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Loc Ho308964c2013-06-26 11:56:09 -06001/*
2 * clk-xgene.c - AppliedMicro X-Gene Clock Interface
3 *
4 * Copyright (c) 2013, Applied Micro Circuits Corporation
5 * Author: Loc Ho <lho@apm.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) 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; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 *
22 */
23#include <linux/module.h>
24#include <linux/spinlock.h>
25#include <linux/io.h>
26#include <linux/of.h>
27#include <linux/clkdev.h>
28#include <linux/clk-provider.h>
29#include <linux/of_address.h>
Loc Ho308964c2013-06-26 11:56:09 -060030
31/* Register SCU_PCPPLL bit fields */
32#define N_DIV_RD(src) (((src) & 0x000001ff))
33
34/* Register SCU_SOCPLL bit fields */
35#define CLKR_RD(src) (((src) & 0x07000000)>>24)
36#define CLKOD_RD(src) (((src) & 0x00300000)>>20)
37#define REGSPEC_RESET_F1_MASK 0x00010000
38#define CLKF_RD(src) (((src) & 0x000001ff))
39
40#define XGENE_CLK_DRIVER_VER "0.1"
41
42static DEFINE_SPINLOCK(clk_lock);
43
Stephen Boyd6ae5fd32015-05-01 14:14:57 -070044static inline u32 xgene_clk_read(void __iomem *csr)
Loc Ho308964c2013-06-26 11:56:09 -060045{
46 return readl_relaxed(csr);
47}
48
Stephen Boyd6ae5fd32015-05-01 14:14:57 -070049static inline void xgene_clk_write(u32 data, void __iomem *csr)
Loc Ho308964c2013-06-26 11:56:09 -060050{
51 return writel_relaxed(data, csr);
52}
53
54/* PLL Clock */
55enum xgene_pll_type {
56 PLL_TYPE_PCP = 0,
57 PLL_TYPE_SOC = 1,
58};
59
60struct xgene_clk_pll {
61 struct clk_hw hw;
Loc Ho308964c2013-06-26 11:56:09 -060062 void __iomem *reg;
63 spinlock_t *lock;
64 u32 pll_offset;
65 enum xgene_pll_type type;
66};
67
68#define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)
69
70static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
71{
72 struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
73 u32 data;
74
75 data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
Stephen Boyd836ee0f2015-08-12 11:42:23 -070076 pr_debug("%s pll %s\n", clk_hw_get_name(hw),
Loc Ho308964c2013-06-26 11:56:09 -060077 data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");
78
79 return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
80}
81
82static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
83 unsigned long parent_rate)
84{
85 struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
86 unsigned long fref;
87 unsigned long fvco;
88 u32 pll;
89 u32 nref;
90 u32 nout;
91 u32 nfb;
92
93 pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
94
95 if (pllclk->type == PLL_TYPE_PCP) {
96 /*
97 * PLL VCO = Reference clock * NF
98 * PCP PLL = PLL_VCO / 2
99 */
100 nout = 2;
101 fvco = parent_rate * (N_DIV_RD(pll) + 4);
102 } else {
103 /*
104 * Fref = Reference Clock / NREF;
105 * Fvco = Fref * NFB;
106 * Fout = Fvco / NOUT;
107 */
108 nref = CLKR_RD(pll) + 1;
109 nout = CLKOD_RD(pll) + 1;
110 nfb = CLKF_RD(pll);
111 fref = parent_rate / nref;
112 fvco = fref * nfb;
113 }
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700114 pr_debug("%s pll recalc rate %ld parent %ld\n", clk_hw_get_name(hw),
Loc Ho308964c2013-06-26 11:56:09 -0600115 fvco / nout, parent_rate);
116
117 return fvco / nout;
118}
119
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700120static const struct clk_ops xgene_clk_pll_ops = {
Loc Ho308964c2013-06-26 11:56:09 -0600121 .is_enabled = xgene_clk_pll_is_enabled,
122 .recalc_rate = xgene_clk_pll_recalc_rate,
123};
124
125static struct clk *xgene_register_clk_pll(struct device *dev,
126 const char *name, const char *parent_name,
127 unsigned long flags, void __iomem *reg, u32 pll_offset,
128 u32 type, spinlock_t *lock)
129{
130 struct xgene_clk_pll *apmclk;
131 struct clk *clk;
132 struct clk_init_data init;
133
134 /* allocate the APM clock structure */
135 apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
136 if (!apmclk) {
137 pr_err("%s: could not allocate APM clk\n", __func__);
138 return ERR_PTR(-ENOMEM);
139 }
140
141 init.name = name;
142 init.ops = &xgene_clk_pll_ops;
143 init.flags = flags;
144 init.parent_names = parent_name ? &parent_name : NULL;
145 init.num_parents = parent_name ? 1 : 0;
146
Loc Ho308964c2013-06-26 11:56:09 -0600147 apmclk->reg = reg;
148 apmclk->lock = lock;
149 apmclk->pll_offset = pll_offset;
150 apmclk->type = type;
151 apmclk->hw.init = &init;
152
153 /* Register the clock */
154 clk = clk_register(dev, &apmclk->hw);
155 if (IS_ERR(clk)) {
156 pr_err("%s: could not register clk %s\n", __func__, name);
157 kfree(apmclk);
158 return NULL;
159 }
160 return clk;
161}
162
163static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
164{
165 const char *clk_name = np->full_name;
166 struct clk *clk;
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700167 void __iomem *reg;
Loc Ho308964c2013-06-26 11:56:09 -0600168
169 reg = of_iomap(np, 0);
170 if (reg == NULL) {
171 pr_err("Unable to map CSR register for %s\n", np->full_name);
172 return;
173 }
174 of_property_read_string(np, "clock-output-names", &clk_name);
175 clk = xgene_register_clk_pll(NULL,
176 clk_name, of_clk_get_parent_name(np, 0),
177 CLK_IS_ROOT, reg, 0, pll_type, &clk_lock);
178 if (!IS_ERR(clk)) {
179 of_clk_add_provider(np, of_clk_src_simple_get, clk);
180 clk_register_clkdev(clk, clk_name, NULL);
181 pr_debug("Add %s clock PLL\n", clk_name);
182 }
183}
184
185static void xgene_socpllclk_init(struct device_node *np)
186{
187 xgene_pllclk_init(np, PLL_TYPE_SOC);
188}
189
190static void xgene_pcppllclk_init(struct device_node *np)
191{
192 xgene_pllclk_init(np, PLL_TYPE_PCP);
193}
194
195/* IP Clock */
196struct xgene_dev_parameters {
197 void __iomem *csr_reg; /* CSR for IP clock */
198 u32 reg_clk_offset; /* Offset to clock enable CSR */
199 u32 reg_clk_mask; /* Mask bit for clock enable */
200 u32 reg_csr_offset; /* Offset to CSR reset */
201 u32 reg_csr_mask; /* Mask bit for disable CSR reset */
202 void __iomem *divider_reg; /* CSR for divider */
203 u32 reg_divider_offset; /* Offset to divider register */
204 u32 reg_divider_shift; /* Bit shift to divider field */
205 u32 reg_divider_width; /* Width of the bit to divider field */
206};
207
208struct xgene_clk {
209 struct clk_hw hw;
Loc Ho308964c2013-06-26 11:56:09 -0600210 spinlock_t *lock;
211 struct xgene_dev_parameters param;
212};
213
214#define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)
215
216static int xgene_clk_enable(struct clk_hw *hw)
217{
218 struct xgene_clk *pclk = to_xgene_clk(hw);
219 unsigned long flags = 0;
220 u32 data;
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700221 phys_addr_t reg;
Loc Ho308964c2013-06-26 11:56:09 -0600222
223 if (pclk->lock)
224 spin_lock_irqsave(pclk->lock, flags);
225
226 if (pclk->param.csr_reg != NULL) {
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700227 pr_debug("%s clock enabled\n", clk_hw_get_name(hw));
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700228 reg = __pa(pclk->param.csr_reg);
Loc Ho308964c2013-06-26 11:56:09 -0600229 /* First enable the clock */
230 data = xgene_clk_read(pclk->param.csr_reg +
231 pclk->param.reg_clk_offset);
232 data |= pclk->param.reg_clk_mask;
233 xgene_clk_write(data, pclk->param.csr_reg +
234 pclk->param.reg_clk_offset);
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700235 pr_debug("%s clock PADDR base %pa clk offset 0x%08X mask 0x%08X value 0x%08X\n",
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700236 clk_hw_get_name(hw), &reg,
Loc Ho308964c2013-06-26 11:56:09 -0600237 pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
238 data);
239
240 /* Second enable the CSR */
241 data = xgene_clk_read(pclk->param.csr_reg +
242 pclk->param.reg_csr_offset);
243 data &= ~pclk->param.reg_csr_mask;
244 xgene_clk_write(data, pclk->param.csr_reg +
245 pclk->param.reg_csr_offset);
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700246 pr_debug("%s CSR RESET PADDR base %pa csr offset 0x%08X mask 0x%08X value 0x%08X\n",
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700247 clk_hw_get_name(hw), &reg,
Loc Ho308964c2013-06-26 11:56:09 -0600248 pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
249 data);
250 }
251
252 if (pclk->lock)
253 spin_unlock_irqrestore(pclk->lock, flags);
254
255 return 0;
256}
257
258static void xgene_clk_disable(struct clk_hw *hw)
259{
260 struct xgene_clk *pclk = to_xgene_clk(hw);
261 unsigned long flags = 0;
262 u32 data;
263
264 if (pclk->lock)
265 spin_lock_irqsave(pclk->lock, flags);
266
267 if (pclk->param.csr_reg != NULL) {
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700268 pr_debug("%s clock disabled\n", clk_hw_get_name(hw));
Loc Ho308964c2013-06-26 11:56:09 -0600269 /* First put the CSR in reset */
270 data = xgene_clk_read(pclk->param.csr_reg +
271 pclk->param.reg_csr_offset);
272 data |= pclk->param.reg_csr_mask;
273 xgene_clk_write(data, pclk->param.csr_reg +
274 pclk->param.reg_csr_offset);
275
276 /* Second disable the clock */
277 data = xgene_clk_read(pclk->param.csr_reg +
278 pclk->param.reg_clk_offset);
279 data &= ~pclk->param.reg_clk_mask;
280 xgene_clk_write(data, pclk->param.csr_reg +
281 pclk->param.reg_clk_offset);
282 }
283
284 if (pclk->lock)
285 spin_unlock_irqrestore(pclk->lock, flags);
286}
287
288static int xgene_clk_is_enabled(struct clk_hw *hw)
289{
290 struct xgene_clk *pclk = to_xgene_clk(hw);
291 u32 data = 0;
292
293 if (pclk->param.csr_reg != NULL) {
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700294 pr_debug("%s clock checking\n", clk_hw_get_name(hw));
Loc Ho308964c2013-06-26 11:56:09 -0600295 data = xgene_clk_read(pclk->param.csr_reg +
296 pclk->param.reg_clk_offset);
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700297 pr_debug("%s clock is %s\n", clk_hw_get_name(hw),
Loc Ho308964c2013-06-26 11:56:09 -0600298 data & pclk->param.reg_clk_mask ? "enabled" :
299 "disabled");
300 }
301
302 if (pclk->param.csr_reg == NULL)
303 return 1;
304 return data & pclk->param.reg_clk_mask ? 1 : 0;
305}
306
307static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
308 unsigned long parent_rate)
309{
310 struct xgene_clk *pclk = to_xgene_clk(hw);
311 u32 data;
312
313 if (pclk->param.divider_reg) {
314 data = xgene_clk_read(pclk->param.divider_reg +
315 pclk->param.reg_divider_offset);
316 data >>= pclk->param.reg_divider_shift;
317 data &= (1 << pclk->param.reg_divider_width) - 1;
318
319 pr_debug("%s clock recalc rate %ld parent %ld\n",
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700320 clk_hw_get_name(hw),
Matthias Brugger78e50c62015-06-17 23:28:49 +0200321 parent_rate / data, parent_rate);
322
Loc Ho308964c2013-06-26 11:56:09 -0600323 return parent_rate / data;
324 } else {
325 pr_debug("%s clock recalc rate %ld parent %ld\n",
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700326 clk_hw_get_name(hw), parent_rate, parent_rate);
Loc Ho308964c2013-06-26 11:56:09 -0600327 return parent_rate;
328 }
329}
330
331static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
332 unsigned long parent_rate)
333{
334 struct xgene_clk *pclk = to_xgene_clk(hw);
335 unsigned long flags = 0;
336 u32 data;
337 u32 divider;
338 u32 divider_save;
339
340 if (pclk->lock)
341 spin_lock_irqsave(pclk->lock, flags);
342
343 if (pclk->param.divider_reg) {
344 /* Let's compute the divider */
345 if (rate > parent_rate)
346 rate = parent_rate;
347 divider_save = divider = parent_rate / rate; /* Rounded down */
348 divider &= (1 << pclk->param.reg_divider_width) - 1;
349 divider <<= pclk->param.reg_divider_shift;
350
351 /* Set new divider */
352 data = xgene_clk_read(pclk->param.divider_reg +
353 pclk->param.reg_divider_offset);
Loc Ho1382ea62015-11-19 12:20:30 -0700354 data &= ~((1 << pclk->param.reg_divider_width) - 1)
355 << pclk->param.reg_divider_shift;
Loc Ho308964c2013-06-26 11:56:09 -0600356 data |= divider;
357 xgene_clk_write(data, pclk->param.divider_reg +
358 pclk->param.reg_divider_offset);
Stephen Boyd836ee0f2015-08-12 11:42:23 -0700359 pr_debug("%s clock set rate %ld\n", clk_hw_get_name(hw),
Loc Ho308964c2013-06-26 11:56:09 -0600360 parent_rate / divider_save);
361 } else {
362 divider_save = 1;
363 }
364
365 if (pclk->lock)
366 spin_unlock_irqrestore(pclk->lock, flags);
367
368 return parent_rate / divider_save;
369}
370
371static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
372 unsigned long *prate)
373{
374 struct xgene_clk *pclk = to_xgene_clk(hw);
375 unsigned long parent_rate = *prate;
376 u32 divider;
377
378 if (pclk->param.divider_reg) {
379 /* Let's compute the divider */
380 if (rate > parent_rate)
381 rate = parent_rate;
382 divider = parent_rate / rate; /* Rounded down */
383 } else {
384 divider = 1;
385 }
386
387 return parent_rate / divider;
388}
389
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700390static const struct clk_ops xgene_clk_ops = {
Loc Ho308964c2013-06-26 11:56:09 -0600391 .enable = xgene_clk_enable,
392 .disable = xgene_clk_disable,
393 .is_enabled = xgene_clk_is_enabled,
394 .recalc_rate = xgene_clk_recalc_rate,
395 .set_rate = xgene_clk_set_rate,
396 .round_rate = xgene_clk_round_rate,
397};
398
399static struct clk *xgene_register_clk(struct device *dev,
400 const char *name, const char *parent_name,
401 struct xgene_dev_parameters *parameters, spinlock_t *lock)
402{
403 struct xgene_clk *apmclk;
404 struct clk *clk;
405 struct clk_init_data init;
406 int rc;
407
408 /* allocate the APM clock structure */
409 apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
410 if (!apmclk) {
411 pr_err("%s: could not allocate APM clk\n", __func__);
412 return ERR_PTR(-ENOMEM);
413 }
414
415 init.name = name;
416 init.ops = &xgene_clk_ops;
417 init.flags = 0;
418 init.parent_names = parent_name ? &parent_name : NULL;
419 init.num_parents = parent_name ? 1 : 0;
420
Loc Ho308964c2013-06-26 11:56:09 -0600421 apmclk->lock = lock;
422 apmclk->hw.init = &init;
423 apmclk->param = *parameters;
424
425 /* Register the clock */
426 clk = clk_register(dev, &apmclk->hw);
427 if (IS_ERR(clk)) {
428 pr_err("%s: could not register clk %s\n", __func__, name);
429 kfree(apmclk);
430 return clk;
431 }
432
433 /* Register the clock for lookup */
434 rc = clk_register_clkdev(clk, name, NULL);
435 if (rc != 0) {
436 pr_err("%s: could not register lookup clk %s\n",
437 __func__, name);
438 }
439 return clk;
440}
441
442static void __init xgene_devclk_init(struct device_node *np)
443{
444 const char *clk_name = np->full_name;
445 struct clk *clk;
446 struct resource res;
447 int rc;
448 struct xgene_dev_parameters parameters;
449 int i;
450
451 /* Check if the entry is disabled */
452 if (!of_device_is_available(np))
453 return;
454
455 /* Parse the DTS register for resource */
456 parameters.csr_reg = NULL;
457 parameters.divider_reg = NULL;
458 for (i = 0; i < 2; i++) {
Stephen Boyd6ae5fd32015-05-01 14:14:57 -0700459 void __iomem *map_res;
Loc Ho308964c2013-06-26 11:56:09 -0600460 rc = of_address_to_resource(np, i, &res);
461 if (rc != 0) {
462 if (i == 0) {
463 pr_err("no DTS register for %s\n",
464 np->full_name);
465 return;
466 }
467 break;
468 }
469 map_res = of_iomap(np, i);
470 if (map_res == NULL) {
471 pr_err("Unable to map resource %d for %s\n",
472 i, np->full_name);
473 goto err;
474 }
475 if (strcmp(res.name, "div-reg") == 0)
476 parameters.divider_reg = map_res;
477 else /* if (strcmp(res->name, "csr-reg") == 0) */
478 parameters.csr_reg = map_res;
479 }
480 if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
481 parameters.reg_csr_offset = 0;
482 if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
483 parameters.reg_csr_mask = 0xF;
484 if (of_property_read_u32(np, "enable-offset",
485 &parameters.reg_clk_offset))
486 parameters.reg_clk_offset = 0x8;
487 if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
488 parameters.reg_clk_mask = 0xF;
489 if (of_property_read_u32(np, "divider-offset",
490 &parameters.reg_divider_offset))
491 parameters.reg_divider_offset = 0;
492 if (of_property_read_u32(np, "divider-width",
493 &parameters.reg_divider_width))
494 parameters.reg_divider_width = 0;
495 if (of_property_read_u32(np, "divider-shift",
496 &parameters.reg_divider_shift))
497 parameters.reg_divider_shift = 0;
498 of_property_read_string(np, "clock-output-names", &clk_name);
499
500 clk = xgene_register_clk(NULL, clk_name,
501 of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
502 if (IS_ERR(clk))
503 goto err;
504 pr_debug("Add %s clock\n", clk_name);
505 rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
506 if (rc != 0)
507 pr_err("%s: could register provider clk %s\n", __func__,
508 np->full_name);
509
510 return;
511
512err:
513 if (parameters.csr_reg)
514 iounmap(parameters.csr_reg);
515 if (parameters.divider_reg)
516 iounmap(parameters.divider_reg);
517}
518
519CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
520CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
521CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);