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

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[ 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>
This commit is contained in:
Hans de Goede 2016-12-14 17:38:52 +01:00 committed by Greg Kroah-Hartman
parent 0010542d3f
commit 9dc7637700
1 changed files with 22 additions and 18 deletions
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40
drivers/power/supply/axp288_fuel_gauge.c
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@ -210,6 +210,22 @@ static int fuel_gauge_read_15bit_word(struct axp288_fg_info *info, int reg)
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_file *s, void *data)
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;
int ret;
/* 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;
ret = fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG);
if (ret >= 0)
*vocv = VOLTAGE_FROM_ADC(ret);
ret = fuel_gauge_reg_readb(info, AXP288_FG_OCVL_REG);
if (ret < 0)
goto vocv_read_fail;
value |= (ret & 0xf);
*vocv = VOLTAGE_FROM_ADC(value);
vocv_read_fail:
return ret;
}