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b5ead1cd | 1 | /* arch/arm/plat-s3c/pwm.c |
6fc601e3 BD |
2 | * |
3 | * Copyright (c) 2007 Ben Dooks | |
4 | * Copyright (c) 2008 Simtec Electronics | |
5 | * Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org> | |
6 | * | |
b5ead1cd | 7 | * S3C series PWM device core |
6fc601e3 BD |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License. | |
12 | */ | |
13 | ||
14 | #include <linux/module.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/platform_device.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
6fc601e3 BD |
18 | #include <linux/err.h> |
19 | #include <linux/clk.h> | |
20 | #include <linux/io.h> | |
21 | #include <linux/pwm.h> | |
22 | ||
80b02c17 | 23 | #include <mach/irqs.h> |
b5ead1cd | 24 | #include <mach/map.h> |
80b02c17 | 25 | |
a2b7ba9c BD |
26 | #include <plat/devs.h> |
27 | #include <plat/regs-timer.h> | |
6fc601e3 BD |
28 | |
29 | struct pwm_device { | |
30 | struct list_head list; | |
31 | struct platform_device *pdev; | |
32 | ||
33 | struct clk *clk_div; | |
34 | struct clk *clk; | |
35 | const char *label; | |
36 | ||
37 | unsigned int period_ns; | |
38 | unsigned int duty_ns; | |
39 | ||
40 | unsigned char tcon_base; | |
41 | unsigned char running; | |
42 | unsigned char use_count; | |
43 | unsigned char pwm_id; | |
44 | }; | |
45 | ||
66592eee | 46 | #define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg) |
6fc601e3 BD |
47 | |
48 | static struct clk *clk_scaler[2]; | |
49 | ||
50 | /* Standard setup for a timer block. */ | |
51 | ||
52 | #define TIMER_RESOURCE_SIZE (1) | |
53 | ||
54 | #define TIMER_RESOURCE(_tmr, _irq) \ | |
55 | (struct resource [TIMER_RESOURCE_SIZE]) { \ | |
56 | [0] = { \ | |
57 | .start = _irq, \ | |
58 | .end = _irq, \ | |
59 | .flags = IORESOURCE_IRQ \ | |
60 | } \ | |
61 | } | |
62 | ||
55b404fd | 63 | #define DEFINE_S3C_TIMER(_tmr_no, _irq) \ |
6fc601e3 BD |
64 | .name = "s3c24xx-pwm", \ |
65 | .id = _tmr_no, \ | |
66 | .num_resources = TIMER_RESOURCE_SIZE, \ | |
67 | .resource = TIMER_RESOURCE(_tmr_no, _irq), \ | |
68 | ||
69 | /* since we already have an static mapping for the timer, we do not | |
70 | * bother setting any IO resource for the base. | |
71 | */ | |
72 | ||
73 | struct platform_device s3c_device_timer[] = { | |
55b404fd NC |
74 | [0] = { DEFINE_S3C_TIMER(0, IRQ_TIMER0) }, |
75 | [1] = { DEFINE_S3C_TIMER(1, IRQ_TIMER1) }, | |
76 | [2] = { DEFINE_S3C_TIMER(2, IRQ_TIMER2) }, | |
77 | [3] = { DEFINE_S3C_TIMER(3, IRQ_TIMER3) }, | |
78 | [4] = { DEFINE_S3C_TIMER(4, IRQ_TIMER4) }, | |
6fc601e3 BD |
79 | }; |
80 | ||
81 | static inline int pwm_is_tdiv(struct pwm_device *pwm) | |
82 | { | |
83 | return clk_get_parent(pwm->clk) == pwm->clk_div; | |
84 | } | |
85 | ||
86 | static DEFINE_MUTEX(pwm_lock); | |
87 | static LIST_HEAD(pwm_list); | |
88 | ||
89 | struct pwm_device *pwm_request(int pwm_id, const char *label) | |
90 | { | |
91 | struct pwm_device *pwm; | |
92 | int found = 0; | |
93 | ||
94 | mutex_lock(&pwm_lock); | |
95 | ||
96 | list_for_each_entry(pwm, &pwm_list, list) { | |
97 | if (pwm->pwm_id == pwm_id) { | |
98 | found = 1; | |
99 | break; | |
100 | } | |
101 | } | |
102 | ||
103 | if (found) { | |
104 | if (pwm->use_count == 0) { | |
105 | pwm->use_count = 1; | |
106 | pwm->label = label; | |
107 | } else | |
108 | pwm = ERR_PTR(-EBUSY); | |
109 | } else | |
110 | pwm = ERR_PTR(-ENOENT); | |
111 | ||
112 | mutex_unlock(&pwm_lock); | |
113 | return pwm; | |
114 | } | |
115 | ||
116 | EXPORT_SYMBOL(pwm_request); | |
117 | ||
118 | ||
119 | void pwm_free(struct pwm_device *pwm) | |
120 | { | |
121 | mutex_lock(&pwm_lock); | |
122 | ||
123 | if (pwm->use_count) { | |
124 | pwm->use_count--; | |
125 | pwm->label = NULL; | |
126 | } else | |
127 | printk(KERN_ERR "PWM%d device already freed\n", pwm->pwm_id); | |
128 | ||
129 | mutex_unlock(&pwm_lock); | |
130 | } | |
131 | ||
132 | EXPORT_SYMBOL(pwm_free); | |
133 | ||
134 | #define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0)) | |
135 | #define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2)) | |
136 | #define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3)) | |
137 | #define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1)) | |
138 | ||
139 | int pwm_enable(struct pwm_device *pwm) | |
140 | { | |
141 | unsigned long flags; | |
142 | unsigned long tcon; | |
143 | ||
144 | local_irq_save(flags); | |
145 | ||
146 | tcon = __raw_readl(S3C2410_TCON); | |
147 | tcon |= pwm_tcon_start(pwm); | |
148 | __raw_writel(tcon, S3C2410_TCON); | |
149 | ||
150 | local_irq_restore(flags); | |
151 | ||
152 | pwm->running = 1; | |
153 | return 0; | |
154 | } | |
155 | ||
156 | EXPORT_SYMBOL(pwm_enable); | |
157 | ||
158 | void pwm_disable(struct pwm_device *pwm) | |
159 | { | |
160 | unsigned long flags; | |
161 | unsigned long tcon; | |
162 | ||
163 | local_irq_save(flags); | |
164 | ||
165 | tcon = __raw_readl(S3C2410_TCON); | |
166 | tcon &= ~pwm_tcon_start(pwm); | |
167 | __raw_writel(tcon, S3C2410_TCON); | |
168 | ||
169 | local_irq_restore(flags); | |
170 | ||
171 | pwm->running = 0; | |
172 | } | |
173 | ||
174 | EXPORT_SYMBOL(pwm_disable); | |
175 | ||
10389592 | 176 | static unsigned long pwm_calc_tin(struct pwm_device *pwm, unsigned long freq) |
6fc601e3 BD |
177 | { |
178 | unsigned long tin_parent_rate; | |
179 | unsigned int div; | |
180 | ||
181 | tin_parent_rate = clk_get_rate(clk_get_parent(pwm->clk_div)); | |
182 | pwm_dbg(pwm, "tin parent at %lu\n", tin_parent_rate); | |
183 | ||
184 | for (div = 2; div <= 16; div *= 2) { | |
185 | if ((tin_parent_rate / (div << 16)) < freq) | |
186 | return tin_parent_rate / div; | |
187 | } | |
188 | ||
189 | return tin_parent_rate / 16; | |
190 | } | |
191 | ||
192 | #define NS_IN_HZ (1000000000UL) | |
193 | ||
194 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
195 | { | |
196 | unsigned long tin_rate; | |
197 | unsigned long tin_ns; | |
198 | unsigned long period; | |
199 | unsigned long flags; | |
200 | unsigned long tcon; | |
201 | unsigned long tcnt; | |
202 | long tcmp; | |
203 | ||
204 | /* We currently avoid using 64bit arithmetic by using the | |
205 | * fact that anything faster than 1Hz is easily representable | |
206 | * by 32bits. */ | |
207 | ||
208 | if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ) | |
209 | return -ERANGE; | |
210 | ||
211 | if (duty_ns > period_ns) | |
212 | return -EINVAL; | |
213 | ||
214 | if (period_ns == pwm->period_ns && | |
215 | duty_ns == pwm->duty_ns) | |
216 | return 0; | |
217 | ||
218 | /* The TCMP and TCNT can be read without a lock, they're not | |
219 | * shared between the timers. */ | |
220 | ||
221 | tcmp = __raw_readl(S3C2410_TCMPB(pwm->pwm_id)); | |
222 | tcnt = __raw_readl(S3C2410_TCNTB(pwm->pwm_id)); | |
223 | ||
224 | period = NS_IN_HZ / period_ns; | |
225 | ||
226 | pwm_dbg(pwm, "duty_ns=%d, period_ns=%d (%lu)\n", | |
227 | duty_ns, period_ns, period); | |
228 | ||
229 | /* Check to see if we are changing the clock rate of the PWM */ | |
230 | ||
231 | if (pwm->period_ns != period_ns) { | |
232 | if (pwm_is_tdiv(pwm)) { | |
233 | tin_rate = pwm_calc_tin(pwm, period); | |
234 | clk_set_rate(pwm->clk_div, tin_rate); | |
235 | } else | |
236 | tin_rate = clk_get_rate(pwm->clk); | |
237 | ||
238 | pwm->period_ns = period_ns; | |
239 | ||
240 | pwm_dbg(pwm, "tin_rate=%lu\n", tin_rate); | |
241 | ||
242 | tin_ns = NS_IN_HZ / tin_rate; | |
243 | tcnt = period_ns / tin_ns; | |
244 | } else | |
245 | tin_ns = NS_IN_HZ / clk_get_rate(pwm->clk); | |
246 | ||
247 | /* Note, counters count down */ | |
248 | ||
249 | tcmp = duty_ns / tin_ns; | |
250 | tcmp = tcnt - tcmp; | |
165f5f64 PK |
251 | /* the pwm hw only checks the compare register after a decrement, |
252 | so the pin never toggles if tcmp = tcnt */ | |
253 | if (tcmp == tcnt) | |
254 | tcmp--; | |
6fc601e3 BD |
255 | |
256 | pwm_dbg(pwm, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt); | |
257 | ||
258 | if (tcmp < 0) | |
259 | tcmp = 0; | |
260 | ||
261 | /* Update the PWM register block. */ | |
262 | ||
263 | local_irq_save(flags); | |
264 | ||
265 | __raw_writel(tcmp, S3C2410_TCMPB(pwm->pwm_id)); | |
266 | __raw_writel(tcnt, S3C2410_TCNTB(pwm->pwm_id)); | |
267 | ||
268 | tcon = __raw_readl(S3C2410_TCON); | |
269 | tcon |= pwm_tcon_manulupdate(pwm); | |
270 | tcon |= pwm_tcon_autoreload(pwm); | |
271 | __raw_writel(tcon, S3C2410_TCON); | |
272 | ||
273 | tcon &= ~pwm_tcon_manulupdate(pwm); | |
274 | __raw_writel(tcon, S3C2410_TCON); | |
275 | ||
276 | local_irq_restore(flags); | |
277 | ||
278 | return 0; | |
279 | } | |
280 | ||
281 | EXPORT_SYMBOL(pwm_config); | |
282 | ||
283 | static int pwm_register(struct pwm_device *pwm) | |
284 | { | |
285 | pwm->duty_ns = -1; | |
286 | pwm->period_ns = -1; | |
287 | ||
288 | mutex_lock(&pwm_lock); | |
289 | list_add_tail(&pwm->list, &pwm_list); | |
290 | mutex_unlock(&pwm_lock); | |
291 | ||
292 | return 0; | |
293 | } | |
294 | ||
295 | static int s3c_pwm_probe(struct platform_device *pdev) | |
296 | { | |
297 | struct device *dev = &pdev->dev; | |
298 | struct pwm_device *pwm; | |
299 | unsigned long flags; | |
300 | unsigned long tcon; | |
301 | unsigned int id = pdev->id; | |
302 | int ret; | |
303 | ||
304 | if (id == 4) { | |
305 | dev_err(dev, "TIMER4 is currently not supported\n"); | |
306 | return -ENXIO; | |
307 | } | |
308 | ||
309 | pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL); | |
310 | if (pwm == NULL) { | |
311 | dev_err(dev, "failed to allocate pwm_device\n"); | |
312 | return -ENOMEM; | |
313 | } | |
314 | ||
315 | pwm->pdev = pdev; | |
316 | pwm->pwm_id = id; | |
317 | ||
318 | /* calculate base of control bits in TCON */ | |
319 | pwm->tcon_base = id == 0 ? 0 : (id * 4) + 4; | |
320 | ||
321 | pwm->clk = clk_get(dev, "pwm-tin"); | |
322 | if (IS_ERR(pwm->clk)) { | |
323 | dev_err(dev, "failed to get pwm tin clk\n"); | |
324 | ret = PTR_ERR(pwm->clk); | |
325 | goto err_alloc; | |
326 | } | |
327 | ||
328 | pwm->clk_div = clk_get(dev, "pwm-tdiv"); | |
329 | if (IS_ERR(pwm->clk_div)) { | |
330 | dev_err(dev, "failed to get pwm tdiv clk\n"); | |
331 | ret = PTR_ERR(pwm->clk_div); | |
332 | goto err_clk_tin; | |
333 | } | |
334 | ||
335 | local_irq_save(flags); | |
336 | ||
337 | tcon = __raw_readl(S3C2410_TCON); | |
338 | tcon |= pwm_tcon_invert(pwm); | |
339 | __raw_writel(tcon, S3C2410_TCON); | |
340 | ||
341 | local_irq_restore(flags); | |
342 | ||
343 | ||
344 | ret = pwm_register(pwm); | |
345 | if (ret) { | |
346 | dev_err(dev, "failed to register pwm\n"); | |
347 | goto err_clk_tdiv; | |
348 | } | |
349 | ||
350 | pwm_dbg(pwm, "config bits %02x\n", | |
351 | (__raw_readl(S3C2410_TCON) >> pwm->tcon_base) & 0x0f); | |
352 | ||
353 | dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n", | |
354 | clk_get_rate(pwm->clk), | |
355 | clk_get_rate(pwm->clk_div), | |
356 | pwm_is_tdiv(pwm) ? "div" : "ext", pwm->tcon_base); | |
357 | ||
358 | platform_set_drvdata(pdev, pwm); | |
359 | return 0; | |
360 | ||
361 | err_clk_tdiv: | |
362 | clk_put(pwm->clk_div); | |
363 | ||
364 | err_clk_tin: | |
365 | clk_put(pwm->clk); | |
366 | ||
367 | err_alloc: | |
368 | kfree(pwm); | |
369 | return ret; | |
370 | } | |
371 | ||
93b0d8c6 | 372 | static int __devexit s3c_pwm_remove(struct platform_device *pdev) |
6fc601e3 BD |
373 | { |
374 | struct pwm_device *pwm = platform_get_drvdata(pdev); | |
375 | ||
376 | clk_put(pwm->clk_div); | |
377 | clk_put(pwm->clk); | |
378 | kfree(pwm); | |
379 | ||
380 | return 0; | |
381 | } | |
382 | ||
e79032aa VK |
383 | #ifdef CONFIG_PM |
384 | static int s3c_pwm_suspend(struct platform_device *pdev, pm_message_t state) | |
385 | { | |
386 | struct pwm_device *pwm = platform_get_drvdata(pdev); | |
387 | ||
388 | /* No one preserve these values during suspend so reset them | |
389 | * Otherwise driver leaves PWM unconfigured if same values | |
390 | * passed to pwm_config | |
391 | */ | |
392 | pwm->period_ns = 0; | |
393 | pwm->duty_ns = 0; | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | static int s3c_pwm_resume(struct platform_device *pdev) | |
399 | { | |
400 | struct pwm_device *pwm = platform_get_drvdata(pdev); | |
401 | unsigned long tcon; | |
402 | ||
403 | /* Restore invertion */ | |
404 | tcon = __raw_readl(S3C2410_TCON); | |
405 | tcon |= pwm_tcon_invert(pwm); | |
406 | __raw_writel(tcon, S3C2410_TCON); | |
407 | ||
408 | return 0; | |
409 | } | |
410 | ||
411 | #else | |
412 | #define s3c_pwm_suspend NULL | |
413 | #define s3c_pwm_resume NULL | |
414 | #endif | |
415 | ||
6fc601e3 BD |
416 | static struct platform_driver s3c_pwm_driver = { |
417 | .driver = { | |
418 | .name = "s3c24xx-pwm", | |
419 | .owner = THIS_MODULE, | |
420 | }, | |
421 | .probe = s3c_pwm_probe, | |
422 | .remove = __devexit_p(s3c_pwm_remove), | |
e79032aa VK |
423 | .suspend = s3c_pwm_suspend, |
424 | .resume = s3c_pwm_resume, | |
6fc601e3 BD |
425 | }; |
426 | ||
427 | static int __init pwm_init(void) | |
428 | { | |
429 | int ret; | |
430 | ||
431 | clk_scaler[0] = clk_get(NULL, "pwm-scaler0"); | |
432 | clk_scaler[1] = clk_get(NULL, "pwm-scaler1"); | |
433 | ||
434 | if (IS_ERR(clk_scaler[0]) || IS_ERR(clk_scaler[1])) { | |
435 | printk(KERN_ERR "%s: failed to get scaler clocks\n", __func__); | |
436 | return -EINVAL; | |
437 | } | |
438 | ||
439 | ret = platform_driver_register(&s3c_pwm_driver); | |
440 | if (ret) | |
441 | printk(KERN_ERR "%s: failed to add pwm driver\n", __func__); | |
442 | ||
443 | return ret; | |
444 | } | |
445 | ||
446 | arch_initcall(pwm_init); |