treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1
[linux-2.6-block.git] / drivers / pwm / pwm-atmel.c
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1/*
2 * Driver for Atmel Pulse Width Modulation Controller
3 *
4 * Copyright (C) 2013 Atmel Corporation
5 * Bo Shen <voice.shen@atmel.com>
6 *
7 * Licensed under GPLv2.
8 */
9
10#include <linux/clk.h>
472ac3dc 11#include <linux/delay.h>
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12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/module.h>
472ac3dc 15#include <linux/mutex.h>
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16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <linux/platform_device.h>
19#include <linux/pwm.h>
20#include <linux/slab.h>
21
22/* The following is global registers for PWM controller */
23#define PWM_ENA 0x04
24#define PWM_DIS 0x08
25#define PWM_SR 0x0C
472ac3dc 26#define PWM_ISR 0x1C
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27/* Bit field in SR */
28#define PWM_SR_ALL_CH_ON 0x0F
29
30/* The following register is PWM channel related registers */
31#define PWM_CH_REG_OFFSET 0x200
32#define PWM_CH_REG_SIZE 0x20
33
34#define PWM_CMR 0x0
35/* Bit field in CMR */
36#define PWM_CMR_CPOL (1 << 9)
37#define PWM_CMR_UPD_CDTY (1 << 10)
8db9e29f 38#define PWM_CMR_CPRE_MSK 0xF
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39
40/* The following registers for PWM v1 */
41#define PWMV1_CDTY 0x04
42#define PWMV1_CPRD 0x08
43#define PWMV1_CUPD 0x10
44
45/* The following registers for PWM v2 */
46#define PWMV2_CDTY 0x04
47#define PWMV2_CDTYUPD 0x08
48#define PWMV2_CPRD 0x0C
49#define PWMV2_CPRDUPD 0x10
50
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51struct atmel_pwm_registers {
52 u8 period;
53 u8 period_upd;
54 u8 duty;
55 u8 duty_upd;
56};
57
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58struct atmel_pwm_config {
59 u32 max_period;
60 u32 max_pres;
61};
62
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63struct atmel_pwm_data {
64 struct atmel_pwm_registers regs;
0285827d 65 struct atmel_pwm_config cfg;
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66};
67
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68struct atmel_pwm_chip {
69 struct pwm_chip chip;
70 struct clk *clk;
71 void __iomem *base;
53784159 72 const struct atmel_pwm_data *data;
32b16d46 73
472ac3dc 74 unsigned int updated_pwms;
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75 /* ISR is cleared when read, ensure only one thread does that */
76 struct mutex isr_lock;
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77};
78
79static inline struct atmel_pwm_chip *to_atmel_pwm_chip(struct pwm_chip *chip)
80{
81 return container_of(chip, struct atmel_pwm_chip, chip);
82}
83
84static inline u32 atmel_pwm_readl(struct atmel_pwm_chip *chip,
85 unsigned long offset)
86{
87 return readl_relaxed(chip->base + offset);
88}
89
90static inline void atmel_pwm_writel(struct atmel_pwm_chip *chip,
91 unsigned long offset, unsigned long val)
92{
93 writel_relaxed(val, chip->base + offset);
94}
95
96static inline u32 atmel_pwm_ch_readl(struct atmel_pwm_chip *chip,
97 unsigned int ch, unsigned long offset)
98{
99 unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE;
100
101 return readl_relaxed(chip->base + base + offset);
102}
103
104static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip,
105 unsigned int ch, unsigned long offset,
106 unsigned long val)
107{
108 unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE;
109
110 writel_relaxed(val, chip->base + base + offset);
111}
112
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113static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
114 const struct pwm_state *state,
115 unsigned long *cprd, u32 *pres)
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116{
117 struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
1a722aad 118 unsigned long long cycles = state->period;
32b16d46 119
e2e08970 120 /* Calculate the period cycles and prescale value */
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121 cycles *= clk_get_rate(atmel_pwm->clk);
122 do_div(cycles, NSEC_PER_SEC);
32b16d46 123
0285827d 124 for (*pres = 0; cycles > atmel_pwm->data->cfg.max_period; cycles >>= 1)
1a722aad 125 (*pres)++;
e2e08970 126
0285827d 127 if (*pres > atmel_pwm->data->cfg.max_pres) {
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128 dev_err(chip->dev, "pres exceeds the maximum value\n");
129 return -EINVAL;
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130 }
131
1a722aad 132 *cprd = cycles;
32b16d46 133
1a722aad 134 return 0;
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135}
136
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137static void atmel_pwm_calculate_cdty(const struct pwm_state *state,
138 unsigned long cprd, unsigned long *cdty)
32b16d46 139{
1a722aad 140 unsigned long long cycles = state->duty_cycle;
32b16d46 141
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142 cycles *= cprd;
143 do_div(cycles, state->period);
144 *cdty = cprd - cycles;
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145}
146
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147static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,
148 unsigned long cdty)
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149{
150 struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
151 u32 val;
32b16d46 152
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153 if (atmel_pwm->data->regs.duty_upd ==
154 atmel_pwm->data->regs.period_upd) {
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155 val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
156 val &= ~PWM_CMR_UPD_CDTY;
157 atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
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158 }
159
1a722aad 160 atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
53784159 161 atmel_pwm->data->regs.duty_upd, cdty);
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162}
163
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164static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
165 struct pwm_device *pwm,
166 unsigned long cprd, unsigned long cdty)
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167{
168 struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
32b16d46 169
1a722aad 170 atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
53784159 171 atmel_pwm->data->regs.duty, cdty);
1a722aad 172 atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
53784159 173 atmel_pwm->data->regs.period, cprd);
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174}
175
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176static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,
177 bool disable_clk)
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178{
179 struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
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180 unsigned long timeout = jiffies + 2 * HZ;
181
182 /*
183 * Wait for at least a complete period to have passed before disabling a
184 * channel to be sure that CDTY has been updated
185 */
186 mutex_lock(&atmel_pwm->isr_lock);
187 atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
188
189 while (!(atmel_pwm->updated_pwms & (1 << pwm->hwpwm)) &&
190 time_before(jiffies, timeout)) {
191 usleep_range(10, 100);
192 atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
193 }
32b16d46 194
472ac3dc 195 mutex_unlock(&atmel_pwm->isr_lock);
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196 atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm);
197
f718c54c
GR
198 /*
199 * Wait for the PWM channel disable operation to be effective before
200 * stopping the clock.
201 */
202 timeout = jiffies + 2 * HZ;
203
204 while ((atmel_pwm_readl(atmel_pwm, PWM_SR) & (1 << pwm->hwpwm)) &&
205 time_before(jiffies, timeout))
206 usleep_range(10, 100);
207
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208 if (disable_clk)
209 clk_disable(atmel_pwm->clk);
210}
211
212static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
213 struct pwm_state *state)
214{
215 struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
216 struct pwm_state cstate;
217 unsigned long cprd, cdty;
218 u32 pres, val;
219 int ret;
220
221 pwm_get_state(pwm, &cstate);
222
223 if (state->enabled) {
224 if (cstate.enabled &&
225 cstate.polarity == state->polarity &&
226 cstate.period == state->period) {
227 cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
53784159 228 atmel_pwm->data->regs.period);
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229 atmel_pwm_calculate_cdty(state, cprd, &cdty);
230 atmel_pwm_update_cdty(chip, pwm, cdty);
231 return 0;
232 }
233
234 ret = atmel_pwm_calculate_cprd_and_pres(chip, state, &cprd,
235 &pres);
236 if (ret) {
237 dev_err(chip->dev,
238 "failed to calculate cprd and prescaler\n");
239 return ret;
240 }
241
242 atmel_pwm_calculate_cdty(state, cprd, &cdty);
243
244 if (cstate.enabled) {
245 atmel_pwm_disable(chip, pwm, false);
246 } else {
247 ret = clk_enable(atmel_pwm->clk);
248 if (ret) {
249 dev_err(chip->dev, "failed to enable clock\n");
250 return ret;
251 }
252 }
253
254 /* It is necessary to preserve CPOL, inside CMR */
255 val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
256 val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK);
257 if (state->polarity == PWM_POLARITY_NORMAL)
258 val &= ~PWM_CMR_CPOL;
259 else
260 val |= PWM_CMR_CPOL;
261 atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
262 atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty);
263 mutex_lock(&atmel_pwm->isr_lock);
264 atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
265 atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm);
266 mutex_unlock(&atmel_pwm->isr_lock);
267 atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);
268 } else if (cstate.enabled) {
269 atmel_pwm_disable(chip, pwm, true);
270 }
271
272 return 0;
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273}
274
275static const struct pwm_ops atmel_pwm_ops = {
1a722aad 276 .apply = atmel_pwm_apply,
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277 .owner = THIS_MODULE,
278};
279
abcbe373 280static const struct atmel_pwm_data atmel_sam9rl_pwm_data = {
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281 .regs = {
282 .period = PWMV1_CPRD,
283 .period_upd = PWMV1_CUPD,
284 .duty = PWMV1_CDTY,
285 .duty_upd = PWMV1_CUPD,
286 },
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287 .cfg = {
288 /* 16 bits to keep period and duty. */
d7d96312
TR
289 .max_period = 0xffff,
290 .max_pres = 10,
0285827d 291 },
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292};
293
abcbe373 294static const struct atmel_pwm_data atmel_sama5_pwm_data = {
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295 .regs = {
296 .period = PWMV2_CPRD,
297 .period_upd = PWMV2_CPRDUPD,
298 .duty = PWMV2_CDTY,
299 .duty_upd = PWMV2_CDTYUPD,
300 },
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301 .cfg = {
302 /* 16 bits to keep period and duty. */
d7d96312
TR
303 .max_period = 0xffff,
304 .max_pres = 10,
0285827d 305 },
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306};
307
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308static const struct atmel_pwm_data mchp_sam9x60_pwm_data = {
309 .regs = {
310 .period = PWMV1_CPRD,
311 .period_upd = PWMV1_CUPD,
312 .duty = PWMV1_CDTY,
313 .duty_upd = PWMV1_CUPD,
314 },
315 .cfg = {
316 /* 32 bits to keep period and duty. */
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TR
317 .max_period = 0xffffffff,
318 .max_pres = 10,
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CB
319 },
320};
321
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322static const struct platform_device_id atmel_pwm_devtypes[] = {
323 {
324 .name = "at91sam9rl-pwm",
abcbe373 325 .driver_data = (kernel_ulong_t)&atmel_sam9rl_pwm_data,
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326 }, {
327 .name = "sama5d3-pwm",
abcbe373 328 .driver_data = (kernel_ulong_t)&atmel_sama5_pwm_data,
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329 }, {
330 /* sentinel */
331 },
332};
333MODULE_DEVICE_TABLE(platform, atmel_pwm_devtypes);
334
335static const struct of_device_id atmel_pwm_dt_ids[] = {
336 {
337 .compatible = "atmel,at91sam9rl-pwm",
abcbe373 338 .data = &atmel_sam9rl_pwm_data,
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339 }, {
340 .compatible = "atmel,sama5d3-pwm",
abcbe373 341 .data = &atmel_sama5_pwm_data,
44521afa
CB
342 }, {
343 .compatible = "atmel,sama5d2-pwm",
abcbe373 344 .data = &atmel_sama5_pwm_data,
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345 }, {
346 .compatible = "microchip,sam9x60-pwm",
347 .data = &mchp_sam9x60_pwm_data,
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348 }, {
349 /* sentinel */
350 },
351};
352MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
353
53784159 354static inline const struct atmel_pwm_data *
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BS
355atmel_pwm_get_driver_data(struct platform_device *pdev)
356{
313b78ef
TR
357 const struct platform_device_id *id;
358
017bb04e
TR
359 if (pdev->dev.of_node)
360 return of_device_get_match_data(&pdev->dev);
32b16d46 361
313b78ef 362 id = platform_get_device_id(pdev);
32b16d46 363
53784159 364 return (struct atmel_pwm_data *)id->driver_data;
32b16d46
BS
365}
366
367static int atmel_pwm_probe(struct platform_device *pdev)
368{
53784159 369 const struct atmel_pwm_data *data;
32b16d46
BS
370 struct atmel_pwm_chip *atmel_pwm;
371 struct resource *res;
372 int ret;
373
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CB
374 data = atmel_pwm_get_driver_data(pdev);
375 if (!data)
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BS
376 return -ENODEV;
377
378 atmel_pwm = devm_kzalloc(&pdev->dev, sizeof(*atmel_pwm), GFP_KERNEL);
379 if (!atmel_pwm)
380 return -ENOMEM;
381
382 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
383 atmel_pwm->base = devm_ioremap_resource(&pdev->dev, res);
384 if (IS_ERR(atmel_pwm->base))
385 return PTR_ERR(atmel_pwm->base);
386
387 atmel_pwm->clk = devm_clk_get(&pdev->dev, NULL);
388 if (IS_ERR(atmel_pwm->clk))
389 return PTR_ERR(atmel_pwm->clk);
390
391 ret = clk_prepare(atmel_pwm->clk);
392 if (ret) {
393 dev_err(&pdev->dev, "failed to prepare PWM clock\n");
394 return ret;
395 }
396
397 atmel_pwm->chip.dev = &pdev->dev;
398 atmel_pwm->chip.ops = &atmel_pwm_ops;
399
400 if (pdev->dev.of_node) {
401 atmel_pwm->chip.of_xlate = of_pwm_xlate_with_flags;
402 atmel_pwm->chip.of_pwm_n_cells = 3;
403 }
404
405 atmel_pwm->chip.base = -1;
406 atmel_pwm->chip.npwm = 4;
53784159 407 atmel_pwm->data = data;
472ac3dc
AB
408 atmel_pwm->updated_pwms = 0;
409 mutex_init(&atmel_pwm->isr_lock);
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BS
410
411 ret = pwmchip_add(&atmel_pwm->chip);
412 if (ret < 0) {
413 dev_err(&pdev->dev, "failed to add PWM chip %d\n", ret);
414 goto unprepare_clk;
415 }
416
417 platform_set_drvdata(pdev, atmel_pwm);
418
6a683356
BS
419 return ret;
420
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421unprepare_clk:
422 clk_unprepare(atmel_pwm->clk);
423 return ret;
424}
425
426static int atmel_pwm_remove(struct platform_device *pdev)
427{
428 struct atmel_pwm_chip *atmel_pwm = platform_get_drvdata(pdev);
429
430 clk_unprepare(atmel_pwm->clk);
472ac3dc 431 mutex_destroy(&atmel_pwm->isr_lock);
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BS
432
433 return pwmchip_remove(&atmel_pwm->chip);
434}
435
436static struct platform_driver atmel_pwm_driver = {
437 .driver = {
438 .name = "atmel-pwm",
439 .of_match_table = of_match_ptr(atmel_pwm_dt_ids),
440 },
441 .id_table = atmel_pwm_devtypes,
442 .probe = atmel_pwm_probe,
443 .remove = atmel_pwm_remove,
444};
445module_platform_driver(atmel_pwm_driver);
446
447MODULE_ALIAS("platform:atmel-pwm");
448MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
449MODULE_DESCRIPTION("Atmel PWM driver");
450MODULE_LICENSE("GPL v2");