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
s3c_adc_convert(struct adc_device * adc)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
s3c_adc_select(struct adc_device * adc,struct s3c_adc_client * client)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
s3c_adc_dbgshow(struct adc_device * adc)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
s3c_adc_try(struct adc_device * adc)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
s3c_adc_start(struct s3c_adc_client * client,unsigned int channel,unsigned int nr_samples)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 if (client->is_ts && adc->ts_pend)
161 return -EAGAIN;
162
163 spin_lock_irqsave(&adc->lock, flags);
164
165 client->channel = channel;
166 client->nr_samples = nr_samples;
167
168 if (client->is_ts)
169 adc->ts_pend = client;
170 else
171 list_add_tail(&client->pend, &adc_pending);
172
173 if (!adc->cur)
174 s3c_adc_try(adc);
175
176 spin_unlock_irqrestore(&adc->lock, flags);
177
178 return 0;
179 }
180 EXPORT_SYMBOL_GPL(s3c_adc_start);
181
s3c_convert_done(struct s3c_adc_client * client,unsigned v,unsigned u,unsigned * left)182 static void s3c_convert_done(struct s3c_adc_client *client,
183 unsigned v, unsigned u, unsigned *left)
184 {
185 client->result = v;
186 wake_up(client->wait);
187 }
188
s3c_adc_read(struct s3c_adc_client * client,unsigned int ch)189 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
190 {
191 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
192 int ret;
193
194 client->convert_cb = s3c_convert_done;
195 client->wait = &wake;
196 client->result = -1;
197
198 ret = s3c_adc_start(client, ch, 1);
199 if (ret < 0)
200 goto err;
201
202 ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
203 if (client->result < 0) {
204 ret = -ETIMEDOUT;
205 goto err;
206 }
207
208 client->convert_cb = NULL;
209 return client->result;
210
211 err:
212 return ret;
213 }
214 EXPORT_SYMBOL_GPL(s3c_adc_read);
215
s3c_adc_default_select(struct s3c_adc_client * client,unsigned select)216 static void s3c_adc_default_select(struct s3c_adc_client *client,
217 unsigned select)
218 {
219 }
220
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)221 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
222 void (*select)(struct s3c_adc_client *client,
223 unsigned int selected),
224 void (*conv)(struct s3c_adc_client *client,
225 unsigned d0, unsigned d1,
226 unsigned *samples_left),
227 unsigned int is_ts)
228 {
229 struct s3c_adc_client *client;
230
231 WARN_ON(!pdev);
232
233 if (!select)
234 select = s3c_adc_default_select;
235
236 if (!pdev)
237 return ERR_PTR(-EINVAL);
238
239 client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
240 if (!client) {
241 dev_err(&pdev->dev, "no memory for adc client\n");
242 return ERR_PTR(-ENOMEM);
243 }
244
245 client->pdev = pdev;
246 client->is_ts = is_ts;
247 client->select_cb = select;
248 client->convert_cb = conv;
249
250 return client;
251 }
252 EXPORT_SYMBOL_GPL(s3c_adc_register);
253
s3c_adc_release(struct s3c_adc_client * client)254 void s3c_adc_release(struct s3c_adc_client *client)
255 {
256 unsigned long flags;
257
258 spin_lock_irqsave(&adc_dev->lock, flags);
259
260 /* We should really check that nothing is in progress. */
261 if (adc_dev->cur == client)
262 adc_dev->cur = NULL;
263 if (adc_dev->ts_pend == client)
264 adc_dev->ts_pend = NULL;
265 else {
266 struct list_head *p, *n;
267 struct s3c_adc_client *tmp;
268
269 list_for_each_safe(p, n, &adc_pending) {
270 tmp = list_entry(p, struct s3c_adc_client, pend);
271 if (tmp == client)
272 list_del(&tmp->pend);
273 }
274 }
275
276 if (adc_dev->cur == NULL)
277 s3c_adc_try(adc_dev);
278
279 spin_unlock_irqrestore(&adc_dev->lock, flags);
280 kfree(client);
281 }
282 EXPORT_SYMBOL_GPL(s3c_adc_release);
283
s3c_adc_irq(int irq,void * pw)284 static irqreturn_t s3c_adc_irq(int irq, void *pw)
285 {
286 struct adc_device *adc = pw;
287 struct s3c_adc_client *client = adc->cur;
288 enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
289 unsigned data0, data1;
290
291 if (!client) {
292 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
293 goto exit;
294 }
295
296 data0 = readl(adc->regs + S3C2410_ADCDAT0);
297 data1 = readl(adc->regs + S3C2410_ADCDAT1);
298 adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
299
300 client->nr_samples--;
301
302 if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {
303 data0 &= 0x3ff;
304 data1 &= 0x3ff;
305 } else {
306 /* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
307 data0 &= 0xfff;
308 data1 &= 0xfff;
309 }
310
311 if (client->convert_cb)
312 (client->convert_cb)(client, data0, data1, &client->nr_samples);
313
314 if (client->nr_samples > 0) {
315 /* fire another conversion for this */
316
317 client->select_cb(client, 1);
318 s3c_adc_convert(adc);
319 } else {
320 spin_lock(&adc->lock);
321 (client->select_cb)(client, 0);
322 adc->cur = NULL;
323
324 s3c_adc_try(adc);
325 spin_unlock(&adc->lock);
326 }
327
328 exit:
329 if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {
330 /* Clear ADC interrupt */
331 writel(0, adc->regs + S3C64XX_ADCCLRINT);
332 }
333 return IRQ_HANDLED;
334 }
335
s3c_adc_probe(struct platform_device * pdev)336 static int s3c_adc_probe(struct platform_device *pdev)
337 {
338 struct device *dev = &pdev->dev;
339 struct adc_device *adc;
340 struct resource *regs;
341 enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
342 int ret;
343 unsigned tmp;
344
345 adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
346 if (adc == NULL) {
347 dev_err(dev, "failed to allocate adc_device\n");
348 return -ENOMEM;
349 }
350
351 spin_lock_init(&adc->lock);
352
353 adc->pdev = pdev;
354 adc->prescale = S3C2410_ADCCON_PRSCVL(49);
355
356 adc->vdd = regulator_get(dev, "vdd");
357 if (IS_ERR(adc->vdd)) {
358 dev_err(dev, "operating without regulator \"vdd\" .\n");
359 ret = PTR_ERR(adc->vdd);
360 goto err_alloc;
361 }
362
363 adc->irq = platform_get_irq(pdev, 1);
364 if (adc->irq <= 0) {
365 dev_err(dev, "failed to get adc irq\n");
366 ret = -ENOENT;
367 goto err_reg;
368 }
369
370 ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
371 if (ret < 0) {
372 dev_err(dev, "failed to attach adc irq\n");
373 goto err_reg;
374 }
375
376 adc->clk = clk_get(dev, "adc");
377 if (IS_ERR(adc->clk)) {
378 dev_err(dev, "failed to get adc clock\n");
379 ret = PTR_ERR(adc->clk);
380 goto err_irq;
381 }
382
383 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
384 if (!regs) {
385 dev_err(dev, "failed to find registers\n");
386 ret = -ENXIO;
387 goto err_clk;
388 }
389
390 adc->regs = ioremap(regs->start, resource_size(regs));
391 if (!adc->regs) {
392 dev_err(dev, "failed to map registers\n");
393 ret = -ENXIO;
394 goto err_clk;
395 }
396
397 ret = regulator_enable(adc->vdd);
398 if (ret)
399 goto err_ioremap;
400
401 clk_enable(adc->clk);
402
403 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
404
405 /* Enable 12-bit ADC resolution */
406 if (cpu == TYPE_ADCV12)
407 tmp |= S3C2416_ADCCON_RESSEL;
408 if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
409 tmp |= S3C64XX_ADCCON_RESSEL;
410
411 writel(tmp, adc->regs + S3C2410_ADCCON);
412
413 dev_info(dev, "attached adc driver\n");
414
415 platform_set_drvdata(pdev, adc);
416 adc_dev = adc;
417
418 return 0;
419
420 err_ioremap:
421 iounmap(adc->regs);
422 err_clk:
423 clk_put(adc->clk);
424
425 err_irq:
426 free_irq(adc->irq, adc);
427 err_reg:
428 regulator_put(adc->vdd);
429 err_alloc:
430 kfree(adc);
431 return ret;
432 }
433
s3c_adc_remove(struct platform_device * pdev)434 static int __devexit s3c_adc_remove(struct platform_device *pdev)
435 {
436 struct adc_device *adc = platform_get_drvdata(pdev);
437
438 iounmap(adc->regs);
439 free_irq(adc->irq, adc);
440 clk_disable(adc->clk);
441 regulator_disable(adc->vdd);
442 regulator_put(adc->vdd);
443 clk_put(adc->clk);
444 kfree(adc);
445
446 return 0;
447 }
448
449 #ifdef CONFIG_PM
s3c_adc_suspend(struct device * dev)450 static int s3c_adc_suspend(struct device *dev)
451 {
452 struct platform_device *pdev = container_of(dev,
453 struct platform_device, dev);
454 struct adc_device *adc = platform_get_drvdata(pdev);
455 unsigned long flags;
456 u32 con;
457
458 spin_lock_irqsave(&adc->lock, flags);
459
460 con = readl(adc->regs + S3C2410_ADCCON);
461 con |= S3C2410_ADCCON_STDBM;
462 writel(con, adc->regs + S3C2410_ADCCON);
463
464 disable_irq(adc->irq);
465 spin_unlock_irqrestore(&adc->lock, flags);
466 clk_disable(adc->clk);
467 regulator_disable(adc->vdd);
468
469 return 0;
470 }
471
s3c_adc_resume(struct device * dev)472 static int s3c_adc_resume(struct device *dev)
473 {
474 struct platform_device *pdev = container_of(dev,
475 struct platform_device, dev);
476 struct adc_device *adc = platform_get_drvdata(pdev);
477 enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
478 int ret;
479 unsigned long tmp;
480
481 ret = regulator_enable(adc->vdd);
482 if (ret)
483 return ret;
484 clk_enable(adc->clk);
485 enable_irq(adc->irq);
486
487 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
488
489 /* Enable 12-bit ADC resolution */
490 if (cpu == TYPE_ADCV12)
491 tmp |= S3C2416_ADCCON_RESSEL;
492 if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
493 tmp |= S3C64XX_ADCCON_RESSEL;
494
495 writel(tmp, adc->regs + S3C2410_ADCCON);
496
497 return 0;
498 }
499
500 #else
501 #define s3c_adc_suspend NULL
502 #define s3c_adc_resume NULL
503 #endif
504
505 static struct platform_device_id s3c_adc_driver_ids[] = {
506 {
507 .name = "s3c24xx-adc",
508 .driver_data = TYPE_ADCV1,
509 }, {
510 .name = "s3c2443-adc",
511 .driver_data = TYPE_ADCV11,
512 }, {
513 .name = "s3c2416-adc",
514 .driver_data = TYPE_ADCV12,
515 }, {
516 .name = "s3c64xx-adc",
517 .driver_data = TYPE_ADCV2,
518 }, {
519 .name = "samsung-adc-v3",
520 .driver_data = TYPE_ADCV3,
521 },
522 { }
523 };
524 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
525
526 static const struct dev_pm_ops adc_pm_ops = {
527 .suspend = s3c_adc_suspend,
528 .resume = s3c_adc_resume,
529 };
530
531 static struct platform_driver s3c_adc_driver = {
532 .id_table = s3c_adc_driver_ids,
533 .driver = {
534 .name = "s3c-adc",
535 .owner = THIS_MODULE,
536 .pm = &adc_pm_ops,
537 },
538 .probe = s3c_adc_probe,
539 .remove = __devexit_p(s3c_adc_remove),
540 };
541
adc_init(void)542 static int __init adc_init(void)
543 {
544 int ret;
545
546 ret = platform_driver_register(&s3c_adc_driver);
547 if (ret)
548 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
549
550 return ret;
551 }
552
553 module_init(adc_init);
554