Re: [PATCH v2 10/17] iio: adc: axp20x_adc: Minor code cleanups

From: Aidan MacDonald
Date: Thu Jun 09 2022 - 13:50:52 EST


Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> writes:

> On Tue, 7 Jun 2022 16:53:17 +0100
> Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx> wrote:
>
>> The code may be clearer if parameters are not re-purposed to hold
>> temporary results like register values, so introduce local variables
>> as necessary to avoid that. Also, use the common FIELD_PREP macro
>> instead of a hand-rolled version.
>>
>> Suggested-by: Jonathan Cameron <jic23@xxxxxxxxxx>
>> Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>
>
> Hi Aidan,
>
> Looks good. One trivial further suggestion inline.
>
> Also, am I fine picking up the IIO patches, or does the whole
> set need to go in via mfd?
>
> Thanks,
>
> Jonathan
>

I think it has to go through mfd because of the GPIO2-3 ADC registers
which are added in the mfd patch. Cleanups are okay to pick up though.

>> ---
>> drivers/iio/adc/axp20x_adc.c | 61 +++++++++++++++++++-----------------
>> 1 file changed, 33 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c
>> index 53bf7d4899d2..9d5b1de24908 100644
>> --- a/drivers/iio/adc/axp20x_adc.c
>> +++ b/drivers/iio/adc/axp20x_adc.c
>> @@ -15,6 +15,7 @@
>> #include <linux/property.h>
>> #include <linux/regmap.h>
>> #include <linux/thermal.h>
>> +#include <linux/bitfield.h>
>>
>> #include <linux/iio/iio.h>
>> #include <linux/iio/driver.h>
>> @@ -22,20 +23,20 @@
>> #include <linux/mfd/axp20x.h>
>>
>> #define AXP20X_ADC_EN1_MASK GENMASK(7, 0)
>> -
>> #define AXP20X_ADC_EN2_MASK (GENMASK(3, 2) | BIT(7))
>> +
>> #define AXP22X_ADC_EN1_MASK (GENMASK(7, 5) | BIT(0))
>>
>> #define AXP20X_GPIO10_IN_RANGE_GPIO0 BIT(0)
>> #define AXP20X_GPIO10_IN_RANGE_GPIO1 BIT(1)
>> -#define AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(x) ((x) & BIT(0))
>> -#define AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(x) (((x) & BIT(0)) << 1)
>>
>> #define AXP20X_ADC_RATE_MASK GENMASK(7, 6)
>> -#define AXP813_V_I_ADC_RATE_MASK GENMASK(5, 4)
>> -#define AXP813_ADC_RATE_MASK (AXP20X_ADC_RATE_MASK | AXP813_V_I_ADC_RATE_MASK)
>> #define AXP20X_ADC_RATE_HZ(x) ((ilog2((x) / 25) << 6) & AXP20X_ADC_RATE_MASK)
>> +
>> #define AXP22X_ADC_RATE_HZ(x) ((ilog2((x) / 100) << 6) & AXP20X_ADC_RATE_MASK)
>> +
>> +#define AXP813_V_I_ADC_RATE_MASK GENMASK(5, 4)
>> +#define AXP813_ADC_RATE_MASK (AXP20X_ADC_RATE_MASK | AXP813_V_I_ADC_RATE_MASK)
>> #define AXP813_TS_GPIO0_ADC_RATE_HZ(x) AXP20X_ADC_RATE_HZ(x)
>> #define AXP813_V_I_ADC_RATE_HZ(x) ((ilog2((x) / 100) << 4) & AXP813_V_I_ADC_RATE_MASK)
>> #define AXP813_ADC_RATE_HZ(x) (AXP20X_ADC_RATE_HZ(x) | AXP813_V_I_ADC_RATE_HZ(x))
>> @@ -234,7 +235,7 @@ static int axp20x_adc_raw(struct iio_dev *indio_dev,
>> struct iio_chan_spec const *chan, int *val)
>> {
>> struct axp20x_adc_iio *info = iio_priv(indio_dev);
>> - int size = 12;
>> + int ret, size;
>>
>> /*
>> * N.B.: Unlike the Chinese datasheets tell, the charging current is
>> @@ -246,10 +247,11 @@ static int axp20x_adc_raw(struct iio_dev *indio_dev,
>> else
>> size = 12;
>>
>> - *val = axp20x_read_variable_width(info->regmap, chan->address, size);
>> - if (*val < 0)
>> - return *val;
>> + ret = axp20x_read_variable_width(info->regmap, chan->address, size);
>> + if (ret < 0)
>> + return ret;
>>
>> + *val = ret;
>> return IIO_VAL_INT;
>> }
>>
>> @@ -257,11 +259,13 @@ static int axp22x_adc_raw(struct iio_dev *indio_dev,
>> struct iio_chan_spec const *chan, int *val)
>> {
>> struct axp20x_adc_iio *info = iio_priv(indio_dev);
>> + int ret;
>>
>> - *val = axp20x_read_variable_width(info->regmap, chan->address, 12);
>> - if (*val < 0)
>> - return *val;
>> + ret = axp20x_read_variable_width(info->regmap, chan->address, 12);
>> + if (ret < 0)
>> + return ret;
>>
>> + *val = ret;
>> return IIO_VAL_INT;
>> }
>>
>> @@ -269,11 +273,13 @@ static int axp813_adc_raw(struct iio_dev *indio_dev,
>> struct iio_chan_spec const *chan, int *val)
>> {
>> struct axp20x_adc_iio *info = iio_priv(indio_dev);
>> + int ret;
>>
>> - *val = axp20x_read_variable_width(info->regmap, chan->address, 12);
>> - if (*val < 0)
>> - return *val;
>> + ret = axp20x_read_variable_width(info->regmap, chan->address, 12);
>> + if (ret < 0)
>> + return ret;
>>
>> + *val = ret;
>> return IIO_VAL_INT;
>> }
>>
>> @@ -443,27 +449,27 @@ static int axp20x_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
>> int *val)
>> {
>> struct axp20x_adc_iio *info = iio_priv(indio_dev);
>> + unsigned int regval;
>> int ret;
>>
>> - ret = regmap_read(info->regmap, AXP20X_GPIO10_IN_RANGE, val);
>> + ret = regmap_read(info->regmap, AXP20X_GPIO10_IN_RANGE, &regval);
>> if (ret < 0)
>> return ret;
>>
>> switch (channel) {
>> case AXP20X_GPIO0_V:
>> - *val &= AXP20X_GPIO10_IN_RANGE_GPIO0;
>> + regval &= AXP20X_GPIO10_IN_RANGE_GPIO0;
>
> Maybe use FIELD_GET() here to be clear you are extracting that
> field (even though we don't care about the shift).
>
> Hopefully the compiler will be clever enough to remove the shift
> anyway and using FIELD_GET() would act as slightly more 'documentation
> in code'.
>

You're probably right; I erred on the side of premature optimization.
I'll go back to FIELD_GET in the v3 since I've got to resend anyway.

>> break;
>>
>> case AXP20X_GPIO1_V:
>> - *val &= AXP20X_GPIO10_IN_RANGE_GPIO1;
>> + regval &= AXP20X_GPIO10_IN_RANGE_GPIO1;
>> break;
>>
>> default:
>> return -EINVAL;
>> }
>>
>> - *val = *val ? 700000 : 0;
>> -
>> + *val = regval ? 700000 : 0;
>> return IIO_VAL_INT;
>> }
>>
>> @@ -548,7 +554,7 @@ static int axp20x_write_raw(struct iio_dev *indio_dev,
>> long mask)
>> {
>> struct axp20x_adc_iio *info = iio_priv(indio_dev);
>> - unsigned int reg, regval;
>> + unsigned int regmask, regval;
>>
>> /*
>> * The AXP20X PMIC allows the user to choose between 0V and 0.7V offsets
>> @@ -560,25 +566,24 @@ static int axp20x_write_raw(struct iio_dev *indio_dev,
>> if (val != 0 && val != 700000)
>> return -EINVAL;
>>
>> - val = val ? 1 : 0;
>> + regval = val ? 1 : 0;
>>
>> switch (chan->channel) {
>> case AXP20X_GPIO0_V:
>> - reg = AXP20X_GPIO10_IN_RANGE_GPIO0;
>> - regval = AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(val);
>> + regmask = AXP20X_GPIO10_IN_RANGE_GPIO0;
>> + regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO0, regval);
>> break;
>>
>> case AXP20X_GPIO1_V:
>> - reg = AXP20X_GPIO10_IN_RANGE_GPIO1;
>> - regval = AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(val);
>> + regmask = AXP20X_GPIO10_IN_RANGE_GPIO1;
>> + regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO1, regval);
>> break;
>>
>> default:
>> return -EINVAL;
>> }
>>
>> - return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, reg,
>> - regval);
>> + return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, regmask, regval);
>> }
>>
>> static const struct iio_info axp20x_adc_iio_info = {