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b505183b XL |
1 | /* |
2 | * Freescale FlexTimer Module (FTM) PWM Driver | |
3 | * | |
4 | * Copyright 2012-2013 Freescale Semiconductor, Inc. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/clk.h> | |
13 | #include <linux/err.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/of_address.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/pwm.h> | |
21 | #include <linux/slab.h> | |
22 | ||
23 | #define FTM_SC 0x00 | |
24 | #define FTM_SC_CLK_MASK 0x3 | |
25 | #define FTM_SC_CLK_SHIFT 3 | |
26 | #define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_SHIFT) | |
27 | #define FTM_SC_PS_MASK 0x7 | |
28 | #define FTM_SC_PS_SHIFT 0 | |
29 | ||
30 | #define FTM_CNT 0x04 | |
31 | #define FTM_MOD 0x08 | |
32 | ||
33 | #define FTM_CSC_BASE 0x0C | |
34 | #define FTM_CSC_MSB BIT(5) | |
35 | #define FTM_CSC_MSA BIT(4) | |
36 | #define FTM_CSC_ELSB BIT(3) | |
37 | #define FTM_CSC_ELSA BIT(2) | |
38 | #define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8)) | |
39 | ||
40 | #define FTM_CV_BASE 0x10 | |
41 | #define FTM_CV(_channel) (FTM_CV_BASE + ((_channel) * 8)) | |
42 | ||
43 | #define FTM_CNTIN 0x4C | |
44 | #define FTM_STATUS 0x50 | |
45 | ||
46 | #define FTM_MODE 0x54 | |
47 | #define FTM_MODE_FTMEN BIT(0) | |
48 | #define FTM_MODE_INIT BIT(2) | |
49 | #define FTM_MODE_PWMSYNC BIT(3) | |
50 | ||
51 | #define FTM_SYNC 0x58 | |
52 | #define FTM_OUTINIT 0x5C | |
53 | #define FTM_OUTMASK 0x60 | |
54 | #define FTM_COMBINE 0x64 | |
55 | #define FTM_DEADTIME 0x68 | |
56 | #define FTM_EXTTRIG 0x6C | |
57 | #define FTM_POL 0x70 | |
58 | #define FTM_FMS 0x74 | |
59 | #define FTM_FILTER 0x78 | |
60 | #define FTM_FLTCTRL 0x7C | |
61 | #define FTM_QDCTRL 0x80 | |
62 | #define FTM_CONF 0x84 | |
63 | #define FTM_FLTPOL 0x88 | |
64 | #define FTM_SYNCONF 0x8C | |
65 | #define FTM_INVCTRL 0x90 | |
66 | #define FTM_SWOCTRL 0x94 | |
67 | #define FTM_PWMLOAD 0x98 | |
68 | ||
69 | enum fsl_pwm_clk { | |
70 | FSL_PWM_CLK_SYS, | |
71 | FSL_PWM_CLK_FIX, | |
72 | FSL_PWM_CLK_EXT, | |
73 | FSL_PWM_CLK_CNTEN, | |
74 | FSL_PWM_CLK_MAX | |
75 | }; | |
76 | ||
77 | struct fsl_pwm_chip { | |
78 | struct pwm_chip chip; | |
79 | ||
80 | struct mutex lock; | |
81 | ||
82 | unsigned int use_count; | |
83 | unsigned int cnt_select; | |
84 | unsigned int clk_ps; | |
85 | ||
86 | void __iomem *base; | |
87 | ||
88 | int period_ns; | |
89 | ||
90 | struct clk *clk[FSL_PWM_CLK_MAX]; | |
91 | }; | |
92 | ||
93 | static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip) | |
94 | { | |
95 | return container_of(chip, struct fsl_pwm_chip, chip); | |
96 | } | |
97 | ||
98 | static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) | |
99 | { | |
100 | struct fsl_pwm_chip *fpc = to_fsl_chip(chip); | |
101 | ||
102 | return clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]); | |
103 | } | |
104 | ||
105 | static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
106 | { | |
107 | struct fsl_pwm_chip *fpc = to_fsl_chip(chip); | |
108 | ||
109 | clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]); | |
110 | } | |
111 | ||
112 | static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc, | |
113 | enum fsl_pwm_clk index) | |
114 | { | |
115 | unsigned long sys_rate, cnt_rate; | |
116 | unsigned long long ratio; | |
117 | ||
118 | sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]); | |
119 | if (!sys_rate) | |
120 | return -EINVAL; | |
121 | ||
122 | cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]); | |
123 | if (!cnt_rate) | |
124 | return -EINVAL; | |
125 | ||
126 | switch (index) { | |
127 | case FSL_PWM_CLK_SYS: | |
128 | fpc->clk_ps = 1; | |
129 | break; | |
130 | case FSL_PWM_CLK_FIX: | |
131 | ratio = 2 * cnt_rate - 1; | |
132 | do_div(ratio, sys_rate); | |
133 | fpc->clk_ps = ratio; | |
134 | break; | |
135 | case FSL_PWM_CLK_EXT: | |
136 | ratio = 4 * cnt_rate - 1; | |
137 | do_div(ratio, sys_rate); | |
138 | fpc->clk_ps = ratio; | |
139 | break; | |
140 | default: | |
141 | return -EINVAL; | |
142 | } | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc, | |
148 | unsigned long period_ns) | |
149 | { | |
150 | unsigned long long c, c0; | |
151 | ||
152 | c = clk_get_rate(fpc->clk[fpc->cnt_select]); | |
153 | c = c * period_ns; | |
154 | do_div(c, 1000000000UL); | |
155 | ||
156 | do { | |
157 | c0 = c; | |
158 | do_div(c0, (1 << fpc->clk_ps)); | |
159 | if (c0 <= 0xFFFF) | |
160 | return (unsigned long)c0; | |
161 | } while (++fpc->clk_ps < 8); | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc, | |
167 | unsigned long period_ns, | |
168 | enum fsl_pwm_clk index) | |
169 | { | |
170 | int ret; | |
171 | ||
172 | ret = fsl_pwm_calculate_default_ps(fpc, index); | |
173 | if (ret) { | |
174 | dev_err(fpc->chip.dev, | |
175 | "failed to calculate default prescaler: %d\n", | |
176 | ret); | |
177 | return 0; | |
178 | } | |
179 | ||
180 | return fsl_pwm_calculate_cycles(fpc, period_ns); | |
181 | } | |
182 | ||
183 | static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc, | |
184 | unsigned long period_ns) | |
185 | { | |
186 | enum fsl_pwm_clk m0, m1; | |
187 | unsigned long fix_rate, ext_rate, cycles; | |
188 | ||
189 | cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, | |
190 | FSL_PWM_CLK_SYS); | |
191 | if (cycles) { | |
192 | fpc->cnt_select = FSL_PWM_CLK_SYS; | |
193 | return cycles; | |
194 | } | |
195 | ||
196 | fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]); | |
197 | ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]); | |
198 | ||
199 | if (fix_rate > ext_rate) { | |
200 | m0 = FSL_PWM_CLK_FIX; | |
201 | m1 = FSL_PWM_CLK_EXT; | |
202 | } else { | |
203 | m0 = FSL_PWM_CLK_EXT; | |
204 | m1 = FSL_PWM_CLK_FIX; | |
205 | } | |
206 | ||
207 | cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0); | |
208 | if (cycles) { | |
209 | fpc->cnt_select = m0; | |
210 | return cycles; | |
211 | } | |
212 | ||
213 | fpc->cnt_select = m1; | |
214 | ||
215 | return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1); | |
216 | } | |
217 | ||
218 | static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc, | |
219 | unsigned long period_ns, | |
220 | unsigned long duty_ns) | |
221 | { | |
222 | unsigned long long val, duty; | |
223 | ||
224 | val = readl(fpc->base + FTM_MOD); | |
225 | duty = duty_ns * (val + 1); | |
226 | do_div(duty, period_ns); | |
227 | ||
228 | return (unsigned long)duty; | |
229 | } | |
230 | ||
231 | static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |
232 | int duty_ns, int period_ns) | |
233 | { | |
234 | struct fsl_pwm_chip *fpc = to_fsl_chip(chip); | |
235 | u32 val, period, duty; | |
236 | ||
237 | mutex_lock(&fpc->lock); | |
238 | ||
239 | /* | |
240 | * The Freescale FTM controller supports only a single period for | |
241 | * all PWM channels, therefore incompatible changes need to be | |
242 | * refused. | |
243 | */ | |
244 | if (fpc->period_ns && fpc->period_ns != period_ns) { | |
245 | dev_err(fpc->chip.dev, | |
246 | "conflicting period requested for PWM %u\n", | |
247 | pwm->hwpwm); | |
248 | mutex_unlock(&fpc->lock); | |
249 | return -EBUSY; | |
250 | } | |
251 | ||
252 | if (!fpc->period_ns && duty_ns) { | |
253 | period = fsl_pwm_calculate_period(fpc, period_ns); | |
254 | if (!period) { | |
255 | dev_err(fpc->chip.dev, "failed to calculate period\n"); | |
256 | mutex_unlock(&fpc->lock); | |
257 | return -EINVAL; | |
258 | } | |
259 | ||
260 | val = readl(fpc->base + FTM_SC); | |
261 | val &= ~(FTM_SC_PS_MASK << FTM_SC_PS_SHIFT); | |
262 | val |= fpc->clk_ps; | |
263 | writel(val, fpc->base + FTM_SC); | |
264 | writel(period - 1, fpc->base + FTM_MOD); | |
265 | ||
266 | fpc->period_ns = period_ns; | |
267 | } | |
268 | ||
269 | mutex_unlock(&fpc->lock); | |
270 | ||
271 | duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns); | |
272 | ||
273 | writel(FTM_CSC_MSB | FTM_CSC_ELSB, fpc->base + FTM_CSC(pwm->hwpwm)); | |
274 | writel(duty, fpc->base + FTM_CV(pwm->hwpwm)); | |
275 | ||
276 | return 0; | |
277 | } | |
278 | ||
279 | static int fsl_pwm_set_polarity(struct pwm_chip *chip, | |
280 | struct pwm_device *pwm, | |
281 | enum pwm_polarity polarity) | |
282 | { | |
283 | struct fsl_pwm_chip *fpc = to_fsl_chip(chip); | |
284 | u32 val; | |
285 | ||
286 | val = readl(fpc->base + FTM_POL); | |
287 | ||
288 | if (polarity == PWM_POLARITY_INVERSED) | |
289 | val |= BIT(pwm->hwpwm); | |
290 | else | |
291 | val &= ~BIT(pwm->hwpwm); | |
292 | ||
293 | writel(val, fpc->base + FTM_POL); | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
298 | static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc) | |
299 | { | |
300 | u32 val; | |
301 | int ret; | |
302 | ||
303 | if (fpc->use_count != 0) | |
304 | return 0; | |
305 | ||
306 | /* select counter clock source */ | |
307 | val = readl(fpc->base + FTM_SC); | |
308 | val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT); | |
309 | val |= FTM_SC_CLK(fpc->cnt_select); | |
310 | writel(val, fpc->base + FTM_SC); | |
311 | ||
312 | ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]); | |
313 | if (ret) | |
314 | return ret; | |
315 | ||
316 | ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]); | |
317 | if (ret) { | |
318 | clk_disable_unprepare(fpc->clk[fpc->cnt_select]); | |
319 | return ret; | |
320 | } | |
321 | ||
322 | fpc->use_count++; | |
323 | ||
324 | return 0; | |
325 | } | |
326 | ||
327 | static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | |
328 | { | |
329 | struct fsl_pwm_chip *fpc = to_fsl_chip(chip); | |
330 | u32 val; | |
331 | int ret; | |
332 | ||
333 | mutex_lock(&fpc->lock); | |
334 | val = readl(fpc->base + FTM_OUTMASK); | |
335 | val &= ~BIT(pwm->hwpwm); | |
336 | writel(val, fpc->base + FTM_OUTMASK); | |
337 | ||
338 | ret = fsl_counter_clock_enable(fpc); | |
339 | mutex_unlock(&fpc->lock); | |
340 | ||
341 | return ret; | |
342 | } | |
343 | ||
344 | static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc) | |
345 | { | |
346 | u32 val; | |
347 | ||
348 | /* | |
349 | * already disabled, do nothing | |
350 | */ | |
351 | if (fpc->use_count == 0) | |
352 | return; | |
353 | ||
354 | /* there are still users, so can't disable yet */ | |
355 | if (--fpc->use_count > 0) | |
356 | return; | |
357 | ||
358 | /* no users left, disable PWM counter clock */ | |
359 | val = readl(fpc->base + FTM_SC); | |
360 | val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT); | |
361 | writel(val, fpc->base + FTM_SC); | |
362 | ||
363 | clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]); | |
364 | clk_disable_unprepare(fpc->clk[fpc->cnt_select]); | |
365 | } | |
366 | ||
367 | static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
368 | { | |
369 | struct fsl_pwm_chip *fpc = to_fsl_chip(chip); | |
370 | u32 val; | |
371 | ||
372 | mutex_lock(&fpc->lock); | |
373 | val = readl(fpc->base + FTM_OUTMASK); | |
374 | val |= BIT(pwm->hwpwm); | |
375 | writel(val, fpc->base + FTM_OUTMASK); | |
376 | ||
377 | fsl_counter_clock_disable(fpc); | |
378 | ||
379 | val = readl(fpc->base + FTM_OUTMASK); | |
380 | ||
381 | if ((val & 0xFF) == 0xFF) | |
382 | fpc->period_ns = 0; | |
383 | ||
384 | mutex_unlock(&fpc->lock); | |
385 | } | |
386 | ||
387 | static const struct pwm_ops fsl_pwm_ops = { | |
388 | .request = fsl_pwm_request, | |
389 | .free = fsl_pwm_free, | |
390 | .config = fsl_pwm_config, | |
391 | .set_polarity = fsl_pwm_set_polarity, | |
392 | .enable = fsl_pwm_enable, | |
393 | .disable = fsl_pwm_disable, | |
394 | .owner = THIS_MODULE, | |
395 | }; | |
396 | ||
397 | static int fsl_pwm_init(struct fsl_pwm_chip *fpc) | |
398 | { | |
399 | int ret; | |
400 | ||
401 | ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]); | |
402 | if (ret) | |
403 | return ret; | |
404 | ||
405 | writel(0x00, fpc->base + FTM_CNTIN); | |
406 | writel(0x00, fpc->base + FTM_OUTINIT); | |
407 | writel(0xFF, fpc->base + FTM_OUTMASK); | |
408 | ||
409 | clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]); | |
410 | ||
411 | return 0; | |
412 | } | |
413 | ||
414 | static int fsl_pwm_probe(struct platform_device *pdev) | |
415 | { | |
416 | struct fsl_pwm_chip *fpc; | |
417 | struct resource *res; | |
418 | int ret; | |
419 | ||
420 | fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL); | |
421 | if (!fpc) | |
422 | return -ENOMEM; | |
423 | ||
424 | mutex_init(&fpc->lock); | |
425 | ||
426 | fpc->chip.dev = &pdev->dev; | |
427 | ||
428 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
429 | fpc->base = devm_ioremap_resource(&pdev->dev, res); | |
430 | if (IS_ERR(fpc->base)) | |
431 | return PTR_ERR(fpc->base); | |
432 | ||
433 | fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys"); | |
434 | if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) { | |
435 | dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n"); | |
436 | return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]); | |
437 | } | |
438 | ||
439 | fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix"); | |
440 | if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX])) | |
441 | return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]); | |
442 | ||
443 | fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext"); | |
444 | if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT])) | |
445 | return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]); | |
446 | ||
447 | fpc->clk[FSL_PWM_CLK_CNTEN] = | |
448 | devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en"); | |
449 | if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN])) | |
450 | return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]); | |
451 | ||
452 | fpc->chip.ops = &fsl_pwm_ops; | |
453 | fpc->chip.of_xlate = of_pwm_xlate_with_flags; | |
454 | fpc->chip.of_pwm_n_cells = 3; | |
455 | fpc->chip.base = -1; | |
456 | fpc->chip.npwm = 8; | |
39fd3f99 | 457 | fpc->chip.can_sleep = true; |
b505183b XL |
458 | |
459 | ret = pwmchip_add(&fpc->chip); | |
460 | if (ret < 0) { | |
461 | dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); | |
462 | return ret; | |
463 | } | |
464 | ||
465 | platform_set_drvdata(pdev, fpc); | |
466 | ||
467 | return fsl_pwm_init(fpc); | |
468 | } | |
469 | ||
470 | static int fsl_pwm_remove(struct platform_device *pdev) | |
471 | { | |
472 | struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev); | |
473 | ||
474 | return pwmchip_remove(&fpc->chip); | |
475 | } | |
476 | ||
477 | static const struct of_device_id fsl_pwm_dt_ids[] = { | |
478 | { .compatible = "fsl,vf610-ftm-pwm", }, | |
479 | { /* sentinel */ } | |
480 | }; | |
481 | MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids); | |
482 | ||
483 | static struct platform_driver fsl_pwm_driver = { | |
484 | .driver = { | |
485 | .name = "fsl-ftm-pwm", | |
486 | .of_match_table = fsl_pwm_dt_ids, | |
487 | }, | |
488 | .probe = fsl_pwm_probe, | |
489 | .remove = fsl_pwm_remove, | |
490 | }; | |
491 | module_platform_driver(fsl_pwm_driver); | |
492 | ||
493 | MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver"); | |
494 | MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>"); | |
495 | MODULE_ALIAS("platform:fsl-ftm-pwm"); | |
496 | MODULE_LICENSE("GPL"); |