From 58eefe2f3f53f294cdb5a2b6121973b5ae508f01 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 8 Jul 2017 15:40:08 +0200 Subject: [PATCH] ACPI / PMIC: xpower: Do pinswitch magic when reading GPADC Testing has shown that the TS-pin's bias-current needs to be disabled when reading the GPIO0 pin in GPADC mode. It seems that there is only 1 bias current source and to be able to use it for the GPIO0 pin in GPADC mode it must be temporarily turned off for the TS pin, but the datasheet does not mention this. This commit adds the necessary writes to turn the TS pin BIAS current off before and back on after reading the GPADC. This fixes the GPADC always returning a reading of 0. Signed-off-by: Hans de Goede Signed-off-by: Rafael J. Wysocki --- drivers/acpi/pmic/intel_pmic_xpower.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/pmic/intel_pmic_xpower.c b/drivers/acpi/pmic/intel_pmic_xpower.c index 3b7d5be..6c99d3f 100644 --- a/drivers/acpi/pmic/intel_pmic_xpower.c +++ b/drivers/acpi/pmic/intel_pmic_xpower.c @@ -27,6 +27,9 @@ #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 + static struct pmic_table power_table[] = { { .address = 0x00, @@ -209,11 +212,23 @@ static int intel_xpower_pmic_update_power(struct regmap *regmap, int reg, static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg) { u8 buf[2]; + int ret; - if (regmap_bulk_read(regmap, AXP288_GP_ADC_H, buf, 2)) - return -EIO; + ret = regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, + AXP288_ADC_TS_PIN_GPADC); + if (ret) + return ret; + + /* After switching to the GPADC pin give things some time to settle */ + 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); - return (buf[0] << 4) + ((buf[1] >> 4) & 0x0F); + return ret; } static struct intel_pmic_opregion_data intel_xpower_pmic_opregion_data = { -- 2.7.4