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

/* arch/arm/plat-s3c24xx/adc.c
 *
 * Copyright (c) 2008 Simtec Electronics
 *	http://armlinux.simtec.co.uk/
 *	Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
 *
 * S3C24XX ADC 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/sched.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>

#include <plat/regs-adc.h>
#include <plat/adc.h>

/* This driver is designed to control the usage of the ADC block between
 * the touchscreen and any other drivers that may need to use it, such as
 * the hwmon driver.
 *
 * Priority will be given to the touchscreen driver, but as this itself is
 * rate limited it should not starve other requests which are processed in
 * order that they are received.
 *
 * Each user registers to get a client block which uniquely identifies it
 * and stores information such as the necessary functions to callback when
 * action is required.
 */

struct s3c_adc_client {
	struct platform_device	*pdev;
	struct list_head	 pend;
	wait_queue_head_t	*wait;

	unsigned int		 nr_samples;
	int			 result;
	unsigned char		 is_ts;
	unsigned char		 channel;

	void	(*select_cb)(struct s3c_adc_client *c, unsigned selected);
	void	(*convert_cb)(struct s3c_adc_client *c,
			      unsigned val1, unsigned val2,
			      unsigned *samples_left);
};

struct adc_device {
	struct platform_device	*pdev;
	struct platform_device	*owner;
	struct clk		*clk;
	struct s3c_adc_client	*cur;
	struct s3c_adc_client	*ts_pend;
	void __iomem		*regs;

	unsigned int		 prescale;

	int			 irq;
};

static struct adc_device *adc_dev;

static LIST_HEAD(adc_pending);

#define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)

static inline void s3c_adc_convert(struct adc_device *adc)
{
	unsigned con = readl(adc->regs + S3C2410_ADCCON);

	con |= S3C2410_ADCCON_ENABLE_START;
	writel(con, adc->regs + S3C2410_ADCCON);
}

static inline void s3c_adc_select(struct adc_device *adc,
				  struct s3c_adc_client *client)
{
	unsigned con = readl(adc->regs + S3C2410_ADCCON);

	client->select_cb(client, 1);

	con &= ~S3C2410_ADCCON_MUXMASK;
	con &= ~S3C2410_ADCCON_STDBM;
	con &= ~S3C2410_ADCCON_STARTMASK;

	if (!client->is_ts)
		con |= S3C2410_ADCCON_SELMUX(client->channel);

	writel(con, adc->regs + S3C2410_ADCCON);
}

static void s3c_adc_dbgshow(struct adc_device *adc)
{
	adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
		readl(adc->regs + S3C2410_ADCCON),
		readl(adc->regs + S3C2410_ADCTSC),
		readl(adc->regs + S3C2410_ADCDLY));
}

static void s3c_adc_try(struct adc_device *adc)
{
	struct s3c_adc_client *next = adc->ts_pend;

	if (!next && !list_empty(&adc_pending)) {
		next = list_first_entry(&adc_pending,
					struct s3c_adc_client, pend);
		list_del(&next->pend);
	} else
		adc->ts_pend = NULL;

	if (next) {
		adc_dbg(adc, "new client is %p\n", next);
		adc->cur = next;
		s3c_adc_select(adc, next);
		s3c_adc_convert(adc);
		s3c_adc_dbgshow(adc);
	}
}

int s3c_adc_start(struct s3c_adc_client *client,
		  unsigned int channel, unsigned int nr_samples)
{
	struct adc_device *adc = adc_dev;
	unsigned long flags;

	if (!adc) {
		printk(KERN_ERR "%s: failed to find adc\n", __func__);
		return -EINVAL;
	}

	if (client->is_ts && adc->ts_pend)
		return -EAGAIN;

	local_irq_save(flags);

	client->channel = channel;
	client->nr_samples = nr_samples;

	if (client->is_ts)
		adc->ts_pend = client;
	else
		list_add_tail(&client->pend, &adc_pending);

	if (!adc->cur)
		s3c_adc_try(adc);
	local_irq_restore(flags);

	return 0;
}
EXPORT_SYMBOL_GPL(s3c_adc_start);

static void s3c_convert_done(struct s3c_adc_client *client,
			     unsigned v, unsigned u, unsigned *left)
{
	client->result = v;
	wake_up(client->wait);
}

int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
{
	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
	int ret;

	client->convert_cb = s3c_convert_done;
	client->wait = &wake;
	client->result = -1;

	ret = s3c_adc_start(client, ch, 1);
	if (ret < 0)
		goto err;

	ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
	if (client->result < 0) {
		ret = -ETIMEDOUT;
		goto err;
	}

	client->convert_cb = NULL;
	return client->result;

err:
	return ret;
}
EXPORT_SYMBOL_GPL(s3c_adc_read);

static void s3c_adc_default_select(struct s3c_adc_client *client,
				   unsigned select)
{
}

struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
					void (*select)(struct s3c_adc_client *client,
						       unsigned int selected),
					void (*conv)(struct s3c_adc_client *client,
						     unsigned d0, unsigned d1,
						     unsigned *samples_left),
					unsigned int is_ts)
{
	struct s3c_adc_client *client;

	WARN_ON(!pdev);

	if (!select)
		select = s3c_adc_default_select;

	if (!pdev)
		return ERR_PTR(-EINVAL);

	client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
	if (!client) {
		dev_err(&pdev->dev, "no memory for adc client\n");
		return ERR_PTR(-ENOMEM);
	}

	client->pdev = pdev;
	client->is_ts = is_ts;
	client->select_cb = select;
	client->convert_cb = conv;

	return client;
}
EXPORT_SYMBOL_GPL(s3c_adc_register);

void s3c_adc_release(struct s3c_adc_client *client)
{
	/* We should really check that nothing is in progress. */
	if (adc_dev->cur == client)
		adc_dev->cur = NULL;
	if (adc_dev->ts_pend == client)
		adc_dev->ts_pend = NULL;
	else {
		struct list_head *p, *n;
		struct s3c_adc_client *tmp;

		list_for_each_safe(p, n, &adc_pending) {
			tmp = list_entry(p, struct s3c_adc_client, pend);
			if (tmp == client)
				list_del(&tmp->pend);
		}
	}

	if (adc_dev->cur == NULL)
		s3c_adc_try(adc_dev);
	kfree(client);
}
EXPORT_SYMBOL_GPL(s3c_adc_release);

static irqreturn_t s3c_adc_irq(int irq, void *pw)
{
	struct adc_device *adc = pw;
	struct s3c_adc_client *client = adc->cur;
	unsigned long flags;
	unsigned data0, data1;

	if (!client) {
		dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
		return IRQ_HANDLED;
	}

	data0 = readl(adc->regs + S3C2410_ADCDAT0);
	data1 = readl(adc->regs + S3C2410_ADCDAT1);
	adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);

	client->nr_samples--;

	if (client->convert_cb)
		(client->convert_cb)(client, data0 & 0x3ff, data1 & 0x3ff,
				     &client->nr_samples);

	if (client->nr_samples > 0) {
		/* fire another conversion for this */

		client->select_cb(client, 1);
		s3c_adc_convert(adc);
	} else {
		local_irq_save(flags);
		(client->select_cb)(client, 0);
		adc->cur = NULL;

		s3c_adc_try(adc);
		local_irq_restore(flags);
	}

	return IRQ_HANDLED;
}

static int s3c_adc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct adc_device *adc;
	struct resource *regs;
	int ret;

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

	adc->pdev = pdev;
	adc->prescale = S3C2410_ADCCON_PRSCVL(49);

	adc->irq = platform_get_irq(pdev, 1);
	if (adc->irq <= 0) {
		dev_err(dev, "failed to get adc irq\n");
		ret = -ENOENT;
		goto err_alloc;
	}

	ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
	if (ret < 0) {
		dev_err(dev, "failed to attach adc irq\n");
		goto err_alloc;
	}

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

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs) {
		dev_err(dev, "failed to find registers\n");
		ret = -ENXIO;
		goto err_clk;
	}

	adc->regs = ioremap(regs->start, resource_size(regs));
	if (!adc->regs) {
		dev_err(dev, "failed to map registers\n");
		ret = -ENXIO;
		goto err_clk;
	}

	clk_enable(adc->clk);

	writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
	       adc->regs + S3C2410_ADCCON);

	dev_info(dev, "attached adc driver\n");

	platform_set_drvdata(pdev, adc);
	adc_dev = adc;

	return 0;

 err_clk:
	clk_put(adc->clk);

 err_irq:
	free_irq(adc->irq, adc);

 err_alloc:
	kfree(adc);
	return ret;
}

static int s3c_adc_remove(struct platform_device *pdev)
{
	struct adc_device *adc = platform_get_drvdata(pdev);

	iounmap(adc->regs);
	free_irq(adc->irq, adc);
	clk_disable(adc->clk);
	clk_put(adc->clk);
	kfree(adc);

	return 0;
}

#ifdef CONFIG_PM
static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct adc_device *adc = platform_get_drvdata(pdev);
	u32 con;

	con = readl(adc->regs + S3C2410_ADCCON);
	con |= S3C2410_ADCCON_STDBM;
	writel(con, adc->regs + S3C2410_ADCCON);

	clk_disable(adc->clk);

	return 0;
}

static int s3c_adc_resume(struct platform_device *pdev)
{
	struct adc_device *adc = platform_get_drvdata(pdev);

	clk_enable(adc->clk);

	writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
	       adc->regs + S3C2410_ADCCON);

	return 0;
}

#else
#define s3c_adc_suspend NULL
#define s3c_adc_resume NULL
#endif

static struct platform_driver s3c_adc_driver = {
	.driver		= {
		.name	= "s3c24xx-adc",
		.owner	= THIS_MODULE,
	},
	.probe		= s3c_adc_probe,
	.remove		= __devexit_p(s3c_adc_remove),
	.suspend	= s3c_adc_suspend,
	.resume		= s3c_adc_resume,
};

static int __init adc_init(void)
{
	int ret;

	ret = platform_driver_register(&s3c_adc_driver);
	if (ret)
		printk(KERN_ERR "%s: failed to add adc driver\n", __func__);

	return ret;
}

arch_initcall(adc_init);
Commit	Line	Data
28ab44c5 BD	1	/* arch/arm/plat-s3c24xx/adc.c
	2	*
	3	* Copyright (c) 2008 Simtec Electronics
	4	* http://armlinux.simtec.co.uk/
	5	* Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
	6	*
	7	* S3C24XX ADC 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>
d43c36dc	17	#include <linux/sched.h>
28ab44c5 BD	18	#include <linux/list.h>
	19	#include <linux/err.h>
	20	#include <linux/clk.h>
	21	#include <linux/interrupt.h>
	22	#include <linux/io.h>
	23
	24	#include <plat/regs-adc.h>
	25	#include <plat/adc.h>
	26
	27	/* This driver is designed to control the usage of the ADC block between
	28	* the touchscreen and any other drivers that may need to use it, such as
	29	* the hwmon driver.
	30	*
	31	* Priority will be given to the touchscreen driver, but as this itself is
	32	* rate limited it should not starve other requests which are processed in
	33	* order that they are received.
	34	*
	35	* Each user registers to get a client block which uniquely identifies it
	36	* and stores information such as the necessary functions to callback when
	37	* action is required.
	38	*/
	39
	40	struct s3c_adc_client {
	41	struct platform_device *pdev;
	42	struct list_head pend;
e170adcb	43	wait_queue_head_t *wait;
28ab44c5 BD	44
28ab44c5 BD	45	unsigned int nr_samples;
e170adcb	46	int result;
28ab44c5 BD	47	unsigned char is_ts;
	48	unsigned char channel;
	49
e170adcb BD	50	void (select_cb)(struct s3c_adc_client c, unsigned selected);
	51	void (convert_cb)(struct s3c_adc_client c,
	52	unsigned val1, unsigned val2,
3f7ea467	53	unsigned *samples_left);
28ab44c5 BD	54	};
	55
	56	struct adc_device {
	57	struct platform_device *pdev;
	58	struct platform_device *owner;
	59	struct clk *clk;
	60	struct s3c_adc_client *cur;
	61	struct s3c_adc_client *ts_pend;
	62	void __iomem *regs;
	63
	64	unsigned int prescale;
	65
	66	int irq;
	67	};
	68
	69	static struct adc_device *adc_dev;
	70
	71	static LIST_HEAD(adc_pending);
	72
	73	#define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
	74
	75	static inline void s3c_adc_convert(struct adc_device *adc)
	76	{
	77	unsigned con = readl(adc->regs + S3C2410_ADCCON);
	78
	79	con \|= S3C2410_ADCCON_ENABLE_START;
	80	writel(con, adc->regs + S3C2410_ADCCON);
	81	}
	82
	83	static inline void s3c_adc_select(struct adc_device *adc,
	84	struct s3c_adc_client *client)
	85	{
	86	unsigned con = readl(adc->regs + S3C2410_ADCCON);
	87
e170adcb	88	client->select_cb(client, 1);
28ab44c5 BD	89
	90	con &= ~S3C2410_ADCCON_MUXMASK;
	91	con &= ~S3C2410_ADCCON_STDBM;
	92	con &= ~S3C2410_ADCCON_STARTMASK;
	93
	94	if (!client->is_ts)
	95	con \|= S3C2410_ADCCON_SELMUX(client->channel);
	96
	97	writel(con, adc->regs + S3C2410_ADCCON);
	98	}
	99
	100	static void s3c_adc_dbgshow(struct adc_device *adc)
	101	{
	102	adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
	103	readl(adc->regs + S3C2410_ADCCON),
	104	readl(adc->regs + S3C2410_ADCTSC),
	105	readl(adc->regs + S3C2410_ADCDLY));
	106	}
	107
f8c8ac81	108	static void s3c_adc_try(struct adc_device *adc)
28ab44c5 BD	109	{
	110	struct s3c_adc_client *next = adc->ts_pend;
	111
	112	if (!next && !list_empty(&adc_pending)) {
	113	next = list_first_entry(&adc_pending,
	114	struct s3c_adc_client, pend);
	115	list_del(&next->pend);
	116	} else
	117	adc->ts_pend = NULL;
	118
	119	if (next) {
	120	adc_dbg(adc, "new client is %p\n", next);
	121	adc->cur = next;
	122	s3c_adc_select(adc, next);
	123	s3c_adc_convert(adc);
	124	s3c_adc_dbgshow(adc);
	125	}
	126	}
	127
	128	int s3c_adc_start(struct s3c_adc_client *client,
	129	unsigned int channel, unsigned int nr_samples)
	130	{
	131	struct adc_device *adc = adc_dev;
	132	unsigned long flags;
	133
	134	if (!adc) {
	135	printk(KERN_ERR "%s: failed to find adc\n", __func__);
	136	return -EINVAL;
	137	}
	138
	139	if (client->is_ts && adc->ts_pend)
	140	return -EAGAIN;
	141
	142	local_irq_save(flags);
	143
	144	client->channel = channel;
	145	client->nr_samples = nr_samples;
	146
	147	if (client->is_ts)
	148	adc->ts_pend = client;
	149	else
	150	list_add_tail(&client->pend, &adc_pending);
	151
	152	if (!adc->cur)
	153	s3c_adc_try(adc);
	154	local_irq_restore(flags);
	155
	156	return 0;
	157	}
	158	EXPORT_SYMBOL_GPL(s3c_adc_start);
	159
e170adcb BD	160	static void s3c_convert_done(struct s3c_adc_client *client,
	161	unsigned v, unsigned u, unsigned *left)
	162	{
	163	client->result = v;
	164	wake_up(client->wait);
	165	}
	166
	167	int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
	168	{
	169	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
	170	int ret;
	171
	172	client->convert_cb = s3c_convert_done;
	173	client->wait = &wake;
	174	client->result = -1;
	175
	176	ret = s3c_adc_start(client, ch, 1);
	177	if (ret < 0)
	178	goto err;
	179
	180	ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
	181	if (client->result < 0) {
	182	ret = -ETIMEDOUT;
	183	goto err;
	184	}
	185
	186	client->convert_cb = NULL;
	187	return client->result;
	188
	189	err:
	190	return ret;
	191	}
d3bf3956	192	EXPORT_SYMBOL_GPL(s3c_adc_read);
e170adcb BD	193
	194	static void s3c_adc_default_select(struct s3c_adc_client *client,
	195	unsigned select)
28ab44c5 BD	196	{
	197	}
	198
	199	struct s3c_adc_client s3c_adc_register(struct platform_device pdev,
e170adcb BD	200	void (select)(struct s3c_adc_client client,
	201	unsigned int selected),
	202	void (conv)(struct s3c_adc_client client,
	203	unsigned d0, unsigned d1,
3f7ea467	204	unsigned *samples_left),
28ab44c5 BD	205	unsigned int is_ts)
	206	{
	207	struct s3c_adc_client *client;
	208
	209	WARN_ON(!pdev);
28ab44c5 BD	210
	211	if (!select)
	212	select = s3c_adc_default_select;
	213
e170adcb	214	if (!pdev)
28ab44c5 BD	215	return ERR_PTR(-EINVAL);
	216
	217	client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
	218	if (!client) {
	219	dev_err(&pdev->dev, "no memory for adc client\n");
	220	return ERR_PTR(-ENOMEM);
	221	}
	222
	223	client->pdev = pdev;
	224	client->is_ts = is_ts;
	225	client->select_cb = select;
	226	client->convert_cb = conv;
	227
	228	return client;
	229	}
	230	EXPORT_SYMBOL_GPL(s3c_adc_register);
	231
	232	void s3c_adc_release(struct s3c_adc_client *client)
	233	{
	234	/* We should really check that nothing is in progress. */
0c3ee078 RL	235	if (adc_dev->cur == client)
	236	adc_dev->cur = NULL;
	237	if (adc_dev->ts_pend == client)
	238	adc_dev->ts_pend = NULL;
	239	else {
	240	struct list_head p, n;
	241	struct s3c_adc_client *tmp;
	242
	243	list_for_each_safe(p, n, &adc_pending) {
	244	tmp = list_entry(p, struct s3c_adc_client, pend);
	245	if (tmp == client)
	246	list_del(&tmp->pend);
	247	}
	248	}
	249
	250	if (adc_dev->cur == NULL)
	251	s3c_adc_try(adc_dev);
28ab44c5 BD	252	kfree(client);
	253	}
	254	EXPORT_SYMBOL_GPL(s3c_adc_release);
	255
	256	static irqreturn_t s3c_adc_irq(int irq, void *pw)
	257	{
	258	struct adc_device *adc = pw;
	259	struct s3c_adc_client *client = adc->cur;
	260	unsigned long flags;
	261	unsigned data0, data1;
	262
	263	if (!client) {
	264	dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
	265	return IRQ_HANDLED;
	266	}
	267
	268	data0 = readl(adc->regs + S3C2410_ADCDAT0);
	269	data1 = readl(adc->regs + S3C2410_ADCDAT1);
	270	adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
	271
3f7ea467	272	client->nr_samples--;
e170adcb BD	273
	274	if (client->convert_cb)
	275	(client->convert_cb)(client, data0 & 0x3ff, data1 & 0x3ff,
	276	&client->nr_samples);
28ab44c5	277
3f7ea467	278	if (client->nr_samples > 0) {
28ab44c5 BD	279	/* fire another conversion for this */
28ab44c5 BD	280
e170adcb	281	client->select_cb(client, 1);
28ab44c5 BD	282	s3c_adc_convert(adc);
	283	} else {
	284	local_irq_save(flags);
e170adcb	285	(client->select_cb)(client, 0);
28ab44c5 BD	286	adc->cur = NULL;
	287
	288	s3c_adc_try(adc);
	289	local_irq_restore(flags);
	290	}
	291
	292	return IRQ_HANDLED;
	293	}
	294
	295	static int s3c_adc_probe(struct platform_device *pdev)
	296	{
	297	struct device *dev = &pdev->dev;
	298	struct adc_device *adc;
	299	struct resource *regs;
	300	int ret;
	301
	302	adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
	303	if (adc == NULL) {
	304	dev_err(dev, "failed to allocate adc_device\n");
	305	return -ENOMEM;
	306	}
	307
	308	adc->pdev = pdev;
	309	adc->prescale = S3C2410_ADCCON_PRSCVL(49);
	310
	311	adc->irq = platform_get_irq(pdev, 1);
	312	if (adc->irq <= 0) {
	313	dev_err(dev, "failed to get adc irq\n");
	314	ret = -ENOENT;
	315	goto err_alloc;
	316	}
	317
	318	ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
	319	if (ret < 0) {
	320	dev_err(dev, "failed to attach adc irq\n");
	321	goto err_alloc;
	322	}
	323
	324	adc->clk = clk_get(dev, "adc");
	325	if (IS_ERR(adc->clk)) {
	326	dev_err(dev, "failed to get adc clock\n");
	327	ret = PTR_ERR(adc->clk);
	328	goto err_irq;
	329	}
	330
	331	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	332	if (!regs) {
	333	dev_err(dev, "failed to find registers\n");
	334	ret = -ENXIO;
	335	goto err_clk;
	336	}
	337
	338	adc->regs = ioremap(regs->start, resource_size(regs));
	339	if (!adc->regs) {
	340	dev_err(dev, "failed to map registers\n");
	341	ret = -ENXIO;
	342	goto err_clk;
	343	}
	344
	345	clk_enable(adc->clk);
	346
	347	writel(adc->prescale \| S3C2410_ADCCON_PRSCEN,
	348	adc->regs + S3C2410_ADCCON);
	349
350	dev_info(dev, "attached adc driver\n");
351
352	platform_set_drvdata(pdev, adc);
353	adc_dev = adc;
354
355	return 0;
356
357	err_clk:
358	clk_put(adc->clk);
359
360	err_irq:
361	free_irq(adc->irq, adc);
362
363	err_alloc:
364	kfree(adc);
365	return ret;
366	}
367
368	static int s3c_adc_remove(struct platform_device *pdev)
369	{
370	struct adc_device *adc = platform_get_drvdata(pdev);
371
372	iounmap(adc->regs);
373	free_irq(adc->irq, adc);
374	clk_disable(adc->clk);
375	clk_put(adc->clk);
376	kfree(adc);
377
378	return 0;
379	}
380
381	#ifdef CONFIG_PM
382	static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
383	{
384	struct adc_device *adc = platform_get_drvdata(pdev);
385	u32 con;
386
387	con = readl(adc->regs + S3C2410_ADCCON);
388	con \|= S3C2410_ADCCON_STDBM;
389	writel(con, adc->regs + S3C2410_ADCCON);
390
391	clk_disable(adc->clk);
392
393	return 0;
394	}
395
396	static int s3c_adc_resume(struct platform_device *pdev)
397	{
398	struct adc_device *adc = platform_get_drvdata(pdev);
399
400	clk_enable(adc->clk);
401
402	writel(adc->prescale \| S3C2410_ADCCON_PRSCEN,
403	adc->regs + S3C2410_ADCCON);
404
405	return 0;
406	}
407
408	#else
409	#define s3c_adc_suspend NULL
410	#define s3c_adc_resume NULL
411	#endif
412
413	static struct platform_driver s3c_adc_driver = {
414	.driver = {
415	.name = "s3c24xx-adc",
416	.owner = THIS_MODULE,
417	},
418	.probe = s3c_adc_probe,
419	.remove = __devexit_p(s3c_adc_remove),
420	.suspend = s3c_adc_suspend,
421	.resume = s3c_adc_resume,
422	};
423
424	static int __init adc_init(void)
425	{
426	int ret;
427
428	ret = platform_driver_register(&s3c_adc_driver);
429	if (ret)
430	printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
431
432	return ret;
433	}
434
435	arch_initcall(adc_init);