diff options
Diffstat (limited to 'drivers/iio/adc/ingenic-adc.c')
| -rw-r--r-- | drivers/iio/adc/ingenic-adc.c | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c index 7886cdca5a5e..34c03a264f74 100644 --- a/drivers/iio/adc/ingenic-adc.c +++ b/drivers/iio/adc/ingenic-adc.c @@ -71,7 +71,7 @@ #define JZ4725B_ADC_BATTERY_HIGH_VREF_BITS 10 #define JZ4740_ADC_BATTERY_HIGH_VREF (7500 * 0.986) #define JZ4740_ADC_BATTERY_HIGH_VREF_BITS 12 -#define JZ4770_ADC_BATTERY_VREF 6600 +#define JZ4770_ADC_BATTERY_VREF 1200 #define JZ4770_ADC_BATTERY_VREF_BITS 12 #define JZ_ADC_IRQ_AUX BIT(0) @@ -177,13 +177,12 @@ static void ingenic_adc_set_config(struct ingenic_adc *adc, mutex_unlock(&adc->lock); } -static void ingenic_adc_enable(struct ingenic_adc *adc, - int engine, - bool enabled) +static void ingenic_adc_enable_unlocked(struct ingenic_adc *adc, + int engine, + bool enabled) { u8 val; - mutex_lock(&adc->lock); val = readb(adc->base + JZ_ADC_REG_ENABLE); if (enabled) @@ -192,20 +191,41 @@ static void ingenic_adc_enable(struct ingenic_adc *adc, val &= ~BIT(engine); writeb(val, adc->base + JZ_ADC_REG_ENABLE); +} + +static void ingenic_adc_enable(struct ingenic_adc *adc, + int engine, + bool enabled) +{ + mutex_lock(&adc->lock); + ingenic_adc_enable_unlocked(adc, engine, enabled); mutex_unlock(&adc->lock); } static int ingenic_adc_capture(struct ingenic_adc *adc, int engine) { + u32 cfg; u8 val; int ret; - ingenic_adc_enable(adc, engine, true); + /* + * Disable CMD_SEL temporarily, because it causes wrong VBAT readings, + * probably due to the switch of VREF. We must keep the lock here to + * avoid races with the buffer enable/disable functions. + */ + mutex_lock(&adc->lock); + cfg = readl(adc->base + JZ_ADC_REG_CFG); + writel(cfg & ~JZ_ADC_REG_CFG_CMD_SEL, adc->base + JZ_ADC_REG_CFG); + + ingenic_adc_enable_unlocked(adc, engine, true); ret = readb_poll_timeout(adc->base + JZ_ADC_REG_ENABLE, val, !(val & BIT(engine)), 250, 1000); if (ret) - ingenic_adc_enable(adc, engine, false); + ingenic_adc_enable_unlocked(adc, engine, false); + + writel(cfg, adc->base + JZ_ADC_REG_CFG); + mutex_unlock(&adc->lock); return ret; } |