry with a NULL ID is assumed to be a wildcard. |
| 412 | * If an entry has a device ID, it must match |
| 413 | * If an entry has a connection ID, it must match |
| 414 | * Then we take the most specific entry - with the following order |
| 415 | * of precedence: dev+con > dev only > con only. |
| 416 | */ |
| 417 | mutex_lock(&pwm_lookup_lock); |
| 418 | |
| 419 | list_for_each_entry(p, &pwm_lookup_list, list) { |
| 420 | match = 0; |
| 421 | |
| 422 | if (p->dev_id) { |
| 423 | if (!dev_id || strcmp(p->dev_id, dev_id)) |
| 424 | continue; |
| 425 | |
| 426 | match += 2; |
| 427 | } |
| 428 | |
| 429 | if (p->con_id) { |
| 430 | if (!con_id || strcmp(p->con_id, con_id)) |
| 431 | continue; |
| 432 | |
| 433 | match += 1; |
| 434 | } |
| 435 | |
| 436 | if (match > best) { |
| 437 | chip = pwmchip_find_by_name(p->provider); |
| 438 | index = p->index; |
| 439 | |
| 440 | if (match != 3) |
| 441 | best = match; |
| 442 | else |
| 443 | break; |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | if (chip) |
| 448 | pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id); |
| 449 | |
| 450 | mutex_unlock(&pwm_lookup_lock); |
| 451 | |
| 452 | return pwm; |
| 453 | } |
| 454 | EXPORT_SYMBOL_GPL(pwm_get); |
| 455 | |
| 456 | /** |
| 457 | * pwm_put() - release a PWM device |
| 458 | * @pwm: PWM device |
| 459 | */ |
| 460 | void pwm_put(struct pwm_device *pwm) |
| 461 | { |
| 462 | if (!pwm) |
| 463 | return; |
| 464 | |
| 465 | mutex_lock(&pwm_lock); |
| 466 | |
| 467 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { |
| 468 | pr_warning("PWM device already freed\n"); |
| 469 | goto out; |
| 470 | } |
| 471 | |
| 472 | if (pwm->chip->ops->free) |
| 473 | pwm->chip->ops->free(pwm->chip, pwm); |
| 474 | |
| 475 | pwm->label = NULL; |
| 476 | |
| 477 | module_put(pwm->chip->ops->owner); |
| 478 | out: |
| 479 | mutex_unlock(&pwm_lock); |
| 480 | } |
| 481 | EXPORT_SYMBOL_GPL(pwm_put); |
| 482 | |
Thierry Reding | 62099ab | 2012-03-26 09:31:48 +0200 | [diff] [blame] | 483 | #ifdef CONFIG_DEBUG_FS |
| 484 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) |
| 485 | { |
| 486 | unsigned int i; |
| 487 | |
| 488 | for (i = 0; i < chip->npwm; i++) { |
| 489 | struct pwm_device *pwm = &chip->pwms[i]; |
| 490 | |
| 491 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); |
| 492 | |
| 493 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| 494 | seq_printf(s, " requested"); |
| 495 | |
| 496 | if (test_bit(PWMF_ENABLED, &pwm->flags)) |
| 497 | seq_printf(s, " enabled"); |
| 498 | |
| 499 | seq_printf(s, "\n"); |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) |
| 504 | { |
| 505 | mutex_lock(&pwm_lock); |
| 506 | s->private = ""; |
| 507 | |
| 508 | return seq_list_start(&pwm_chips, *pos); |
| 509 | } |
| 510 | |
| 511 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) |
| 512 | { |
| 513 | s->private = "\n"; |
| 514 | |
| 515 | return seq_list_next(v, &pwm_chips, pos); |
| 516 | } |
| 517 | |
| 518 | static void pwm_seq_stop(struct seq_file *s, void *v) |
| 519 | { |
| 520 | mutex_unlock(&pwm_lock); |
| 521 | } |
| 522 | |
| 523 | static int pwm_seq_show(struct seq_file *s, void *v) |
| 524 | { |
| 525 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); |
| 526 | |
| 527 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, |
| 528 | chip->dev->bus ? chip->dev->bus->name : "no-bus", |
| 529 | dev_name(chip->dev), chip->npwm, |
| 530 | (chip->npwm != 1) ? "s" : ""); |
| 531 | |
| 532 | if (chip->ops->dbg_show) |
| 533 | chip->ops->dbg_show(chip, s); |
| 534 | else |
| 535 | pwm_dbg_show(chip, s); |
| 536 | |
| 537 | return 0; |
| 538 | } |
| 539 | |
| 540 | static const struct seq_operations pwm_seq_ops = { |
| 541 | .start = pwm_seq_start, |
| 542 | .next = pwm_seq_next, |
| 543 | .stop = pwm_seq_stop, |
| 544 | .show = pwm_seq_show, |
| 545 | }; |
| 546 | |
| 547 | static int pwm_seq_open(struct inode *inode, struct file *file) |
| 548 | { |
| 549 | return seq_open(file, &pwm_seq_ops); |
| 550 | } |
| 551 | |
| 552 | static const struct file_operations pwm_debugfs_ops = { |
| 553 | .owner = THIS_MODULE, |
| 554 | .open = pwm_seq_open, |
| 555 | .read = seq_read, |
| 556 | .llseek = seq_lseek, |
| 557 | .release = seq_release, |
| 558 | }; |
| 559 | |
| 560 | static int __init pwm_debugfs_init(void) |
| 561 | { |
| 562 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, |
| 563 | &pwm_debugfs_ops); |
| 564 | |
| 565 | return 0; |
| 566 | } |
| 567 | |
| 568 | subsys_initcall(pwm_debugfs_init); |
| 569 | #endif /* CONFIG_DEBUG_FS */ |