?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ARM: S3C64XX: Add S3C64XX support to the generic Samsung ADC driver
[linux-2.6/btrfs-unstable.git] / arch / arm / plat-samsung / adc.c
blob120b7902fc2fd02a6b55512cbfaf74d296ac4775
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/err.h>
20 #include <linux/clk.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23
24 #include <plat/regs-adc.h>
25 #include <plat/adc.h>
26
27 /* This driver is designed to control the usage of the ADC block between
28 * the touchscreen and any other drivers that may need to use it, such as
29 * the hwmon driver.
30 *
31 * Priority will be given to the touchscreen driver, but as this itself is
32 * rate limited it should not starve other requests which are processed in
33 * order that they are received.
34 *
35 * Each user registers to get a client block which uniquely identifies it
36 * and stores information such as the necessary functions to callback when
37 * action is required.
38 */
39
40 enum s3c_cpu_type {
41 TYPE_S3C24XX,
42 TYPE_S3C64XX
43 };
44
45 struct s3c_adc_client {
46 struct platform_device *pdev;
47 struct list_head pend;
48 wait_queue_head_t *wait;
49
50 unsigned int nr_samples;
51 int result;
52 unsigned char is_ts;
53 unsigned char channel;
54
55 void (*select_cb)(struct s3c_adc_client *c, unsigned selected);
56 void (*convert_cb)(struct s3c_adc_client *c,
57 unsigned val1, unsigned val2,
58 unsigned *samples_left);
59 };
60
61 struct adc_device {
62 struct platform_device *pdev;
63 struct platform_device *owner;
64 struct clk *clk;
65 struct s3c_adc_client *cur;
66 struct s3c_adc_client *ts_pend;
67 void __iomem *regs;
68
69 unsigned int prescale;
70
71 int irq;
72 };
73
74 static struct adc_device *adc_dev;
75
76 static LIST_HEAD(adc_pending);
77
78 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
79
80 static inline void s3c_adc_convert(struct adc_device *adc)
81 {
82 unsigned con = readl(adc->regs + S3C2410_ADCCON);
83
84 con |= S3C2410_ADCCON_ENABLE_START;
85 writel(con, adc->regs + S3C2410_ADCCON);
86 }
87
88 static inline void s3c_adc_select(struct adc_device *adc,
89 struct s3c_adc_client *client)
90 {
91 unsigned con = readl(adc->regs + S3C2410_ADCCON);
92
93 client->select_cb(client, 1);
94
95 con &= ~S3C2410_ADCCON_MUXMASK;
96 con &= ~S3C2410_ADCCON_STDBM;
97 con &= ~S3C2410_ADCCON_STARTMASK;
98
99 if (!client->is_ts)
100 con |= S3C2410_ADCCON_SELMUX(client->channel);
101
102 writel(con, adc->regs + S3C2410_ADCCON);
103 }
104
105 static void s3c_adc_dbgshow(struct adc_device *adc)
106 {
107 adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
108 readl(adc->regs + S3C2410_ADCCON),
109 readl(adc->regs + S3C2410_ADCTSC),
110 readl(adc->regs + S3C2410_ADCDLY));
111 }
112
113 static void s3c_adc_try(struct adc_device *adc)
114 {
115 struct s3c_adc_client *next = adc->ts_pend;
116
117 if (!next && !list_empty(&adc_pending)) {
118 next = list_first_entry(&adc_pending,
119 struct s3c_adc_client, pend);
120 list_del(&next->pend);
121 } else
122 adc->ts_pend = NULL;
123
124 if (next) {
125 adc_dbg(adc, "new client is %p\n", next);
126 adc->cur = next;
127 s3c_adc_select(adc, next);
128 s3c_adc_convert(adc);
129 s3c_adc_dbgshow(adc);
130 }
131 }
132
133 int s3c_adc_start(struct s3c_adc_client *client,
134 unsigned int channel, unsigned int nr_samples)
135 {
136 struct adc_device *adc = adc_dev;
137 unsigned long flags;
138
139 if (!adc) {
140 printk(KERN_ERR "%s: failed to find adc\n", __func__);
141 return -EINVAL;
142 }
143
144 if (client->is_ts && adc->ts_pend)
145 return -EAGAIN;
146
147 local_irq_save(flags);
148
149 client->channel = channel;
150 client->nr_samples = nr_samples;
151
152 if (client->is_ts)
153 adc->ts_pend = client;
154 else
155 list_add_tail(&client->pend, &adc_pending);
156
157 if (!adc->cur)
158 s3c_adc_try(adc);
159 local_irq_restore(flags);
160
161 return 0;
162 }
163 EXPORT_SYMBOL_GPL(s3c_adc_start);
164
165 static void s3c_convert_done(struct s3c_adc_client *client,
166 unsigned v, unsigned u, unsigned *left)
167 {
168 client->result = v;
169 wake_up(client->wait);
170 }
171
172 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
173 {
174 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
175 int ret;
176
177 client->convert_cb = s3c_convert_done;
178 client->wait = &wake;
179 client->result = -1;
180
181 ret = s3c_adc_start(client, ch, 1);
182 if (ret < 0)
183 goto err;
184
185 ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
186 if (client->result < 0) {
187 ret = -ETIMEDOUT;
188 goto err;
189 }
190
191 client->convert_cb = NULL;
192 return client->result;
193
194 err:
195 return ret;
196 }
197 EXPORT_SYMBOL_GPL(s3c_adc_read);
198
199 static void s3c_adc_default_select(struct s3c_adc_client *client,
200 unsigned select)
201 {
202 }
203
204 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
205 void (*select)(struct s3c_adc_client *client,
206 unsigned int selected),
207 void (*conv)(struct s3c_adc_client *client,
208 unsigned d0, unsigned d1,
209 unsigned *samples_left),
210 unsigned int is_ts)
211 {
212 struct s3c_adc_client *client;
213
214 WARN_ON(!pdev);
215
216 if (!select)
217 select = s3c_adc_default_select;
218
219 if (!pdev)
220 return ERR_PTR(-EINVAL);
221
222 client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
223 if (!client) {
224 dev_err(&pdev->dev, "no memory for adc client\n");
225 return ERR_PTR(-ENOMEM);
226 }
227
228 client->pdev = pdev;
229 client->is_ts = is_ts;
230 client->select_cb = select;
231 client->convert_cb = conv;
232
233 return client;
234 }
235 EXPORT_SYMBOL_GPL(s3c_adc_register);
236
237 void s3c_adc_release(struct s3c_adc_client *client)
238 {
239 /* We should really check that nothing is in progress. */
240 if (adc_dev->cur == client)
241 adc_dev->cur = NULL;
242 if (adc_dev->ts_pend == client)
243 adc_dev->ts_pend = NULL;
244 else {
245 struct list_head *p, *n;
246 struct s3c_adc_client *tmp;
247
248 list_for_each_safe(p, n, &adc_pending) {
249 tmp = list_entry(p, struct s3c_adc_client, pend);
250 if (tmp == client)
251 list_del(&tmp->pend);
252 }
253 }
254
255 if (adc_dev->cur == NULL)
256 s3c_adc_try(adc_dev);
257 kfree(client);
258 }
259 EXPORT_SYMBOL_GPL(s3c_adc_release);
260
261 static irqreturn_t s3c_adc_irq(int irq, void *pw)
262 {
263 struct adc_device *adc = pw;
264 struct s3c_adc_client *client = adc->cur;
265 unsigned long flags;
266 unsigned data0, data1;
267
268 if (!client) {
269 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
270 goto exit;
271 }
272
273 data0 = readl(adc->regs + S3C2410_ADCDAT0);
274 data1 = readl(adc->regs + S3C2410_ADCDAT1);
275 adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
276
277 client->nr_samples--;
278
279 if (client->convert_cb)
280 (client->convert_cb)(client, data0 & 0x3ff, data1 & 0x3ff,
281 &client->nr_samples);
282
283 if (client->nr_samples > 0) {
284 /* fire another conversion for this */
285
286 client->select_cb(client, 1);
287 s3c_adc_convert(adc);
288 } else {
289 local_irq_save(flags);
290 (client->select_cb)(client, 0);
291 adc->cur = NULL;
292
293 s3c_adc_try(adc);
294 local_irq_restore(flags);
295 }
296
297 exit:
298 if (platform_get_device_id(client->pdev)->driver_data == TYPE_S3C64XX) {
299 /* Clear ADC interrupt */
300 writel(0, adc->regs + S3C64XX_ADCCLRINT);
301 }
302 return IRQ_HANDLED;
303 }
304
305 static int s3c_adc_probe(struct platform_device *pdev)
306 {
307 struct device *dev = &pdev->dev;
308 struct adc_device *adc;
309 struct resource *regs;
310 int ret;
311
312 adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
313 if (adc == NULL) {
314 dev_err(dev, "failed to allocate adc_device\n");
315 return -ENOMEM;
316 }
317
318 adc->pdev = pdev;
319 adc->prescale = S3C2410_ADCCON_PRSCVL(49);
320
321 adc->irq = platform_get_irq(pdev, 1);
322 if (adc->irq <= 0) {
323 dev_err(dev, "failed to get adc irq\n");
324 ret = -ENOENT;
325 goto err_alloc;
326 }
327
328 ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
329 if (ret < 0) {
330 dev_err(dev, "failed to attach adc irq\n");
331 goto err_alloc;
332 }
333
334 adc->clk = clk_get(dev, "adc");
335 if (IS_ERR(adc->clk)) {
336 dev_err(dev, "failed to get adc clock\n");
337 ret = PTR_ERR(adc->clk);
338 goto err_irq;
339 }
340
341 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
342 if (!regs) {
343 dev_err(dev, "failed to find registers\n");
344 ret = -ENXIO;
345 goto err_clk;
346 }
347
348 adc->regs = ioremap(regs->start, resource_size(regs));
349 if (!adc->regs) {
350 dev_err(dev, "failed to map registers\n");
351 ret = -ENXIO;
352 goto err_clk;
353 }
354
355 clk_enable(adc->clk);
356
357 writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
358 adc->regs + S3C2410_ADCCON);
359
360 dev_info(dev, "attached adc driver\n");
361
362 platform_set_drvdata(pdev, adc);
363 adc_dev = adc;
364
365 return 0;
366
367 err_clk:
368 clk_put(adc->clk);
369
370 err_irq:
371 free_irq(adc->irq, adc);
372
373 err_alloc:
374 kfree(adc);
375 return ret;
376 }
377
378 static int __devexit s3c_adc_remove(struct platform_device *pdev)
379 {
380 struct adc_device *adc = platform_get_drvdata(pdev);
381
382 iounmap(adc->regs);
383 free_irq(adc->irq, adc);
384 clk_disable(adc->clk);
385 clk_put(adc->clk);
386 kfree(adc);
387
388 return 0;
389 }
390
391 #ifdef CONFIG_PM
392 static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
393 {
394 struct adc_device *adc = platform_get_drvdata(pdev);
395 u32 con;
396
397 con = readl(adc->regs + S3C2410_ADCCON);
398 con |= S3C2410_ADCCON_STDBM;
399 writel(con, adc->regs + S3C2410_ADCCON);
400
401 clk_disable(adc->clk);
402
403 return 0;
404 }
405
406 static int s3c_adc_resume(struct platform_device *pdev)
407 {
408 struct adc_device *adc = platform_get_drvdata(pdev);
409
410 clk_enable(adc->clk);
411
412 writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
413 adc->regs + S3C2410_ADCCON);
414
415 return 0;
416 }
417
418 #else
419 #define s3c_adc_suspend NULL
420 #define s3c_adc_resume NULL
421 #endif
422
423 static struct platform_device_id s3c_adc_driver_ids[] = {
424 {
425 .name = "s3c24xx-adc",
426 .driver_data = TYPE_S3C24XX,
427 }, {
428 .name = "s3c64xx-adc",
429 .driver_data = TYPE_S3C64XX,
430 },
431 { }
432 };
433 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
434
435 static struct platform_driver s3c_adc_driver = {
436 .id_table = s3c_adc_driver_ids,
437 .driver = {
438 .name = "s3c-adc",
439 .owner = THIS_MODULE,
440 },
441 .probe = s3c_adc_probe,
442 .remove = __devexit_p(s3c_adc_remove),
443 .suspend = s3c_adc_suspend,
444 .resume = s3c_adc_resume,
445 };
446
447 static int __init adc_init(void)
448 {
449 int ret;
450
451 ret = platform_driver_register(&s3c_adc_driver);
452 if (ret)
453 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
454
455 return ret;
456 }
457
458 arch_initcall(adc_init);
(deprecated) Btrfs devel tree