iio: mcp4531: provide range of available raw values

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531 b/Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531
new file mode 100644 (file)
index 0000000..2a91fbe
--- /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 ec1ee3ef112e9bd1a571a675f865fd472f21c545..1395246819d21d311d5845950f5d9b0cf15eb0e5 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7709,6 +7709,7 @@ 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 13b6ae2fcf7b2cda84553ec95372cfc38020fcfc..0d1bcf89ae17cedbc4405970197554f6548e75d0 100644 (file)
--- 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,
 };