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e4ab5172 | 1 | // SPDX-License-Identifier: GPL-2.0 |
99b82abb LP |
2 | /* |
3 | * R-Mobile TPU PWM driver | |
4 | * | |
5 | * Copyright (C) 2012 Renesas Solutions Corp. | |
99b82abb LP |
6 | */ |
7 | ||
8 | #include <linux/clk.h> | |
9 | #include <linux/err.h> | |
10 | #include <linux/io.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/ioport.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mutex.h> | |
382457e5 | 15 | #include <linux/of.h> |
99b82abb LP |
16 | #include <linux/platform_device.h> |
17 | #include <linux/pm_runtime.h> | |
18 | #include <linux/pwm.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/spinlock.h> | |
21 | ||
dc671157 AB |
22 | #define TPU_CHANNEL_MAX 4 |
23 | ||
99b82abb LP |
24 | #define TPU_TSTR 0x00 /* Timer start register (shared) */ |
25 | ||
26 | #define TPU_TCRn 0x00 /* Timer control register */ | |
27 | #define TPU_TCR_CCLR_NONE (0 << 5) | |
28 | #define TPU_TCR_CCLR_TGRA (1 << 5) | |
29 | #define TPU_TCR_CCLR_TGRB (2 << 5) | |
30 | #define TPU_TCR_CCLR_TGRC (5 << 5) | |
31 | #define TPU_TCR_CCLR_TGRD (6 << 5) | |
32 | #define TPU_TCR_CKEG_RISING (0 << 3) | |
33 | #define TPU_TCR_CKEG_FALLING (1 << 3) | |
34 | #define TPU_TCR_CKEG_BOTH (2 << 3) | |
35 | #define TPU_TMDRn 0x04 /* Timer mode register */ | |
36 | #define TPU_TMDR_BFWT (1 << 6) | |
37 | #define TPU_TMDR_BFB (1 << 5) | |
38 | #define TPU_TMDR_BFA (1 << 4) | |
39 | #define TPU_TMDR_MD_NORMAL (0 << 0) | |
40 | #define TPU_TMDR_MD_PWM (2 << 0) | |
41 | #define TPU_TIORn 0x08 /* Timer I/O control register */ | |
42 | #define TPU_TIOR_IOA_0 (0 << 0) | |
43 | #define TPU_TIOR_IOA_0_CLR (1 << 0) | |
44 | #define TPU_TIOR_IOA_0_SET (2 << 0) | |
45 | #define TPU_TIOR_IOA_0_TOGGLE (3 << 0) | |
46 | #define TPU_TIOR_IOA_1 (4 << 0) | |
47 | #define TPU_TIOR_IOA_1_CLR (5 << 0) | |
48 | #define TPU_TIOR_IOA_1_SET (6 << 0) | |
49 | #define TPU_TIOR_IOA_1_TOGGLE (7 << 0) | |
50 | #define TPU_TIERn 0x0c /* Timer interrupt enable register */ | |
51 | #define TPU_TSRn 0x10 /* Timer status register */ | |
52 | #define TPU_TCNTn 0x14 /* Timer counter */ | |
53 | #define TPU_TGRAn 0x18 /* Timer general register A */ | |
54 | #define TPU_TGRBn 0x1c /* Timer general register B */ | |
55 | #define TPU_TGRCn 0x20 /* Timer general register C */ | |
56 | #define TPU_TGRDn 0x24 /* Timer general register D */ | |
57 | ||
58 | #define TPU_CHANNEL_OFFSET 0x10 | |
59 | #define TPU_CHANNEL_SIZE 0x40 | |
60 | ||
61 | enum tpu_pin_state { | |
62 | TPU_PIN_INACTIVE, /* Pin is driven inactive */ | |
63 | TPU_PIN_PWM, /* Pin is driven by PWM */ | |
64 | TPU_PIN_ACTIVE, /* Pin is driven active */ | |
65 | }; | |
66 | ||
67 | struct tpu_device; | |
68 | ||
69 | struct tpu_pwm_device { | |
70 | bool timer_on; /* Whether the timer is running */ | |
71 | ||
72 | struct tpu_device *tpu; | |
73 | unsigned int channel; /* Channel number in the TPU */ | |
74 | ||
75 | enum pwm_polarity polarity; | |
76 | unsigned int prescaler; | |
77 | u16 period; | |
78 | u16 duty; | |
79 | }; | |
80 | ||
81 | struct tpu_device { | |
82 | struct platform_device *pdev; | |
99b82abb LP |
83 | struct pwm_chip chip; |
84 | spinlock_t lock; | |
85 | ||
86 | void __iomem *base; | |
87 | struct clk *clk; | |
88 | }; | |
89 | ||
90 | #define to_tpu_device(c) container_of(c, struct tpu_device, chip) | |
91 | ||
208ab867 | 92 | static void tpu_pwm_write(struct tpu_pwm_device *tpd, int reg_nr, u16 value) |
99b82abb | 93 | { |
208ab867 UKK |
94 | void __iomem *base = tpd->tpu->base + TPU_CHANNEL_OFFSET |
95 | + tpd->channel * TPU_CHANNEL_SIZE; | |
99b82abb LP |
96 | |
97 | iowrite16(value, base + reg_nr); | |
98 | } | |
99 | ||
208ab867 | 100 | static void tpu_pwm_set_pin(struct tpu_pwm_device *tpd, |
99b82abb LP |
101 | enum tpu_pin_state state) |
102 | { | |
103 | static const char * const states[] = { "inactive", "PWM", "active" }; | |
104 | ||
208ab867 UKK |
105 | dev_dbg(&tpd->tpu->pdev->dev, "%u: configuring pin as %s\n", |
106 | tpd->channel, states[state]); | |
99b82abb LP |
107 | |
108 | switch (state) { | |
109 | case TPU_PIN_INACTIVE: | |
208ab867 UKK |
110 | tpu_pwm_write(tpd, TPU_TIORn, |
111 | tpd->polarity == PWM_POLARITY_INVERSED ? | |
99b82abb LP |
112 | TPU_TIOR_IOA_1 : TPU_TIOR_IOA_0); |
113 | break; | |
114 | case TPU_PIN_PWM: | |
208ab867 UKK |
115 | tpu_pwm_write(tpd, TPU_TIORn, |
116 | tpd->polarity == PWM_POLARITY_INVERSED ? | |
99b82abb LP |
117 | TPU_TIOR_IOA_0_SET : TPU_TIOR_IOA_1_CLR); |
118 | break; | |
119 | case TPU_PIN_ACTIVE: | |
208ab867 UKK |
120 | tpu_pwm_write(tpd, TPU_TIORn, |
121 | tpd->polarity == PWM_POLARITY_INVERSED ? | |
99b82abb LP |
122 | TPU_TIOR_IOA_0 : TPU_TIOR_IOA_1); |
123 | break; | |
124 | } | |
125 | } | |
126 | ||
208ab867 | 127 | static void tpu_pwm_start_stop(struct tpu_pwm_device *tpd, int start) |
99b82abb LP |
128 | { |
129 | unsigned long flags; | |
130 | u16 value; | |
131 | ||
208ab867 UKK |
132 | spin_lock_irqsave(&tpd->tpu->lock, flags); |
133 | value = ioread16(tpd->tpu->base + TPU_TSTR); | |
99b82abb LP |
134 | |
135 | if (start) | |
208ab867 | 136 | value |= 1 << tpd->channel; |
99b82abb | 137 | else |
208ab867 | 138 | value &= ~(1 << tpd->channel); |
99b82abb | 139 | |
208ab867 UKK |
140 | iowrite16(value, tpd->tpu->base + TPU_TSTR); |
141 | spin_unlock_irqrestore(&tpd->tpu->lock, flags); | |
99b82abb LP |
142 | } |
143 | ||
208ab867 | 144 | static int tpu_pwm_timer_start(struct tpu_pwm_device *tpd) |
99b82abb LP |
145 | { |
146 | int ret; | |
147 | ||
208ab867 | 148 | if (!tpd->timer_on) { |
99b82abb | 149 | /* Wake up device and enable clock. */ |
208ab867 UKK |
150 | pm_runtime_get_sync(&tpd->tpu->pdev->dev); |
151 | ret = clk_prepare_enable(tpd->tpu->clk); | |
99b82abb | 152 | if (ret) { |
208ab867 | 153 | dev_err(&tpd->tpu->pdev->dev, "cannot enable clock\n"); |
99b82abb LP |
154 | return ret; |
155 | } | |
208ab867 | 156 | tpd->timer_on = true; |
99b82abb LP |
157 | } |
158 | ||
159 | /* | |
160 | * Make sure the channel is stopped, as we need to reconfigure it | |
161 | * completely. First drive the pin to the inactive state to avoid | |
162 | * glitches. | |
163 | */ | |
208ab867 UKK |
164 | tpu_pwm_set_pin(tpd, TPU_PIN_INACTIVE); |
165 | tpu_pwm_start_stop(tpd, false); | |
99b82abb LP |
166 | |
167 | /* | |
168 | * - Clear TCNT on TGRB match | |
169 | * - Count on rising edge | |
170 | * - Set prescaler | |
171 | * - Output 0 until TGRA, output 1 until TGRB (active low polarity) | |
172 | * - Output 1 until TGRA, output 0 until TGRB (active high polarity | |
173 | * - PWM mode | |
174 | */ | |
208ab867 UKK |
175 | tpu_pwm_write(tpd, TPU_TCRn, TPU_TCR_CCLR_TGRB | TPU_TCR_CKEG_RISING | |
176 | tpd->prescaler); | |
177 | tpu_pwm_write(tpd, TPU_TMDRn, TPU_TMDR_MD_PWM); | |
178 | tpu_pwm_set_pin(tpd, TPU_PIN_PWM); | |
179 | tpu_pwm_write(tpd, TPU_TGRAn, tpd->duty); | |
180 | tpu_pwm_write(tpd, TPU_TGRBn, tpd->period); | |
99b82abb | 181 | |
208ab867 UKK |
182 | dev_dbg(&tpd->tpu->pdev->dev, "%u: TGRA 0x%04x TGRB 0x%04x\n", |
183 | tpd->channel, tpd->duty, tpd->period); | |
99b82abb LP |
184 | |
185 | /* Start the channel. */ | |
208ab867 | 186 | tpu_pwm_start_stop(tpd, true); |
99b82abb LP |
187 | |
188 | return 0; | |
189 | } | |
190 | ||
208ab867 | 191 | static void tpu_pwm_timer_stop(struct tpu_pwm_device *tpd) |
99b82abb | 192 | { |
208ab867 | 193 | if (!tpd->timer_on) |
99b82abb LP |
194 | return; |
195 | ||
196 | /* Disable channel. */ | |
208ab867 | 197 | tpu_pwm_start_stop(tpd, false); |
99b82abb LP |
198 | |
199 | /* Stop clock and mark device as idle. */ | |
208ab867 UKK |
200 | clk_disable_unprepare(tpd->tpu->clk); |
201 | pm_runtime_put(&tpd->tpu->pdev->dev); | |
99b82abb | 202 | |
208ab867 | 203 | tpd->timer_on = false; |
99b82abb LP |
204 | } |
205 | ||
206 | /* ----------------------------------------------------------------------------- | |
207 | * PWM API | |
208 | */ | |
209 | ||
208ab867 | 210 | static int tpu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
99b82abb LP |
211 | { |
212 | struct tpu_device *tpu = to_tpu_device(chip); | |
208ab867 | 213 | struct tpu_pwm_device *tpd; |
99b82abb | 214 | |
208ab867 | 215 | if (pwm->hwpwm >= TPU_CHANNEL_MAX) |
99b82abb LP |
216 | return -EINVAL; |
217 | ||
208ab867 UKK |
218 | tpd = kzalloc(sizeof(*tpd), GFP_KERNEL); |
219 | if (tpd == NULL) | |
99b82abb LP |
220 | return -ENOMEM; |
221 | ||
208ab867 UKK |
222 | tpd->tpu = tpu; |
223 | tpd->channel = pwm->hwpwm; | |
224 | tpd->polarity = PWM_POLARITY_NORMAL; | |
225 | tpd->prescaler = 0; | |
226 | tpd->period = 0; | |
227 | tpd->duty = 0; | |
99b82abb | 228 | |
208ab867 | 229 | tpd->timer_on = false; |
99b82abb | 230 | |
208ab867 | 231 | pwm_set_chip_data(pwm, tpd); |
99b82abb LP |
232 | |
233 | return 0; | |
234 | } | |
235 | ||
208ab867 | 236 | static void tpu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) |
99b82abb | 237 | { |
208ab867 | 238 | struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); |
99b82abb | 239 | |
208ab867 UKK |
240 | tpu_pwm_timer_stop(tpd); |
241 | kfree(tpd); | |
99b82abb LP |
242 | } |
243 | ||
208ab867 | 244 | static int tpu_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, |
ec00cd5e | 245 | int duty_ns, int period_ns, bool enabled) |
99b82abb LP |
246 | { |
247 | static const unsigned int prescalers[] = { 1, 4, 16, 64 }; | |
208ab867 | 248 | struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); |
99b82abb LP |
249 | struct tpu_device *tpu = to_tpu_device(chip); |
250 | unsigned int prescaler; | |
251 | bool duty_only = false; | |
252 | u32 clk_rate; | |
253 | u32 period; | |
254 | u32 duty; | |
255 | int ret; | |
256 | ||
257 | /* | |
258 | * Pick a prescaler to avoid overflowing the counter. | |
259 | * TODO: Pick the highest acceptable prescaler. | |
260 | */ | |
261 | clk_rate = clk_get_rate(tpu->clk); | |
262 | ||
263 | for (prescaler = 0; prescaler < ARRAY_SIZE(prescalers); ++prescaler) { | |
264 | period = clk_rate / prescalers[prescaler] | |
265 | / (NSEC_PER_SEC / period_ns); | |
266 | if (period <= 0xffff) | |
267 | break; | |
268 | } | |
269 | ||
270 | if (prescaler == ARRAY_SIZE(prescalers) || period == 0) { | |
271 | dev_err(&tpu->pdev->dev, "clock rate mismatch\n"); | |
272 | return -ENOTSUPP; | |
273 | } | |
274 | ||
275 | if (duty_ns) { | |
276 | duty = clk_rate / prescalers[prescaler] | |
277 | / (NSEC_PER_SEC / duty_ns); | |
278 | if (duty > period) | |
279 | return -EINVAL; | |
280 | } else { | |
281 | duty = 0; | |
282 | } | |
283 | ||
284 | dev_dbg(&tpu->pdev->dev, | |
285 | "rate %u, prescaler %u, period %u, duty %u\n", | |
286 | clk_rate, prescalers[prescaler], period, duty); | |
287 | ||
208ab867 | 288 | if (tpd->prescaler == prescaler && tpd->period == period) |
99b82abb LP |
289 | duty_only = true; |
290 | ||
208ab867 UKK |
291 | tpd->prescaler = prescaler; |
292 | tpd->period = period; | |
293 | tpd->duty = duty; | |
99b82abb LP |
294 | |
295 | /* If the channel is disabled we're done. */ | |
ec00cd5e | 296 | if (!enabled) |
99b82abb LP |
297 | return 0; |
298 | ||
208ab867 | 299 | if (duty_only && tpd->timer_on) { |
99b82abb LP |
300 | /* |
301 | * If only the duty cycle changed and the timer is already | |
302 | * running, there's no need to reconfigure it completely, Just | |
303 | * modify the duty cycle. | |
304 | */ | |
208ab867 UKK |
305 | tpu_pwm_write(tpd, TPU_TGRAn, tpd->duty); |
306 | dev_dbg(&tpu->pdev->dev, "%u: TGRA 0x%04x\n", tpd->channel, | |
307 | tpd->duty); | |
99b82abb LP |
308 | } else { |
309 | /* Otherwise perform a full reconfiguration. */ | |
208ab867 | 310 | ret = tpu_pwm_timer_start(tpd); |
99b82abb LP |
311 | if (ret < 0) |
312 | return ret; | |
313 | } | |
314 | ||
315 | if (duty == 0 || duty == period) { | |
316 | /* | |
317 | * To avoid running the timer when not strictly required, handle | |
318 | * 0% and 100% duty cycles as fixed levels and stop the timer. | |
319 | */ | |
208ab867 UKK |
320 | tpu_pwm_set_pin(tpd, duty ? TPU_PIN_ACTIVE : TPU_PIN_INACTIVE); |
321 | tpu_pwm_timer_stop(tpd); | |
99b82abb LP |
322 | } |
323 | ||
324 | return 0; | |
325 | } | |
326 | ||
208ab867 | 327 | static int tpu_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, |
99b82abb LP |
328 | enum pwm_polarity polarity) |
329 | { | |
208ab867 | 330 | struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); |
99b82abb | 331 | |
208ab867 | 332 | tpd->polarity = polarity; |
99b82abb LP |
333 | |
334 | return 0; | |
335 | } | |
336 | ||
208ab867 | 337 | static int tpu_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
99b82abb | 338 | { |
208ab867 | 339 | struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); |
99b82abb LP |
340 | int ret; |
341 | ||
208ab867 | 342 | ret = tpu_pwm_timer_start(tpd); |
99b82abb LP |
343 | if (ret < 0) |
344 | return ret; | |
345 | ||
346 | /* | |
347 | * To avoid running the timer when not strictly required, handle 0% and | |
348 | * 100% duty cycles as fixed levels and stop the timer. | |
349 | */ | |
208ab867 UKK |
350 | if (tpd->duty == 0 || tpd->duty == tpd->period) { |
351 | tpu_pwm_set_pin(tpd, tpd->duty ? | |
99b82abb | 352 | TPU_PIN_ACTIVE : TPU_PIN_INACTIVE); |
208ab867 | 353 | tpu_pwm_timer_stop(tpd); |
99b82abb LP |
354 | } |
355 | ||
356 | return 0; | |
357 | } | |
358 | ||
208ab867 | 359 | static void tpu_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) |
99b82abb | 360 | { |
208ab867 | 361 | struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); |
99b82abb LP |
362 | |
363 | /* The timer must be running to modify the pin output configuration. */ | |
208ab867 UKK |
364 | tpu_pwm_timer_start(tpd); |
365 | tpu_pwm_set_pin(tpd, TPU_PIN_INACTIVE); | |
366 | tpu_pwm_timer_stop(tpd); | |
99b82abb LP |
367 | } |
368 | ||
ec00cd5e UKK |
369 | static int tpu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
370 | const struct pwm_state *state) | |
371 | { | |
372 | int err; | |
373 | bool enabled = pwm->state.enabled; | |
374 | ||
375 | if (state->polarity != pwm->state.polarity) { | |
376 | if (enabled) { | |
377 | tpu_pwm_disable(chip, pwm); | |
378 | enabled = false; | |
379 | } | |
380 | ||
381 | err = tpu_pwm_set_polarity(chip, pwm, state->polarity); | |
382 | if (err) | |
383 | return err; | |
384 | } | |
385 | ||
386 | if (!state->enabled) { | |
387 | if (enabled) | |
388 | tpu_pwm_disable(chip, pwm); | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
393 | err = tpu_pwm_config(pwm->chip, pwm, | |
394 | state->duty_cycle, state->period, enabled); | |
395 | if (err) | |
396 | return err; | |
397 | ||
398 | if (!enabled) | |
399 | err = tpu_pwm_enable(chip, pwm); | |
400 | ||
401 | return err; | |
402 | } | |
403 | ||
99b82abb LP |
404 | static const struct pwm_ops tpu_pwm_ops = { |
405 | .request = tpu_pwm_request, | |
406 | .free = tpu_pwm_free, | |
ec00cd5e | 407 | .apply = tpu_pwm_apply, |
99b82abb LP |
408 | .owner = THIS_MODULE, |
409 | }; | |
410 | ||
411 | /* ----------------------------------------------------------------------------- | |
412 | * Probe and remove | |
413 | */ | |
414 | ||
415 | static int tpu_probe(struct platform_device *pdev) | |
416 | { | |
417 | struct tpu_device *tpu; | |
99b82abb LP |
418 | int ret; |
419 | ||
420 | tpu = devm_kzalloc(&pdev->dev, sizeof(*tpu), GFP_KERNEL); | |
6c5059cc | 421 | if (tpu == NULL) |
99b82abb | 422 | return -ENOMEM; |
99b82abb | 423 | |
382457e5 LP |
424 | spin_lock_init(&tpu->lock); |
425 | tpu->pdev = pdev; | |
426 | ||
99b82abb | 427 | /* Map memory, get clock and pin control. */ |
e3f22bc2 | 428 | tpu->base = devm_platform_ioremap_resource(pdev, 0); |
00cf99ee WY |
429 | if (IS_ERR(tpu->base)) |
430 | return PTR_ERR(tpu->base); | |
99b82abb LP |
431 | |
432 | tpu->clk = devm_clk_get(&pdev->dev, NULL); | |
6eb3af76 UKK |
433 | if (IS_ERR(tpu->clk)) |
434 | return dev_err_probe(&pdev->dev, PTR_ERR(tpu->clk), "Failed to get clock\n"); | |
99b82abb LP |
435 | |
436 | /* Initialize and register the device. */ | |
437 | platform_set_drvdata(pdev, tpu); | |
438 | ||
99b82abb LP |
439 | tpu->chip.dev = &pdev->dev; |
440 | tpu->chip.ops = &tpu_pwm_ops; | |
99b82abb LP |
441 | tpu->chip.npwm = TPU_CHANNEL_MAX; |
442 | ||
ff4bcd56 UKK |
443 | ret = devm_pm_runtime_enable(&pdev->dev); |
444 | if (ret < 0) | |
445 | return dev_err_probe(&pdev->dev, ret, "Failed to enable runtime PM\n"); | |
d5a3c7a4 | 446 | |
ff4bcd56 UKK |
447 | ret = devm_pwmchip_add(&pdev->dev, &tpu->chip); |
448 | if (ret < 0) | |
6eb3af76 | 449 | return dev_err_probe(&pdev->dev, ret, "Failed to register PWM chip\n"); |
99b82abb | 450 | |
81d4b5c4 | 451 | return 0; |
99b82abb LP |
452 | } |
453 | ||
382457e5 LP |
454 | #ifdef CONFIG_OF |
455 | static const struct of_device_id tpu_of_table[] = { | |
456 | { .compatible = "renesas,tpu-r8a73a4", }, | |
457 | { .compatible = "renesas,tpu-r8a7740", }, | |
458 | { .compatible = "renesas,tpu-r8a7790", }, | |
382457e5 LP |
459 | { .compatible = "renesas,tpu", }, |
460 | { }, | |
461 | }; | |
462 | ||
463 | MODULE_DEVICE_TABLE(of, tpu_of_table); | |
464 | #endif | |
465 | ||
99b82abb LP |
466 | static struct platform_driver tpu_driver = { |
467 | .probe = tpu_probe, | |
99b82abb LP |
468 | .driver = { |
469 | .name = "renesas-tpu-pwm", | |
382457e5 | 470 | .of_match_table = of_match_ptr(tpu_of_table), |
99b82abb LP |
471 | } |
472 | }; | |
473 | ||
474 | module_platform_driver(tpu_driver); | |
475 | ||
476 | MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); | |
477 | MODULE_DESCRIPTION("Renesas TPU PWM Driver"); | |
478 | MODULE_LICENSE("GPL v2"); | |
71077bc8 | 479 | MODULE_ALIAS("platform:renesas-tpu-pwm"); |