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iio: adc: axp288: Fix TS-pin handling

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Prior to this commit there were 3 issues with our handling of the TS-pin:

1) There are 2 ways how the firmware can disable monitoring of the TS-pin
for designs which do not have a temperature-sensor for the battery:
a) Clearing bit 0 of the AXP20X_ADC_EN1 register
b) Setting bit 2 of the AXP288_ADC_TS_PIN_CTRL monitoring

Prior to this commit we were unconditionally setting both bits to the
value used on devices with a TS. This causes the temperature protection to
kick in on devices without a TS, such as the Jumper ezbook v2, causing
them to not charge under Linux.

This commit fixes this by using regmap_update_bits when updating these 2
registers, leaving the 2 mentioned bits alone.

The next 2 problems are related to our handling of the current-source
for the TS-pin. 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.

2) Problem 2 is we were writing hardcoded values to the ADC TS pin-ctrl
register, overwriting various other unrelated bits. Specifically we were
overwriting the current-source setting for the TS and GPIO0 pins, forcing
it to 80ųA independent of its original setting. On a Chuwi Vi10 tablet
this was causing us to get a too high adc value (due to a too high
current-source) resulting in the following errors being logged:

ACPI Error: AE_ERROR, Returned by Handler for [UserDefinedRegion]
ACPI Error: Method parse/execution failed \_SB.SXP1._TMP, AE_ERROR

This commit fixes this by using regmap_update_bits to change only the
relevant bits.

3) After reading the GPADC channel we were unconditionally enabling the
TS current-source even on devices where the TS-pin is not used and the
current-source thus was off before axp288_adc_read_raw call.

This commit fixes this by making axp288_adc_set_ts a nop on devices where
the ADC is not enabled for the TS-pin.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1610545
Fixes: 3091141d78 ("iio: adc: axp288: Fix the GPADC pin ...")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Hans de Goede 2019-01-05 19:36:18 +01:00 committed by Jonathan Cameron
parent 0808831dc6
commit 9bcf15f75c
1 changed files with 60 additions and 16 deletions
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76
drivers/iio/adc/axp288_adc.c
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@ -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 +186,35 @@ 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;
return regmap_write(regmap, AXP20X_ADC_EN1, AXP288_ADC_EN_MASK);
/*
* Determine if the TS pin is enabled and set the TS current-source
* accordingly.
*/
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;
ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
AXP288_ADC_TS_CURRENT_ON);
} 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;
/* 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 +244,7 @@ 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;