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ACPI / PMIC: xpower: Fix TS-pin current-source handling

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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.

The switching from on to on-ondemand is not necessary when the TS
current-source is off (this happens on devices which do not have a TS).

Prior to this commit there were 2 issues with our handling of the TS
current-source switching:

 1) 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 acpi_lpat_raw_to_temp() returning -ENOENT, resulting in:

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.

 2) At the end of intel_xpower_pmic_get_raw_temp() 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 on entry of the function.

This commit fixes this by checking if the TS current-source is off when
entering intel_xpower_pmic_get_raw_temp() and if so it is left as is.

Fixes: 58eefe2f3f (ACPI / PMIC: xpower: Do pinswitch ... reading GPADC)
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Hans de Goede 2019-01-04 23:10:54 +01:00 committed by Rafael J. Wysocki
parent bfeffd1552
commit 2b531d7159
1 changed files with 33 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
drivers/acpi/pmic/intel_pmic_xpower.c
View File

@ -20,8 +20,11 @@
#define GPI1_LDO_ON (3 << 0)
#define GPI1_LDO_OFF (4 << 0)
#define AXP288_ADC_TS_PIN_GPADC 0xf2
#define AXP288_ADC_TS_PIN_ON 0xf3
#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)
static struct pmic_table power_table[] = {
{
@ -212,22 +215,44 @@ out:
*/
static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg)
{
int ret, adc_ts_pin_ctrl;
u8 buf[2];
int ret;
ret = regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_PIN_GPADC);
/*
* 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.
*
* Note that the switching from on to on-ondemand is not necessary
* when the TS current-source is off (this happens on devices which
* do not use the TS-pin).
*/
ret = regmap_read(regmap, AXP288_ADC_TS_PIN_CTRL, &adc_ts_pin_ctrl);
if (ret)
return ret;
/* After switching to the GPADC pin give things some time to settle */
usleep_range(6000, 10000);
if (adc_ts_pin_ctrl & AXP288_ADC_TS_CURRENT_ON_OFF_MASK) {
ret = regmap_update_bits(regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
AXP288_ADC_TS_CURRENT_ON_ONDEMAND);
if (ret)
return ret;
/* Wait a bit after switching the current-source */
usleep_range(6000, 10000);
}
ret = regmap_bulk_read(regmap, AXP288_GP_ADC_H, buf, 2);
if (ret == 0)
ret = (buf[0] << 4) + ((buf[1] >> 4) & 0x0f);
regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, AXP288_ADC_TS_PIN_ON);
if (adc_ts_pin_ctrl & AXP288_ADC_TS_CURRENT_ON_OFF_MASK) {
regmap_update_bits(regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
AXP288_ADC_TS_CURRENT_ON);
}
return ret;
}