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>
24 #include <linux/regulator/consumer.h>
26 #include <plat/regs-adc.h>
29 /* This driver is designed to control the usage of the ADC block between
30 * the touchscreen and any other drivers that may need to use it, such as
33 * Priority will be given to the touchscreen driver, but as this itself is
34 * rate limited it should not starve other requests which are processed in
35 * order that they are received.
37 * Each user registers to get a client block which uniquely identifies it
38 * and stores information such as the necessary functions to callback when
43 TYPE_ADCV1
, /* S3C24XX */
44 TYPE_ADCV11
, /* S3C2443 */
45 TYPE_ADCV12
, /* S3C2416, S3C2450 */
46 TYPE_ADCV2
, /* S3C64XX, S5P64X0, S5PC100 */
47 TYPE_ADCV3
, /* S5PV210, S5PC110, EXYNOS4210 */
50 struct s3c_adc_client
{
51 struct platform_device
*pdev
;
52 struct list_head pend
;
53 wait_queue_head_t
*wait
;
55 unsigned int nr_samples
;
58 unsigned char channel
;
60 void (*select_cb
)(struct s3c_adc_client
*c
, unsigned selected
);
61 void (*convert_cb
)(struct s3c_adc_client
*c
,
62 unsigned val1
, unsigned val2
,
63 unsigned *samples_left
);
67 struct platform_device
*pdev
;
68 struct platform_device
*owner
;
70 struct s3c_adc_client
*cur
;
71 struct s3c_adc_client
*ts_pend
;
75 unsigned int prescale
;
78 struct regulator
*vdd
;
81 static struct adc_device
*adc_dev
;
83 static LIST_HEAD(adc_pending
); /* protected by adc_device.lock */
85 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
87 static inline void s3c_adc_convert(struct adc_device
*adc
)
89 unsigned con
= readl(adc
->regs
+ S3C2410_ADCCON
);
91 con
|= S3C2410_ADCCON_ENABLE_START
;
92 writel(con
, adc
->regs
+ S3C2410_ADCCON
);
95 static inline void s3c_adc_select(struct adc_device
*adc
,
96 struct s3c_adc_client
*client
)
98 unsigned con
= readl(adc
->regs
+ S3C2410_ADCCON
);
99 enum s3c_cpu_type cpu
= platform_get_device_id(adc
->pdev
)->driver_data
;
101 client
->select_cb(client
, 1);
103 if (cpu
== TYPE_ADCV1
|| cpu
== TYPE_ADCV2
)
104 con
&= ~S3C2410_ADCCON_MUXMASK
;
105 con
&= ~S3C2410_ADCCON_STDBM
;
106 con
&= ~S3C2410_ADCCON_STARTMASK
;
108 if (!client
->is_ts
) {
109 if (cpu
== TYPE_ADCV3
)
110 writel(client
->channel
& 0xf, adc
->regs
+ S5P_ADCMUX
);
111 else if (cpu
== TYPE_ADCV11
|| cpu
== TYPE_ADCV12
)
112 writel(client
->channel
& 0xf,
113 adc
->regs
+ S3C2443_ADCMUX
);
115 con
|= S3C2410_ADCCON_SELMUX(client
->channel
);
118 writel(con
, adc
->regs
+ S3C2410_ADCCON
);
121 static void s3c_adc_dbgshow(struct adc_device
*adc
)
123 adc_dbg(adc
, "CON=%08x, TSC=%08x, DLY=%08x\n",
124 readl(adc
->regs
+ S3C2410_ADCCON
),
125 readl(adc
->regs
+ S3C2410_ADCTSC
),
126 readl(adc
->regs
+ S3C2410_ADCDLY
));
129 static void s3c_adc_try(struct adc_device
*adc
)
131 struct s3c_adc_client
*next
= adc
->ts_pend
;
133 if (!next
&& !list_empty(&adc_pending
)) {
134 next
= list_first_entry(&adc_pending
,
135 struct s3c_adc_client
, pend
);
136 list_del(&next
->pend
);
141 adc_dbg(adc
, "new client is %p\n", next
);
143 s3c_adc_select(adc
, next
);
144 s3c_adc_convert(adc
);
145 s3c_adc_dbgshow(adc
);
149 int s3c_adc_start(struct s3c_adc_client
*client
,
150 unsigned int channel
, unsigned int nr_samples
)
152 struct adc_device
*adc
= adc_dev
;
156 printk(KERN_ERR
"%s: failed to find adc\n", __func__
);
160 if (client
->is_ts
&& adc
->ts_pend
)
163 spin_lock_irqsave(&adc
->lock
, flags
);
165 client
->channel
= channel
;
166 client
->nr_samples
= nr_samples
;
169 adc
->ts_pend
= client
;
171 list_add_tail(&client
->pend
, &adc_pending
);
176 spin_unlock_irqrestore(&adc
->lock
, flags
);
180 EXPORT_SYMBOL_GPL(s3c_adc_start
);
182 static void s3c_convert_done(struct s3c_adc_client
*client
,
183 unsigned v
, unsigned u
, unsigned *left
)
186 wake_up(client
->wait
);
189 int s3c_adc_read(struct s3c_adc_client
*client
, unsigned int ch
)
191 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake
);
194 client
->convert_cb
= s3c_convert_done
;
195 client
->wait
= &wake
;
198 ret
= s3c_adc_start(client
, ch
, 1);
202 ret
= wait_event_timeout(wake
, client
->result
>= 0, HZ
/ 2);
203 if (client
->result
< 0) {
208 client
->convert_cb
= NULL
;
209 return client
->result
;
214 EXPORT_SYMBOL_GPL(s3c_adc_read
);
216 static void s3c_adc_default_select(struct s3c_adc_client
*client
,
221 struct s3c_adc_client
*s3c_adc_register(struct platform_device
*pdev
,
222 void (*select
)(struct s3c_adc_client
*client
,
223 unsigned int selected
),
224 void (*conv
)(struct s3c_adc_client
*client
,
225 unsigned d0
, unsigned d1
,
226 unsigned *samples_left
),
229 struct s3c_adc_client
*client
;
234 select
= s3c_adc_default_select
;
237 return ERR_PTR(-EINVAL
);
239 client
= kzalloc(sizeof(struct s3c_adc_client
), GFP_KERNEL
);
241 dev_err(&pdev
->dev
, "no memory for adc client\n");
242 return ERR_PTR(-ENOMEM
);
246 client
->is_ts
= is_ts
;
247 client
->select_cb
= select
;
248 client
->convert_cb
= conv
;
252 EXPORT_SYMBOL_GPL(s3c_adc_register
);
254 void s3c_adc_release(struct s3c_adc_client
*client
)
258 spin_lock_irqsave(&adc_dev
->lock
, flags
);
260 /* We should really check that nothing is in progress. */
261 if (adc_dev
->cur
== client
)
263 if (adc_dev
->ts_pend
== client
)
264 adc_dev
->ts_pend
= NULL
;
266 struct list_head
*p
, *n
;
267 struct s3c_adc_client
*tmp
;
269 list_for_each_safe(p
, n
, &adc_pending
) {
270 tmp
= list_entry(p
, struct s3c_adc_client
, pend
);
272 list_del(&tmp
->pend
);
276 if (adc_dev
->cur
== NULL
)
277 s3c_adc_try(adc_dev
);
279 spin_unlock_irqrestore(&adc_dev
->lock
, flags
);
282 EXPORT_SYMBOL_GPL(s3c_adc_release
);
284 static irqreturn_t
s3c_adc_irq(int irq
, void *pw
)
286 struct adc_device
*adc
= pw
;
287 struct s3c_adc_client
*client
= adc
->cur
;
288 enum s3c_cpu_type cpu
= platform_get_device_id(adc
->pdev
)->driver_data
;
289 unsigned data0
, data1
;
292 dev_warn(&adc
->pdev
->dev
, "%s: no adc pending\n", __func__
);
296 data0
= readl(adc
->regs
+ S3C2410_ADCDAT0
);
297 data1
= readl(adc
->regs
+ S3C2410_ADCDAT1
);
298 adc_dbg(adc
, "read %d: 0x%04x, 0x%04x\n", client
->nr_samples
, data0
, data1
);
300 client
->nr_samples
--;
302 if (cpu
== TYPE_ADCV1
|| cpu
== TYPE_ADCV11
) {
306 /* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
311 if (client
->convert_cb
)
312 (client
->convert_cb
)(client
, data0
, data1
, &client
->nr_samples
);
314 if (client
->nr_samples
> 0) {
315 /* fire another conversion for this */
317 client
->select_cb(client
, 1);
318 s3c_adc_convert(adc
);
320 spin_lock(&adc
->lock
);
321 (client
->select_cb
)(client
, 0);
325 spin_unlock(&adc
->lock
);
329 if (cpu
== TYPE_ADCV2
|| cpu
== TYPE_ADCV3
) {
330 /* Clear ADC interrupt */
331 writel(0, adc
->regs
+ S3C64XX_ADCCLRINT
);
336 static int s3c_adc_probe(struct platform_device
*pdev
)
338 struct device
*dev
= &pdev
->dev
;
339 struct adc_device
*adc
;
340 struct resource
*regs
;
341 enum s3c_cpu_type cpu
= platform_get_device_id(pdev
)->driver_data
;
345 adc
= kzalloc(sizeof(struct adc_device
), GFP_KERNEL
);
347 dev_err(dev
, "failed to allocate adc_device\n");
351 spin_lock_init(&adc
->lock
);
354 adc
->prescale
= S3C2410_ADCCON_PRSCVL(49);
356 adc
->vdd
= regulator_get(dev
, "vdd");
357 if (IS_ERR(adc
->vdd
)) {
358 dev_err(dev
, "operating without regulator \"vdd\" .\n");
359 ret
= PTR_ERR(adc
->vdd
);
363 adc
->irq
= platform_get_irq(pdev
, 1);
365 dev_err(dev
, "failed to get adc irq\n");
370 ret
= request_irq(adc
->irq
, s3c_adc_irq
, 0, dev_name(dev
), adc
);
372 dev_err(dev
, "failed to attach adc irq\n");
376 adc
->clk
= clk_get(dev
, "adc");
377 if (IS_ERR(adc
->clk
)) {
378 dev_err(dev
, "failed to get adc clock\n");
379 ret
= PTR_ERR(adc
->clk
);
383 regs
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
385 dev_err(dev
, "failed to find registers\n");
390 adc
->regs
= ioremap(regs
->start
, resource_size(regs
));
392 dev_err(dev
, "failed to map registers\n");
397 ret
= regulator_enable(adc
->vdd
);
401 clk_enable(adc
->clk
);
403 tmp
= adc
->prescale
| S3C2410_ADCCON_PRSCEN
;
405 /* Enable 12-bit ADC resolution */
406 if (cpu
== TYPE_ADCV12
)
407 tmp
|= S3C2416_ADCCON_RESSEL
;
408 if (cpu
== TYPE_ADCV2
|| cpu
== TYPE_ADCV3
)
409 tmp
|= S3C64XX_ADCCON_RESSEL
;
411 writel(tmp
, adc
->regs
+ S3C2410_ADCCON
);
413 dev_info(dev
, "attached adc driver\n");
415 platform_set_drvdata(pdev
, adc
);
426 free_irq(adc
->irq
, adc
);
428 regulator_put(adc
->vdd
);
434 static int __devexit
s3c_adc_remove(struct platform_device
*pdev
)
436 struct adc_device
*adc
= platform_get_drvdata(pdev
);
439 free_irq(adc
->irq
, adc
);
440 clk_disable(adc
->clk
);
441 regulator_disable(adc
->vdd
);
442 regulator_put(adc
->vdd
);
450 static int s3c_adc_suspend(struct device
*dev
)
452 struct platform_device
*pdev
= container_of(dev
,
453 struct platform_device
, dev
);
454 struct adc_device
*adc
= platform_get_drvdata(pdev
);
458 spin_lock_irqsave(&adc
->lock
, flags
);
460 con
= readl(adc
->regs
+ S3C2410_ADCCON
);
461 con
|= S3C2410_ADCCON_STDBM
;
462 writel(con
, adc
->regs
+ S3C2410_ADCCON
);
464 disable_irq(adc
->irq
);
465 spin_unlock_irqrestore(&adc
->lock
, flags
);
466 clk_disable(adc
->clk
);
467 regulator_disable(adc
->vdd
);
472 static int s3c_adc_resume(struct device
*dev
)
474 struct platform_device
*pdev
= container_of(dev
,
475 struct platform_device
, dev
);
476 struct adc_device
*adc
= platform_get_drvdata(pdev
);
477 enum s3c_cpu_type cpu
= platform_get_device_id(pdev
)->driver_data
;
481 ret
= regulator_enable(adc
->vdd
);
484 clk_enable(adc
->clk
);
485 enable_irq(adc
->irq
);
487 tmp
= adc
->prescale
| S3C2410_ADCCON_PRSCEN
;
489 /* Enable 12-bit ADC resolution */
490 if (cpu
== TYPE_ADCV12
)
491 tmp
|= S3C2416_ADCCON_RESSEL
;
492 if (cpu
== TYPE_ADCV2
|| cpu
== TYPE_ADCV3
)
493 tmp
|= S3C64XX_ADCCON_RESSEL
;
495 writel(tmp
, adc
->regs
+ S3C2410_ADCCON
);
501 #define s3c_adc_suspend NULL
502 #define s3c_adc_resume NULL
505 static struct platform_device_id s3c_adc_driver_ids
[] = {
507 .name
= "s3c24xx-adc",
508 .driver_data
= TYPE_ADCV1
,
510 .name
= "s3c2443-adc",
511 .driver_data
= TYPE_ADCV11
,
513 .name
= "s3c2416-adc",
514 .driver_data
= TYPE_ADCV12
,
516 .name
= "s3c64xx-adc",
517 .driver_data
= TYPE_ADCV2
,
519 .name
= "samsung-adc-v3",
520 .driver_data
= TYPE_ADCV3
,
524 MODULE_DEVICE_TABLE(platform
, s3c_adc_driver_ids
);
526 static const struct dev_pm_ops adc_pm_ops
= {
527 .suspend
= s3c_adc_suspend
,
528 .resume
= s3c_adc_resume
,
531 static struct platform_driver s3c_adc_driver
= {
532 .id_table
= s3c_adc_driver_ids
,
535 .owner
= THIS_MODULE
,
538 .probe
= s3c_adc_probe
,
539 .remove
= __devexit_p(s3c_adc_remove
),
542 static int __init
adc_init(void)
546 ret
= platform_driver_register(&s3c_adc_driver
);
548 printk(KERN_ERR
"%s: failed to add adc driver\n", __func__
);
553 module_init(adc_init
);