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authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 12:22:37 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 12:22:37 -0400
commit9ec97169e7d6afe2f8206d694d1411fb3bb49853 (patch)
tree9d24c8cd440a312f96b70db5cdaaef1136787003 /arch/arm/plat-samsung
parenta410963ba4c0c768302f0298e258b1ee940e8316 (diff)
parent19891b20e7c275feb92d669f4b1879861f7e8c25 (diff)
Merge branch 'for-3.6' of git://gitorious.org/linux-pwm/linux-pwm
Pull PWM subsystem from Thierry Reding: "The new PWM subsystem aims at collecting all implementations of the legacy PWM API and to eventually replace it completely. The subsystem has been in development for over half a year now and many drivers have already been converted. It has been in linux-next for a couple of weeks and there have been no major issues so I think it is ready for inclusion in your tree." Arnd Bergmann <arnd@arndb.de>: "Very much Ack on the new subsystem. It uses the interface declarations as the previously separate pwm drivers, so nothing changes for now in the drivers using it, although it enables us to change those more easily in the future if we want to. This work is also one of the missing pieces that are required to eventually build ARM kernels for multiple platforms, which is currently prohibited (amongs other things) by the fact that you cannot have more than one driver exporting the pwm functions." Tested-and-acked-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Philip, Avinash <avinashphilip@ti.com> # TI's AM33xx platforms Acked-By: Alexandre Pereira da Silva <aletes.xgr@gmail.com> # LPC32XX Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Sachin Kamat <sachin.kamat@linaro.org> Fix up trivial conflicts with other cleanups and DT updates. * 'for-3.6' of git://gitorious.org/linux-pwm/linux-pwm: (36 commits) pwm: pwm-tiehrpwm: PWM driver support for EHRPWM pwm: pwm-tiecap: PWM driver support for ECAP APWM pwm: fix used-uninitialized warning in pwm_get() pwm: add lpc32xx PWM support pwm_backlight: pass correct brightness to callback pwm: Use pr_* functions in pwm-samsung.c file pwm: Convert pwm-samsung to use devm_* APIs pwm: Convert pwm-tegra to use devm_clk_get() pwm: pwm-mxs: Return proper error if pwmchip_remove() fails pwm: pwm-bfin: Return proper error if pwmchip_remove() fails pwm: pxa: Propagate pwmchip_remove() error pwm: Convert pwm-pxa to use devm_* APIs pwm: Convert pwm-vt8500 to use devm_* APIs pwm: Convert pwm-imx to use devm_* APIs pwm: Conflict with legacy PWM API pwm: pwm-mxs: add pinctrl support pwm: pwm-mxs: use devm_* managed functions pwm: pwm-mxs: use global reset function stmp_reset_block pwm: pwm-mxs: encode soc name in compatible string pwm: Take over maintainership of the PWM subsystem ...
Diffstat (limited to 'arch/arm/plat-samsung')
-rw-r--r--arch/arm/plat-samsung/Makefile4
-rw-r--r--arch/arm/plat-samsung/pwm.c416
2 files changed, 0 insertions, 420 deletions
diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile
index b78717496677..9e40e8d00740 100644
--- a/arch/arm/plat-samsung/Makefile
+++ b/arch/arm/plat-samsung/Makefile
@@ -59,7 +59,3 @@ obj-$(CONFIG_SAMSUNG_WAKEMASK) += wakeup-mask.o
59 59
60obj-$(CONFIG_S5P_PM) += s5p-pm.o s5p-irq-pm.o 60obj-$(CONFIG_S5P_PM) += s5p-pm.o s5p-irq-pm.o
61obj-$(CONFIG_S5P_SLEEP) += s5p-sleep.o 61obj-$(CONFIG_S5P_SLEEP) += s5p-sleep.o
62
63# PWM support
64
65obj-$(CONFIG_HAVE_PWM) += pwm.o
diff --git a/arch/arm/plat-samsung/pwm.c b/arch/arm/plat-samsung/pwm.c
deleted file mode 100644
index d3583050fb05..000000000000
--- a/arch/arm/plat-samsung/pwm.c
+++ /dev/null
@@ -1,416 +0,0 @@
1/* arch/arm/plat-s3c/pwm.c
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 *
7 * S3C series PWM device core
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/export.h>
15#include <linux/kernel.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/err.h>
19#include <linux/clk.h>
20#include <linux/io.h>
21#include <linux/pwm.h>
22
23#include <mach/map.h>
24
25#include <plat/regs-timer.h>
26
27struct pwm_device {
28 struct list_head list;
29 struct platform_device *pdev;
30
31 struct clk *clk_div;
32 struct clk *clk;
33 const char *label;
34
35 unsigned int period_ns;
36 unsigned int duty_ns;
37
38 unsigned char tcon_base;
39 unsigned char use_count;
40 unsigned char pwm_id;
41};
42
43#define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg)
44
45static struct clk *clk_scaler[2];
46
47static inline int pwm_is_tdiv(struct pwm_device *pwm)
48{
49 return clk_get_parent(pwm->clk) == pwm->clk_div;
50}
51
52static DEFINE_MUTEX(pwm_lock);
53static LIST_HEAD(pwm_list);
54
55struct pwm_device *pwm_request(int pwm_id, const char *label)
56{
57 struct pwm_device *pwm;
58 int found = 0;
59
60 mutex_lock(&pwm_lock);
61
62 list_for_each_entry(pwm, &pwm_list, list) {
63 if (pwm->pwm_id == pwm_id) {
64 found = 1;
65 break;
66 }
67 }
68
69 if (found) {
70 if (pwm->use_count == 0) {
71 pwm->use_count = 1;
72 pwm->label = label;
73 } else
74 pwm = ERR_PTR(-EBUSY);
75 } else
76 pwm = ERR_PTR(-ENOENT);
77
78 mutex_unlock(&pwm_lock);
79 return pwm;
80}
81
82EXPORT_SYMBOL(pwm_request);
83
84
85void pwm_free(struct pwm_device *pwm)
86{
87 mutex_lock(&pwm_lock);
88
89 if (pwm->use_count) {
90 pwm->use_count--;
91 pwm->label = NULL;
92 } else
93 printk(KERN_ERR "PWM%d device already freed\n", pwm->pwm_id);
94
95 mutex_unlock(&pwm_lock);
96}
97
98EXPORT_SYMBOL(pwm_free);
99
100#define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0))
101#define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2))
102#define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3))
103#define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1))
104
105int pwm_enable(struct pwm_device *pwm)
106{
107 unsigned long flags;
108 unsigned long tcon;
109
110 local_irq_save(flags);
111
112 tcon = __raw_readl(S3C2410_TCON);
113 tcon |= pwm_tcon_start(pwm);
114 __raw_writel(tcon, S3C2410_TCON);
115
116 local_irq_restore(flags);
117
118 return 0;
119}
120
121EXPORT_SYMBOL(pwm_enable);
122
123void pwm_disable(struct pwm_device *pwm)
124{
125 unsigned long flags;
126 unsigned long tcon;
127
128 local_irq_save(flags);
129
130 tcon = __raw_readl(S3C2410_TCON);
131 tcon &= ~pwm_tcon_start(pwm);
132 __raw_writel(tcon, S3C2410_TCON);
133
134 local_irq_restore(flags);
135}
136
137EXPORT_SYMBOL(pwm_disable);
138
139static unsigned long pwm_calc_tin(struct pwm_device *pwm, unsigned long freq)
140{
141 unsigned long tin_parent_rate;
142 unsigned int div;
143
144 tin_parent_rate = clk_get_rate(clk_get_parent(pwm->clk_div));
145 pwm_dbg(pwm, "tin parent at %lu\n", tin_parent_rate);
146
147 for (div = 2; div <= 16; div *= 2) {
148 if ((tin_parent_rate / (div << 16)) < freq)
149 return tin_parent_rate / div;
150 }
151
152 return tin_parent_rate / 16;
153}
154
155#define NS_IN_HZ (1000000000UL)
156
157int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
158{
159 unsigned long tin_rate;
160 unsigned long tin_ns;
161 unsigned long period;
162 unsigned long flags;
163 unsigned long tcon;
164 unsigned long tcnt;
165 long tcmp;
166
167 /* We currently avoid using 64bit arithmetic by using the
168 * fact that anything faster than 1Hz is easily representable
169 * by 32bits. */
170
171 if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
172 return -ERANGE;
173
174 if (duty_ns > period_ns)
175 return -EINVAL;
176
177 if (period_ns == pwm->period_ns &&
178 duty_ns == pwm->duty_ns)
179 return 0;
180
181 /* The TCMP and TCNT can be read without a lock, they're not
182 * shared between the timers. */
183
184 tcmp = __raw_readl(S3C2410_TCMPB(pwm->pwm_id));
185 tcnt = __raw_readl(S3C2410_TCNTB(pwm->pwm_id));
186
187 period = NS_IN_HZ / period_ns;
188
189 pwm_dbg(pwm, "duty_ns=%d, period_ns=%d (%lu)\n",
190 duty_ns, period_ns, period);
191
192 /* Check to see if we are changing the clock rate of the PWM */
193
194 if (pwm->period_ns != period_ns) {
195 if (pwm_is_tdiv(pwm)) {
196 tin_rate = pwm_calc_tin(pwm, period);
197 clk_set_rate(pwm->clk_div, tin_rate);
198 } else
199 tin_rate = clk_get_rate(pwm->clk);
200
201 pwm->period_ns = period_ns;
202
203 pwm_dbg(pwm, "tin_rate=%lu\n", tin_rate);
204
205 tin_ns = NS_IN_HZ / tin_rate;
206 tcnt = period_ns / tin_ns;
207 } else
208 tin_ns = NS_IN_HZ / clk_get_rate(pwm->clk);
209
210 /* Note, counters count down */
211
212 tcmp = duty_ns / tin_ns;
213 tcmp = tcnt - tcmp;
214 /* the pwm hw only checks the compare register after a decrement,
215 so the pin never toggles if tcmp = tcnt */
216 if (tcmp == tcnt)
217 tcmp--;
218
219 pwm_dbg(pwm, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt);
220
221 if (tcmp < 0)
222 tcmp = 0;
223
224 /* Update the PWM register block. */
225
226 local_irq_save(flags);
227
228 __raw_writel(tcmp, S3C2410_TCMPB(pwm->pwm_id));
229 __raw_writel(tcnt, S3C2410_TCNTB(pwm->pwm_id));
230
231 tcon = __raw_readl(S3C2410_TCON);
232 tcon |= pwm_tcon_manulupdate(pwm);
233 tcon |= pwm_tcon_autoreload(pwm);
234 __raw_writel(tcon, S3C2410_TCON);
235
236 tcon &= ~pwm_tcon_manulupdate(pwm);
237 __raw_writel(tcon, S3C2410_TCON);
238
239 local_irq_restore(flags);
240
241 return 0;
242}
243
244EXPORT_SYMBOL(pwm_config);
245
246static int pwm_register(struct pwm_device *pwm)
247{
248 pwm->duty_ns = -1;
249 pwm->period_ns = -1;
250
251 mutex_lock(&pwm_lock);
252 list_add_tail(&pwm->list, &pwm_list);
253 mutex_unlock(&pwm_lock);
254
255 return 0;
256}
257
258static int s3c_pwm_probe(struct platform_device *pdev)
259{
260 struct device *dev = &pdev->dev;
261 struct pwm_device *pwm;
262 unsigned long flags;
263 unsigned long tcon;
264 unsigned int id = pdev->id;
265 int ret;
266
267 if (id == 4) {
268 dev_err(dev, "TIMER4 is currently not supported\n");
269 return -ENXIO;
270 }
271
272 pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
273 if (pwm == NULL) {
274 dev_err(dev, "failed to allocate pwm_device\n");
275 return -ENOMEM;
276 }
277
278 pwm->pdev = pdev;
279 pwm->pwm_id = id;
280
281 /* calculate base of control bits in TCON */
282 pwm->tcon_base = id == 0 ? 0 : (id * 4) + 4;
283
284 pwm->clk = clk_get(dev, "pwm-tin");
285 if (IS_ERR(pwm->clk)) {
286 dev_err(dev, "failed to get pwm tin clk\n");
287 ret = PTR_ERR(pwm->clk);
288 goto err_alloc;
289 }
290
291 pwm->clk_div = clk_get(dev, "pwm-tdiv");
292 if (IS_ERR(pwm->clk_div)) {
293 dev_err(dev, "failed to get pwm tdiv clk\n");
294 ret = PTR_ERR(pwm->clk_div);
295 goto err_clk_tin;
296 }
297
298 clk_enable(pwm->clk);
299 clk_enable(pwm->clk_div);
300
301 local_irq_save(flags);
302
303 tcon = __raw_readl(S3C2410_TCON);
304 tcon |= pwm_tcon_invert(pwm);
305 __raw_writel(tcon, S3C2410_TCON);
306
307 local_irq_restore(flags);
308
309
310 ret = pwm_register(pwm);
311 if (ret) {
312 dev_err(dev, "failed to register pwm\n");
313 goto err_clk_tdiv;
314 }
315
316 pwm_dbg(pwm, "config bits %02x\n",
317 (__raw_readl(S3C2410_TCON) >> pwm->tcon_base) & 0x0f);
318
319 dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n",
320 clk_get_rate(pwm->clk),
321 clk_get_rate(pwm->clk_div),
322 pwm_is_tdiv(pwm) ? "div" : "ext", pwm->tcon_base);
323
324 platform_set_drvdata(pdev, pwm);
325 return 0;
326
327 err_clk_tdiv:
328 clk_disable(pwm->clk_div);
329 clk_disable(pwm->clk);
330 clk_put(pwm->clk_div);
331
332 err_clk_tin:
333 clk_put(pwm->clk);
334
335 err_alloc:
336 kfree(pwm);
337 return ret;
338}
339
340static int __devexit s3c_pwm_remove(struct platform_device *pdev)
341{
342 struct pwm_device *pwm = platform_get_drvdata(pdev);
343
344 clk_disable(pwm->clk_div);
345 clk_disable(pwm->clk);
346 clk_put(pwm->clk_div);
347 clk_put(pwm->clk);
348 kfree(pwm);
349
350 return 0;
351}
352
353#ifdef CONFIG_PM
354static int s3c_pwm_suspend(struct platform_device *pdev, pm_message_t state)
355{
356 struct pwm_device *pwm = platform_get_drvdata(pdev);
357
358 /* No one preserve these values during suspend so reset them
359 * Otherwise driver leaves PWM unconfigured if same values
360 * passed to pwm_config
361 */
362 pwm->period_ns = 0;
363 pwm->duty_ns = 0;
364
365 return 0;
366}
367
368static int s3c_pwm_resume(struct platform_device *pdev)
369{
370 struct pwm_device *pwm = platform_get_drvdata(pdev);
371 unsigned long tcon;
372
373 /* Restore invertion */
374 tcon = __raw_readl(S3C2410_TCON);
375 tcon |= pwm_tcon_invert(pwm);
376 __raw_writel(tcon, S3C2410_TCON);
377
378 return 0;
379}
380
381#else
382#define s3c_pwm_suspend NULL
383#define s3c_pwm_resume NULL
384#endif
385
386static struct platform_driver s3c_pwm_driver = {
387 .driver = {
388 .name = "s3c24xx-pwm",
389 .owner = THIS_MODULE,
390 },
391 .probe = s3c_pwm_probe,
392 .remove = __devexit_p(s3c_pwm_remove),
393 .suspend = s3c_pwm_suspend,
394 .resume = s3c_pwm_resume,
395};
396
397static int __init pwm_init(void)
398{
399 int ret;
400
401 clk_scaler[0] = clk_get(NULL, "pwm-scaler0");
402 clk_scaler[1] = clk_get(NULL, "pwm-scaler1");
403
404 if (IS_ERR(clk_scaler[0]) || IS_ERR(clk_scaler[1])) {
405 printk(KERN_ERR "%s: failed to get scaler clocks\n", __func__);
406 return -EINVAL;
407 }
408
409 ret = platform_driver_register(&s3c_pwm_driver);
410 if (ret)
411 printk(KERN_ERR "%s: failed to add pwm driver\n", __func__);
412
413 return ret;
414}
415
416arch_initcall(pwm_init);