The I2C-bus to the XPower AXP288 is shared between the Linux kernel and
the SoCs PUNIT. The PUNIT has a semaphore which the kernel must "lock"
before it may use the bus and while the kernel holds the semaphore the CPU
and GPU power-states must not be changed otherwise the system will freeze.
This is a complex process, which is quite expensive. This is all done by
iosf_mbi_block_punit_i2c_access(). To ensure that no unguarded I2C-bus
accesses happen, iosf_mbi_block_punit_i2c_access() gets called by the
I2C-bus-driver for every I2C transfer. Because this is so expensive it
is allowed to call iosf_mbi_block_punit_i2c_access() in a nested
fashion, so that higher-level code which does multiple I2C-transfers can
call it once for a group of transfers, turning the calls done by the
I2C-bus-driver into no-ops.
Move / add iosf_mbi_block_punit_i2c_access() calls in / to the XPower
OpRegion code so that the PUNIT semaphore only needs to be taken once
for each OpRegion access.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/acpi/pmic/intel_pmic_xpower.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/pmic/intel_pmic_xpower.c b/drivers/acpi/pmic/intel_pmic_xpower.c
index a091d5a8392c..644a495a4f13 100644
--- a/drivers/acpi/pmic/intel_pmic_xpower.c
+++ b/drivers/acpi/pmic/intel_pmic_xpower.c
@@ -178,15 +178,17 @@ static int intel_xpower_pmic_update_power(struct regmap *regmap, int reg,
{
int data, ret;
- /* GPIO1 LDO regulator needs special handling */
- if (reg == XPOWER_GPI1_CTRL)
- return regmap_update_bits(regmap, reg, GPI1_LDO_MASK,
- on ? GPI1_LDO_ON : GPI1_LDO_OFF);
-
ret = iosf_mbi_block_punit_i2c_access();
if (ret)
return ret;
+ /* GPIO1 LDO regulator needs special handling */
+ if (reg == XPOWER_GPI1_CTRL) {
+ ret = regmap_update_bits(regmap, reg, GPI1_LDO_MASK,
+ on ? GPI1_LDO_ON : GPI1_LDO_OFF);
+ goto out;
+ }
+
if (regmap_read(regmap, reg, &data)) {
ret = -EIO;
goto out;
@@ -218,6 +220,10 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg)
int ret, adc_ts_pin_ctrl;
u8 buf[2];
+ ret = iosf_mbi_block_punit_i2c_access();
+ if (ret)
+ return ret;
+
/*
* The current-source used for the battery temp-sensor (TS) is shared
* with the GPADC. For proper fuel-gauge and charger operation the TS
@@ -231,14 +237,14 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg)
*/
ret = regmap_read(regmap, AXP288_ADC_TS_PIN_CTRL, &adc_ts_pin_ctrl);
if (ret)
- return ret;
+ goto out;
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;
+ goto out;
/* Wait a bit after switching the current-source */
usleep_range(6000, 10000);
@@ -254,6 +260,9 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg)
AXP288_ADC_TS_CURRENT_ON);
}
+out:
+ iosf_mbi_unblock_punit_i2c_access();
+
return ret;
}
--
2.31.1
