This is a note to let you know that I've just added the patch titled

power: supply: axp288_fuel_gauge: Read 12 bit values 2 registers at a time

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: power-supply-axp288_fuel_gauge-read-12-bit-values-2-registers-at-a-time.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Sun Nov 19 11:32:28 CET 2017

From: Hans de Goede hdegoede@redhat.com Date: Wed, 14 Dec 2016 17:38:52 +0100 Subject: power: supply: axp288_fuel_gauge: Read 12 bit values 2 registers at a time

From: Hans de Goede hdegoede@redhat.com

[ Upstream commit 248efcf00602f0282587999bcc221a872bd72530 ]

In order for the MSB -> LSB latching to work correctly we must read the 2 8 bit registers of a 12 bit value in one consecutive read.

This fixes voltage_ocv reporting inconsistent values on my tablet.

Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sebastian Reichel sre@kernel.org Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/power/supply/axp288_fuel_gauge.c | 40 +++++++++++++++++-------------- 1 file changed, 22 insertions(+), 18 deletions(-)

--- a/drivers/power/supply/axp288_fuel_gauge.c +++ b/drivers/power/supply/axp288_fuel_gauge.c @@ -210,6 +210,22 @@ static int fuel_gauge_read_15bit_word(st return ret & FG_15BIT_VAL_MASK; }

+static int fuel_gauge_read_12bit_word(struct axp288_fg_info *info, int reg) +{ + unsigned char buf[2]; + int ret; + + ret = regmap_bulk_read(info->regmap, reg, buf, 2); + if (ret < 0) { + dev_err(&info->pdev->dev, "Error reading reg 0x%02x err: %d\n", + reg, ret); + return ret; + } + + /* 12-bit data values have upper 8 bits in buf[0], lower 4 in buf[1] */ + return (buf[0] << 4) | ((buf[1] >> 4) & 0x0f); +} + static int pmic_read_adc_val(const char *name, int *raw_val, struct axp288_fg_info *info) { @@ -270,12 +286,9 @@ static int fuel_gauge_debug_show(struct seq_printf(s, " FG_RDC0[%02x] : %02x\n", AXP288_FG_RDC0_REG, fuel_gauge_reg_readb(info, AXP288_FG_RDC0_REG)); - seq_printf(s, " FG_OCVH[%02x] : %02x\n", + seq_printf(s, " FG_OCV[%02x] : %04x\n", AXP288_FG_OCVH_REG, - fuel_gauge_reg_readb(info, AXP288_FG_OCVH_REG)); - seq_printf(s, " FG_OCVL[%02x] : %02x\n", - AXP288_FG_OCVL_REG, - fuel_gauge_reg_readb(info, AXP288_FG_OCVL_REG)); + fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG)); seq_printf(s, " FG_DES_CAP[%02x] : %04x\n", AXP288_FG_DES_CAP1_REG, fuel_gauge_read_15bit_word(info, AXP288_FG_DES_CAP1_REG)); @@ -532,21 +545,12 @@ temp_read_fail:

static int fuel_gauge_get_vocv(struct axp288_fg_info *info, int *vocv) { - int ret, value; - - /* 12-bit data value, upper 8 in OCVH, lower 4 in OCVL */ - ret = fuel_gauge_reg_readb(info, AXP288_FG_OCVH_REG); - if (ret < 0) - goto vocv_read_fail; - value = ret << 4; + int ret;

- ret = fuel_gauge_reg_readb(info, AXP288_FG_OCVL_REG); - if (ret < 0) - goto vocv_read_fail; - value |= (ret & 0xf); + ret = fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG); + if (ret >= 0) + *vocv = VOLTAGE_FROM_ADC(ret);

- *vocv = VOLTAGE_FROM_ADC(value); -vocv_read_fail: return ret; }

Patches currently in stable-queue which might be from hdegoede@redhat.com are

queue-4.9/power-supply-axp288_fuel_gauge-read-15-bit-values-2-registers-at-a-time.patch queue-4.9/power-supply-axp288_fuel_gauge-read-12-bit-values-2-registers-at-a-time.patch