---
drivers/iio/adc/axp288_adc.c | 74 ++++++++++++++++++++++++++++--------
1 file changed, 58 insertions(+), 16 deletions(-)
diff --git a/drivers/iio/adc/axp288_adc.c b/drivers/iio/adc/axp288_adc.c
index 031d568b4972..99a6b804fd49 100644
--- a/drivers/iio/adc/axp288_adc.c
+++ b/drivers/iio/adc/axp288_adc.c
@@ -27,9 +27,18 @@
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
-#define AXP288_ADC_EN_MASK 0xF1
-#define AXP288_ADC_TS_PIN_GPADC 0xF2
-#define AXP288_ADC_TS_PIN_ON 0xF3
+/*
+ * This mask enables all ADCs except for the battery temp-sensor (TS), that is
+ * left as-is to avoid breaking charging on devices without a temp-sensor.
+ */
+#define AXP288_ADC_EN_MASK 0xF0
+#define AXP288_ADC_TS_ENABLE 0x01
+
+#define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
+#define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
+#define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
+#define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0)
+#define AXP288_ADC_TS_CURRENT_ON (3 << 0)
enum axp288_adc_id {
AXP288_ADC_TS,
@@ -44,6 +53,7 @@ enum axp288_adc_id {
struct axp288_adc_info {
int irq;
struct regmap *regmap;
+ bool ts_enabled;
};
static const struct iio_chan_spec axp288_adc_channels[] = {
@@ -115,21 +125,33 @@ static int axp288_adc_read_channel(int *val, unsigned long address,
return IIO_VAL_INT;
}
-static int axp288_adc_set_ts(struct regmap *regmap, unsigned int mode,
- unsigned long address)
+/*
+ * The current-source used for the battery temp-sensor (TS) is shared
+ * with the GPADC. For proper fuel-gauge and charger operation the TS
+ * current-source needs to be permanently on. But to read the GPADC we
+ * need to temporary switch the TS current-source to ondemand, so that
+ * the GPADC can use it, otherwise we will always read an all 0 value.
+ */
+static int axp288_adc_set_ts(struct axp288_adc_info *info,
+ unsigned int mode, unsigned long address)
{
int ret;
- /* channels other than GPADC do not need to switch TS pin */
+ /* No need to switch the current-source if the TS pin is disabled */
+ if (!info->ts_enabled)
+ return 0;
+
+ /* Channels other than GPADC do not need the current source */
if (address != AXP288_GP_ADC_H)
return 0;
- ret = regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, mode);
+ ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
+ AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
if (ret)
return ret;
/* When switching to the GPADC pin give things some time to settle */
- if (mode == AXP288_ADC_TS_PIN_GPADC)
+ if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
usleep_range(6000, 10000);
return 0;
@@ -145,14 +167,14 @@ static int axp288_adc_read_raw(struct iio_dev *indio_dev,
mutex_lock(&indio_dev->mlock);
switch (mask) {
case IIO_CHAN_INFO_RAW:
- if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_GPADC,
+ if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
chan->address)) {
dev_err(&indio_dev->dev, "GPADC mode\n");
ret = -EINVAL;
break;
}
ret = axp288_adc_read_channel(val, chan->address, info->regmap);
- if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_ON,
+ if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
chan->address))
dev_err(&indio_dev->dev, "TS pin restore\n");
break;
@@ -164,13 +186,33 @@ static int axp288_adc_read_raw(struct iio_dev *indio_dev,
return ret;
}
-static int axp288_adc_set_state(struct regmap *regmap)
+static int axp288_adc_initialize(struct axp288_adc_info *info)
{
- /* ADC should be always enabled for internal FG to function */
- if (regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, AXP288_ADC_TS_PIN_ON))
- return -EIO;
+ int ret, adc_enable_val;
+
+ /*
+ * Determine if the TS pin is enabled and if it is not enabled,
+ * turn the TS current-source off, so that the shared current-source
+ * will be available for the GPADC.
+ */
+ ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
+ if (ret)
+ return ret;
+
+ if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
+ info->ts_enabled = true;
+ } else {
+ info->ts_enabled = false;
+ ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
+ AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
+ AXP288_ADC_TS_CURRENT_OFF);
+ if (ret)
+ return ret;
+ }
- return regmap_write(regmap, AXP20X_ADC_EN1, AXP288_ADC_EN_MASK);
+ /* Turn on the ADC for all channels except TS, leave TS as is */
+ return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
+ AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
}
static const struct iio_info axp288_adc_iio_info = {
@@ -200,7 +242,7 @@ static int axp288_adc_probe(struct platform_device *pdev)
* Set ADC to enabled state at all time, including system suspend.
* otherwise internal fuel gauge functionality may be affected.
*/
- ret = axp288_adc_set_state(axp20x->regmap);
+ ret = axp288_adc_initialize(info);
if (ret) {
dev_err(&pdev->dev, "unable to enable ADC device\n");
return ret;
