Commit | Line | Data |
---|---|---|
f50a7f3d | 1 | // SPDX-License-Identifier: GPL-2.0-only |
09853ce7 AB |
2 | /* |
3 | * Driver for Allwinner sun4i Pulse Width Modulation Controller | |
4 | * | |
5 | * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@free-electrons.com> | |
09853ce7 AB |
6 | */ |
7 | ||
8 | #include <linux/bitops.h> | |
9 | #include <linux/clk.h> | |
c32c5c50 | 10 | #include <linux/delay.h> |
09853ce7 AB |
11 | #include <linux/err.h> |
12 | #include <linux/io.h> | |
c32c5c50 | 13 | #include <linux/jiffies.h> |
09853ce7 AB |
14 | #include <linux/module.h> |
15 | #include <linux/of.h> | |
16 | #include <linux/of_device.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/pwm.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/spinlock.h> | |
21 | #include <linux/time.h> | |
22 | ||
23 | #define PWM_CTRL_REG 0x0 | |
24 | ||
25 | #define PWM_CH_PRD_BASE 0x4 | |
26 | #define PWM_CH_PRD_OFFSET 0x4 | |
27 | #define PWM_CH_PRD(ch) (PWM_CH_PRD_BASE + PWM_CH_PRD_OFFSET * (ch)) | |
28 | ||
29 | #define PWMCH_OFFSET 15 | |
30 | #define PWM_PRESCAL_MASK GENMASK(3, 0) | |
31 | #define PWM_PRESCAL_OFF 0 | |
32 | #define PWM_EN BIT(4) | |
33 | #define PWM_ACT_STATE BIT(5) | |
34 | #define PWM_CLK_GATING BIT(6) | |
35 | #define PWM_MODE BIT(7) | |
36 | #define PWM_PULSE BIT(8) | |
37 | #define PWM_BYPASS BIT(9) | |
38 | ||
39 | #define PWM_RDY_BASE 28 | |
40 | #define PWM_RDY_OFFSET 1 | |
41 | #define PWM_RDY(ch) BIT(PWM_RDY_BASE + PWM_RDY_OFFSET * (ch)) | |
42 | ||
43 | #define PWM_PRD(prd) (((prd) - 1) << 16) | |
44 | #define PWM_PRD_MASK GENMASK(15, 0) | |
45 | ||
46 | #define PWM_DTY_MASK GENMASK(15, 0) | |
47 | ||
93e0dfb2 AB |
48 | #define PWM_REG_PRD(reg) ((((reg) >> 16) & PWM_PRD_MASK) + 1) |
49 | #define PWM_REG_DTY(reg) ((reg) & PWM_DTY_MASK) | |
50 | #define PWM_REG_PRESCAL(reg, chan) (((reg) >> ((chan) * PWMCH_OFFSET)) & PWM_PRESCAL_MASK) | |
51 | ||
09853ce7 AB |
52 | #define BIT_CH(bit, chan) ((bit) << ((chan) * PWMCH_OFFSET)) |
53 | ||
54 | static const u32 prescaler_table[] = { | |
55 | 120, | |
56 | 180, | |
57 | 240, | |
58 | 360, | |
59 | 480, | |
60 | 0, | |
61 | 0, | |
62 | 0, | |
63 | 12000, | |
64 | 24000, | |
65 | 36000, | |
66 | 48000, | |
67 | 72000, | |
68 | 0, | |
69 | 0, | |
70 | 0, /* Actually 1 but tested separately */ | |
71 | }; | |
72 | ||
73 | struct sun4i_pwm_data { | |
74 | bool has_prescaler_bypass; | |
f6649f7a | 75 | unsigned int npwm; |
09853ce7 AB |
76 | }; |
77 | ||
78 | struct sun4i_pwm_chip { | |
79 | struct pwm_chip chip; | |
80 | struct clk *clk; | |
81 | void __iomem *base; | |
82 | spinlock_t ctrl_lock; | |
83 | const struct sun4i_pwm_data *data; | |
c32c5c50 AB |
84 | unsigned long next_period[2]; |
85 | bool needs_delay[2]; | |
09853ce7 AB |
86 | }; |
87 | ||
88 | static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip) | |
89 | { | |
90 | return container_of(chip, struct sun4i_pwm_chip, chip); | |
91 | } | |
92 | ||
93 | static inline u32 sun4i_pwm_readl(struct sun4i_pwm_chip *chip, | |
94 | unsigned long offset) | |
95 | { | |
96 | return readl(chip->base + offset); | |
97 | } | |
98 | ||
99 | static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip, | |
100 | u32 val, unsigned long offset) | |
101 | { | |
102 | writel(val, chip->base + offset); | |
103 | } | |
104 | ||
93e0dfb2 AB |
105 | static void sun4i_pwm_get_state(struct pwm_chip *chip, |
106 | struct pwm_device *pwm, | |
107 | struct pwm_state *state) | |
108 | { | |
109 | struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip); | |
110 | u64 clk_rate, tmp; | |
111 | u32 val; | |
112 | unsigned int prescaler; | |
113 | ||
114 | clk_rate = clk_get_rate(sun4i_pwm->clk); | |
115 | ||
116 | val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG); | |
117 | ||
989ae7a5 AB |
118 | if ((PWM_REG_PRESCAL(val, pwm->hwpwm) == PWM_PRESCAL_MASK) && |
119 | sun4i_pwm->data->has_prescaler_bypass) | |
93e0dfb2 AB |
120 | prescaler = 1; |
121 | else | |
122 | prescaler = prescaler_table[PWM_REG_PRESCAL(val, pwm->hwpwm)]; | |
123 | ||
124 | if (prescaler == 0) | |
125 | return; | |
126 | ||
127 | if (val & BIT_CH(PWM_ACT_STATE, pwm->hwpwm)) | |
128 | state->polarity = PWM_POLARITY_NORMAL; | |
129 | else | |
130 | state->polarity = PWM_POLARITY_INVERSED; | |
131 | ||
989ae7a5 AB |
132 | if ((val & BIT_CH(PWM_CLK_GATING | PWM_EN, pwm->hwpwm)) == |
133 | BIT_CH(PWM_CLK_GATING | PWM_EN, pwm->hwpwm)) | |
93e0dfb2 AB |
134 | state->enabled = true; |
135 | else | |
136 | state->enabled = false; | |
137 | ||
138 | val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm)); | |
139 | ||
140 | tmp = prescaler * NSEC_PER_SEC * PWM_REG_DTY(val); | |
141 | state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); | |
142 | ||
143 | tmp = prescaler * NSEC_PER_SEC * PWM_REG_PRD(val); | |
144 | state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); | |
145 | } | |
146 | ||
c32c5c50 AB |
147 | static int sun4i_pwm_calculate(struct sun4i_pwm_chip *sun4i_pwm, |
148 | struct pwm_state *state, | |
149 | u32 *dty, u32 *prd, unsigned int *prsclr) | |
150 | { | |
151 | u64 clk_rate, div = 0; | |
152 | unsigned int pval, prescaler = 0; | |
153 | ||
154 | clk_rate = clk_get_rate(sun4i_pwm->clk); | |
155 | ||
156 | if (sun4i_pwm->data->has_prescaler_bypass) { | |
157 | /* First, test without any prescaler when available */ | |
158 | prescaler = PWM_PRESCAL_MASK; | |
159 | pval = 1; | |
160 | /* | |
161 | * When not using any prescaler, the clock period in nanoseconds | |
162 | * is not an integer so round it half up instead of | |
163 | * truncating to get less surprising values. | |
164 | */ | |
165 | div = clk_rate * state->period + NSEC_PER_SEC / 2; | |
166 | do_div(div, NSEC_PER_SEC); | |
167 | if (div - 1 > PWM_PRD_MASK) | |
168 | prescaler = 0; | |
169 | } | |
170 | ||
171 | if (prescaler == 0) { | |
172 | /* Go up from the first divider */ | |
173 | for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) { | |
174 | if (!prescaler_table[prescaler]) | |
175 | continue; | |
176 | pval = prescaler_table[prescaler]; | |
177 | div = clk_rate; | |
178 | do_div(div, pval); | |
179 | div = div * state->period; | |
180 | do_div(div, NSEC_PER_SEC); | |
181 | if (div - 1 <= PWM_PRD_MASK) | |
182 | break; | |
183 | } | |
184 | ||
185 | if (div - 1 > PWM_PRD_MASK) | |
186 | return -EINVAL; | |
187 | } | |
188 | ||
189 | *prd = div; | |
190 | div *= state->duty_cycle; | |
191 | do_div(div, state->period); | |
192 | *dty = div; | |
193 | *prsclr = prescaler; | |
194 | ||
195 | div = (u64)pval * NSEC_PER_SEC * *prd; | |
196 | state->period = DIV_ROUND_CLOSEST_ULL(div, clk_rate); | |
197 | ||
198 | div = (u64)pval * NSEC_PER_SEC * *dty; | |
199 | state->duty_cycle = DIV_ROUND_CLOSEST_ULL(div, clk_rate); | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, | |
205 | struct pwm_state *state) | |
206 | { | |
207 | struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip); | |
208 | struct pwm_state cstate; | |
209 | u32 ctrl; | |
210 | int ret; | |
211 | unsigned int delay_us; | |
212 | unsigned long now; | |
213 | ||
214 | pwm_get_state(pwm, &cstate); | |
215 | ||
216 | if (!cstate.enabled) { | |
217 | ret = clk_prepare_enable(sun4i_pwm->clk); | |
218 | if (ret) { | |
219 | dev_err(chip->dev, "failed to enable PWM clock\n"); | |
220 | return ret; | |
221 | } | |
222 | } | |
223 | ||
224 | spin_lock(&sun4i_pwm->ctrl_lock); | |
225 | ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG); | |
226 | ||
227 | if ((cstate.period != state->period) || | |
228 | (cstate.duty_cycle != state->duty_cycle)) { | |
229 | u32 period, duty, val; | |
230 | unsigned int prescaler; | |
231 | ||
232 | ret = sun4i_pwm_calculate(sun4i_pwm, state, | |
233 | &duty, &period, &prescaler); | |
234 | if (ret) { | |
235 | dev_err(chip->dev, "period exceeds the maximum value\n"); | |
236 | spin_unlock(&sun4i_pwm->ctrl_lock); | |
237 | if (!cstate.enabled) | |
238 | clk_disable_unprepare(sun4i_pwm->clk); | |
239 | return ret; | |
240 | } | |
241 | ||
242 | if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) { | |
243 | /* Prescaler changed, the clock has to be gated */ | |
244 | ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); | |
245 | sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG); | |
246 | ||
247 | ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm); | |
248 | ctrl |= BIT_CH(prescaler, pwm->hwpwm); | |
249 | } | |
250 | ||
251 | val = (duty & PWM_DTY_MASK) | PWM_PRD(period); | |
252 | sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm)); | |
253 | sun4i_pwm->next_period[pwm->hwpwm] = jiffies + | |
254 | usecs_to_jiffies(cstate.period / 1000 + 1); | |
255 | sun4i_pwm->needs_delay[pwm->hwpwm] = true; | |
256 | } | |
257 | ||
258 | if (state->polarity != PWM_POLARITY_NORMAL) | |
259 | ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm); | |
260 | else | |
261 | ctrl |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm); | |
262 | ||
263 | ctrl |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm); | |
264 | if (state->enabled) { | |
265 | ctrl |= BIT_CH(PWM_EN, pwm->hwpwm); | |
266 | } else if (!sun4i_pwm->needs_delay[pwm->hwpwm]) { | |
267 | ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm); | |
268 | ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); | |
269 | } | |
270 | ||
271 | sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG); | |
272 | ||
273 | spin_unlock(&sun4i_pwm->ctrl_lock); | |
274 | ||
275 | if (state->enabled) | |
276 | return 0; | |
277 | ||
278 | if (!sun4i_pwm->needs_delay[pwm->hwpwm]) { | |
279 | clk_disable_unprepare(sun4i_pwm->clk); | |
280 | return 0; | |
281 | } | |
282 | ||
283 | /* We need a full period to elapse before disabling the channel. */ | |
284 | now = jiffies; | |
285 | if (sun4i_pwm->needs_delay[pwm->hwpwm] && | |
286 | time_before(now, sun4i_pwm->next_period[pwm->hwpwm])) { | |
287 | delay_us = jiffies_to_usecs(sun4i_pwm->next_period[pwm->hwpwm] - | |
288 | now); | |
289 | if ((delay_us / 500) > MAX_UDELAY_MS) | |
290 | msleep(delay_us / 1000 + 1); | |
291 | else | |
292 | usleep_range(delay_us, delay_us * 2); | |
293 | } | |
294 | sun4i_pwm->needs_delay[pwm->hwpwm] = false; | |
295 | ||
296 | spin_lock(&sun4i_pwm->ctrl_lock); | |
297 | ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG); | |
298 | ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); | |
299 | ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm); | |
300 | sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG); | |
301 | spin_unlock(&sun4i_pwm->ctrl_lock); | |
302 | ||
303 | clk_disable_unprepare(sun4i_pwm->clk); | |
304 | ||
305 | return 0; | |
306 | } | |
307 | ||
09853ce7 | 308 | static const struct pwm_ops sun4i_pwm_ops = { |
c32c5c50 | 309 | .apply = sun4i_pwm_apply, |
93e0dfb2 | 310 | .get_state = sun4i_pwm_get_state, |
09853ce7 AB |
311 | .owner = THIS_MODULE, |
312 | }; | |
313 | ||
7b4c7c56 | 314 | static const struct sun4i_pwm_data sun4i_pwm_dual_nobypass = { |
09853ce7 | 315 | .has_prescaler_bypass = false, |
f6649f7a HG |
316 | .npwm = 2, |
317 | }; | |
318 | ||
7b4c7c56 | 319 | static const struct sun4i_pwm_data sun4i_pwm_dual_bypass = { |
f6649f7a | 320 | .has_prescaler_bypass = true, |
f6649f7a HG |
321 | .npwm = 2, |
322 | }; | |
323 | ||
7b4c7c56 | 324 | static const struct sun4i_pwm_data sun4i_pwm_single_bypass = { |
42ddcf4f | 325 | .has_prescaler_bypass = true, |
42ddcf4f MK |
326 | .npwm = 1, |
327 | }; | |
328 | ||
09853ce7 AB |
329 | static const struct of_device_id sun4i_pwm_dt_ids[] = { |
330 | { | |
331 | .compatible = "allwinner,sun4i-a10-pwm", | |
7b4c7c56 | 332 | .data = &sun4i_pwm_dual_nobypass, |
f6649f7a HG |
333 | }, { |
334 | .compatible = "allwinner,sun5i-a10s-pwm", | |
7b4c7c56 | 335 | .data = &sun4i_pwm_dual_bypass, |
f6649f7a HG |
336 | }, { |
337 | .compatible = "allwinner,sun5i-a13-pwm", | |
7b4c7c56 | 338 | .data = &sun4i_pwm_single_bypass, |
09853ce7 AB |
339 | }, { |
340 | .compatible = "allwinner,sun7i-a20-pwm", | |
7b4c7c56 | 341 | .data = &sun4i_pwm_dual_bypass, |
42ddcf4f MK |
342 | }, { |
343 | .compatible = "allwinner,sun8i-h3-pwm", | |
7b4c7c56 | 344 | .data = &sun4i_pwm_single_bypass, |
09853ce7 AB |
345 | }, { |
346 | /* sentinel */ | |
347 | }, | |
348 | }; | |
349 | MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids); | |
350 | ||
351 | static int sun4i_pwm_probe(struct platform_device *pdev) | |
352 | { | |
353 | struct sun4i_pwm_chip *pwm; | |
354 | struct resource *res; | |
93e0dfb2 | 355 | int ret; |
09853ce7 AB |
356 | |
357 | pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); | |
358 | if (!pwm) | |
359 | return -ENOMEM; | |
360 | ||
df4f6e8c CL |
361 | pwm->data = of_device_get_match_data(&pdev->dev); |
362 | if (!pwm->data) | |
363 | return -ENODEV; | |
364 | ||
09853ce7 AB |
365 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
366 | pwm->base = devm_ioremap_resource(&pdev->dev, res); | |
367 | if (IS_ERR(pwm->base)) | |
368 | return PTR_ERR(pwm->base); | |
369 | ||
370 | pwm->clk = devm_clk_get(&pdev->dev, NULL); | |
371 | if (IS_ERR(pwm->clk)) | |
372 | return PTR_ERR(pwm->clk); | |
373 | ||
374 | pwm->chip.dev = &pdev->dev; | |
375 | pwm->chip.ops = &sun4i_pwm_ops; | |
376 | pwm->chip.base = -1; | |
f6649f7a | 377 | pwm->chip.npwm = pwm->data->npwm; |
09853ce7 AB |
378 | pwm->chip.of_xlate = of_pwm_xlate_with_flags; |
379 | pwm->chip.of_pwm_n_cells = 3; | |
09853ce7 AB |
380 | |
381 | spin_lock_init(&pwm->ctrl_lock); | |
382 | ||
383 | ret = pwmchip_add(&pwm->chip); | |
384 | if (ret < 0) { | |
385 | dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); | |
386 | return ret; | |
387 | } | |
388 | ||
389 | platform_set_drvdata(pdev, pwm); | |
390 | ||
09853ce7 | 391 | return 0; |
09853ce7 AB |
392 | } |
393 | ||
394 | static int sun4i_pwm_remove(struct platform_device *pdev) | |
395 | { | |
396 | struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev); | |
397 | ||
398 | return pwmchip_remove(&pwm->chip); | |
399 | } | |
400 | ||
401 | static struct platform_driver sun4i_pwm_driver = { | |
402 | .driver = { | |
403 | .name = "sun4i-pwm", | |
404 | .of_match_table = sun4i_pwm_dt_ids, | |
405 | }, | |
406 | .probe = sun4i_pwm_probe, | |
407 | .remove = sun4i_pwm_remove, | |
408 | }; | |
409 | module_platform_driver(sun4i_pwm_driver); | |
410 | ||
411 | MODULE_ALIAS("platform:sun4i-pwm"); | |
412 | MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>"); | |
413 | MODULE_DESCRIPTION("Allwinner sun4i PWM driver"); | |
414 | MODULE_LICENSE("GPL v2"); |