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

Peter Rosin
2016-11-08T19:36:56Z

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>
---
.../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,
};
--
2.1.4