Re: [PATCH 08/10] iio: adc: axp20x_adc: Add support for AXP192

From: Jonathan Cameron
Date: Fri Jun 03 2022 - 12:38:56 EST

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In reply to: Aidan MacDonald: "[PATCH 08/10] iio: adc: axp20x_adc: Add support for AXP192"
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On Fri, 3 Jun 2022 14:57:12 +0100
Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx> wrote:

> The AXP192 is identical to the AXP20x, except for the addition of
> two more GPIO ADC channels.
>
> Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>
Hi Aidan,

A few minor questions and comments inline.

Thanks,

Jonathan

> ---
> drivers/iio/adc/axp20x_adc.c | 289 +++++++++++++++++++++++++++++++++--
> 1 file changed, 280 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c
> index 53bf7d4899d2..7d2bf9529420 100644
> --- a/drivers/iio/adc/axp20x_adc.c
> +++ b/drivers/iio/adc/axp20x_adc.c
> @@ -21,6 +21,9 @@
> #include <linux/iio/machine.h>
> #include <linux/mfd/axp20x.h>
>
> +#define AXP192_ADC_EN1_MASK GENMASK(7, 0)
> +#define AXP192_ADC_EN2_MASK (BIT(7) | GENMASK(3, 0))

Obviously doesn't really mater, but for consistency, maybe match the
ordering in AXP20X_ADC_EN2_MASK below?

> +
> #define AXP20X_ADC_EN1_MASK GENMASK(7, 0)
>
> #define AXP20X_ADC_EN2_MASK (GENMASK(3, 2) | BIT(7))
> @@ -31,6 +34,15 @@
> #define AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(x) ((x) & BIT(0))
> #define AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(x) (((x) & BIT(0)) << 1)
>
> +#define AXP192_GPIO30_IN_RANGE_GPIO0 BIT(0)
> +#define AXP192_GPIO30_IN_RANGE_GPIO1 BIT(1)
> +#define AXP192_GPIO30_IN_RANGE_GPIO2 BIT(2)
> +#define AXP192_GPIO30_IN_RANGE_GPIO3 BIT(3)
> +#define AXP192_GPIO30_IN_RANGE_GPIO0_VAL(x) ((x) & BIT(0))
> +#define AXP192_GPIO30_IN_RANGE_GPIO1_VAL(x) (((x) & BIT(0)) << 1)
> +#define AXP192_GPIO30_IN_RANGE_GPIO2_VAL(x) (((x) & BIT(0)) << 2)
> +#define AXP192_GPIO30_IN_RANGE_GPIO3_VAL(x) (((x) & BIT(0)) << 3)

FIELD_PREP() using the masks is cleaner than hand rolling it.
If you fancy updating the driver in general whilst here that would be great,
but I don't mind if not.

> +
> #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)
> @@ -70,6 +82,25 @@ struct axp20x_adc_iio {
> const struct axp_data *data;
> };
>
> +enum axp192_adc_channel_v {
> + AXP192_ACIN_V = 0,
> + AXP192_VBUS_V,
> + AXP192_TS_IN,
> + AXP192_GPIO0_V,
> + AXP192_GPIO1_V,
> + AXP192_GPIO2_V,
> + AXP192_GPIO3_V,
> + AXP192_IPSOUT_V,
> + AXP192_BATT_V,
> +};
> +
> +enum axp192_adc_channel_i {
> + AXP192_ACIN_I = 0,
> + AXP192_VBUS_I,
> + AXP192_BATT_CHRG_I,
> + AXP192_BATT_DISCHRG_I,
> +};
> +
> enum axp20x_adc_channel_v {
> AXP20X_ACIN_V = 0,
> AXP20X_VBUS_V,
> @@ -157,6 +188,43 @@ static struct iio_map axp22x_maps[] = {
> * The only exception is for the battery. batt_v will be in_voltage6_raw and
> * charge current in_current6_raw and discharge current will be in_current7_raw.
> */
> +static const struct iio_chan_spec axp192_adc_channels[] = {
> + AXP20X_ADC_CHANNEL(AXP192_ACIN_V, "acin_v", IIO_VOLTAGE,
> + AXP20X_ACIN_V_ADC_H),
> + AXP20X_ADC_CHANNEL(AXP192_ACIN_I, "acin_i", IIO_CURRENT,
> + AXP20X_ACIN_I_ADC_H),
> + AXP20X_ADC_CHANNEL(AXP192_VBUS_V, "vbus_v", IIO_VOLTAGE,
> + AXP20X_VBUS_V_ADC_H),
> + AXP20X_ADC_CHANNEL(AXP192_VBUS_I, "vbus_i", IIO_CURRENT,
> + AXP20X_VBUS_I_ADC_H),
> + {
> + .type = IIO_TEMP,
> + .address = AXP20X_TEMP_ADC_H,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) |
> + BIT(IIO_CHAN_INFO_OFFSET),
> + .datasheet_name = "pmic_temp",
> + },
> + AXP20X_ADC_CHANNEL_OFFSET(AXP192_GPIO0_V, "gpio0_v", IIO_VOLTAGE,
> + AXP20X_GPIO0_V_ADC_H),
> + AXP20X_ADC_CHANNEL_OFFSET(AXP192_GPIO1_V, "gpio1_v", IIO_VOLTAGE,
> + AXP20X_GPIO1_V_ADC_H),
> + AXP20X_ADC_CHANNEL_OFFSET(AXP192_GPIO2_V, "gpio2_v", IIO_VOLTAGE,
> + AXP192_GPIO2_V_ADC_H),
> + AXP20X_ADC_CHANNEL_OFFSET(AXP192_GPIO3_V, "gpio3_v", IIO_VOLTAGE,
> + AXP192_GPIO3_V_ADC_H),
> + AXP20X_ADC_CHANNEL(AXP192_IPSOUT_V, "ipsout_v", IIO_VOLTAGE,
> + AXP20X_IPSOUT_V_HIGH_H),
> + AXP20X_ADC_CHANNEL(AXP192_BATT_V, "batt_v", IIO_VOLTAGE,
> + AXP20X_BATT_V_H),
> + AXP20X_ADC_CHANNEL(AXP192_BATT_CHRG_I, "batt_chrg_i", IIO_CURRENT,
> + AXP20X_BATT_CHRG_I_H),
> + AXP20X_ADC_CHANNEL(AXP192_BATT_DISCHRG_I, "batt_dischrg_i", IIO_CURRENT,
> + AXP20X_BATT_DISCHRG_I_H),
> + AXP20X_ADC_CHANNEL(AXP192_TS_IN, "ts_v", IIO_VOLTAGE,
> + AXP20X_TS_IN_H),
> +};
> +
> static const struct iio_chan_spec axp20x_adc_channels[] = {
> AXP20X_ADC_CHANNEL(AXP20X_ACIN_V, "acin_v", IIO_VOLTAGE,
> AXP20X_ACIN_V_ADC_H),
> @@ -277,6 +345,44 @@ static int axp813_adc_raw(struct iio_dev *indio_dev,
> return IIO_VAL_INT;
> }
>
> +static int axp192_adc_scale_voltage(int channel, int *val, int *val2)
> +{
> + switch (channel) {
> + case AXP192_ACIN_V:
> + case AXP192_VBUS_V:
> + *val = 1;
> + *val2 = 700000;
> + return IIO_VAL_INT_PLUS_MICRO;
> +
> + case AXP192_GPIO0_V:
> + case AXP192_GPIO1_V:
> + case AXP192_GPIO2_V:
> + case AXP192_GPIO3_V:
> + *val = 0;
> + *val2 = 500000;
> + return IIO_VAL_INT_PLUS_MICRO;
> +
> + case AXP192_BATT_V:
> + *val = 1;
> + *val2 = 100000;
> + return IIO_VAL_INT_PLUS_MICRO;
> +
> + case AXP192_IPSOUT_V:
> + *val = 1;
> + *val2 = 400000;
> + return IIO_VAL_INT_PLUS_MICRO;
> +
> + case AXP192_TS_IN:
> + /* 0.8 mV per LSB */
> + *val = 0;
> + *val2 = 800000;
> + return IIO_VAL_INT_PLUS_MICRO;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static int axp20x_adc_scale_voltage(int channel, int *val, int *val2)
> {
> switch (channel) {
> @@ -380,6 +486,29 @@ static int axp20x_adc_scale_current(int channel, int *val, int *val2)
> }
> }
>
> +static int axp192_adc_scale(struct iio_chan_spec const *chan, int *val,
> + int *val2)
> +{
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + return axp192_adc_scale_voltage(chan->channel, val, val2);
> +
> + case IIO_CURRENT:
> + /*
> + * AXP192 current channels are identical to the AXP20x,
> + * therefore we can re-use the scaling function.
> + */
> + return axp20x_adc_scale_current(chan->channel, val, val2);
> +
> + case IIO_TEMP:
> + *val = 100;
> + return IIO_VAL_INT;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static int axp20x_adc_scale(struct iio_chan_spec const *chan, int *val,
> int *val2)
> {
> @@ -439,6 +568,42 @@ static int axp813_adc_scale(struct iio_chan_spec const *chan, int *val,
> }
> }
>
> +static int axp192_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
> + int *val)
> +{
> + struct axp20x_adc_iio *info = iio_priv(indio_dev);
> + int ret;
> +
> + ret = regmap_read(info->regmap, AXP192_GPIO30_IN_RANGE, val);
> + if (ret < 0)
> + return ret;
> +
> + switch (channel) {
> + case AXP192_GPIO0_V:
> + *val &= AXP192_GPIO30_IN_RANGE_GPIO0;

Obviously existing case does it this way, but I'd prefer a local variable
and FIELD_GET() for these. Reusing *val for this is confusing.

A precursor patch to tidy up earlier code would be great if you have
time.

> + break;
> +
> + case AXP192_GPIO1_V:
> + *val &= AXP192_GPIO30_IN_RANGE_GPIO1;
> + break;
> +
> + case AXP192_GPIO2_V:
> + *val &= AXP192_GPIO30_IN_RANGE_GPIO2;
> + break;
> +
> + case AXP192_GPIO3_V:
> + *val &= AXP192_GPIO30_IN_RANGE_GPIO3;
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> +
> + *val = *val ? 700000 : 0;
> +
> + return IIO_VAL_INT;
> +}
> +
> static int axp20x_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
> int *val)
> {
> @@ -467,6 +632,22 @@ static int axp20x_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
> return IIO_VAL_INT;
> }
>
> +static int axp192_adc_offset(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val)
> +{
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + return axp192_adc_offset_voltage(indio_dev, chan->channel, val);
> +
> + case IIO_TEMP:
> + *val = -1447;
> + return IIO_VAL_INT;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static int axp20x_adc_offset(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan, int *val)
> {
> @@ -483,6 +664,25 @@ static int axp20x_adc_offset(struct iio_dev *indio_dev,
> }
> }
>
> +static int axp192_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val,
> + int *val2, long mask)
> +{
> + switch (mask) {
> + case IIO_CHAN_INFO_OFFSET:
> + return axp192_adc_offset(indio_dev, chan, val);
> +
> + case IIO_CHAN_INFO_SCALE:
> + return axp192_adc_scale(chan, val, val2);
> +
> + case IIO_CHAN_INFO_RAW:
> + return axp20x_adc_raw(indio_dev, chan, val);
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static int axp20x_read_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan, int *val,
> int *val2, long mask)
> @@ -543,6 +743,54 @@ static int axp813_read_raw(struct iio_dev *indio_dev,
> }
> }
>
> +static int axp192_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int val, int val2,
> + long mask)
> +{
> + struct axp20x_adc_iio *info = iio_priv(indio_dev);
> + unsigned int reg, regval;
> +
> + /*
> + * The AXP192 PMIC allows the user to choose between 0V and 0.7V offsets
> + * for (independently) GPIO0-3 when in ADC mode.
> + */
> + if (mask != IIO_CHAN_INFO_OFFSET)
> + return -EINVAL;
> +
> + if (val != 0 && val != 700000)
> + return -EINVAL;
> +
> + val = val ? 1 : 0;

Use a local variable for this. It's no longer val in any way so the
reuse is confusing.

> +
> + switch (chan->channel) {
> + case AXP192_GPIO0_V:
> + reg = AXP192_GPIO30_IN_RANGE_GPIO0;
> + regval = AXP192_GPIO30_IN_RANGE_GPIO0_VAL(val);

FIELD_PREP()

> + break;
> +
> + case AXP192_GPIO1_V:
> + reg = AXP192_GPIO30_IN_RANGE_GPIO1;
> + regval = AXP192_GPIO30_IN_RANGE_GPIO1_VAL(val);
> + break;
> +
> + case AXP192_GPIO2_V:
> + reg = AXP192_GPIO30_IN_RANGE_GPIO2;
> + regval = AXP192_GPIO30_IN_RANGE_GPIO2_VAL(val);
> + break;
> +
> + case AXP192_GPIO3_V:
> + reg = AXP192_GPIO30_IN_RANGE_GPIO3;
> + regval = AXP192_GPIO30_IN_RANGE_GPIO3_VAL(val);
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> +
> + return regmap_update_bits(info->regmap, AXP192_GPIO30_IN_RANGE, reg,
> + regval);
> +}
> +
> static int axp20x_write_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan, int val, int val2,
> long mask)
> @@ -581,6 +829,18 @@ static int axp20x_write_raw(struct iio_dev *indio_dev,
> regval);
> }
>
> +static int axp192_read_label(struct iio_dev *iio_dev,
> + const struct iio_chan_spec *chan, char *label)
> +{
> + return snprintf(label, PAGE_SIZE, "%s\n", chan->datasheet_name);
> +}

Unless I missed a previous patch adding labels to the other devices supported,
this is the first driver to use these. Why do they make sense here but not
to add to existing supported devices?

I don't particularly mind this addition, just looking for an explanation.

> +
> +static const struct iio_info axp192_adc_iio_info = {
> + .read_raw = axp192_read_raw,
> + .write_raw = axp192_write_raw,
> + .read_label = axp192_read_label,
> +};
> +
> static const struct iio_info axp20x_adc_iio_info = {
> .read_raw = axp20x_read_raw,
> .write_raw = axp20x_write_raw,
> @@ -620,19 +880,29 @@ struct axp_data {
> int num_channels;
> struct iio_chan_spec const *channels;
> unsigned long adc_en1_mask;
> + unsigned long adc_en2_mask;
> int (*adc_rate)(struct axp20x_adc_iio *info,
> int rate);
> - bool adc_en2;
> struct iio_map *maps;
> };
>
> +static const struct axp_data axp192_data = {
> + .iio_info = &axp192_adc_iio_info,
> + .num_channels = ARRAY_SIZE(axp192_adc_channels),
> + .channels = axp192_adc_channels,
> + .adc_en1_mask = AXP192_ADC_EN1_MASK,
> + .adc_en2_mask = AXP192_ADC_EN2_MASK,
> + .adc_rate = axp20x_adc_rate,
> + .maps = axp20x_maps,
> +};
> +
> static const struct axp_data axp20x_data = {
> .iio_info = &axp20x_adc_iio_info,
> .num_channels = ARRAY_SIZE(axp20x_adc_channels),
> .channels = axp20x_adc_channels,
> .adc_en1_mask = AXP20X_ADC_EN1_MASK,
> + .adc_en2_mask = AXP20X_ADC_EN2_MASK,
> .adc_rate = axp20x_adc_rate,
> - .adc_en2 = true,
> .maps = axp20x_maps,
> };
>
> @@ -642,7 +912,6 @@ static const struct axp_data axp22x_data = {
> .channels = axp22x_adc_channels,
> .adc_en1_mask = AXP22X_ADC_EN1_MASK,
> .adc_rate = axp22x_adc_rate,
> - .adc_en2 = false,
> .maps = axp22x_maps,
> };
>
> @@ -652,11 +921,11 @@ static const struct axp_data axp813_data = {
> .channels = axp813_adc_channels,
> .adc_en1_mask = AXP22X_ADC_EN1_MASK,
> .adc_rate = axp813_adc_rate,
> - .adc_en2 = false,
> .maps = axp22x_maps,
> };
>
> static const struct of_device_id axp20x_adc_of_match[] = {
> + { .compatible = "x-powers,axp192-adc", .data = (void *)&axp192_data, },
> { .compatible = "x-powers,axp209-adc", .data = (void *)&axp20x_data, },
> { .compatible = "x-powers,axp221-adc", .data = (void *)&axp22x_data, },
> { .compatible = "x-powers,axp813-adc", .data = (void *)&axp813_data, },
> @@ -665,6 +934,7 @@ static const struct of_device_id axp20x_adc_of_match[] = {
> MODULE_DEVICE_TABLE(of, axp20x_adc_of_match);
>
> static const struct platform_device_id axp20x_adc_id_match[] = {
> + { .name = "axp192-adc", .driver_data = (kernel_ulong_t)&axp192_data, },
> { .name = "axp20x-adc", .driver_data = (kernel_ulong_t)&axp20x_data, },
> { .name = "axp22x-adc", .driver_data = (kernel_ulong_t)&axp22x_data, },
> { .name = "axp813-adc", .driver_data = (kernel_ulong_t)&axp813_data, },
> @@ -710,10 +980,11 @@ static int axp20x_probe(struct platform_device *pdev)
> /* Enable the ADCs on IP */
> regmap_write(info->regmap, AXP20X_ADC_EN1, info->data->adc_en1_mask);
>
> - if (info->data->adc_en2)
> - /* Enable GPIO0/1 and internal temperature ADCs */
> + if (info->data->adc_en2_mask)
> + /* Enable GPIO and internal temperature ADCs */
> regmap_update_bits(info->regmap, AXP20X_ADC_EN2,
> - AXP20X_ADC_EN2_MASK, AXP20X_ADC_EN2_MASK);
> + info->data->adc_en2_mask,
> + info->data->adc_en2_mask);
>
> /* Configure ADCs rate */
> info->data->adc_rate(info, 100);
> @@ -738,7 +1009,7 @@ static int axp20x_probe(struct platform_device *pdev)
> fail_map:
> regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
>
> - if (info->data->adc_en2)
> + if (info->data->adc_en2_mask)
> regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
>
> return ret;
> @@ -754,7 +1025,7 @@ static int axp20x_remove(struct platform_device *pdev)
>
> regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
>
> - if (info->data->adc_en2)
> + if (info->data->adc_en2_mask)
> regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
>
> return 0;

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