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Merge tag 'gpio-v3.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[linux-2.6.git] / arch / arm / plat-samsung / adc.c
blob79690f2f6d3f8a5164495c7758b392cc43bae268
1 /* arch/arm/plat-samsung/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 * Samsung 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/sched.h>
18 #include <linux/list.h>
19 #include <linux/slab.h>
20 #include <linux/err.h>
21 #include <linux/clk.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/regulator/consumer.h>
25
26 #include <plat/regs-adc.h>
27 #include <plat/adc.h>
28
29 /* This driver is designed to control the usage of the ADC block between
30 * the touchscreen and any other drivers that may need to use it, such as
31 * the hwmon driver.
32 *
33 * Priority will be given to the touchscreen driver, but as this itself is
34 * rate limited it should not starve other requests which are processed in
35 * order that they are received.
36 *
37 * Each user registers to get a client block which uniquely identifies it
38 * and stores information such as the necessary functions to callback when
39 * action is required.
40 */
41
42 enum s3c_cpu_type {
43 TYPE_ADCV1, /* S3C24XX */
44 TYPE_ADCV11, /* S3C2443 */
45 TYPE_ADCV12, /* S3C2416, S3C2450 */
46 TYPE_ADCV2, /* S3C64XX, S5P64X0, S5PC100 */
47 TYPE_ADCV3, /* S5PV210, S5PC110, EXYNOS4210 */
48 };
49
50 struct s3c_adc_client {
51 struct platform_device *pdev;
52 struct list_head pend;
53 wait_queue_head_t *wait;
54
55 unsigned int nr_samples;
56 int result;
57 unsigned char is_ts;
58 unsigned char channel;
59
60 void (*select_cb)(struct s3c_adc_client *c, unsigned selected);
61 void (*convert_cb)(struct s3c_adc_client *c,
62 unsigned val1, unsigned val2,
63 unsigned *samples_left);
64 };
65
66 struct adc_device {
67 struct platform_device *pdev;
68 struct platform_device *owner;
69 struct clk *clk;
70 struct s3c_adc_client *cur;
71 struct s3c_adc_client *ts_pend;
72 void __iomem *regs;
73 spinlock_t lock;
74
75 unsigned int prescale;
76
77 int irq;
78 struct regulator *vdd;
79 };
80
81 static struct adc_device *adc_dev;
82
83 static LIST_HEAD(adc_pending); /* protected by adc_device.lock */
84
85 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
86
87 static inline void s3c_adc_convert(struct adc_device *adc)
88 {
89 unsigned con = readl(adc->regs + S3C2410_ADCCON);
90
91 con |= S3C2410_ADCCON_ENABLE_START;
92 writel(con, adc->regs + S3C2410_ADCCON);
93 }
94
95 static inline void s3c_adc_select(struct adc_device *adc,
96 struct s3c_adc_client *client)
97 {
98 unsigned con = readl(adc->regs + S3C2410_ADCCON);
99 enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
100
101 client->select_cb(client, 1);
102
103 if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV2)
104 con &= ~S3C2410_ADCCON_MUXMASK;
105 con &= ~S3C2410_ADCCON_STDBM;
106 con &= ~S3C2410_ADCCON_STARTMASK;
107
108 if (!client->is_ts) {
109 if (cpu == TYPE_ADCV3)
110 writel(client->channel & 0xf, adc->regs + S5P_ADCMUX);
111 else if (cpu == TYPE_ADCV11 || cpu == TYPE_ADCV12)
112 writel(client->channel & 0xf,
113 adc->regs + S3C2443_ADCMUX);
114 else
115 con |= S3C2410_ADCCON_SELMUX(client->channel);
116 }
117
118 writel(con, adc->regs + S3C2410_ADCCON);
119 }
120
121 static void s3c_adc_dbgshow(struct adc_device *adc)
122 {
123 adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
124 readl(adc->regs + S3C2410_ADCCON),
125 readl(adc->regs + S3C2410_ADCTSC),
126 readl(adc->regs + S3C2410_ADCDLY));
127 }
128
129 static void s3c_adc_try(struct adc_device *adc)
130 {
131 struct s3c_adc_client *next = adc->ts_pend;
132
133 if (!next && !list_empty(&adc_pending)) {
134 next = list_first_entry(&adc_pending,
135 struct s3c_adc_client, pend);
136 list_del(&next->pend);
137 } else
138 adc->ts_pend = NULL;
139
140 if (next) {
141 adc_dbg(adc, "new client is %p\n", next);
142 adc->cur = next;
143 s3c_adc_select(adc, next);
144 s3c_adc_convert(adc);
145 s3c_adc_dbgshow(adc);
146 }
147 }
148
149 int s3c_adc_start(struct s3c_adc_client *client,
150 unsigned int channel, unsigned int nr_samples)
151 {
152 struct adc_device *adc = adc_dev;
153 unsigned long flags;
154
155 if (!adc) {
156 printk(KERN_ERR "%s: failed to find adc\n", __func__);
157 return -EINVAL;
158 }
159
160 spin_lock_irqsave(&adc->lock, flags);
161
162 if (client->is_ts && adc->ts_pend) {
163 spin_unlock_irqrestore(&adc->lock, flags);
164 return -EAGAIN;
165 }
166
167 client->channel = channel;
168 client->nr_samples = nr_samples;
169
170 if (client->is_ts)
171 adc->ts_pend = client;
172 else
173 list_add_tail(&client->pend, &adc_pending);
174
175 if (!adc->cur)
176 s3c_adc_try(adc);
177
178 spin_unlock_irqrestore(&adc->lock, flags);
179
180 return 0;
181 }
182 EXPORT_SYMBOL_GPL(s3c_adc_start);
183
184 static void s3c_convert_done(struct s3c_adc_client *client,
185 unsigned v, unsigned u, unsigned *left)
186 {
187 client->result = v;
188 wake_up(client->wait);
189 }
190
191 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
192 {
193 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
194 int ret;
195
196 client->convert_cb = s3c_convert_done;
197 client->wait = &wake;
198 client->result = -1;
199
200 ret = s3c_adc_start(client, ch, 1);
201 if (ret < 0)
202 goto err;
203
204 ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
205 if (client->result < 0) {
206 ret = -ETIMEDOUT;
207 goto err;
208 }
209
210 client->convert_cb = NULL;
211 return client->result;
212
213 err:
214 return ret;
215 }
216 EXPORT_SYMBOL_GPL(s3c_adc_read);
217
218 static void s3c_adc_default_select(struct s3c_adc_client *client,
219 unsigned select)
220 {
221 }
222
223 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
224 void (*select)(struct s3c_adc_client *client,
225 unsigned int selected),
226 void (*conv)(struct s3c_adc_client *client,
227 unsigned d0, unsigned d1,
228 unsigned *samples_left),
229 unsigned int is_ts)
230 {
231 struct s3c_adc_client *client;
232
233 WARN_ON(!pdev);
234
235 if (!select)
236 select = s3c_adc_default_select;
237
238 if (!pdev)
239 return ERR_PTR(-EINVAL);
240
241 client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
242 if (!client) {
243 dev_err(&pdev->dev, "no memory for adc client\n");
244 return ERR_PTR(-ENOMEM);
245 }
246
247 client->pdev = pdev;
248 client->is_ts = is_ts;
249 client->select_cb = select;
250 client->convert_cb = conv;
251
252 return client;
253 }
254 EXPORT_SYMBOL_GPL(s3c_adc_register);
255
256 void s3c_adc_release(struct s3c_adc_client *client)
257 {
258 unsigned long flags;
259
260 spin_lock_irqsave(&adc_dev->lock, flags);
261
262 /* We should really check that nothing is in progress. */
263 if (adc_dev->cur == client)
264 adc_dev->cur = NULL;
265 if (adc_dev->ts_pend == client)
266 adc_dev->ts_pend = NULL;
267 else {
268 struct list_head *p, *n;
269 struct s3c_adc_client *tmp;
270
271 list_for_each_safe(p, n, &adc_pending) {
272 tmp = list_entry(p, struct s3c_adc_client, pend);
273 if (tmp == client)
274 list_del(&tmp->pend);
275 }
276 }
277
278 if (adc_dev->cur == NULL)
279 s3c_adc_try(adc_dev);
280
281 spin_unlock_irqrestore(&adc_dev->lock, flags);
282 kfree(client);
283 }
284 EXPORT_SYMBOL_GPL(s3c_adc_release);
285
286 static irqreturn_t s3c_adc_irq(int irq, void *pw)
287 {
288 struct adc_device *adc = pw;
289 struct s3c_adc_client *client = adc->cur;
290 enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
291 unsigned data0, data1;
292
293 if (!client) {
294 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
295 goto exit;
296 }
297
298 data0 = readl(adc->regs + S3C2410_ADCDAT0);
299 data1 = readl(adc->regs + S3C2410_ADCDAT1);
300 adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
301
302 client->nr_samples--;
303
304 if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {
305 data0 &= 0x3ff;
306 data1 &= 0x3ff;
307 } else {
308 /* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
309 data0 &= 0xfff;
310 data1 &= 0xfff;
311 }
312
313 if (client->convert_cb)
314 (client->convert_cb)(client, data0, data1, &client->nr_samples);
315
316 if (client->nr_samples > 0) {
317 /* fire another conversion for this */
318
319 client->select_cb(client, 1);
320 s3c_adc_convert(adc);
321 } else {
322 spin_lock(&adc->lock);
323 (client->select_cb)(client, 0);
324 adc->cur = NULL;
325
326 s3c_adc_try(adc);
327 spin_unlock(&adc->lock);
328 }
329
330 exit:
331 if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {
332 /* Clear ADC interrupt */
333 writel(0, adc->regs + S3C64XX_ADCCLRINT);
334 }
335 return IRQ_HANDLED;
336 }
337
338 static int s3c_adc_probe(struct platform_device *pdev)
339 {
340 struct device *dev = &pdev->dev;
341 struct adc_device *adc;
342 struct resource *regs;
343 enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
344 int ret;
345 unsigned tmp;
346
347 adc = devm_kzalloc(dev, sizeof(struct adc_device), GFP_KERNEL);
348 if (adc == NULL) {
349 dev_err(dev, "failed to allocate adc_device\n");
350 return -ENOMEM;
351 }
352
353 spin_lock_init(&adc->lock);
354
355 adc->pdev = pdev;
356 adc->prescale = S3C2410_ADCCON_PRSCVL(49);
357
358 adc->vdd = devm_regulator_get(dev, "vdd");
359 if (IS_ERR(adc->vdd)) {
360 dev_err(dev, "operating without regulator \"vdd\" .\n");
361 return PTR_ERR(adc->vdd);
362 }
363
364 adc->irq = platform_get_irq(pdev, 1);
365 if (adc->irq <= 0) {
366 dev_err(dev, "failed to get adc irq\n");
367 return -ENOENT;
368 }
369
370 ret = devm_request_irq(dev, adc->irq, s3c_adc_irq, 0, dev_name(dev),
371 adc);
372 if (ret < 0) {
373 dev_err(dev, "failed to attach adc irq\n");
374 return ret;
375 }
376
377 adc->clk = devm_clk_get(dev, "adc");
378 if (IS_ERR(adc->clk)) {
379 dev_err(dev, "failed to get adc clock\n");
380 return PTR_ERR(adc->clk);
381 }
382
383 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
384 adc->regs = devm_ioremap_resource(dev, regs);
385 if (IS_ERR(adc->regs))
386 return PTR_ERR(adc->regs);
387
388 ret = regulator_enable(adc->vdd);
389 if (ret)
390 return ret;
391
392 clk_enable(adc->clk);
393
394 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
395
396 /* Enable 12-bit ADC resolution */
397 if (cpu == TYPE_ADCV12)
398 tmp |= S3C2416_ADCCON_RESSEL;
399 if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
400 tmp |= S3C64XX_ADCCON_RESSEL;
401
402 writel(tmp, adc->regs + S3C2410_ADCCON);
403
404 dev_info(dev, "attached adc driver\n");
405
406 platform_set_drvdata(pdev, adc);
407 adc_dev = adc;
408
409 return 0;
410 }
411
412 static int s3c_adc_remove(struct platform_device *pdev)
413 {
414 struct adc_device *adc = platform_get_drvdata(pdev);
415
416 clk_disable(adc->clk);
417 regulator_disable(adc->vdd);
418
419 return 0;
420 }
421
422 #ifdef CONFIG_PM
423 static int s3c_adc_suspend(struct device *dev)
424 {
425 struct platform_device *pdev = container_of(dev,
426 struct platform_device, dev);
427 struct adc_device *adc = platform_get_drvdata(pdev);
428 unsigned long flags;
429 u32 con;
430
431 spin_lock_irqsave(&adc->lock, flags);
432
433 con = readl(adc->regs + S3C2410_ADCCON);
434 con |= S3C2410_ADCCON_STDBM;
435 writel(con, adc->regs + S3C2410_ADCCON);
436
437 disable_irq(adc->irq);
438 spin_unlock_irqrestore(&adc->lock, flags);
439 clk_disable(adc->clk);
440 regulator_disable(adc->vdd);
441
442 return 0;
443 }
444
445 static int s3c_adc_resume(struct device *dev)
446 {
447 struct platform_device *pdev = container_of(dev,
448 struct platform_device, dev);
449 struct adc_device *adc = platform_get_drvdata(pdev);
450 enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
451 int ret;
452 unsigned long tmp;
453
454 ret = regulator_enable(adc->vdd);
455 if (ret)
456 return ret;
457 clk_enable(adc->clk);
458 enable_irq(adc->irq);
459
460 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
461
462 /* Enable 12-bit ADC resolution */
463 if (cpu == TYPE_ADCV12)
464 tmp |= S3C2416_ADCCON_RESSEL;
465 if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
466 tmp |= S3C64XX_ADCCON_RESSEL;
467
468 writel(tmp, adc->regs + S3C2410_ADCCON);
469
470 return 0;
471 }
472
473 #else
474 #define s3c_adc_suspend NULL
475 #define s3c_adc_resume NULL
476 #endif
477
478 static struct platform_device_id s3c_adc_driver_ids[] = {
479 {
480 .name = "s3c24xx-adc",
481 .driver_data = TYPE_ADCV1,
482 }, {
483 .name = "s3c2443-adc",
484 .driver_data = TYPE_ADCV11,
485 }, {
486 .name = "s3c2416-adc",
487 .driver_data = TYPE_ADCV12,
488 }, {
489 .name = "s3c64xx-adc",
490 .driver_data = TYPE_ADCV2,
491 }, {
492 .name = "samsung-adc-v3",
493 .driver_data = TYPE_ADCV3,
494 },
495 { }
496 };
497 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
498
499 static const struct dev_pm_ops adc_pm_ops = {
500 .suspend = s3c_adc_suspend,
501 .resume = s3c_adc_resume,
502 };
503
504 static struct platform_driver s3c_adc_driver = {
505 .id_table = s3c_adc_driver_ids,
506 .driver = {
507 .name = "s3c-adc",
508 .owner = THIS_MODULE,
509 .pm = &adc_pm_ops,
510 },
511 .probe = s3c_adc_probe,
512 .remove = s3c_adc_remove,
513 };
514
515 static int __init adc_init(void)
516 {
517 int ret;
518
519 ret = platform_driver_register(&s3c_adc_driver);
520 if (ret)
521 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
522
523 return ret;
524 }
525
526 module_init(adc_init);
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