From 060ffa70ee3663b90decaeabb9c7ea18ff7995ac Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Sat, 30 Jan 2010 13:12:17 +0000 Subject: [PATCH] Dynamically gate adc clock SVN-Revision: 19394 --- .../files-2.6.32/drivers/misc/jz4740-adc.c | 47 ++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) diff --git a/target/linux/xburst/files-2.6.32/drivers/misc/jz4740-adc.c b/target/linux/xburst/files-2.6.32/drivers/misc/jz4740-adc.c index 7da3bccc35..c60f939a43 100644 --- a/target/linux/xburst/files-2.6.32/drivers/misc/jz4740-adc.c +++ b/target/linux/xburst/files-2.6.32/drivers/misc/jz4740-adc.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include #include #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); -- 2.30.2