[net-next-2.6.git] / arch / arm / plat-s3c24xx / pwm.c

/* arch/arm/plat-s3c24xx/pwm.c
 *
 * Copyright (c) 2007 Ben Dooks
 * Copyright (c) 2008 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
 *
 * S3C24XX PWM device core
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/pwm.h>

#include <plat/devs.h>
#include <plat/regs-timer.h>

struct pwm_device {
	struct list_head	 list;
	struct platform_device	*pdev;

	struct clk		*clk_div;
	struct clk		*clk;
	const char		*label;

	unsigned int		 period_ns;
	unsigned int		 duty_ns;

	unsigned char		 tcon_base;
	unsigned char		 running;
	unsigned char		 use_count;
	unsigned char		 pwm_id;
};

#define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg)

static struct clk *clk_scaler[2];

/* Standard setup for a timer block. */

#define TIMER_RESOURCE_SIZE (1)

#define TIMER_RESOURCE(_tmr, _irq)			\
	(struct resource [TIMER_RESOURCE_SIZE]) {	\
		[0] = {					\
			.start	= _irq,			\
			.end	= _irq,			\
			.flags	= IORESOURCE_IRQ	\
		}					\
	}

#define DEFINE_TIMER(_tmr_no, _irq)			\
	.name		= "s3c24xx-pwm",		\
	.id		= _tmr_no,			\
	.num_resources	= TIMER_RESOURCE_SIZE,		\
	.resource	= TIMER_RESOURCE(_tmr_no, _irq),	\

/* since we already have an static mapping for the timer, we do not
 * bother setting any IO resource for the base.
 */

struct platform_device s3c_device_timer[] = {
	[0] = { DEFINE_TIMER(0, IRQ_TIMER0) },
	[1] = { DEFINE_TIMER(1, IRQ_TIMER1) },
	[2] = { DEFINE_TIMER(2, IRQ_TIMER2) },
	[3] = { DEFINE_TIMER(3, IRQ_TIMER3) },
	[4] = { DEFINE_TIMER(4, IRQ_TIMER4) },
};

static inline int pwm_is_tdiv(struct pwm_device *pwm)
{
	return clk_get_parent(pwm->clk) == pwm->clk_div;
}

static DEFINE_MUTEX(pwm_lock);
static LIST_HEAD(pwm_list);

struct pwm_device *pwm_request(int pwm_id, const char *label)
{
	struct pwm_device *pwm;
	int found = 0;

	mutex_lock(&pwm_lock);

	list_for_each_entry(pwm, &pwm_list, list) {
		if (pwm->pwm_id == pwm_id) {
			found = 1;
			break;
		}
	}

	if (found) {
		if (pwm->use_count == 0) {
			pwm->use_count = 1;
			pwm->label = label;
		} else
			pwm = ERR_PTR(-EBUSY);
	} else
		pwm = ERR_PTR(-ENOENT);

	mutex_unlock(&pwm_lock);
	return pwm;
}

EXPORT_SYMBOL(pwm_request);


void pwm_free(struct pwm_device *pwm)
{
	mutex_lock(&pwm_lock);

	if (pwm->use_count) {
		pwm->use_count--;
		pwm->label = NULL;
	} else
		printk(KERN_ERR "PWM%d device already freed\n", pwm->pwm_id);

	mutex_unlock(&pwm_lock);
}

EXPORT_SYMBOL(pwm_free);

#define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0))
#define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2))
#define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3))
#define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1))

int pwm_enable(struct pwm_device *pwm)
{
	unsigned long flags;
	unsigned long tcon;

	local_irq_save(flags);

	tcon = __raw_readl(S3C2410_TCON);
	tcon |= pwm_tcon_start(pwm);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);

	pwm->running = 1;
	return 0;
}

EXPORT_SYMBOL(pwm_enable);

void pwm_disable(struct pwm_device *pwm)
{
	unsigned long flags;
	unsigned long tcon;

	local_irq_save(flags);

	tcon = __raw_readl(S3C2410_TCON);
	tcon &= ~pwm_tcon_start(pwm);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);

	pwm->running = 0;
}

EXPORT_SYMBOL(pwm_disable);

static unsigned long pwm_calc_tin(struct pwm_device *pwm, unsigned long freq)
{
	unsigned long tin_parent_rate;
	unsigned int div;

	tin_parent_rate = clk_get_rate(clk_get_parent(pwm->clk_div));
	pwm_dbg(pwm, "tin parent at %lu\n", tin_parent_rate);

	for (div = 2; div <= 16; div *= 2) {
		if ((tin_parent_rate / (div << 16)) < freq)
			return tin_parent_rate / div;
	}

	return tin_parent_rate / 16;
}

#define NS_IN_HZ (1000000000UL)

int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
	unsigned long tin_rate;
	unsigned long tin_ns;
	unsigned long period;
	unsigned long flags;
	unsigned long tcon;
	unsigned long tcnt;
	long tcmp;

	/* We currently avoid using 64bit arithmetic by using the
	 * fact that anything faster than 1Hz is easily representable
	 * by 32bits. */

	if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
		return -ERANGE;

	if (duty_ns > period_ns)
		return -EINVAL;

	if (period_ns == pwm->period_ns &&
	    duty_ns == pwm->duty_ns)
		return 0;

	/* The TCMP and TCNT can be read without a lock, they're not
	 * shared between the timers. */

	tcmp = __raw_readl(S3C2410_TCMPB(pwm->pwm_id));
	tcnt = __raw_readl(S3C2410_TCNTB(pwm->pwm_id));

	period = NS_IN_HZ / period_ns;

	pwm_dbg(pwm, "duty_ns=%d, period_ns=%d (%lu)\n",
		duty_ns, period_ns, period);

	/* Check to see if we are changing the clock rate of the PWM */

	if (pwm->period_ns != period_ns) {
		if (pwm_is_tdiv(pwm)) {
			tin_rate = pwm_calc_tin(pwm, period);
			clk_set_rate(pwm->clk_div, tin_rate);
		} else
			tin_rate = clk_get_rate(pwm->clk);

		pwm->period_ns = period_ns;

		pwm_dbg(pwm, "tin_rate=%lu\n", tin_rate);

		tin_ns = NS_IN_HZ / tin_rate;
		tcnt = period_ns / tin_ns;
	} else
		tin_ns = NS_IN_HZ / clk_get_rate(pwm->clk);

	/* Note, counters count down */

	tcmp = duty_ns / tin_ns;
	tcmp = tcnt - tcmp;

	pwm_dbg(pwm, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt);

	if (tcmp < 0)
		tcmp = 0;

	/* Update the PWM register block. */

	local_irq_save(flags);

	__raw_writel(tcmp, S3C2410_TCMPB(pwm->pwm_id));
	__raw_writel(tcnt, S3C2410_TCNTB(pwm->pwm_id));

	tcon = __raw_readl(S3C2410_TCON);
	tcon |= pwm_tcon_manulupdate(pwm);
	tcon |= pwm_tcon_autoreload(pwm);
	__raw_writel(tcon, S3C2410_TCON);

	tcon &= ~pwm_tcon_manulupdate(pwm);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);

	return 0;
}

EXPORT_SYMBOL(pwm_config);

static int pwm_register(struct pwm_device *pwm)
{
	pwm->duty_ns = -1;
	pwm->period_ns = -1;

	mutex_lock(&pwm_lock);
	list_add_tail(&pwm->list, &pwm_list);
	mutex_unlock(&pwm_lock);

	return 0;
}

static int s3c_pwm_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct pwm_device *pwm;
	unsigned long flags;
	unsigned long tcon;
	unsigned int id = pdev->id;
	int ret;

	if (id == 4) {
		dev_err(dev, "TIMER4 is currently not supported\n");
		return -ENXIO;
	}

	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
	if (pwm == NULL) {
		dev_err(dev, "failed to allocate pwm_device\n");
		return -ENOMEM;
	}

	pwm->pdev = pdev;
	pwm->pwm_id = id;

	/* calculate base of control bits in TCON */
	pwm->tcon_base = id == 0 ? 0 : (id * 4) + 4;

	pwm->clk = clk_get(dev, "pwm-tin");
	if (IS_ERR(pwm->clk)) {
		dev_err(dev, "failed to get pwm tin clk\n");
		ret = PTR_ERR(pwm->clk);
		goto err_alloc;
	}

	pwm->clk_div = clk_get(dev, "pwm-tdiv");
	if (IS_ERR(pwm->clk_div)) {
		dev_err(dev, "failed to get pwm tdiv clk\n");
		ret = PTR_ERR(pwm->clk_div);
		goto err_clk_tin;
	}

	local_irq_save(flags);

	tcon = __raw_readl(S3C2410_TCON);
	tcon |= pwm_tcon_invert(pwm);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);


	ret = pwm_register(pwm);
	if (ret) {
		dev_err(dev, "failed to register pwm\n");
		goto err_clk_tdiv;
	}

	pwm_dbg(pwm, "config bits %02x\n",
		(__raw_readl(S3C2410_TCON) >> pwm->tcon_base) & 0x0f);

	dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n",
		 clk_get_rate(pwm->clk),
		 clk_get_rate(pwm->clk_div),
		 pwm_is_tdiv(pwm) ? "div" : "ext", pwm->tcon_base);

	platform_set_drvdata(pdev, pwm);
	return 0;

 err_clk_tdiv:
	clk_put(pwm->clk_div);

 err_clk_tin:
	clk_put(pwm->clk);

 err_alloc:
	kfree(pwm);
	return ret;
}

static int s3c_pwm_remove(struct platform_device *pdev)
{
	struct pwm_device *pwm = platform_get_drvdata(pdev);

	clk_put(pwm->clk_div);
	clk_put(pwm->clk);
	kfree(pwm);

	return 0;
}

static struct platform_driver s3c_pwm_driver = {
	.driver		= {
		.name	= "s3c24xx-pwm",
		.owner	= THIS_MODULE,
	},
	.probe		= s3c_pwm_probe,
	.remove		= __devexit_p(s3c_pwm_remove),
};

static int __init pwm_init(void)
{
	int ret;

	clk_scaler[0] = clk_get(NULL, "pwm-scaler0");
	clk_scaler[1] = clk_get(NULL, "pwm-scaler1");

	if (IS_ERR(clk_scaler[0]) || IS_ERR(clk_scaler[1])) {
		printk(KERN_ERR "%s: failed to get scaler clocks\n", __func__);
		return -EINVAL;
	}

	ret = platform_driver_register(&s3c_pwm_driver);
	if (ret)
		printk(KERN_ERR "%s: failed to add pwm driver\n", __func__);

	return ret;
}

arch_initcall(pwm_init);
Commit	Line	Data
6fc601e3 BD	1	/* arch/arm/plat-s3c24xx/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	* S3C24XX 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/module.h>
	15	#include <linux/kernel.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/err.h>
	18	#include <linux/clk.h>
	19	#include <linux/io.h>
	20	#include <linux/pwm.h>
	21
a2b7ba9c BD	22	#include <plat/devs.h>
a2b7ba9c BD	23	#include <plat/regs-timer.h>
6fc601e3 BD	24
	25	struct pwm_device {
	26	struct list_head list;
	27	struct platform_device *pdev;
	28
	29	struct clk *clk_div;
	30	struct clk *clk;
	31	const char *label;
	32
	33	unsigned int period_ns;
	34	unsigned int duty_ns;
	35
	36	unsigned char tcon_base;
	37	unsigned char running;
	38	unsigned char use_count;
	39	unsigned char pwm_id;
	40	};
	41
66592eee	42	#define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg)
6fc601e3 BD	43
	44	static struct clk *clk_scaler[2];
	45
	46	/* Standard setup for a timer block. */
	47
	48	#define TIMER_RESOURCE_SIZE (1)
	49
	50	#define TIMER_RESOURCE(_tmr, _irq) \
	51	(struct resource [TIMER_RESOURCE_SIZE]) { \
	52	[0] = { \
	53	.start = _irq, \
	54	.end = _irq, \
	55	.flags = IORESOURCE_IRQ \
	56	} \
	57	}
	58
	59	#define DEFINE_TIMER(_tmr_no, _irq) \
	60	.name = "s3c24xx-pwm", \
	61	.id = _tmr_no, \
	62	.num_resources = TIMER_RESOURCE_SIZE, \
	63	.resource = TIMER_RESOURCE(_tmr_no, _irq), \
	64
	65	/* since we already have an static mapping for the timer, we do not
	66	* bother setting any IO resource for the base.
	67	*/
	68
	69	struct platform_device s3c_device_timer[] = {
	70	[0] = { DEFINE_TIMER(0, IRQ_TIMER0) },
	71	[1] = { DEFINE_TIMER(1, IRQ_TIMER1) },
	72	[2] = { DEFINE_TIMER(2, IRQ_TIMER2) },
	73	[3] = { DEFINE_TIMER(3, IRQ_TIMER3) },
	74	[4] = { DEFINE_TIMER(4, IRQ_TIMER4) },
	75	};
	76
	77	static inline int pwm_is_tdiv(struct pwm_device *pwm)
	78	{
	79	return clk_get_parent(pwm->clk) == pwm->clk_div;
	80	}
	81
	82	static DEFINE_MUTEX(pwm_lock);
	83	static LIST_HEAD(pwm_list);
	84
	85	struct pwm_device pwm_request(int pwm_id, const char label)
	86	{
	87	struct pwm_device *pwm;
	88	int found = 0;
	89
	90	mutex_lock(&pwm_lock);
	91
	92	list_for_each_entry(pwm, &pwm_list, list) {
	93	if (pwm->pwm_id == pwm_id) {
	94	found = 1;
	95	break;
	96	}
	97	}
	98
	99	if (found) {
	100	if (pwm->use_count == 0) {
	101	pwm->use_count = 1;
	102	pwm->label = label;
	103	} else
	104	pwm = ERR_PTR(-EBUSY);
	105	} else
	106	pwm = ERR_PTR(-ENOENT);
107
108	mutex_unlock(&pwm_lock);
109	return pwm;
110	}
111
112	EXPORT_SYMBOL(pwm_request);
113
114
115	void pwm_free(struct pwm_device *pwm)
116	{
117	mutex_lock(&pwm_lock);
118
119	if (pwm->use_count) {
120	pwm->use_count--;
121	pwm->label = NULL;
122	} else
123	printk(KERN_ERR "PWM%d device already freed\n", pwm->pwm_id);
124
125	mutex_unlock(&pwm_lock);
126	}
127
128	EXPORT_SYMBOL(pwm_free);
129
130	#define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0))
131	#define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2))
132	#define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3))
133	#define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1))
134
135	int pwm_enable(struct pwm_device *pwm)
136	{
137	unsigned long flags;
138	unsigned long tcon;
139
140	local_irq_save(flags);
141
142	tcon = __raw_readl(S3C2410_TCON);
143	tcon \|= pwm_tcon_start(pwm);
144	__raw_writel(tcon, S3C2410_TCON);
145
146	local_irq_restore(flags);
147
148	pwm->running = 1;
149	return 0;
150	}
151
152	EXPORT_SYMBOL(pwm_enable);
153
154	void pwm_disable(struct pwm_device *pwm)
155	{
156	unsigned long flags;
157	unsigned long tcon;
158
159	local_irq_save(flags);
160
161	tcon = __raw_readl(S3C2410_TCON);
162	tcon &= ~pwm_tcon_start(pwm);
163	__raw_writel(tcon, S3C2410_TCON);
164
165	local_irq_restore(flags);
166
167	pwm->running = 0;
168	}
169
170	EXPORT_SYMBOL(pwm_disable);
171
10389592	172	static unsigned long pwm_calc_tin(struct pwm_device *pwm, unsigned long freq)
6fc601e3 BD	173	{
	174	unsigned long tin_parent_rate;
	175	unsigned int div;
	176
	177	tin_parent_rate = clk_get_rate(clk_get_parent(pwm->clk_div));
	178	pwm_dbg(pwm, "tin parent at %lu\n", tin_parent_rate);
	179
	180	for (div = 2; div <= 16; div *= 2) {
	181	if ((tin_parent_rate / (div << 16)) < freq)
	182	return tin_parent_rate / div;
	183	}
	184
	185	return tin_parent_rate / 16;
	186	}
	187
	188	#define NS_IN_HZ (1000000000UL)
	189
	190	int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
	191	{
	192	unsigned long tin_rate;
	193	unsigned long tin_ns;
	194	unsigned long period;
	195	unsigned long flags;
	196	unsigned long tcon;
	197	unsigned long tcnt;
	198	long tcmp;
	199
	200	/* We currently avoid using 64bit arithmetic by using the
	201	* fact that anything faster than 1Hz is easily representable
	202	* by 32bits. */
	203
	204	if (period_ns > NS_IN_HZ \|\| duty_ns > NS_IN_HZ)
	205	return -ERANGE;
	206
	207	if (duty_ns > period_ns)
	208	return -EINVAL;
	209
	210	if (period_ns == pwm->period_ns &&
	211	duty_ns == pwm->duty_ns)
	212	return 0;
	213
	214	/* The TCMP and TCNT can be read without a lock, they're not
	215	* shared between the timers. */
	216
	217	tcmp = __raw_readl(S3C2410_TCMPB(pwm->pwm_id));
	218	tcnt = __raw_readl(S3C2410_TCNTB(pwm->pwm_id));
	219
	220	period = NS_IN_HZ / period_ns;
	221
	222	pwm_dbg(pwm, "duty_ns=%d, period_ns=%d (%lu)\n",
	223	duty_ns, period_ns, period);
	224
	225	/* Check to see if we are changing the clock rate of the PWM */
	226
	227	if (pwm->period_ns != period_ns) {
	228	if (pwm_is_tdiv(pwm)) {
	229	tin_rate = pwm_calc_tin(pwm, period);
	230	clk_set_rate(pwm->clk_div, tin_rate);
	231	} else
	232	tin_rate = clk_get_rate(pwm->clk);
	233
	234	pwm->period_ns = period_ns;
	235
	236	pwm_dbg(pwm, "tin_rate=%lu\n", tin_rate);
237
238	tin_ns = NS_IN_HZ / tin_rate;
239	tcnt = period_ns / tin_ns;
240	} else
241	tin_ns = NS_IN_HZ / clk_get_rate(pwm->clk);
242
243	/* Note, counters count down */
244
245	tcmp = duty_ns / tin_ns;
246	tcmp = tcnt - tcmp;
247
248	pwm_dbg(pwm, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt);
249
250	if (tcmp < 0)
251	tcmp = 0;
252
253	/* Update the PWM register block. */
254
255	local_irq_save(flags);
256
257	__raw_writel(tcmp, S3C2410_TCMPB(pwm->pwm_id));
258	__raw_writel(tcnt, S3C2410_TCNTB(pwm->pwm_id));
259
260	tcon = __raw_readl(S3C2410_TCON);
261	tcon \|= pwm_tcon_manulupdate(pwm);
262	tcon \|= pwm_tcon_autoreload(pwm);
263	__raw_writel(tcon, S3C2410_TCON);
264
265	tcon &= ~pwm_tcon_manulupdate(pwm);
266	__raw_writel(tcon, S3C2410_TCON);
267
268	local_irq_restore(flags);
269
270	return 0;
271	}
272
273	EXPORT_SYMBOL(pwm_config);
274
275	static int pwm_register(struct pwm_device *pwm)
276	{
277	pwm->duty_ns = -1;
278	pwm->period_ns = -1;
279
280	mutex_lock(&pwm_lock);
281	list_add_tail(&pwm->list, &pwm_list);
282	mutex_unlock(&pwm_lock);
283
284	return 0;
285	}
286
287	static int s3c_pwm_probe(struct platform_device *pdev)
288	{
289	struct device *dev = &pdev->dev;
290	struct pwm_device *pwm;
291	unsigned long flags;
292	unsigned long tcon;
293	unsigned int id = pdev->id;
294	int ret;
295
296	if (id == 4) {
297	dev_err(dev, "TIMER4 is currently not supported\n");
298	return -ENXIO;
299	}
300
301	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
302	if (pwm == NULL) {
303	dev_err(dev, "failed to allocate pwm_device\n");
304	return -ENOMEM;
305	}
306
307	pwm->pdev = pdev;
308	pwm->pwm_id = id;
309
310	/* calculate base of control bits in TCON */
311	pwm->tcon_base = id == 0 ? 0 : (id * 4) + 4;
312
313	pwm->clk = clk_get(dev, "pwm-tin");
314	if (IS_ERR(pwm->clk)) {
315	dev_err(dev, "failed to get pwm tin clk\n");
316	ret = PTR_ERR(pwm->clk);
317	goto err_alloc;
318	}
319
320	pwm->clk_div = clk_get(dev, "pwm-tdiv");
321	if (IS_ERR(pwm->clk_div)) {
322	dev_err(dev, "failed to get pwm tdiv clk\n");
323	ret = PTR_ERR(pwm->clk_div);
324	goto err_clk_tin;
325	}
326
327	local_irq_save(flags);
328
329	tcon = __raw_readl(S3C2410_TCON);
330	tcon \|= pwm_tcon_invert(pwm);
331	__raw_writel(tcon, S3C2410_TCON);
332
333	local_irq_restore(flags);
334
335
336	ret = pwm_register(pwm);
337	if (ret) {
338	dev_err(dev, "failed to register pwm\n");
339	goto err_clk_tdiv;
340	}
341
342	pwm_dbg(pwm, "config bits %02x\n",
343	(__raw_readl(S3C2410_TCON) >> pwm->tcon_base) & 0x0f);
344
345	dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n",
346	clk_get_rate(pwm->clk),
347	clk_get_rate(pwm->clk_div),
348	pwm_is_tdiv(pwm) ? "div" : "ext", pwm->tcon_base);
349
350	platform_set_drvdata(pdev, pwm);
351	return 0;
352
353	err_clk_tdiv:
354	clk_put(pwm->clk_div);
355
356	err_clk_tin:
357	clk_put(pwm->clk);
358
359	err_alloc:
360	kfree(pwm);
361	return ret;
362	}
363
364	static int s3c_pwm_remove(struct platform_device *pdev)
365	{
366	struct pwm_device *pwm = platform_get_drvdata(pdev);
367
368	clk_put(pwm->clk_div);
369	clk_put(pwm->clk);
370	kfree(pwm);
371
372	return 0;
373	}
374
375	static struct platform_driver s3c_pwm_driver = {
376	.driver = {
377	.name = "s3c24xx-pwm",
378	.owner = THIS_MODULE,
379	},
380	.probe = s3c_pwm_probe,
381	.remove = __devexit_p(s3c_pwm_remove),
382	};
383
384	static int __init pwm_init(void)
385	{
386	int ret;
387
388	clk_scaler[0] = clk_get(NULL, "pwm-scaler0");
389	clk_scaler[1] = clk_get(NULL, "pwm-scaler1");
390
391	if (IS_ERR(clk_scaler[0]) \|\| IS_ERR(clk_scaler[1])) {
392	printk(KERN_ERR "%s: failed to get scaler clocks\n", __func__);
393	return -EINVAL;
394	}
395
396	ret = platform_driver_register(&s3c_pwm_driver);
397	if (ret)
398	printk(KERN_ERR "%s: failed to add pwm driver\n", __func__);
399
400	return ret;
401	}
402
403	arch_initcall(pwm_init);