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Staging: comedi: hwdrv_apci2032.c: static sparse fix
[linux/fpc-iii.git] / arch / arm / plat-samsung / adc.c
blob210030d5cfe13e3761e99f19732ab9a3b97a893c
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
70 unsigned int prescale;
71
72 int irq;
73 };
74
75 static struct adc_device *adc_dev;
76
77 static LIST_HEAD(adc_pending);
78
79 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
80
81 static inline void s3c_adc_convert(struct adc_device *adc)
82 {
83 unsigned con = readl(adc->regs + S3C2410_ADCCON);
84
85 con |= S3C2410_ADCCON_ENABLE_START;
86 writel(con, adc->regs + S3C2410_ADCCON);
87 }
88
89 static inline void s3c_adc_select(struct adc_device *adc,
90 struct s3c_adc_client *client)
91 {
92 unsigned con = readl(adc->regs + S3C2410_ADCCON);
93
94 client->select_cb(client, 1);
95
96 con &= ~S3C2410_ADCCON_MUXMASK;
97 con &= ~S3C2410_ADCCON_STDBM;
98 con &= ~S3C2410_ADCCON_STARTMASK;
99
100 if (!client->is_ts)
101 con |= S3C2410_ADCCON_SELMUX(client->channel);
102
103 writel(con, adc->regs + S3C2410_ADCCON);
104 }
105
106 static void s3c_adc_dbgshow(struct adc_device *adc)
107 {
108 adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
109 readl(adc->regs + S3C2410_ADCCON),
110 readl(adc->regs + S3C2410_ADCTSC),
111 readl(adc->regs + S3C2410_ADCDLY));
112 }
113
114 static void s3c_adc_try(struct adc_device *adc)
115 {
116 struct s3c_adc_client *next = adc->ts_pend;
117
118 if (!next && !list_empty(&adc_pending)) {
119 next = list_first_entry(&adc_pending,
120 struct s3c_adc_client, pend);
121 list_del(&next->pend);
122 } else
123 adc->ts_pend = NULL;
124
125 if (next) {
126 adc_dbg(adc, "new client is %p\n", next);
127 adc->cur = next;
128 s3c_adc_select(adc, next);
129 s3c_adc_convert(adc);
130 s3c_adc_dbgshow(adc);
131 }
132 }
133
134 int s3c_adc_start(struct s3c_adc_client *client,
135 unsigned int channel, unsigned int nr_samples)
136 {
137 struct adc_device *adc = adc_dev;
138 unsigned long flags;
139
140 if (!adc) {
141 printk(KERN_ERR "%s: failed to find adc\n", __func__);
142 return -EINVAL;
143 }
144
145 if (client->is_ts && adc->ts_pend)
146 return -EAGAIN;
147
148 local_irq_save(flags);
149
150 client->channel = channel;
151 client->nr_samples = nr_samples;
152
153 if (client->is_ts)
154 adc->ts_pend = client;
155 else
156 list_add_tail(&client->pend, &adc_pending);
157
158 if (!adc->cur)
159 s3c_adc_try(adc);
160 local_irq_restore(flags);
161
162 return 0;
163 }
164 EXPORT_SYMBOL_GPL(s3c_adc_start);
165
166 static void s3c_convert_done(struct s3c_adc_client *client,
167 unsigned v, unsigned u, unsigned *left)
168 {
169 client->result = v;
170 wake_up(client->wait);
171 }
172
173 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
174 {
175 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
176 int ret;
177
178 client->convert_cb = s3c_convert_done;
179 client->wait = &wake;
180 client->result = -1;
181
182 ret = s3c_adc_start(client, ch, 1);
183 if (ret < 0)
184 goto err;
185
186 ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
187 if (client->result < 0) {
188 ret = -ETIMEDOUT;
189 goto err;
190 }
191
192 client->convert_cb = NULL;
193 return client->result;
194
195 err:
196 return ret;
197 }
198 EXPORT_SYMBOL_GPL(s3c_adc_read);
199
200 static void s3c_adc_default_select(struct s3c_adc_client *client,
201 unsigned select)
202 {
203 }
204
205 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
206 void (*select)(struct s3c_adc_client *client,
207 unsigned int selected),
208 void (*conv)(struct s3c_adc_client *client,
209 unsigned d0, unsigned d1,
210 unsigned *samples_left),
211 unsigned int is_ts)
212 {
213 struct s3c_adc_client *client;
214
215 WARN_ON(!pdev);
216
217 if (!select)
218 select = s3c_adc_default_select;
219
220 if (!pdev)
221 return ERR_PTR(-EINVAL);
222
223 client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
224 if (!client) {
225 dev_err(&pdev->dev, "no memory for adc client\n");
226 return ERR_PTR(-ENOMEM);
227 }
228
229 client->pdev = pdev;
230 client->is_ts = is_ts;
231 client->select_cb = select;
232 client->convert_cb = conv;
233
234 return client;
235 }
236 EXPORT_SYMBOL_GPL(s3c_adc_register);
237
238 void s3c_adc_release(struct s3c_adc_client *client)
239 {
240 /* We should really check that nothing is in progress. */
241 if (adc_dev->cur == client)
242 adc_dev->cur = NULL;
243 if (adc_dev->ts_pend == client)
244 adc_dev->ts_pend = NULL;
245 else {
246 struct list_head *p, *n;
247 struct s3c_adc_client *tmp;
248
249 list_for_each_safe(p, n, &adc_pending) {
250 tmp = list_entry(p, struct s3c_adc_client, pend);
251 if (tmp == client)
252 list_del(&tmp->pend);
253 }
254 }
255
256 if (adc_dev->cur == NULL)
257 s3c_adc_try(adc_dev);
258 kfree(client);
259 }
260 EXPORT_SYMBOL_GPL(s3c_adc_release);
261
262 static irqreturn_t s3c_adc_irq(int irq, void *pw)
263 {
264 struct adc_device *adc = pw;
265 struct s3c_adc_client *client = adc->cur;
266 enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
267 unsigned long flags;
268 unsigned data0, data1;
269
270 if (!client) {
271 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
272 goto exit;
273 }
274
275 data0 = readl(adc->regs + S3C2410_ADCDAT0);
276 data1 = readl(adc->regs + S3C2410_ADCDAT1);
277 adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
278
279 client->nr_samples--;
280
281 if (cpu == TYPE_S3C64XX) {
282 /* S3C64XX ADC resolution is 12-bit */
283 data0 &= 0xfff;
284 data1 &= 0xfff;
285 } else {
286 data0 &= 0x3ff;
287 data1 &= 0x3ff;
288 }
289
290 if (client->convert_cb)
291 (client->convert_cb)(client, data0, data1, &client->nr_samples);
292
293 if (client->nr_samples > 0) {
294 /* fire another conversion for this */
295
296 client->select_cb(client, 1);
297 s3c_adc_convert(adc);
298 } else {
299 local_irq_save(flags);
300 (client->select_cb)(client, 0);
301 adc->cur = NULL;
302
303 s3c_adc_try(adc);
304 local_irq_restore(flags);
305 }
306
307 exit:
308 if (cpu == TYPE_S3C64XX) {
309 /* Clear ADC interrupt */
310 writel(0, adc->regs + S3C64XX_ADCCLRINT);
311 }
312 return IRQ_HANDLED;
313 }
314
315 static int s3c_adc_probe(struct platform_device *pdev)
316 {
317 struct device *dev = &pdev->dev;
318 struct adc_device *adc;
319 struct resource *regs;
320 int ret;
321 unsigned tmp;
322
323 adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
324 if (adc == NULL) {
325 dev_err(dev, "failed to allocate adc_device\n");
326 return -ENOMEM;
327 }
328
329 adc->pdev = pdev;
330 adc->prescale = S3C2410_ADCCON_PRSCVL(49);
331
332 adc->irq = platform_get_irq(pdev, 1);
333 if (adc->irq <= 0) {
334 dev_err(dev, "failed to get adc irq\n");
335 ret = -ENOENT;
336 goto err_alloc;
337 }
338
339 ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
340 if (ret < 0) {
341 dev_err(dev, "failed to attach adc irq\n");
342 goto err_alloc;
343 }
344
345 adc->clk = clk_get(dev, "adc");
346 if (IS_ERR(adc->clk)) {
347 dev_err(dev, "failed to get adc clock\n");
348 ret = PTR_ERR(adc->clk);
349 goto err_irq;
350 }
351
352 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
353 if (!regs) {
354 dev_err(dev, "failed to find registers\n");
355 ret = -ENXIO;
356 goto err_clk;
357 }
358
359 adc->regs = ioremap(regs->start, resource_size(regs));
360 if (!adc->regs) {
361 dev_err(dev, "failed to map registers\n");
362 ret = -ENXIO;
363 goto err_clk;
364 }
365
366 clk_enable(adc->clk);
367
368 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
369 if (platform_get_device_id(pdev)->driver_data == TYPE_S3C64XX) {
370 /* Enable 12-bit ADC resolution */
371 tmp |= S3C64XX_ADCCON_RESSEL;
372 }
373 writel(tmp, adc->regs + S3C2410_ADCCON);
374
375 dev_info(dev, "attached adc driver\n");
376
377 platform_set_drvdata(pdev, adc);
378 adc_dev = adc;
379
380 return 0;
381
382 err_clk:
383 clk_put(adc->clk);
384
385 err_irq:
386 free_irq(adc->irq, adc);
387
388 err_alloc:
389 kfree(adc);
390 return ret;
391 }
392
393 static int __devexit s3c_adc_remove(struct platform_device *pdev)
394 {
395 struct adc_device *adc = platform_get_drvdata(pdev);
396
397 iounmap(adc->regs);
398 free_irq(adc->irq, adc);
399 clk_disable(adc->clk);
400 clk_put(adc->clk);
401 kfree(adc);
402
403 return 0;
404 }
405
406 #ifdef CONFIG_PM
407 static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
408 {
409 struct adc_device *adc = platform_get_drvdata(pdev);
410 u32 con;
411
412 con = readl(adc->regs + S3C2410_ADCCON);
413 con |= S3C2410_ADCCON_STDBM;
414 writel(con, adc->regs + S3C2410_ADCCON);
415
416 disable_irq(adc->irq);
417 clk_disable(adc->clk);
418
419 return 0;
420 }
421
422 static int s3c_adc_resume(struct platform_device *pdev)
423 {
424 struct adc_device *adc = platform_get_drvdata(pdev);
425
426 clk_enable(adc->clk);
427 enable_irq(adc->irq);
428
429 writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
430 adc->regs + S3C2410_ADCCON);
431
432 return 0;
433 }
434
435 #else
436 #define s3c_adc_suspend NULL
437 #define s3c_adc_resume NULL
438 #endif
439
440 static struct platform_device_id s3c_adc_driver_ids[] = {
441 {
442 .name = "s3c24xx-adc",
443 .driver_data = TYPE_S3C24XX,
444 }, {
445 .name = "s3c64xx-adc",
446 .driver_data = TYPE_S3C64XX,
447 },
448 { }
449 };
450 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
451
452 static struct platform_driver s3c_adc_driver = {
453 .id_table = s3c_adc_driver_ids,
454 .driver = {
455 .name = "s3c-adc",
456 .owner = THIS_MODULE,
457 },
458 .probe = s3c_adc_probe,
459 .remove = __devexit_p(s3c_adc_remove),
460 .suspend = s3c_adc_suspend,
461 .resume = s3c_adc_resume,
462 };
463
464 static int __init adc_init(void)
465 {
466 int ret;
467
468 ret = platform_driver_register(&s3c_adc_driver);
469 if (ret)
470 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
471
472 return ret;
473 }
474
475 arch_initcall(adc_init);
Linux with added FPC-III support