From: Matti Vaittinen Date: Mon, 8 May 2023 11:01:25 +0000 (+0300) Subject: iio: bu27034: Ensure reset is written X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d049151adde4ec17392592d145e94f0086f8ee80;p=linux.git iio: bu27034: Ensure reset is written The reset bit must be always written to the hardware no matter what value is in a cache or register. Ensure this by using regmap_write_bits() instead of the regmap_update_bits(). Furthermore, the SWRESET bit may be self-clearing, so mark the SYSTEM_CONTROL register volatile to guarantee we do also read the right state - should we ever need to read it. Finally, writing the SWRESET bit will restore the default register values. This can cause register cache to be outdated if there are any register values cached. Rebuild register cache after SWRESET and use regmap_update_bits() when performing the reset. Signed-off-by: Matti Vaittinen Fixes: e52afbd61039 ("iio: light: ROHM BU27034 Ambient Light Sensor") Link: https://lore.kernel.org/r/ZFjWhbfuN5XcKty+@fedora Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/light/rohm-bu27034.c b/drivers/iio/light/rohm-bu27034.c index 25c9b79574a53..f85194fda6b09 100644 --- a/drivers/iio/light/rohm-bu27034.c +++ b/drivers/iio/light/rohm-bu27034.c @@ -231,6 +231,9 @@ struct bu27034_result { static const struct regmap_range bu27034_volatile_ranges[] = { { + .range_min = BU27034_REG_SYSTEM_CONTROL, + .range_max = BU27034_REG_SYSTEM_CONTROL, + }, { .range_min = BU27034_REG_MODE_CONTROL4, .range_max = BU27034_REG_MODE_CONTROL4, }, { @@ -1272,12 +1275,19 @@ static int bu27034_chip_init(struct bu27034_data *data) int ret, sel; /* Reset */ - ret = regmap_update_bits(data->regmap, BU27034_REG_SYSTEM_CONTROL, + ret = regmap_write_bits(data->regmap, BU27034_REG_SYSTEM_CONTROL, BU27034_MASK_SW_RESET, BU27034_MASK_SW_RESET); if (ret) return dev_err_probe(data->dev, ret, "Sensor reset failed\n"); msleep(1); + + ret = regmap_reinit_cache(data->regmap, &bu27034_regmap); + if (ret) { + dev_err(data->dev, "Failed to reinit reg cache\n"); + return ret; + } + /* * Read integration time here to ensure it is in regmap cache. We do * this to speed-up the int-time acquisition in the start of the buffer