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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Allwinner sun4i Pulse Width Modulation Controller
4 *
5 * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@free-electrons.com>
6 *
7 * Limitations:
8 * - When outputing the source clock directly, the PWM logic will be bypassed
9 * and the currently running period is not guaranteed to be completed
10 */
11
12#include <linux/bitops.h>
13#include <linux/clk.h>
14#include <linux/delay.h>
15#include <linux/err.h>
16#include <linux/io.h>
17#include <linux/jiffies.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_device.h>
21#include <linux/platform_device.h>
22#include <linux/pwm.h>
23#include <linux/reset.h>
24#include <linux/slab.h>
25#include <linux/spinlock.h>
26#include <linux/time.h>
27
28#define PWM_CTRL_REG 0x0
29
30#define PWM_CH_PRD_BASE 0x4
31#define PWM_CH_PRD_OFFSET 0x4
32#define PWM_CH_PRD(ch) (PWM_CH_PRD_BASE + PWM_CH_PRD_OFFSET * (ch))
33
34#define PWMCH_OFFSET 15
35#define PWM_PRESCAL_MASK GENMASK(3, 0)
36#define PWM_PRESCAL_OFF 0
37#define PWM_EN BIT(4)
38#define PWM_ACT_STATE BIT(5)
39#define PWM_CLK_GATING BIT(6)
40#define PWM_MODE BIT(7)
41#define PWM_PULSE BIT(8)
42#define PWM_BYPASS BIT(9)
43
44#define PWM_RDY_BASE 28
45#define PWM_RDY_OFFSET 1
46#define PWM_RDY(ch) BIT(PWM_RDY_BASE + PWM_RDY_OFFSET * (ch))
47
48#define PWM_PRD(prd) (((prd) - 1) << 16)
49#define PWM_PRD_MASK GENMASK(15, 0)
50
51#define PWM_DTY_MASK GENMASK(15, 0)
52
53#define PWM_REG_PRD(reg) ((((reg) >> 16) & PWM_PRD_MASK) + 1)
54#define PWM_REG_DTY(reg) ((reg) & PWM_DTY_MASK)
55#define PWM_REG_PRESCAL(reg, chan) (((reg) >> ((chan) * PWMCH_OFFSET)) & PWM_PRESCAL_MASK)
56
57#define BIT_CH(bit, chan) ((bit) << ((chan) * PWMCH_OFFSET))
58
59static const u32 prescaler_table[] = {
60 120,
61 180,
62 240,
63 360,
64 480,
65 0,
66 0,
67 0,
68 12000,
69 24000,
70 36000,
71 48000,
72 72000,
73 0,
74 0,
75 0, /* Actually 1 but tested separately */
76};
77
78struct sun4i_pwm_data {
79 bool has_prescaler_bypass;
80 bool has_direct_mod_clk_output;
81 unsigned int npwm;
82};
83
84struct sun4i_pwm_chip {
85 struct pwm_chip chip;
86 struct clk *bus_clk;
87 struct clk *clk;
88 struct reset_control *rst;
89 void __iomem *base;
90 spinlock_t ctrl_lock;
91 const struct sun4i_pwm_data *data;
92 unsigned long next_period[2];
93};
94
95static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
96{
97 return container_of(chip, struct sun4i_pwm_chip, chip);
98}
99
100static inline u32 sun4i_pwm_readl(struct sun4i_pwm_chip *chip,
101 unsigned long offset)
102{
103 return readl(chip->base + offset);
104}
105
106static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip,
107 u32 val, unsigned long offset)
108{
109 writel(val, chip->base + offset);
110}
111
112static void sun4i_pwm_get_state(struct pwm_chip *chip,
113 struct pwm_device *pwm,
114 struct pwm_state *state)
115{
116 struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
117 u64 clk_rate, tmp;
118 u32 val;
119 unsigned int prescaler;
120
121 clk_rate = clk_get_rate(sun4i_pwm->clk);
122
123 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
124
125 /*
126 * PWM chapter in H6 manual has a diagram which explains that if bypass
127 * bit is set, no other setting has any meaning. Even more, experiment
128 * proved that also enable bit is ignored in this case.
129 */
130 if ((val & BIT_CH(PWM_BYPASS, pwm->hwpwm)) &&
131 sun4i_pwm->data->has_direct_mod_clk_output) {
132 state->period = DIV_ROUND_UP_ULL(NSEC_PER_SEC, clk_rate);
133 state->duty_cycle = DIV_ROUND_UP_ULL(state->period, 2);
134 state->polarity = PWM_POLARITY_NORMAL;
135 state->enabled = true;
136 return;
137 }
138
139 if ((PWM_REG_PRESCAL(val, pwm->hwpwm) == PWM_PRESCAL_MASK) &&
140 sun4i_pwm->data->has_prescaler_bypass)
141 prescaler = 1;
142 else
143 prescaler = prescaler_table[PWM_REG_PRESCAL(val, pwm->hwpwm)];
144
145 if (prescaler == 0)
146 return;
147
148 if (val & BIT_CH(PWM_ACT_STATE, pwm->hwpwm))
149 state->polarity = PWM_POLARITY_NORMAL;
150 else
151 state->polarity = PWM_POLARITY_INVERSED;
152
153 if ((val & BIT_CH(PWM_CLK_GATING | PWM_EN, pwm->hwpwm)) ==
154 BIT_CH(PWM_CLK_GATING | PWM_EN, pwm->hwpwm))
155 state->enabled = true;
156 else
157 state->enabled = false;
158
159 val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm));
160
161 tmp = (u64)prescaler * NSEC_PER_SEC * PWM_REG_DTY(val);
162 state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
163
164 tmp = (u64)prescaler * NSEC_PER_SEC * PWM_REG_PRD(val);
165 state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
166}
167
168static int sun4i_pwm_calculate(struct sun4i_pwm_chip *sun4i_pwm,
169 const struct pwm_state *state,
170 u32 *dty, u32 *prd, unsigned int *prsclr,
171 bool *bypass)
172{
173 u64 clk_rate, div = 0;
174 unsigned int prescaler = 0;
175
176 clk_rate = clk_get_rate(sun4i_pwm->clk);
177
178 *bypass = sun4i_pwm->data->has_direct_mod_clk_output &&
179 state->enabled &&
180 (state->period * clk_rate >= NSEC_PER_SEC) &&
181 (state->period * clk_rate < 2 * NSEC_PER_SEC) &&
182 (state->duty_cycle * clk_rate * 2 >= NSEC_PER_SEC);
183
184 /* Skip calculation of other parameters if we bypass them */
185 if (*bypass)
186 return 0;
187
188 if (sun4i_pwm->data->has_prescaler_bypass) {
189 /* First, test without any prescaler when available */
190 prescaler = PWM_PRESCAL_MASK;
191 /*
192 * When not using any prescaler, the clock period in nanoseconds
193 * is not an integer so round it half up instead of
194 * truncating to get less surprising values.
195 */
196 div = clk_rate * state->period + NSEC_PER_SEC / 2;
197 do_div(div, NSEC_PER_SEC);
198 if (div - 1 > PWM_PRD_MASK)
199 prescaler = 0;
200 }
201
202 if (prescaler == 0) {
203 /* Go up from the first divider */
204 for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
205 unsigned int pval = prescaler_table[prescaler];
206
207 if (!pval)
208 continue;
209
210 div = clk_rate;
211 do_div(div, pval);
212 div = div * state->period;
213 do_div(div, NSEC_PER_SEC);
214 if (div - 1 <= PWM_PRD_MASK)
215 break;
216 }
217
218 if (div - 1 > PWM_PRD_MASK)
219 return -EINVAL;
220 }
221
222 *prd = div;
223 div *= state->duty_cycle;
224 do_div(div, state->period);
225 *dty = div;
226 *prsclr = prescaler;
227
228 return 0;
229}
230
231static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
232 const struct pwm_state *state)
233{
234 struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
235 struct pwm_state cstate;
236 u32 ctrl, duty = 0, period = 0, val;
237 int ret;
238 unsigned int delay_us, prescaler = 0;
239 unsigned long now;
240 bool bypass;
241
242 pwm_get_state(pwm, &cstate);
243
244 if (!cstate.enabled) {
245 ret = clk_prepare_enable(sun4i_pwm->clk);
246 if (ret) {
247 dev_err(chip->dev, "failed to enable PWM clock\n");
248 return ret;
249 }
250 }
251
252 ret = sun4i_pwm_calculate(sun4i_pwm, state, &duty, &period, &prescaler,
253 &bypass);
254 if (ret) {
255 dev_err(chip->dev, "period exceeds the maximum value\n");
256 if (!cstate.enabled)
257 clk_disable_unprepare(sun4i_pwm->clk);
258 return ret;
259 }
260
261 spin_lock(&sun4i_pwm->ctrl_lock);
262 ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
263
264 if (sun4i_pwm->data->has_direct_mod_clk_output) {
265 if (bypass) {
266 ctrl |= BIT_CH(PWM_BYPASS, pwm->hwpwm);
267 /* We can skip other parameter */
268 sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
269 spin_unlock(&sun4i_pwm->ctrl_lock);
270 return 0;
271 }
272
273 ctrl &= ~BIT_CH(PWM_BYPASS, pwm->hwpwm);
274 }
275
276 if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) {
277 /* Prescaler changed, the clock has to be gated */
278 ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
279 sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
280
281 ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
282 ctrl |= BIT_CH(prescaler, pwm->hwpwm);
283 }
284
285 val = (duty & PWM_DTY_MASK) | PWM_PRD(period);
286 sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
287 sun4i_pwm->next_period[pwm->hwpwm] = jiffies +
288 nsecs_to_jiffies(cstate.period + 1000);
289
290 if (state->polarity != PWM_POLARITY_NORMAL)
291 ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
292 else
293 ctrl |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
294
295 ctrl |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
296
297 if (state->enabled) {
298 ctrl |= BIT_CH(PWM_EN, pwm->hwpwm);
299 } else {
300 ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm);
301 ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
302 }
303
304 sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
305
306 spin_unlock(&sun4i_pwm->ctrl_lock);
307
308 if (state->enabled)
309 return 0;
310
311 /* We need a full period to elapse before disabling the channel. */
312 now = jiffies;
313 if (time_before(now, sun4i_pwm->next_period[pwm->hwpwm])) {
314 delay_us = jiffies_to_usecs(sun4i_pwm->next_period[pwm->hwpwm] -
315 now);
316 if ((delay_us / 500) > MAX_UDELAY_MS)
317 msleep(delay_us / 1000 + 1);
318 else
319 usleep_range(delay_us, delay_us * 2);
320 }
321
322 spin_lock(&sun4i_pwm->ctrl_lock);
323 ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
324 ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
325 ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm);
326 sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
327 spin_unlock(&sun4i_pwm->ctrl_lock);
328
329 clk_disable_unprepare(sun4i_pwm->clk);
330
331 return 0;
332}
333
334static const struct pwm_ops sun4i_pwm_ops = {
335 .apply = sun4i_pwm_apply,
336 .get_state = sun4i_pwm_get_state,
337 .owner = THIS_MODULE,
338};
339
340static const struct sun4i_pwm_data sun4i_pwm_dual_nobypass = {
341 .has_prescaler_bypass = false,
342 .npwm = 2,
343};
344
345static const struct sun4i_pwm_data sun4i_pwm_dual_bypass = {
346 .has_prescaler_bypass = true,
347 .npwm = 2,
348};
349
350static const struct sun4i_pwm_data sun4i_pwm_single_bypass = {
351 .has_prescaler_bypass = true,
352 .npwm = 1,
353};
354
355static const struct sun4i_pwm_data sun50i_a64_pwm_data = {
356 .has_prescaler_bypass = true,
357 .has_direct_mod_clk_output = true,
358 .npwm = 1,
359};
360
361static const struct sun4i_pwm_data sun50i_h6_pwm_data = {
362 .has_prescaler_bypass = true,
363 .has_direct_mod_clk_output = true,
364 .npwm = 2,
365};
366
367static const struct of_device_id sun4i_pwm_dt_ids[] = {
368 {
369 .compatible = "allwinner,sun4i-a10-pwm",
370 .data = &sun4i_pwm_dual_nobypass,
371 }, {
372 .compatible = "allwinner,sun5i-a10s-pwm",
373 .data = &sun4i_pwm_dual_bypass,
374 }, {
375 .compatible = "allwinner,sun5i-a13-pwm",
376 .data = &sun4i_pwm_single_bypass,
377 }, {
378 .compatible = "allwinner,sun7i-a20-pwm",
379 .data = &sun4i_pwm_dual_bypass,
380 }, {
381 .compatible = "allwinner,sun8i-h3-pwm",
382 .data = &sun4i_pwm_single_bypass,
383 }, {
384 .compatible = "allwinner,sun50i-a64-pwm",
385 .data = &sun50i_a64_pwm_data,
386 }, {
387 .compatible = "allwinner,sun50i-h6-pwm",
388 .data = &sun50i_h6_pwm_data,
389 }, {
390 /* sentinel */
391 },
392};
393MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids);
394
395static int sun4i_pwm_probe(struct platform_device *pdev)
396{
397 struct sun4i_pwm_chip *pwm;
398 struct resource *res;
399 int ret;
400
401 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
402 if (!pwm)
403 return -ENOMEM;
404
405 pwm->data = of_device_get_match_data(&pdev->dev);
406 if (!pwm->data)
407 return -ENODEV;
408
409 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
410 pwm->base = devm_ioremap_resource(&pdev->dev, res);
411 if (IS_ERR(pwm->base))
412 return PTR_ERR(pwm->base);
413
414 /*
415 * All hardware variants need a source clock that is divided and
416 * then feeds the counter that defines the output wave form. In the
417 * device tree this clock is either unnamed or called "mod".
418 * Some variants (e.g. H6) need another clock to access the
419 * hardware registers; this is called "bus".
420 * So we request "mod" first (and ignore the corner case that a
421 * parent provides a "mod" clock while the right one would be the
422 * unnamed one of the PWM device) and if this is not found we fall
423 * back to the first clock of the PWM.
424 */
425 pwm->clk = devm_clk_get_optional(&pdev->dev, "mod");
426 if (IS_ERR(pwm->clk)) {
427 if (PTR_ERR(pwm->clk) != -EPROBE_DEFER)
428 dev_err(&pdev->dev, "get mod clock failed %pe\n",
429 pwm->clk);
430 return PTR_ERR(pwm->clk);
431 }
432
433 if (!pwm->clk) {
434 pwm->clk = devm_clk_get(&pdev->dev, NULL);
435 if (IS_ERR(pwm->clk)) {
436 if (PTR_ERR(pwm->clk) != -EPROBE_DEFER)
437 dev_err(&pdev->dev, "get unnamed clock failed %pe\n",
438 pwm->clk);
439 return PTR_ERR(pwm->clk);
440 }
441 }
442
443 pwm->bus_clk = devm_clk_get_optional(&pdev->dev, "bus");
444 if (IS_ERR(pwm->bus_clk)) {
445 if (PTR_ERR(pwm->bus_clk) != -EPROBE_DEFER)
446 dev_err(&pdev->dev, "get bus clock failed %pe\n",
447 pwm->bus_clk);
448 return PTR_ERR(pwm->bus_clk);
449 }
450
451 pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
452 if (IS_ERR(pwm->rst)) {
453 if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
454 dev_err(&pdev->dev, "get reset failed %pe\n",
455 pwm->rst);
456 return PTR_ERR(pwm->rst);
457 }
458
459 /* Deassert reset */
460 ret = reset_control_deassert(pwm->rst);
461 if (ret) {
462 dev_err(&pdev->dev, "cannot deassert reset control: %pe\n",
463 ERR_PTR(ret));
464 return ret;
465 }
466
467 /*
468 * We're keeping the bus clock on for the sake of simplicity.
469 * Actually it only needs to be on for hardware register accesses.
470 */
471 ret = clk_prepare_enable(pwm->bus_clk);
472 if (ret) {
473 dev_err(&pdev->dev, "cannot prepare and enable bus_clk %pe\n",
474 ERR_PTR(ret));
475 goto err_bus;
476 }
477
478 pwm->chip.dev = &pdev->dev;
479 pwm->chip.ops = &sun4i_pwm_ops;
480 pwm->chip.base = -1;
481 pwm->chip.npwm = pwm->data->npwm;
482 pwm->chip.of_xlate = of_pwm_xlate_with_flags;
483 pwm->chip.of_pwm_n_cells = 3;
484
485 spin_lock_init(&pwm->ctrl_lock);
486
487 ret = pwmchip_add(&pwm->chip);
488 if (ret < 0) {
489 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
490 goto err_pwm_add;
491 }
492
493 platform_set_drvdata(pdev, pwm);
494
495 return 0;
496
497err_pwm_add:
498 clk_disable_unprepare(pwm->bus_clk);
499err_bus:
500 reset_control_assert(pwm->rst);
501
502 return ret;
503}
504
505static int sun4i_pwm_remove(struct platform_device *pdev)
506{
507 struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
508 int ret;
509
510 ret = pwmchip_remove(&pwm->chip);
511 if (ret)
512 return ret;
513
514 clk_disable_unprepare(pwm->bus_clk);
515 reset_control_assert(pwm->rst);
516
517 return 0;
518}
519
520static struct platform_driver sun4i_pwm_driver = {
521 .driver = {
522 .name = "sun4i-pwm",
523 .of_match_table = sun4i_pwm_dt_ids,
524 },
525 .probe = sun4i_pwm_probe,
526 .remove = sun4i_pwm_remove,
527};
528module_platform_driver(sun4i_pwm_driver);
529
530MODULE_ALIAS("platform:sun4i-pwm");
531MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
532MODULE_DESCRIPTION("Allwinner sun4i PWM driver");
533MODULE_LICENSE("GPL v2");
1/*
2 * Driver for Allwinner sun4i Pulse Width Modulation Controller
3 *
4 * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@free-electrons.com>
5 *
6 * Licensed under GPLv2.
7 */
8
9#include <linux/bitops.h>
10#include <linux/clk.h>
11#include <linux/err.h>
12#include <linux/io.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/of_device.h>
16#include <linux/platform_device.h>
17#include <linux/pwm.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/time.h>
21
22#define PWM_CTRL_REG 0x0
23
24#define PWM_CH_PRD_BASE 0x4
25#define PWM_CH_PRD_OFFSET 0x4
26#define PWM_CH_PRD(ch) (PWM_CH_PRD_BASE + PWM_CH_PRD_OFFSET * (ch))
27
28#define PWMCH_OFFSET 15
29#define PWM_PRESCAL_MASK GENMASK(3, 0)
30#define PWM_PRESCAL_OFF 0
31#define PWM_EN BIT(4)
32#define PWM_ACT_STATE BIT(5)
33#define PWM_CLK_GATING BIT(6)
34#define PWM_MODE BIT(7)
35#define PWM_PULSE BIT(8)
36#define PWM_BYPASS BIT(9)
37
38#define PWM_RDY_BASE 28
39#define PWM_RDY_OFFSET 1
40#define PWM_RDY(ch) BIT(PWM_RDY_BASE + PWM_RDY_OFFSET * (ch))
41
42#define PWM_PRD(prd) (((prd) - 1) << 16)
43#define PWM_PRD_MASK GENMASK(15, 0)
44
45#define PWM_DTY_MASK GENMASK(15, 0)
46
47#define BIT_CH(bit, chan) ((bit) << ((chan) * PWMCH_OFFSET))
48
49static const u32 prescaler_table[] = {
50 120,
51 180,
52 240,
53 360,
54 480,
55 0,
56 0,
57 0,
58 12000,
59 24000,
60 36000,
61 48000,
62 72000,
63 0,
64 0,
65 0, /* Actually 1 but tested separately */
66};
67
68struct sun4i_pwm_data {
69 bool has_prescaler_bypass;
70 bool has_rdy;
71 unsigned int npwm;
72};
73
74struct sun4i_pwm_chip {
75 struct pwm_chip chip;
76 struct clk *clk;
77 void __iomem *base;
78 spinlock_t ctrl_lock;
79 const struct sun4i_pwm_data *data;
80};
81
82static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
83{
84 return container_of(chip, struct sun4i_pwm_chip, chip);
85}
86
87static inline u32 sun4i_pwm_readl(struct sun4i_pwm_chip *chip,
88 unsigned long offset)
89{
90 return readl(chip->base + offset);
91}
92
93static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip,
94 u32 val, unsigned long offset)
95{
96 writel(val, chip->base + offset);
97}
98
99static int sun4i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
100 int duty_ns, int period_ns)
101{
102 struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
103 u32 prd, dty, val, clk_gate;
104 u64 clk_rate, div = 0;
105 unsigned int prescaler = 0;
106 int err;
107
108 clk_rate = clk_get_rate(sun4i_pwm->clk);
109
110 if (sun4i_pwm->data->has_prescaler_bypass) {
111 /* First, test without any prescaler when available */
112 prescaler = PWM_PRESCAL_MASK;
113 /*
114 * When not using any prescaler, the clock period in nanoseconds
115 * is not an integer so round it half up instead of
116 * truncating to get less surprising values.
117 */
118 div = clk_rate * period_ns + NSEC_PER_SEC / 2;
119 do_div(div, NSEC_PER_SEC);
120 if (div - 1 > PWM_PRD_MASK)
121 prescaler = 0;
122 }
123
124 if (prescaler == 0) {
125 /* Go up from the first divider */
126 for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
127 if (!prescaler_table[prescaler])
128 continue;
129 div = clk_rate;
130 do_div(div, prescaler_table[prescaler]);
131 div = div * period_ns;
132 do_div(div, NSEC_PER_SEC);
133 if (div - 1 <= PWM_PRD_MASK)
134 break;
135 }
136
137 if (div - 1 > PWM_PRD_MASK) {
138 dev_err(chip->dev, "period exceeds the maximum value\n");
139 return -EINVAL;
140 }
141 }
142
143 prd = div;
144 div *= duty_ns;
145 do_div(div, period_ns);
146 dty = div;
147
148 err = clk_prepare_enable(sun4i_pwm->clk);
149 if (err) {
150 dev_err(chip->dev, "failed to enable PWM clock\n");
151 return err;
152 }
153
154 spin_lock(&sun4i_pwm->ctrl_lock);
155 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
156
157 if (sun4i_pwm->data->has_rdy && (val & PWM_RDY(pwm->hwpwm))) {
158 spin_unlock(&sun4i_pwm->ctrl_lock);
159 clk_disable_unprepare(sun4i_pwm->clk);
160 return -EBUSY;
161 }
162
163 clk_gate = val & BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
164 if (clk_gate) {
165 val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
166 sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
167 }
168
169 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
170 val &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
171 val |= BIT_CH(prescaler, pwm->hwpwm);
172 sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
173
174 val = (dty & PWM_DTY_MASK) | PWM_PRD(prd);
175 sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
176
177 if (clk_gate) {
178 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
179 val |= clk_gate;
180 sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
181 }
182
183 spin_unlock(&sun4i_pwm->ctrl_lock);
184 clk_disable_unprepare(sun4i_pwm->clk);
185
186 return 0;
187}
188
189static int sun4i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
190 enum pwm_polarity polarity)
191{
192 struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
193 u32 val;
194 int ret;
195
196 ret = clk_prepare_enable(sun4i_pwm->clk);
197 if (ret) {
198 dev_err(chip->dev, "failed to enable PWM clock\n");
199 return ret;
200 }
201
202 spin_lock(&sun4i_pwm->ctrl_lock);
203 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
204
205 if (polarity != PWM_POLARITY_NORMAL)
206 val &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
207 else
208 val |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
209
210 sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
211
212 spin_unlock(&sun4i_pwm->ctrl_lock);
213 clk_disable_unprepare(sun4i_pwm->clk);
214
215 return 0;
216}
217
218static int sun4i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
219{
220 struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
221 u32 val;
222 int ret;
223
224 ret = clk_prepare_enable(sun4i_pwm->clk);
225 if (ret) {
226 dev_err(chip->dev, "failed to enable PWM clock\n");
227 return ret;
228 }
229
230 spin_lock(&sun4i_pwm->ctrl_lock);
231 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
232 val |= BIT_CH(PWM_EN, pwm->hwpwm);
233 val |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
234 sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
235 spin_unlock(&sun4i_pwm->ctrl_lock);
236
237 return 0;
238}
239
240static void sun4i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
241{
242 struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
243 u32 val;
244
245 spin_lock(&sun4i_pwm->ctrl_lock);
246 val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
247 val &= ~BIT_CH(PWM_EN, pwm->hwpwm);
248 val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
249 sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
250 spin_unlock(&sun4i_pwm->ctrl_lock);
251
252 clk_disable_unprepare(sun4i_pwm->clk);
253}
254
255static const struct pwm_ops sun4i_pwm_ops = {
256 .config = sun4i_pwm_config,
257 .set_polarity = sun4i_pwm_set_polarity,
258 .enable = sun4i_pwm_enable,
259 .disable = sun4i_pwm_disable,
260 .owner = THIS_MODULE,
261};
262
263static const struct sun4i_pwm_data sun4i_pwm_data_a10 = {
264 .has_prescaler_bypass = false,
265 .has_rdy = false,
266 .npwm = 2,
267};
268
269static const struct sun4i_pwm_data sun4i_pwm_data_a10s = {
270 .has_prescaler_bypass = true,
271 .has_rdy = true,
272 .npwm = 2,
273};
274
275static const struct sun4i_pwm_data sun4i_pwm_data_a13 = {
276 .has_prescaler_bypass = true,
277 .has_rdy = true,
278 .npwm = 1,
279};
280
281static const struct sun4i_pwm_data sun4i_pwm_data_a20 = {
282 .has_prescaler_bypass = true,
283 .has_rdy = true,
284 .npwm = 2,
285};
286
287static const struct of_device_id sun4i_pwm_dt_ids[] = {
288 {
289 .compatible = "allwinner,sun4i-a10-pwm",
290 .data = &sun4i_pwm_data_a10,
291 }, {
292 .compatible = "allwinner,sun5i-a10s-pwm",
293 .data = &sun4i_pwm_data_a10s,
294 }, {
295 .compatible = "allwinner,sun5i-a13-pwm",
296 .data = &sun4i_pwm_data_a13,
297 }, {
298 .compatible = "allwinner,sun7i-a20-pwm",
299 .data = &sun4i_pwm_data_a20,
300 }, {
301 /* sentinel */
302 },
303};
304MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids);
305
306static int sun4i_pwm_probe(struct platform_device *pdev)
307{
308 struct sun4i_pwm_chip *pwm;
309 struct resource *res;
310 u32 val;
311 int i, ret;
312 const struct of_device_id *match;
313
314 match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);
315
316 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
317 if (!pwm)
318 return -ENOMEM;
319
320 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
321 pwm->base = devm_ioremap_resource(&pdev->dev, res);
322 if (IS_ERR(pwm->base))
323 return PTR_ERR(pwm->base);
324
325 pwm->clk = devm_clk_get(&pdev->dev, NULL);
326 if (IS_ERR(pwm->clk))
327 return PTR_ERR(pwm->clk);
328
329 pwm->data = match->data;
330 pwm->chip.dev = &pdev->dev;
331 pwm->chip.ops = &sun4i_pwm_ops;
332 pwm->chip.base = -1;
333 pwm->chip.npwm = pwm->data->npwm;
334 pwm->chip.can_sleep = true;
335 pwm->chip.of_xlate = of_pwm_xlate_with_flags;
336 pwm->chip.of_pwm_n_cells = 3;
337
338 spin_lock_init(&pwm->ctrl_lock);
339
340 ret = pwmchip_add(&pwm->chip);
341 if (ret < 0) {
342 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
343 return ret;
344 }
345
346 platform_set_drvdata(pdev, pwm);
347
348 ret = clk_prepare_enable(pwm->clk);
349 if (ret) {
350 dev_err(&pdev->dev, "failed to enable PWM clock\n");
351 goto clk_error;
352 }
353
354 val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
355 for (i = 0; i < pwm->chip.npwm; i++)
356 if (!(val & BIT_CH(PWM_ACT_STATE, i)))
357 pwm->chip.pwms[i].polarity = PWM_POLARITY_INVERSED;
358 clk_disable_unprepare(pwm->clk);
359
360 return 0;
361
362clk_error:
363 pwmchip_remove(&pwm->chip);
364 return ret;
365}
366
367static int sun4i_pwm_remove(struct platform_device *pdev)
368{
369 struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
370
371 return pwmchip_remove(&pwm->chip);
372}
373
374static struct platform_driver sun4i_pwm_driver = {
375 .driver = {
376 .name = "sun4i-pwm",
377 .of_match_table = sun4i_pwm_dt_ids,
378 },
379 .probe = sun4i_pwm_probe,
380 .remove = sun4i_pwm_remove,
381};
382module_platform_driver(sun4i_pwm_driver);
383
384MODULE_ALIAS("platform:sun4i-pwm");
385MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
386MODULE_DESCRIPTION("Allwinner sun4i PWM driver");
387MODULE_LICENSE("GPL v2");