The ADC in the JZ4740 can work either in high-precision mode with a 2.5V range, or in low-precision mode with a 7.5V range. The code in place in this driver will select the proper scale according to the maximum voltage of the battery.
The JZ4770 however only has one mode, with a 6.6V range. If only one scale is available, there's no need to change it (and nothing to change it to), and trying to do so will fail with -EINVAL.
Fixes: fb24ccfbe1e0 ("power: supply: add Ingenic JZ47xx battery driver.")
Signed-off-by: Paul Cercueil paul@crapouillou.net Cc: stable@vger.kernel.org ---
Notes: v2: Rebased on v5.4-rc7 v3: Move code after check for max scale voltage
drivers/power/supply/ingenic-battery.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/power/supply/ingenic-battery.c b/drivers/power/supply/ingenic-battery.c index 35816d4b3012..2748715c4c75 100644 --- a/drivers/power/supply/ingenic-battery.c +++ b/drivers/power/supply/ingenic-battery.c @@ -100,10 +100,17 @@ static int ingenic_battery_set_scale(struct ingenic_battery *bat) return -EINVAL; }
- return iio_write_channel_attribute(bat->channel, - scale_raw[best_idx], - scale_raw[best_idx + 1], - IIO_CHAN_INFO_SCALE); + /* Only set scale if there is more than one (fractional) entry */ + if (scale_len > 2) { + ret = iio_write_channel_attribute(bat->channel, + scale_raw[best_idx], + scale_raw[best_idx + 1], + IIO_CHAN_INFO_SCALE); + if (ret) + return ret; + } + + return 0; }
static enum power_supply_property ingenic_battery_properties[] = {