Commit | Line | Data |
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3929e1e7 | 1 | /* arch/arm/plat-samsung/adc.c |
28ab44c5 BD |
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 | * | |
3929e1e7 | 7 | * Samsung ADC device core |
28ab44c5 BD |
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> | |
d43c36dc | 17 | #include <linux/sched.h> |
28ab44c5 | 18 | #include <linux/list.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
28ab44c5 BD |
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 | ||
bcedfa98 MC |
41 | enum s3c_cpu_type { |
42 | TYPE_S3C24XX, | |
43 | TYPE_S3C64XX | |
44 | }; | |
45 | ||
28ab44c5 BD |
46 | struct s3c_adc_client { |
47 | struct platform_device *pdev; | |
48 | struct list_head pend; | |
e170adcb | 49 | wait_queue_head_t *wait; |
28ab44c5 BD |
50 | |
51 | unsigned int nr_samples; | |
e170adcb | 52 | int result; |
28ab44c5 BD |
53 | unsigned char is_ts; |
54 | unsigned char channel; | |
55 | ||
e170adcb BD |
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, | |
3f7ea467 | 59 | unsigned *samples_left); |
28ab44c5 BD |
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 | ||
e170adcb | 94 | client->select_cb(client, 1); |
28ab44c5 BD |
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 | ||
f8c8ac81 | 114 | static void s3c_adc_try(struct adc_device *adc) |
28ab44c5 BD |
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 | ||
e170adcb BD |
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 | } | |
d3bf3956 | 198 | EXPORT_SYMBOL_GPL(s3c_adc_read); |
e170adcb BD |
199 | |
200 | static void s3c_adc_default_select(struct s3c_adc_client *client, | |
201 | unsigned select) | |
28ab44c5 BD |
202 | { |
203 | } | |
204 | ||
205 | struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev, | |
e170adcb BD |
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, | |
3f7ea467 | 210 | unsigned *samples_left), |
28ab44c5 BD |
211 | unsigned int is_ts) |
212 | { | |
213 | struct s3c_adc_client *client; | |
214 | ||
215 | WARN_ON(!pdev); | |
28ab44c5 BD |
216 | |
217 | if (!select) | |
218 | select = s3c_adc_default_select; | |
219 | ||
e170adcb | 220 | if (!pdev) |
28ab44c5 BD |
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. */ | |
0c3ee078 RL |
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); | |
28ab44c5 BD |
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; | |
91492b4a | 266 | enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data; |
28ab44c5 BD |
267 | unsigned long flags; |
268 | unsigned data0, data1; | |
269 | ||
270 | if (!client) { | |
271 | dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__); | |
bcedfa98 | 272 | goto exit; |
28ab44c5 BD |
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 | ||
3f7ea467 | 279 | client->nr_samples--; |
e170adcb | 280 | |
91492b4a MC |
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 | ||
e170adcb | 290 | if (client->convert_cb) |
91492b4a | 291 | (client->convert_cb)(client, data0, data1, &client->nr_samples); |
28ab44c5 | 292 | |
3f7ea467 | 293 | if (client->nr_samples > 0) { |
28ab44c5 BD |
294 | /* fire another conversion for this */ |
295 | ||
e170adcb | 296 | client->select_cb(client, 1); |
28ab44c5 BD |
297 | s3c_adc_convert(adc); |
298 | } else { | |
299 | local_irq_save(flags); | |
e170adcb | 300 | (client->select_cb)(client, 0); |
28ab44c5 BD |
301 | adc->cur = NULL; |
302 | ||
303 | s3c_adc_try(adc); | |
304 | local_irq_restore(flags); | |
305 | } | |
306 | ||
bcedfa98 | 307 | exit: |
91492b4a | 308 | if (cpu == TYPE_S3C64XX) { |
bcedfa98 MC |
309 | /* Clear ADC interrupt */ |
310 | writel(0, adc->regs + S3C64XX_ADCCLRINT); | |
311 | } | |
28ab44c5 BD |
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; | |
91492b4a | 321 | unsigned tmp; |
28ab44c5 BD |
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 | ||
91492b4a MC |
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); | |
28ab44c5 BD |
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 | ||
ad4e22fa | 393 | static int __devexit s3c_adc_remove(struct platform_device *pdev) |
28ab44c5 BD |
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 | ||
a0af8b3c | 416 | disable_irq(adc->irq); |
28ab44c5 BD |
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); | |
a0af8b3c | 427 | enable_irq(adc->irq); |
28ab44c5 BD |
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 | ||
bcedfa98 MC |
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 | ||
28ab44c5 | 452 | static struct platform_driver s3c_adc_driver = { |
bcedfa98 | 453 | .id_table = s3c_adc_driver_ids, |
28ab44c5 | 454 | .driver = { |
bcedfa98 | 455 | .name = "s3c-adc", |
28ab44c5 BD |
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); |