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Dynamically gate adc clock

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SVN-Revision: 19394
This commit is contained in:
Lars-Peter Clausen 2010-01-30 13:12:17 +00:00
parent e474081797
commit 060ffa70ee
1 changed files with 46 additions and 1 deletions
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47
target/linux/xburst/files-2.6.32/drivers/misc/jz4740-adc.c
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@ -21,6 +21,8 @@
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/jz4740-adc.h>
#define JZ_REG_ADC_ENABLE 0x00
@ -72,6 +74,9 @@ struct jz4740_adc {
int irq;
struct clk *clk;
unsigned int clk_ref;
struct completion bat_completion;
struct completion adc_completion;
@ -169,6 +174,26 @@ uint32_t val)
spin_unlock_irqrestore(&adc->lock, flags);
}
static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
{
unsigned long flags;
spin_lock_irqsave(&adc->lock, flags);
if (adc->clk_ref++ == 0)
clk_enable(adc->clk);
spin_unlock_irqrestore(&adc->lock, flags);
}
static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
{
unsigned long flags;
spin_lock_irqsave(&adc->lock, flags);
if (--adc->clk_ref == 0)
clk_disable(adc->clk);
spin_unlock_irqrestore(&adc->lock, flags);
}
long jz4740_adc_read_battery_voltage(struct device *dev,
enum jz_adc_battery_scale scale)
{
@ -180,6 +205,8 @@ long jz4740_adc_read_battery_voltage(struct device *dev,
if (!adc)
return -ENODEV;
jz4740_adc_clk_enable(adc);
if (scale == JZ_ADC_BATTERY_SCALE_2V5)
jz4740_adc_set_cfg(adc, JZ_ADC_CFG_BAT_MB, JZ_ADC_CFG_BAT_MB);
else
@ -200,6 +227,8 @@ long jz4740_adc_read_battery_voltage(struct device *dev,
val = readw(adc->base + JZ_REG_ADC_BATTERY);
jz4740_adc_clk_disable(adc);
if (scale == JZ_ADC_BATTERY_SCALE_2V5)
voltage = (((long long)val) * 2500000LL) >> 12LL;
else
@ -217,6 +246,8 @@ static ssize_t jz4740_adc_read_adcin(struct device *dev,
unsigned long t;
uint16_t val;
jz4740_adc_clk_enable(adc);
jz4740_adc_enable_irq(adc, JZ_ADC_IRQ_ADCIN);
jz4740_adc_enable_adc(adc, JZ_ADC_ENABLE_ADCIN);
@ -231,6 +262,7 @@ static ssize_t jz4740_adc_read_adcin(struct device *dev,
}
val = readw(adc->base + JZ_REG_ADC_ADCIN);
jz4740_adc_clk_disable(adc);
return sprintf(buf, "%d\n", val);
}
@ -277,19 +309,28 @@ static int __devinit jz4740_adc_probe(struct platform_device *pdev)
goto err_release_mem_region;
}
adc->clk = clk_get(&pdev->dev, "adc");
if (IS_ERR(adc->clk)) {
ret = PTR_ERR(adc->clk);
dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
goto err_iounmap;
}
init_completion(&adc->bat_completion);
init_completion(&adc->adc_completion);
spin_lock_init(&adc->lock);
adc->clk_ref = 0;
platform_set_drvdata(pdev, adc);
ret = request_irq(adc->irq, jz4740_adc_irq, 0, pdev->name, adc);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
goto err_iounmap;
goto err_clk_put;
}
ret = device_create_file(&pdev->dev, &dev_attr_adcin);
@ -305,6 +346,8 @@ static int __devinit jz4740_adc_probe(struct platform_device *pdev)
err_free_irq:
free_irq(adc->irq, adc);
err_clk_put:
clk_put(adc->clk);
err_iounmap:
platform_set_drvdata(pdev, NULL);
iounmap(adc->base);
@ -327,6 +370,8 @@ static int __devexit jz4740_adc_remove(struct platform_device *pdev)
iounmap(adc->base);
release_mem_region(adc->mem->start, resource_size(adc->mem));
clk_put(adc->clk);
platform_set_drvdata(pdev, NULL);
kfree(adc);