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path: root/drivers/iio/adc/ingenic-adc.c
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Diffstat (limited to 'drivers/iio/adc/ingenic-adc.c')
-rw-r--r--drivers/iio/adc/ingenic-adc.c34
1 files changed, 27 insertions, 7 deletions
diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c
index 92b25083e23f..1aafbe2cfe67 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;
}