summaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-samsung/adc.c
blob: 2da35735fa388fae33a5ed705ef5f5b1a9fdcaa8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
// SPDX-License-Identifier: GPL-1.0+
//
// Copyright (c) 2008 Simtec Electronics
//	http://armlinux.simtec.co.uk/
//	Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
//
// Samsung ADC device core

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/regulator/consumer.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.
 */

enum s3c_cpu_type {
	TYPE_ADCV1, /* S3C24XX */
	TYPE_ADCV11, /* S3C2443 */
	TYPE_ADCV12, /* S3C2416, S3C2450 */
	TYPE_ADCV2, /* S3C64XX */
	TYPE_ADCV3, /* S5PV210, S5PC110, EXYNOS4210 */
};

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;
	spinlock_t		 lock;

	unsigned int		 prescale;

	int			 irq;
	struct regulator	*vdd;
};

static struct adc_device *adc_dev;

static LIST_HEAD(adc_pending);	/* protected by adc_device.lock */

#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);
	enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;

	client->select_cb(client, 1);

	if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV2)
		con &= ~S3C2410_ADCCON_MUXMASK;
	con &= ~S3C2410_ADCCON_STDBM;
	con &= ~S3C2410_ADCCON_STARTMASK;

	if (!client->is_ts) {
		if (cpu == TYPE_ADCV3)
			writel(client->channel & 0xf, adc->regs + S5P_ADCMUX);
		else if (cpu == TYPE_ADCV11 || cpu == TYPE_ADCV12)
			writel(client->channel & 0xf,
						adc->regs + S3C2443_ADCMUX);
		else
			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;
	}

	spin_lock_irqsave(&adc->lock, flags);

	if (client->is_ts && adc->ts_pend) {
		spin_unlock_irqrestore(&adc->lock, flags);
		return -EAGAIN;
	}

	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);

	spin_unlock_irqrestore(&adc->lock, 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(*client), GFP_KERNEL);
	if (!client)
		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)
{
	unsigned long flags;

	spin_lock_irqsave(&adc_dev->lock, flags);

	/* 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);

	spin_unlock_irqrestore(&adc_dev->lock, flags);
	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;
	enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
	unsigned data0, data1;

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

	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 (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {
		data0 &= 0x3ff;
		data1 &= 0x3ff;
	} else {
		/* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
		data0 &= 0xfff;
		data1 &= 0xfff;
	}

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

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

		client->select_cb(client, 1);
		s3c_adc_convert(adc);
	} else {
		spin_lock(&adc->lock);
		(client->select_cb)(client, 0);
		adc->cur = NULL;

		s3c_adc_try(adc);
		spin_unlock(&adc->lock);
	}

exit:
	if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {
		/* Clear ADC interrupt */
		writel(0, adc->regs + S3C64XX_ADCCLRINT);
	}
	return IRQ_HANDLED;
}

static int s3c_adc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct adc_device *adc;
	struct resource *regs;
	enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
	int ret;
	unsigned tmp;

	adc = devm_kzalloc(dev, sizeof(*adc), GFP_KERNEL);
	if (!adc)
		return -ENOMEM;

	spin_lock_init(&adc->lock);

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

	adc->vdd = devm_regulator_get(dev, "vdd");
	if (IS_ERR(adc->vdd)) {
		dev_err(dev, "operating without regulator \"vdd\" .\n");
		return PTR_ERR(adc->vdd);
	}

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

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

	adc->clk = devm_clk_get(dev, "adc");
	if (IS_ERR(adc->clk)) {
		dev_err(dev, "failed to get adc clock\n");
		return PTR_ERR(adc->clk);
	}

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	adc->regs = devm_ioremap_resource(dev, regs);
	if (IS_ERR(adc->regs))
		return PTR_ERR(adc->regs);

	ret = regulator_enable(adc->vdd);
	if (ret)
		return ret;

	clk_prepare_enable(adc->clk);

	tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;

	/* Enable 12-bit ADC resolution */
	if (cpu == TYPE_ADCV12)
		tmp |= S3C2416_ADCCON_RESSEL;
	if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
		tmp |= S3C64XX_ADCCON_RESSEL;

	writel(tmp, adc->regs + S3C2410_ADCCON);

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

	platform_set_drvdata(pdev, adc);
	adc_dev = adc;

	return 0;
}

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

	clk_disable_unprepare(adc->clk);
	regulator_disable(adc->vdd);

	return 0;
}

#ifdef CONFIG_PM
static int s3c_adc_suspend(struct device *dev)
{
	struct adc_device *adc = dev_get_drvdata(dev);
	unsigned long flags;
	u32 con;

	spin_lock_irqsave(&adc->lock, flags);

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

	disable_irq(adc->irq);
	spin_unlock_irqrestore(&adc->lock, flags);
	clk_disable(adc->clk);
	regulator_disable(adc->vdd);

	return 0;
}

static int s3c_adc_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct adc_device *adc = platform_get_drvdata(pdev);
	enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
	int ret;
	unsigned long tmp;

	ret = regulator_enable(adc->vdd);
	if (ret)
		return ret;
	clk_enable(adc->clk);
	enable_irq(adc->irq);

	tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;

	/* Enable 12-bit ADC resolution */
	if (cpu == TYPE_ADCV12)
		tmp |= S3C2416_ADCCON_RESSEL;
	if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
		tmp |= S3C64XX_ADCCON_RESSEL;

	writel(tmp, adc->regs + S3C2410_ADCCON);

	return 0;
}

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

static const struct platform_device_id s3c_adc_driver_ids[] = {
	{
		.name           = "s3c24xx-adc",
		.driver_data    = TYPE_ADCV1,
	}, {
		.name		= "s3c2443-adc",
		.driver_data	= TYPE_ADCV11,
	}, {
		.name		= "s3c2416-adc",
		.driver_data	= TYPE_ADCV12,
	}, {
		.name           = "s3c64xx-adc",
		.driver_data    = TYPE_ADCV2,
	}, {
		.name		= "samsung-adc-v3",
		.driver_data	= TYPE_ADCV3,
	},
	{ }
};
MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);

static const struct dev_pm_ops adc_pm_ops = {
	.suspend	= s3c_adc_suspend,
	.resume		= s3c_adc_resume,
};

static struct platform_driver s3c_adc_driver = {
	.id_table	= s3c_adc_driver_ids,
	.driver		= {
		.name	= "s3c-adc",
		.pm	= &adc_pm_ops,
	},
	.probe		= s3c_adc_probe,
	.remove		= s3c_adc_remove,
};

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;
}

module_init(adc_init);