mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 05:48:40 +00:00
[ARM] S3C24XX: ADC driver core
A common core driver for the S3C24XX ADC block so that the touchscreen, hwmon and any other drivers can share the resource. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
parent
e7aa6f46f6
commit
28ab44c5be
5 changed files with 418 additions and 1 deletions
29
arch/arm/plat-s3c/include/plat/adc.h
Normal file
29
arch/arm/plat-s3c/include/plat/adc.h
Normal file
|
@ -0,0 +1,29 @@
|
|||
/* arch/arm/plat-s3c/include/plat/adc.h
|
||||
*
|
||||
* Copyright (c) 2008 Simtec Electronics
|
||||
* http://armlinux.simnte.co.uk/
|
||||
* Ben Dooks <ben@simtec.co.uk>
|
||||
*
|
||||
* S3C24XX ADC driver information
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*/
|
||||
|
||||
#ifndef __ASM_PLAT_ADC_H
|
||||
#define __ASM_PLAT_ADC_H __FILE__
|
||||
|
||||
struct s3c_adc_client;
|
||||
|
||||
extern int s3c_adc_start(struct s3c_adc_client *client,
|
||||
unsigned int channel, unsigned int nr_samples);
|
||||
|
||||
extern struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
|
||||
void (*select)(unsigned selected),
|
||||
void (*conv)(unsigned d0, unsigned d1),
|
||||
unsigned int is_ts);
|
||||
|
||||
extern void s3c_adc_release(struct s3c_adc_client *client);
|
||||
|
||||
#endif /* __ASM_PLAT_ADC_H */
|
|
@ -62,6 +62,13 @@ config S3C2410_DMA_DEBUG
|
|||
Enable debugging output for the DMA code. This option sends info
|
||||
to the kernel log, at priority KERN_DEBUG.
|
||||
|
||||
config S3C24XX_ADC
|
||||
bool "ADC common driver support"
|
||||
help
|
||||
Core support for the ADC block found in the S3C24XX SoC systems
|
||||
for drivers such as the touchscreen and hwmon to use to share
|
||||
this resource.
|
||||
|
||||
# SPI default pin configuration code
|
||||
|
||||
config S3C24XX_SPI_BUS0_GPE11_GPE12_GPE13
|
||||
|
|
|
@ -31,6 +31,7 @@ obj-$(CONFIG_PM) += sleep.o
|
|||
obj-$(CONFIG_HAVE_PWM) += pwm.o
|
||||
obj-$(CONFIG_S3C2410_CLOCK) += s3c2410-clock.o
|
||||
obj-$(CONFIG_S3C2410_DMA) += dma.o
|
||||
obj-$(CONFIG_S3C24XX_ADC) += adc.o
|
||||
|
||||
# SPI gpio central GPIO functions
|
||||
|
||||
|
|
372
arch/arm/plat-s3c24xx/adc.c
Normal file
372
arch/arm/plat-s3c24xx/adc.c
Normal file
|
@ -0,0 +1,372 @@
|
|||
/* arch/arm/plat-s3c24xx/adc.c
|
||||
*
|
||||
* Copyright (c) 2008 Simtec Electronics
|
||||
* http://armlinux.simtec.co.uk/
|
||||
* Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
|
||||
*
|
||||
* S3C24XX ADC device core
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License.
|
||||
*/
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/clk.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/io.h>
|
||||
|
||||
#include <plat/regs-adc.h>
|
||||
#include <plat/adc.h>
|
||||
|
||||
/* This driver is designed to control the usage of the ADC block between
|
||||
* the touchscreen and any other drivers that may need to use it, such as
|
||||
* the hwmon driver.
|
||||
*
|
||||
* Priority will be given to the touchscreen driver, but as this itself is
|
||||
* rate limited it should not starve other requests which are processed in
|
||||
* order that they are received.
|
||||
*
|
||||
* Each user registers to get a client block which uniquely identifies it
|
||||
* and stores information such as the necessary functions to callback when
|
||||
* action is required.
|
||||
*/
|
||||
|
||||
struct s3c_adc_client {
|
||||
struct platform_device *pdev;
|
||||
struct list_head pend;
|
||||
|
||||
unsigned int nr_samples;
|
||||
unsigned char is_ts;
|
||||
unsigned char channel;
|
||||
|
||||
void (*select_cb)(unsigned selected);
|
||||
void (*convert_cb)(unsigned val1, unsigned val2);
|
||||
};
|
||||
|
||||
struct adc_device {
|
||||
struct platform_device *pdev;
|
||||
struct platform_device *owner;
|
||||
struct clk *clk;
|
||||
struct s3c_adc_client *cur;
|
||||
struct s3c_adc_client *ts_pend;
|
||||
void __iomem *regs;
|
||||
|
||||
unsigned int prescale;
|
||||
|
||||
int irq;
|
||||
};
|
||||
|
||||
static struct adc_device *adc_dev;
|
||||
|
||||
static LIST_HEAD(adc_pending);
|
||||
|
||||
#define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
|
||||
|
||||
static inline void s3c_adc_convert(struct adc_device *adc)
|
||||
{
|
||||
unsigned con = readl(adc->regs + S3C2410_ADCCON);
|
||||
|
||||
con |= S3C2410_ADCCON_ENABLE_START;
|
||||
writel(con, adc->regs + S3C2410_ADCCON);
|
||||
}
|
||||
|
||||
static inline void s3c_adc_select(struct adc_device *adc,
|
||||
struct s3c_adc_client *client)
|
||||
{
|
||||
unsigned con = readl(adc->regs + S3C2410_ADCCON);
|
||||
|
||||
client->select_cb(1);
|
||||
|
||||
con &= ~S3C2410_ADCCON_MUXMASK;
|
||||
con &= ~S3C2410_ADCCON_STDBM;
|
||||
con &= ~S3C2410_ADCCON_STARTMASK;
|
||||
|
||||
if (!client->is_ts)
|
||||
con |= S3C2410_ADCCON_SELMUX(client->channel);
|
||||
|
||||
writel(con, adc->regs + S3C2410_ADCCON);
|
||||
}
|
||||
|
||||
static void s3c_adc_dbgshow(struct adc_device *adc)
|
||||
{
|
||||
adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
|
||||
readl(adc->regs + S3C2410_ADCCON),
|
||||
readl(adc->regs + S3C2410_ADCTSC),
|
||||
readl(adc->regs + S3C2410_ADCDLY));
|
||||
}
|
||||
|
||||
void s3c_adc_try(struct adc_device *adc)
|
||||
{
|
||||
struct s3c_adc_client *next = adc->ts_pend;
|
||||
|
||||
if (!next && !list_empty(&adc_pending)) {
|
||||
next = list_first_entry(&adc_pending,
|
||||
struct s3c_adc_client, pend);
|
||||
list_del(&next->pend);
|
||||
} else
|
||||
adc->ts_pend = NULL;
|
||||
|
||||
if (next) {
|
||||
adc_dbg(adc, "new client is %p\n", next);
|
||||
adc->cur = next;
|
||||
s3c_adc_select(adc, next);
|
||||
s3c_adc_convert(adc);
|
||||
s3c_adc_dbgshow(adc);
|
||||
}
|
||||
}
|
||||
|
||||
int s3c_adc_start(struct s3c_adc_client *client,
|
||||
unsigned int channel, unsigned int nr_samples)
|
||||
{
|
||||
struct adc_device *adc = adc_dev;
|
||||
unsigned long flags;
|
||||
|
||||
if (!adc) {
|
||||
printk(KERN_ERR "%s: failed to find adc\n", __func__);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (client->is_ts && adc->ts_pend)
|
||||
return -EAGAIN;
|
||||
|
||||
local_irq_save(flags);
|
||||
|
||||
client->channel = channel;
|
||||
client->nr_samples = nr_samples;
|
||||
|
||||
if (client->is_ts)
|
||||
adc->ts_pend = client;
|
||||
else
|
||||
list_add_tail(&client->pend, &adc_pending);
|
||||
|
||||
if (!adc->cur)
|
||||
s3c_adc_try(adc);
|
||||
local_irq_restore(flags);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(s3c_adc_start);
|
||||
|
||||
static void s3c_adc_default_select(unsigned select)
|
||||
{
|
||||
}
|
||||
|
||||
struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
|
||||
void (*select)(unsigned int selected),
|
||||
void (*conv)(unsigned d0, unsigned d1),
|
||||
unsigned int is_ts)
|
||||
{
|
||||
struct s3c_adc_client *client;
|
||||
|
||||
WARN_ON(!pdev);
|
||||
WARN_ON(!conv);
|
||||
|
||||
if (!select)
|
||||
select = s3c_adc_default_select;
|
||||
|
||||
if (!conv || !pdev)
|
||||
return ERR_PTR(-EINVAL);
|
||||
|
||||
client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
|
||||
if (!client) {
|
||||
dev_err(&pdev->dev, "no memory for adc client\n");
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
|
||||
client->pdev = pdev;
|
||||
client->is_ts = is_ts;
|
||||
client->select_cb = select;
|
||||
client->convert_cb = conv;
|
||||
|
||||
return client;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(s3c_adc_register);
|
||||
|
||||
void s3c_adc_release(struct s3c_adc_client *client)
|
||||
{
|
||||
/* We should really check that nothing is in progress. */
|
||||
kfree(client);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(s3c_adc_release);
|
||||
|
||||
static irqreturn_t s3c_adc_irq(int irq, void *pw)
|
||||
{
|
||||
struct adc_device *adc = pw;
|
||||
struct s3c_adc_client *client = adc->cur;
|
||||
unsigned long flags;
|
||||
unsigned data0, data1;
|
||||
|
||||
if (!client) {
|
||||
dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
|
||||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
data0 = readl(adc->regs + S3C2410_ADCDAT0);
|
||||
data1 = readl(adc->regs + S3C2410_ADCDAT1);
|
||||
adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
|
||||
|
||||
(client->convert_cb)(data0 & 0x3ff, data1 & 0x3ff);
|
||||
|
||||
if (--client->nr_samples > 0) {
|
||||
/* fire another conversion for this */
|
||||
|
||||
client->select_cb(1);
|
||||
s3c_adc_convert(adc);
|
||||
} else {
|
||||
local_irq_save(flags);
|
||||
(client->select_cb)(0);
|
||||
adc->cur = NULL;
|
||||
|
||||
s3c_adc_try(adc);
|
||||
local_irq_restore(flags);
|
||||
}
|
||||
|
||||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
static int s3c_adc_probe(struct platform_device *pdev)
|
||||
{
|
||||
struct device *dev = &pdev->dev;
|
||||
struct adc_device *adc;
|
||||
struct resource *regs;
|
||||
int ret;
|
||||
|
||||
adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
|
||||
if (adc == NULL) {
|
||||
dev_err(dev, "failed to allocate adc_device\n");
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
adc->pdev = pdev;
|
||||
adc->prescale = S3C2410_ADCCON_PRSCVL(49);
|
||||
|
||||
adc->irq = platform_get_irq(pdev, 1);
|
||||
if (adc->irq <= 0) {
|
||||
dev_err(dev, "failed to get adc irq\n");
|
||||
ret = -ENOENT;
|
||||
goto err_alloc;
|
||||
}
|
||||
|
||||
ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
|
||||
if (ret < 0) {
|
||||
dev_err(dev, "failed to attach adc irq\n");
|
||||
goto err_alloc;
|
||||
}
|
||||
|
||||
adc->clk = clk_get(dev, "adc");
|
||||
if (IS_ERR(adc->clk)) {
|
||||
dev_err(dev, "failed to get adc clock\n");
|
||||
ret = PTR_ERR(adc->clk);
|
||||
goto err_irq;
|
||||
}
|
||||
|
||||
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||||
if (!regs) {
|
||||
dev_err(dev, "failed to find registers\n");
|
||||
ret = -ENXIO;
|
||||
goto err_clk;
|
||||
}
|
||||
|
||||
adc->regs = ioremap(regs->start, resource_size(regs));
|
||||
if (!adc->regs) {
|
||||
dev_err(dev, "failed to map registers\n");
|
||||
ret = -ENXIO;
|
||||
goto err_clk;
|
||||
}
|
||||
|
||||
clk_enable(adc->clk);
|
||||
|
||||
writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
|
||||
adc->regs + S3C2410_ADCCON);
|
||||
|
||||
dev_info(dev, "attached adc driver\n");
|
||||
|
||||
platform_set_drvdata(pdev, adc);
|
||||
adc_dev = adc;
|
||||
|
||||
return 0;
|
||||
|
||||
err_clk:
|
||||
clk_put(adc->clk);
|
||||
|
||||
err_irq:
|
||||
free_irq(adc->irq, adc);
|
||||
|
||||
err_alloc:
|
||||
kfree(adc);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int s3c_adc_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct adc_device *adc = platform_get_drvdata(pdev);
|
||||
|
||||
iounmap(adc->regs);
|
||||
free_irq(adc->irq, adc);
|
||||
clk_disable(adc->clk);
|
||||
clk_put(adc->clk);
|
||||
kfree(adc);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_PM
|
||||
static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
|
||||
{
|
||||
struct adc_device *adc = platform_get_drvdata(pdev);
|
||||
u32 con;
|
||||
|
||||
con = readl(adc->regs + S3C2410_ADCCON);
|
||||
con |= S3C2410_ADCCON_STDBM;
|
||||
writel(con, adc->regs + S3C2410_ADCCON);
|
||||
|
||||
clk_disable(adc->clk);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int s3c_adc_resume(struct platform_device *pdev)
|
||||
{
|
||||
struct adc_device *adc = platform_get_drvdata(pdev);
|
||||
|
||||
clk_enable(adc->clk);
|
||||
|
||||
writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
|
||||
adc->regs + S3C2410_ADCCON);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#else
|
||||
#define s3c_adc_suspend NULL
|
||||
#define s3c_adc_resume NULL
|
||||
#endif
|
||||
|
||||
static struct platform_driver s3c_adc_driver = {
|
||||
.driver = {
|
||||
.name = "s3c24xx-adc",
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = s3c_adc_probe,
|
||||
.remove = __devexit_p(s3c_adc_remove),
|
||||
.suspend = s3c_adc_suspend,
|
||||
.resume = s3c_adc_resume,
|
||||
};
|
||||
|
||||
static int __init adc_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = platform_driver_register(&s3c_adc_driver);
|
||||
if (ret)
|
||||
printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
arch_initcall(adc_init);
|
|
@ -372,12 +372,20 @@ static struct resource s3c_adc_resource[] = {
|
|||
};
|
||||
|
||||
struct platform_device s3c_device_adc = {
|
||||
.name = "s3c2410-adc",
|
||||
.name = "s3c24xx-adc",
|
||||
.id = -1,
|
||||
.num_resources = ARRAY_SIZE(s3c_adc_resource),
|
||||
.resource = s3c_adc_resource,
|
||||
};
|
||||
|
||||
/* HWMON */
|
||||
|
||||
struct platform_device s3c_device_hwmon = {
|
||||
.name = "s3c24xx-hwmon",
|
||||
.id = -1,
|
||||
.dev.parent = &s3c_device_adc.dev,
|
||||
};
|
||||
|
||||
/* SDI */
|
||||
|
||||
static struct resource s3c_sdi_resource[] = {
|
||||
|
|
Loading…
Reference in a new issue