1 /* arch/arm/plat-samsung/adc.c
3 * Copyright (c) 2008 Simtec Electronics
4 * http://armlinux.simtec.co.uk/
5 * Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
7 * Samsung ADC device core
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.
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>
25 #include <plat/regs-adc.h>
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
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.
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
47 struct s3c_adc_client {
48 struct platform_device *pdev;
49 struct list_head pend;
50 wait_queue_head_t *wait;
52 unsigned int nr_samples;
55 unsigned char channel;
57 void (*select_cb)(struct s3c_adc_client *c, unsigned selected);
58 void (*convert_cb)(struct s3c_adc_client *c,
59 unsigned val1, unsigned val2,
60 unsigned *samples_left);
64 struct platform_device *pdev;
65 struct platform_device *owner;
67 struct s3c_adc_client *cur;
68 struct s3c_adc_client *ts_pend;
70 enum s3c_cpu_type cputype;
73 unsigned int prescale;
78 static struct adc_device *adc_dev;
80 static LIST_HEAD(adc_pending); /* protected by adc_device.lock */
82 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
84 static inline void s3c_adc_convert(struct adc_device *adc)
86 unsigned con = readl(adc->regs + S3C2410_ADCCON);
88 con |= S3C2410_ADCCON_ENABLE_START;
89 writel(con, adc->regs + S3C2410_ADCCON);
92 static inline void s3c_adc_select(struct adc_device *adc,
93 struct s3c_adc_client *client)
95 unsigned con = readl(adc->regs + S3C2410_ADCCON);
97 client->select_cb(client, 1);
99 con &= ~S3C2410_ADCCON_MUXMASK;
100 con &= ~S3C2410_ADCCON_STDBM;
101 con &= ~S3C2410_ADCCON_STARTMASK;
102 con |= S3C2410_ADCCON_PRSCEN;
104 if (!client->is_ts) {
105 if (adc->cputype == TYPE_S5PV210)
106 writel(S5PV210_ADCCON_SELMUX(client->channel),
107 adc->regs + S5PV210_ADCMUX);
109 con |= S3C2410_ADCCON_SELMUX(client->channel);
112 writel(con, adc->regs + S3C2410_ADCCON);
115 static void s3c_adc_dbgshow(struct adc_device *adc)
117 adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
118 readl(adc->regs + S3C2410_ADCCON),
119 readl(adc->regs + S3C2410_ADCTSC),
120 readl(adc->regs + S3C2410_ADCDLY));
123 static void s3c_adc_try(struct adc_device *adc)
125 struct s3c_adc_client *next = adc->ts_pend;
126 unsigned int con = readl(adc->regs + S3C2410_ADCCON);
128 if (!next && !list_empty(&adc_pending)) {
129 next = list_first_entry(&adc_pending,
130 struct s3c_adc_client, pend);
131 list_del(&next->pend);
136 adc_dbg(adc, "new client is %p\n", next);
138 s3c_adc_select(adc, next);
139 s3c_adc_convert(adc);
140 s3c_adc_dbgshow(adc);
142 con &= ~S3C2410_ADCCON_PRSCEN;
143 con |= S3C2410_ADCCON_STDBM;
144 writel(con, adc->regs + S3C2410_ADCCON);
148 int s3c_adc_start(struct s3c_adc_client *client,
149 unsigned int channel, unsigned int nr_samples)
151 struct adc_device *adc = adc_dev;
155 printk(KERN_ERR "%s: failed to find adc\n", __func__);
159 if (client->is_ts && adc->ts_pend)
162 spin_lock_irqsave(&adc->lock, flags);
164 client->channel = channel;
165 client->nr_samples = nr_samples;
168 adc->ts_pend = client;
170 list_add_tail(&client->pend, &adc_pending);
175 spin_unlock_irqrestore(&adc->lock, flags);
179 EXPORT_SYMBOL_GPL(s3c_adc_start);
181 static void s3c_convert_done(struct s3c_adc_client *client,
182 unsigned v, unsigned u, unsigned *left)
185 wake_up(client->wait);
188 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
190 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
193 client->convert_cb = s3c_convert_done;
194 client->wait = &wake;
197 ret = s3c_adc_start(client, ch, 1);
201 ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
202 if (client->result < 0) {
207 client->convert_cb = NULL;
208 return client->result;
213 EXPORT_SYMBOL_GPL(s3c_adc_read);
215 static void s3c_adc_default_select(struct s3c_adc_client *client,
220 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
221 void (*select)(struct s3c_adc_client *client,
222 unsigned int selected),
223 void (*conv)(struct s3c_adc_client *client,
224 unsigned d0, unsigned d1,
225 unsigned *samples_left),
228 struct s3c_adc_client *client;
233 select = s3c_adc_default_select;
236 return ERR_PTR(-EINVAL);
238 client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
240 dev_err(&pdev->dev, "no memory for adc client\n");
241 return ERR_PTR(-ENOMEM);
245 client->is_ts = is_ts;
246 client->select_cb = select;
247 client->convert_cb = conv;
251 EXPORT_SYMBOL_GPL(s3c_adc_register);
253 void s3c_adc_release(struct s3c_adc_client *client)
257 spin_lock_irqsave(&adc_dev->lock, flags);
259 /* We should really check that nothing is in progress. */
260 if (adc_dev->cur == client)
262 if (adc_dev->ts_pend == client)
263 adc_dev->ts_pend = NULL;
265 struct list_head *p, *n;
266 struct s3c_adc_client *tmp;
268 list_for_each_safe(p, n, &adc_pending) {
269 tmp = list_entry(p, struct s3c_adc_client, pend);
271 list_del(&tmp->pend);
275 if (adc_dev->cur == NULL)
276 s3c_adc_try(adc_dev);
278 spin_unlock_irqrestore(&adc_dev->lock, flags);
281 EXPORT_SYMBOL_GPL(s3c_adc_release);
283 static irqreturn_t s3c_adc_irq(int irq, void *pw)
285 struct adc_device *adc = pw;
286 struct s3c_adc_client *client = adc->cur;
287 unsigned data0, data1;
290 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
294 data0 = readl(adc->regs + S3C2410_ADCDAT0);
295 data1 = readl(adc->regs + S3C2410_ADCDAT1);
296 adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
298 if (client->nr_samples > 0)
299 client->nr_samples--;
301 if ((adc->cputype == TYPE_S3C64XX) || (adc->cputype == TYPE_S5PV210)) {
302 /* S3C64XX ADC resolution is 12-bit */
310 if (client->convert_cb)
311 (client->convert_cb)(client, data0, data1, &client->nr_samples);
313 if (client->nr_samples > 0) {
314 /* fire another conversion for this */
316 client->select_cb(client, 1);
317 s3c_adc_convert(adc);
319 spin_lock(&adc->lock);
320 (client->select_cb)(client, 0);
324 spin_unlock(&adc->lock);
328 if ((adc->cputype == TYPE_S3C64XX) || (adc->cputype == TYPE_S5PV210)) {
329 /* Clear ADC interrupt */
330 writel(0, adc->regs + S3C64XX_ADCCLRINT);
335 static int s3c_adc_probe(struct platform_device *pdev)
337 struct device *dev = &pdev->dev;
338 struct adc_device *adc;
339 struct resource *regs;
343 adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
345 dev_err(dev, "failed to allocate adc_device\n");
349 spin_lock_init(&adc->lock);
352 adc->prescale = S3C2410_ADCCON_PRSCVL(49);
353 adc->cputype = platform_get_device_id(adc->pdev)->driver_data;
355 adc->irq = platform_get_irq(pdev, 1);
357 dev_err(dev, "failed to get adc irq\n");
362 ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
364 dev_err(dev, "failed to attach adc irq\n");
368 adc->clk = clk_get(dev, "adc");
369 if (IS_ERR(adc->clk)) {
370 dev_err(dev, "failed to get adc clock\n");
371 ret = PTR_ERR(adc->clk);
375 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
377 dev_err(dev, "failed to find registers\n");
382 adc->regs = ioremap(regs->start, resource_size(regs));
384 dev_err(dev, "failed to map registers\n");
389 clk_enable(adc->clk);
391 #if defined(CONFIG_S3C_DEV_ADC1)
392 tmp = readl(adc->regs + S3C2410_ADCCON);
393 tmp |= S3C64XX_ADCCON_TSSEL;
394 writel(tmp, adc->regs + S3C2410_ADCCON);
398 tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
399 if ((adc->cputype == TYPE_S3C64XX) || (adc->cputype == TYPE_S5PV210)){
400 /* Enable 12-bit ADC resolution */
401 tmp |= S3C64XX_ADCCON_RESSEL;
403 tmp |= S3C2410_ADCCON_STDBM;
404 writel(tmp, adc->regs + S3C2410_ADCCON);
406 dev_info(dev, "attached adc driver\n");
408 platform_set_drvdata(pdev, adc);
417 free_irq(adc->irq, adc);
424 static int __devexit s3c_adc_remove(struct platform_device *pdev)
426 struct adc_device *adc = platform_get_drvdata(pdev);
429 free_irq(adc->irq, adc);
430 clk_disable(adc->clk);
438 static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
440 struct adc_device *adc = platform_get_drvdata(pdev);
444 spin_lock_irqsave(&adc->lock, flags);
446 con = readl(adc->regs + S3C2410_ADCCON);
447 con |= S3C2410_ADCCON_STDBM;
448 writel(con, adc->regs + S3C2410_ADCCON);
450 disable_irq(adc->irq);
451 spin_unlock_irqrestore(&adc->lock, flags);
452 clk_disable(adc->clk);
457 static int s3c_adc_resume(struct platform_device *pdev)
459 struct adc_device *adc = platform_get_drvdata(pdev);
461 clk_enable(adc->clk);
462 enable_irq(adc->irq);
464 writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
465 adc->regs + S3C2410_ADCCON);
471 #define s3c_adc_suspend NULL
472 #define s3c_adc_resume NULL
475 static struct platform_device_id s3c_adc_driver_ids[] = {
477 .name = "s3c24xx-adc",
478 .driver_data = TYPE_S3C24XX,
480 .name = "s3c64xx-adc",
481 .driver_data = TYPE_S3C64XX,
483 .name = "s5pv210-adc",
484 .driver_data = TYPE_S5PV210,
488 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
490 static struct platform_driver s3c_adc_driver = {
491 .id_table = s3c_adc_driver_ids,
494 .owner = THIS_MODULE,
496 .probe = s3c_adc_probe,
497 .remove = __devexit_p(s3c_adc_remove),
498 .suspend = s3c_adc_suspend,
499 .resume = s3c_adc_resume,
502 static int __init adc_init(void)
506 ret = platform_driver_register(&s3c_adc_driver);
508 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
513 arch_initcall(adc_init);