Re: [PATCH v4 3/8] iio: mcp4531: provide range of available raw values

Jonathan Cameron
2016-11-12T17:22:45Z

On 08/11/16 11:58, Peter Rosin wrote:
> Example:
>
> $ cat '/sys/bus/iio/devices/iio:device0/out_resistance_raw_available'
> [0 1 256]
>
> Meaning: min 0, step 1 and max 256.
>
> Signed-off-by: Peter Rosin <peda@axentia.se>
Applied.
> ---
> .../testing/sysfs-bus-iio-potentiometer-mcp4531 | 8 ++
> MAINTAINERS | 1 +
> drivers/iio/potentiometer/mcp4531.c | 104 ++++++++++++---------
> 3 files changed, 71 insertions(+), 42 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531 b/Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531
> new file mode 100644
> index 000000000000..2a91fbe394fc
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531
> @@ -0,0 +1,8 @@
> +What: /sys/bus/iio/devices/iio:deviceX/out_resistance_raw_available
> +Date: October 2016
> +KernelVersion: 4.9
> +Contact: Peter Rosin <peda@axentia.se>
> +Description:
> + The range of available values represented as the minimum value,
> + the step and the maximum value, all enclosed in square brackets.
> + Example: [0 1 256]
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 411e3b87b8c2..2409e1d79cb6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7707,6 +7707,7 @@ MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVER
> M: Peter Rosin <peda@axentia.se>
> L: linux-iio@vger.kernel.org
> S: Maintained
> +F: Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531
> F: drivers/iio/potentiometer/mcp4531.c
>
> MEASUREMENT COMPUTING CIO-DAC IIO DRIVER
> diff --git a/drivers/iio/potentiometer/mcp4531.c b/drivers/iio/potentiometer/mcp4531.c
> index 13b6ae2fcf7b..0d1bcf89ae17 100644
> --- a/drivers/iio/potentiometer/mcp4531.c
> +++ b/drivers/iio/potentiometer/mcp4531.c
> @@ -38,7 +38,7 @@
>
> struct mcp4531_cfg {
> int wipers;
> - int max_pos;
> + int avail[3];
> int kohms;
> };
>
> @@ -78,38 +78,38 @@ enum mcp4531_type {
> };
>
> static const struct mcp4531_cfg mcp4531_cfg[] = {
> - [MCP453x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, },
> - [MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
> - [MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
> - [MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
> - [MCP454x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, },
> - [MCP454x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
> - [MCP454x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
> - [MCP454x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
> - [MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
> - [MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
> - [MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
> - [MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
> - [MCP456x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
> - [MCP456x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
> - [MCP456x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
> - [MCP456x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
> - [MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
> - [MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
> - [MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
> - [MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
> - [MCP464x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
> - [MCP464x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
> - [MCP464x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
> - [MCP464x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
> - [MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
> - [MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
> - [MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
> - [MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
> - [MCP466x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
> - [MCP466x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
> - [MCP466x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
> - [MCP466x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
> + [MCP453x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 5, },
> + [MCP453x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 10, },
> + [MCP453x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 50, },
> + [MCP453x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
> + [MCP454x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 5, },
> + [MCP454x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 10, },
> + [MCP454x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 50, },
> + [MCP454x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
> + [MCP455x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 5, },
> + [MCP455x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 10, },
> + [MCP455x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 50, },
> + [MCP455x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
> + [MCP456x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 5, },
> + [MCP456x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 10, },
> + [MCP456x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 50, },
> + [MCP456x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
> + [MCP463x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 5, },
> + [MCP463x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 10, },
> + [MCP463x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 50, },
> + [MCP463x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
> + [MCP464x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 5, },
> + [MCP464x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 10, },
> + [MCP464x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 50, },
> + [MCP464x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
> + [MCP465x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 5, },
> + [MCP465x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 10, },
> + [MCP465x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 50, },
> + [MCP465x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
> + [MCP466x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 5, },
> + [MCP466x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 10, },
> + [MCP466x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 50, },
> + [MCP466x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
> };
>
> #define MCP4531_WRITE (0 << 2)
> @@ -124,13 +124,14 @@ struct mcp4531_data {
> const struct mcp4531_cfg *cfg;
> };
>
> -#define MCP4531_CHANNEL(ch) { \
> - .type = IIO_RESISTANCE, \
> - .indexed = 1, \
> - .output = 1, \
> - .channel = (ch), \
> - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> +#define MCP4531_CHANNEL(ch) { \
> + .type = IIO_RESISTANCE, \
> + .indexed = 1, \
> + .output = 1, \
> + .channel = (ch), \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> + .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
> }
>
> static const struct iio_chan_spec mcp4531_channels[] = {
> @@ -156,13 +157,31 @@ static int mcp4531_read_raw(struct iio_dev *indio_dev,
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SCALE:
> *val = 1000 * data->cfg->kohms;
> - *val2 = data->cfg->max_pos;
> + *val2 = data->cfg->avail[2];
> return IIO_VAL_FRACTIONAL;
> }
>
> return -EINVAL;
> }
>
> +static int mcp4531_read_avail(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + const int **vals, int *type, int *length,
> + long mask)
> +{
> + struct mcp4531_data *data = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + *length = ARRAY_SIZE(data->cfg->avail);
> + *vals = data->cfg->avail;
> + *type = IIO_VAL_INT;
> + return IIO_AVAIL_RANGE;
> + }
> +
> + return -EINVAL;
> +}
> +
> static int mcp4531_write_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int val, int val2, long mask)
> @@ -172,7 +191,7 @@ static int mcp4531_write_raw(struct iio_dev *indio_dev,
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> - if (val > data->cfg->max_pos || val < 0)
> + if (val > data->cfg->avail[2] || val < 0)
> return -EINVAL;
> break;
> default:
> @@ -186,6 +205,7 @@ static int mcp4531_write_raw(struct iio_dev *indio_dev,
>
> static const struct iio_info mcp4531_info = {
> .read_raw = mcp4531_read_raw,
> + .read_avail = mcp4531_read_avail,
> .write_raw = mcp4531_write_raw,
> .driver_module = THIS_MODULE,
> };
>