On Sun, 9 Jul 2017 18:56:56 +0200
Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx> wrote:
> Move bit-shift in hts221_write_with_mask() instead of coding
> the shift depth in the configured value. That change will be necessary
> to fix an issue in device power-down procedure
>
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@xxxxxx>
A could of questions inline.
Jonathan
> ---
> drivers/iio/humidity/hts221_core.c | 74 +++++++++++++++++---------------------
> 1 file changed, 32 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/iio/humidity/hts221_core.c b/drivers/iio/humidity/hts221_core.c
> index a56da3999e00..f5181e4e1eff 100644
> --- a/drivers/iio/humidity/hts221_core.c
> +++ b/drivers/iio/humidity/hts221_core.c
> @@ -32,30 +32,12 @@
> #define HTS221_HUMIDITY_AVG_MASK 0x07
> #define HTS221_TEMP_AVG_MASK 0x38
>
> -#define HTS221_ODR_MASK 0x87
> +#define HTS221_ODR_MASK 0x03
> #define HTS221_BDU_MASK BIT(2)
> +#define HTS221_ENABLE_MASK BIT(7)
>
> #define HTS221_DRDY_MASK BIT(2)
>
> -#define HTS221_ENABLE_SENSOR BIT(7)
> -
> -#define HTS221_HUMIDITY_AVG_4 0x00 /* 0.4 %RH */
> -#define HTS221_HUMIDITY_AVG_8 0x01 /* 0.3 %RH */
> -#define HTS221_HUMIDITY_AVG_16 0x02 /* 0.2 %RH */
> -#define HTS221_HUMIDITY_AVG_32 0x03 /* 0.15 %RH */
> -#define HTS221_HUMIDITY_AVG_64 0x04 /* 0.1 %RH */
> -#define HTS221_HUMIDITY_AVG_128 0x05 /* 0.07 %RH */
> -#define HTS221_HUMIDITY_AVG_256 0x06 /* 0.05 %RH */
> -#define HTS221_HUMIDITY_AVG_512 0x07 /* 0.03 %RH */
> -
> -#define HTS221_TEMP_AVG_2 0x00 /* 0.08 degC */
> -#define HTS221_TEMP_AVG_4 0x08 /* 0.05 degC */
> -#define HTS221_TEMP_AVG_8 0x10 /* 0.04 degC */
> -#define HTS221_TEMP_AVG_16 0x18 /* 0.03 degC */
> -#define HTS221_TEMP_AVG_32 0x20 /* 0.02 degC */
> -#define HTS221_TEMP_AVG_64 0x28 /* 0.015 degC */
> -#define HTS221_TEMP_AVG_128 0x30 /* 0.01 degC */
> -#define HTS221_TEMP_AVG_256 0x38 /* 0.007 degC */
>
> /* calibration registers */
> #define HTS221_REG_0RH_CAL_X_H 0x36
> @@ -90,28 +72,28 @@ static const struct hts221_avg hts221_avg_list[] = {
> .addr = HTS221_REG_AVG_ADDR,
> .mask = HTS221_HUMIDITY_AVG_MASK,
> .avg_avl = {
> - { 4, HTS221_HUMIDITY_AVG_4 },
> - { 8, HTS221_HUMIDITY_AVG_8 },
> - { 16, HTS221_HUMIDITY_AVG_16 },
> - { 32, HTS221_HUMIDITY_AVG_32 },
> - { 64, HTS221_HUMIDITY_AVG_64 },
> - { 128, HTS221_HUMIDITY_AVG_128 },
> - { 256, HTS221_HUMIDITY_AVG_256 },
> - { 512, HTS221_HUMIDITY_AVG_512 },
> + { 4, 0x0 }, /* 0.4 %RH */
> + { 8, 0x1 }, /* 0.3 %RH */
> + { 16, 0x2 }, /* 0.2 %RH */
> + { 32, 0x3 }, /* 0.15 %RH */
> + { 64, 0x4 }, /* 0.1 %RH */
> + { 128, 0x5 }, /* 0.07 %RH */
> + { 256, 0x6 }, /* 0.05 %RH */
> + { 512, 0x7 }, /* 0.03 %RH */
> },
> },
> {
> .addr = HTS221_REG_AVG_ADDR,
> .mask = HTS221_TEMP_AVG_MASK,
> .avg_avl = {
> - { 2, HTS221_TEMP_AVG_2 },
> - { 4, HTS221_TEMP_AVG_4 },
> - { 8, HTS221_TEMP_AVG_8 },
> - { 16, HTS221_TEMP_AVG_16 },
> - { 32, HTS221_TEMP_AVG_32 },
> - { 64, HTS221_TEMP_AVG_64 },
> - { 128, HTS221_TEMP_AVG_128 },
> - { 256, HTS221_TEMP_AVG_256 },
> + { 2, 0x0 }, /* 0.08 degC */
> + { 4, 0x1 }, /* 0.05 degC */
> + { 8, 0x2 }, /* 0.04 degC */
> + { 16, 0x3 }, /* 0.03 degC */
> + { 32, 0x4 }, /* 0.02 degC */
> + { 64, 0x5 }, /* 0.015 degC */
> + { 128, 0x6 }, /* 0.01 degC */
> + { 256, 0x7 }, /* 0.007 degC */
Could we potentially use the index directly here rather than
having to explicitly store it? Would be more elegant perhaps..
> },
> },
> };
> @@ -166,7 +148,7 @@ static int hts221_write_with_mask(struct hts221_hw *hw, u8 addr, u8 mask,
> goto unlock;
> }
>
> - data = (data & ~mask) | (val & mask);
> + data = (data & ~mask) | ((val << __ffs(mask)) & mask);
>
> err = hw->tf->write(hw->dev, addr, sizeof(data), &data);
> if (err < 0)
> @@ -201,11 +183,10 @@ static int hts221_check_whoami(struct hts221_hw *hw)
>
> int hts221_config_drdy(struct hts221_hw *hw, bool enable)
> {
> - u8 val = enable ? BIT(2) : 0;
> int err;
>
> err = hts221_write_with_mask(hw, HTS221_REG_CNTRL3_ADDR,
> - HTS221_DRDY_MASK, val);
> + HTS221_DRDY_MASK, enable);
>
> return err < 0 ? err : 0;
> }
> @@ -213,7 +194,6 @@ int hts221_config_drdy(struct hts221_hw *hw, bool enable)
> static int hts221_update_odr(struct hts221_hw *hw, u8 odr)
> {
> int i, err;
> - u8 val;
>
> for (i = 0; i < ARRAY_SIZE(hts221_odr_table); i++)
> if (hts221_odr_table[i].hz == odr)
> @@ -222,9 +202,19 @@ static int hts221_update_odr(struct hts221_hw *hw, u8 odr)
> if (i == ARRAY_SIZE(hts221_odr_table))
> return -EINVAL;
>
> - val = HTS221_ENABLE_SENSOR | HTS221_BDU_MASK | hts221_odr_table[i].val;
> + /* enable Block Data Update */
> + err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
> + HTS221_BDU_MASK, 1);
> + if (err < 0)
> + return err;
> +
> + err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
> + HTS221_ODR_MASK, hts221_odr_table[i].val);
> + if (err < 0)
> + return err;
> +
> err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
> - HTS221_ODR_MASK, val);
This original code looks like a bug given the odr mask should only
cover the odr bits, not the enable and bdu.
Am I missing something?
Taking one write and changing it to 3 isn't that nice, but I guess
we aren't in a fast path here so fair enough given the cleaner
resulting code.
> + HTS221_ENABLE_MASK, 1);
> if (err < 0)
> return err;
>
--
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