[deliverable/linux.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/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;

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

	void	(*select_cb)(unsigned selected);
	void	(*convert_cb)(unsigned val1, unsigned val2);
};

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(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));
}

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_adc_default_select(unsigned select)
{
}

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

	WARN_ON(!pdev);
	WARN_ON(!conv);

	if (!select)
		select = s3c_adc_default_select;

	if (!conv || !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. */
	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->convert_cb)(data0 & 0x3ff, data1 & 0x3ff);

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

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