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Merge branch 'v6v7' into devel
[linux/fpc-iii.git] / arch / arm / plat-samsung / adc.c
blobe8f2be2d67f2cac33961487b47a7880b68f33832
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
25 #include <plat/regs-adc.h>
26 #include <plat/adc.h>
27
28 /* This driver is designed to control the usage of the ADC block between
29 * the touchscreen and any other drivers that may need to use it, such as
30 * the hwmon driver.
31 *
32 * Priority will be given to the touchscreen driver, but as this itself is
33 * rate limited it should not starve other requests which are processed in
34 * order that they are received.
35 *
36 * Each user registers to get a client block which uniquely identifies it
37 * and stores information such as the necessary functions to callback when
38 * action is required.
39 */
40
41 enum s3c_cpu_type {
42 TYPE_S3C24XX,
43 TYPE_S3C64XX
44 };
45
46 struct s3c_adc_client {
47 struct platform_device *pdev;
48 struct list_head pend;
49 wait_queue_head_t *wait;
50
51 unsigned int nr_samples;
52 int result;
53 unsigned char is_ts;
54 unsigned char channel;
55
56 void (*select_cb)(struct s3c_adc_client *c, unsigned selected);
57 void (*convert_cb)(struct s3c_adc_client *c,
58 unsigned val1, unsigned val2,
59 unsigned *samples_left);
60 };
61
62 struct adc_device {
63 struct platform_device *pdev;
64 struct platform_device *owner;
65 struct clk *clk;
66 struct s3c_adc_client *cur;
67 struct s3c_adc_client *ts_pend;
68 void __iomem *regs;
69 spinlock_t lock;
70
71 unsigned int prescale;
72
73 int irq;
74 };
75
76 static struct adc_device *adc_dev;
77
78 static LIST_HEAD(adc_pending); /* protected by adc_device.lock */
79
80 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
81
82 static inline void s3c_adc_convert(struct adc_device *adc)
83 {
84 unsigned con = readl(adc->regs + S3C2410_ADCCON);
85
86 con |= S3C2410_ADCCON_ENABLE_START;
87 writel(con, adc->regs + S3C2410_ADCCON);
88 }
89
90 static inline void s3c_adc_select(struct adc_device *adc,
91 struct s3c_adc_client *client)
92 {
93 unsigned con = readl(adc->regs + S3C2410_ADCCON);
94
95 client->select_cb(client, 1);
96
97 con &= ~S3C2410_ADCCON_MUXMASK;
98 con &= ~S3C2410_ADCCON_STDBM;
99 con &= ~S3C2410_ADCCON_STARTMASK;
100
101 if (!client->is_ts)
102 con |= S3C2410_ADCCON_SELMUX(client->channel);
103
104 writel(con, adc->regs + S3C2410_ADCCON);
105 }
106
107 static void s3c_adc_dbgshow(struct adc_device *adc)
108 {
109 adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
110 readl(adc->regs + S3C2410_ADCCON),
111 readl(adc->regs + S3C2410_ADCTSC),
112 readl(adc->regs + S3C2410_ADCDLY));
113 }
114
115 static void s3c_adc_try(struct adc_device *adc)
116 {
117 struct s3c_adc_client *next = adc->ts_pend;
118
119 if (!next && !list_empty(&adc_pending)) {
120 next = list_first_entry(&adc_pending,
121 struct s3c_adc_client, pend);
122 list_del(&next->pend);
123 } else
124 adc->ts_pend = NULL;
125
126 if (next) {
127 adc_dbg(adc, "new client is %p\n", next);
128 adc->cur = next;
129 s3c_adc_select(adc, next);
130 s3c_adc_convert(adc);
131 s3c_adc_dbgshow(adc);
132 }
133 }
134
135 int s3c_adc_start(struct s3c_adc_client *client,
136 unsigned int channel, unsigned int nr_samples)
137 {
138 struct adc_device *adc = adc_dev;
139 unsigned long flags;
140
141 if (!adc) {
142 printk(KERN_ERR "%s: failed to find adc\n", __func__);
143 return -EINVAL;
144 }
145
146 if (client->is_ts && adc->ts_pend)
147 return -EAGAIN;
148
149 spin_lock_irqsave(&adc->lock, flags);
150
151 client->channel = channel;
152 client->nr_samples = nr_samples;
153
154 if (client->is_ts)
155 adc->ts_pend = client;
156 else
157 list_add_tail(&client->pend, &adc_pending);
158
159 if (!adc->cur)
160 s3c_adc_try(adc);
161
162 spin_unlock_irqrestore(&adc->lock, flags);
163
164 return 0;
165 }
166 EXPORT_SYMBOL_GPL(s3c_adc_start);
167
168 static void s3c_convert_done(struct s3c_adc_client *client,
169 unsigned v, unsigned u, unsigned *left)
170 {
171 client->result = v;
172 wake_up(client->wait);
173 }
174
175 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
176 {
177 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
178 int ret;
179
180 client->convert_cb = s3c_convert_done;
181 client->wait = &wake;
182 client->result = -1;
183
184 ret = s3c_adc_start(client, ch, 1);
185 if (ret < 0)
186 goto err;
187
188 ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
189 if (client->result < 0) {
190 ret = -ETIMEDOUT;
191 goto err;
192 }
193
194 client->convert_cb = NULL;
195 return client->result;
196
197 err:
198 return ret;
199 }
200 EXPORT_SYMBOL_GPL(s3c_adc_read);
201
202 static void s3c_adc_default_select(struct s3c_adc_client *client,
203 unsigned select)
204 {
205 }
206
207 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
208 void (*select)(struct s3c_adc_client *client,
209 unsigned int selected),
210 void (*conv)(struct s3c_adc_client *client,
211 unsigned d0, unsigned d1,
212 unsigned *samples_left),
213 unsigned int is_ts)
214 {
215 struct s3c_adc_client *client;
216
217 WARN_ON(!pdev);
218
219 if (!select)
220 select = s3c_adc_default_select;
221
222 if (!pdev)
223 return ERR_PTR(-EINVAL);
224
225 client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
226 if (!client) {
227 dev_err(&pdev->dev, "no memory for adc client\n");
228 return ERR_PTR(-ENOMEM);
229 }
230
231 client->pdev = pdev;
232 client->is_ts = is_ts;
233 client->select_cb = select;
234 client->convert_cb = conv;
235
236 return client;
237 }
238 EXPORT_SYMBOL_GPL(s3c_adc_register);
239
240 void s3c_adc_release(struct s3c_adc_client *client)
241 {
242 unsigned long flags;
243
244 spin_lock_irqsave(&adc_dev->lock, flags);
245
246 /* We should really check that nothing is in progress. */
247 if (adc_dev->cur == client)
248 adc_dev->cur = NULL;
249 if (adc_dev->ts_pend == client)
250 adc_dev->ts_pend = NULL;
251 else {
252 struct list_head *p, *n;
253 struct s3c_adc_client *tmp;
254
255 list_for_each_safe(p, n, &adc_pending) {
256 tmp = list_entry(p, struct s3c_adc_client, pend);
257 if (tmp == client)
258 list_del(&tmp->pend);
259 }
260 }
261
262 if (adc_dev->cur == NULL)
263 s3c_adc_try(adc_dev);
264
265 spin_unlock_irqrestore(&adc_dev->lock, flags);
266 kfree(client);
267 }
268 EXPORT_SYMBOL_GPL(s3c_adc_release);
269
270 static irqreturn_t s3c_adc_irq(int irq, void *pw)
271 {
272 struct adc_device *adc = pw;
273 struct s3c_adc_client *client = adc->cur;
274 enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
275 unsigned data0, data1;
276
277 if (!client) {
278 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
279 goto exit;
280 }
281
282 data0 = readl(adc->regs + S3C2410_ADCDAT0);
283 data1 = readl(adc->regs + S3C2410_ADCDAT1);
284 adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
285
286 client->nr_samples--;
287
288 if (cpu == TYPE_S3C64XX) {
289 /* S3C64XX ADC resolution is 12-bit */
290 data0 &= 0xfff;
291 data1 &= 0xfff;
292 } else {
293 data0 &= 0x3ff;
294 data1 &= 0x3ff;
295 }
296
297 if (client->convert_cb)
298 (client->convert_cb)(client, data0, data1, &client->nr_samples);
299
300 if (client->nr_samples > 0) {
301 /* fire another conversion for this */
302
303 client->select_cb(client, 1);
304 s3c_adc_convert(adc);
305 } else {
306 spin_lock(&adc->lock);
307 (client->select_cb)(client, 0);
308 adc->cur = NULL;
309
310 s3c_adc_try(adc);
311 spin_unlock(&adc->lock);
312 }
313
314 exit:
315 if (cpu == TYPE_S3C64XX) {
316 /* Clear ADC interrupt */
317 writel(0, adc->regs + S3C64XX_ADCCLRINT);
318 }
319 return IRQ_HANDLED;
320 }
321
322 static int s3c_adc_probe(struct platform_device *pdev)
323 {
324 struct device *dev = &pdev->dev;
325 struct adc_device *adc;
326 struct resource *regs;
327 int ret;
328 unsigned tmp;
329
330 adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
331 if (adc == NULL) {
332 dev_err(dev, "failed to allocate adc_device\n");
333 return -ENOMEM;
334 }
335
336 spin_lock_init(&adc->lock);
337
338 adc->pdev = pdev;
339 adc->prescale = S3C2410_ADCCON_PRSCVL(49);
340
341 adc->irq = platform_get_irq(pdev, 1);
342 if (adc->irq <= 0) {
343 dev_err(dev, "failed to get adc irq\n");
344 ret = -ENOENT;
345 goto err_alloc;
346 }
347
348 ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
349 if (ret < 0) {
350 dev_err(dev, "failed to attach adc irq\n");
351 goto err_alloc;
352 }
353
354 adc->clk = clk_get(dev, "adc");
355 if (IS_ERR(adc->clk)) {
356 dev_err(dev, "failed to get adc clock\n");
357 ret = PTR_ERR(adc->clk);
358 goto err_irq;
359 }
360
361 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
362 if (!regs) {
363 dev_err(dev, "failed to find registers\n");
364 ret = -ENXIO;
365 goto err_clk;
366 }
367
368 adc->regs = ioremap(regs->start, resource_size(regs));
369 if (!adc->regs) {
370 dev_err(dev, "failed to map registers\n");
371 ret = -ENXIO;
372 goto err_clk;
373 }
374
375 clk_enable(adc->clk);
376
377 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
378 if (platform_get_device_id(pdev)->driver_data == TYPE_S3C64XX) {
379 /* Enable 12-bit ADC resolution */
380 tmp |= S3C64XX_ADCCON_RESSEL;
381 }
382 writel(tmp, adc->regs + S3C2410_ADCCON);
383
384 dev_info(dev, "attached adc driver\n");
385
386 platform_set_drvdata(pdev, adc);
387 adc_dev = adc;
388
389 return 0;
390
391 err_clk:
392 clk_put(adc->clk);
393
394 err_irq:
395 free_irq(adc->irq, adc);
396
397 err_alloc:
398 kfree(adc);
399 return ret;
400 }
401
402 static int __devexit s3c_adc_remove(struct platform_device *pdev)
403 {
404 struct adc_device *adc = platform_get_drvdata(pdev);
405
406 iounmap(adc->regs);
407 free_irq(adc->irq, adc);
408 clk_disable(adc->clk);
409 clk_put(adc->clk);
410 kfree(adc);
411
412 return 0;
413 }
414
415 #ifdef CONFIG_PM
416 static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
417 {
418 struct adc_device *adc = platform_get_drvdata(pdev);
419 unsigned long flags;
420 u32 con;
421
422 spin_lock_irqsave(&adc->lock, flags);
423
424 con = readl(adc->regs + S3C2410_ADCCON);
425 con |= S3C2410_ADCCON_STDBM;
426 writel(con, adc->regs + S3C2410_ADCCON);
427
428 disable_irq(adc->irq);
429 spin_unlock_irqrestore(&adc->lock, flags);
430 clk_disable(adc->clk);
431
432 return 0;
433 }
434
435 static int s3c_adc_resume(struct platform_device *pdev)
436 {
437 struct adc_device *adc = platform_get_drvdata(pdev);
438
439 clk_enable(adc->clk);
440 enable_irq(adc->irq);
441
442 writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
443 adc->regs + S3C2410_ADCCON);
444
445 return 0;
446 }
447
448 #else
449 #define s3c_adc_suspend NULL
450 #define s3c_adc_resume NULL
451 #endif
452
453 static struct platform_device_id s3c_adc_driver_ids[] = {
454 {
455 .name = "s3c24xx-adc",
456 .driver_data = TYPE_S3C24XX,
457 }, {
458 .name = "s3c64xx-adc",
459 .driver_data = TYPE_S3C64XX,
460 },
461 { }
462 };
463 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
464
465 static struct platform_driver s3c_adc_driver = {
466 .id_table = s3c_adc_driver_ids,
467 .driver = {
468 .name = "s3c-adc",
469 .owner = THIS_MODULE,
470 },
471 .probe = s3c_adc_probe,
472 .remove = __devexit_p(s3c_adc_remove),
473 .suspend = s3c_adc_suspend,
474 .resume = s3c_adc_resume,
475 };
476
477 static int __init adc_init(void)
478 {
479 int ret;
480
481 ret = platform_driver_register(&s3c_adc_driver);
482 if (ret)
483 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
484
485 return ret;
486 }
487
488 arch_initcall(adc_init);
Linux with added FPC-III support