[PATCH v4 1/1] iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs

From: Fabien Lahoudere
Date: Tue Jul 09 2019 - 07:54:16 EST


Embedded controller return minimum and maximum frequencies, unfortunately
we have no way to know the step for all available frequencies.
Even if not complete, we can return a list of known values using the
standard read_avail callback (IIO_CHAN_INFO_SAMP_FREQ) to provide them to
userland.

Now cros_ec_* sensors provides frequencies values in sysfs like this:
"0 min max". 0 is always true to disable the sensor.

Default frequencies are provided for earlier protocol.

Signed-off-by: Nick Vaccaro <nvaccaro@xxxxxxxxxxxx>
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@xxxxxxxxxxxxx>
---
.../common/cros_ec_sensors/cros_ec_sensors.c | 3 +
.../cros_ec_sensors/cros_ec_sensors_core.c | 65 +++++++++++++++++++
drivers/iio/light/cros_ec_light_prox.c | 3 +
.../linux/iio/common/cros_ec_sensors_core.h | 21 ++++++
4 files changed, 92 insertions(+)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index 17af4e0fd5f8..2f1b6d8d617b 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -175,6 +175,7 @@ static int cros_ec_sensors_write(struct iio_dev *indio_dev,
static const struct iio_info ec_sensors_info = {
.read_raw = &cros_ec_sensors_read,
.write_raw = &cros_ec_sensors_write,
+ .read_avail = &cros_ec_sensors_core_read_avail,
};

static int cros_ec_sensors_probe(struct platform_device *pdev)
@@ -211,6 +212,8 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_FREQUENCY) |
BIT(IIO_CHAN_INFO_SAMP_FREQ);
+ channel->info_mask_shared_by_all_available =
+ BIT(IIO_CHAN_INFO_SAMP_FREQ);
channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
channel->scan_index = i;
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 81111af8a167..805652250960 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -50,6 +50,37 @@ static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
return ret;
}

+static void get_default_min_max_freq(enum motionsensor_type type,
+ u32 *min_freq,
+ u32 *max_freq)
+{
+ switch (type) {
+ case MOTIONSENSE_TYPE_ACCEL:
+ case MOTIONSENSE_TYPE_GYRO:
+ *min_freq = 12500;
+ *max_freq = 100000;
+ break;
+ case MOTIONSENSE_TYPE_MAG:
+ *min_freq = 5000;
+ *max_freq = 25000;
+ break;
+ case MOTIONSENSE_TYPE_PROX:
+ case MOTIONSENSE_TYPE_LIGHT:
+ *min_freq = 100;
+ *max_freq = 50000;
+ break;
+ case MOTIONSENSE_TYPE_BARO:
+ *min_freq = 250;
+ *max_freq = 20000;
+ break;
+ case MOTIONSENSE_TYPE_ACTIVITY:
+ default:
+ *min_freq = 0;
+ *max_freq = 0;
+ break;
+ }
+}
+
int cros_ec_sensors_core_init(struct platform_device *pdev,
struct iio_dev *indio_dev,
bool physical_device)
@@ -100,6 +131,19 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
}
state->type = state->resp->info.type;
state->loc = state->resp->info.location;
+
+ /* 0 is a correct value used to stop the device */
+ state->frequencies[0] = 0;
+ if (state->msg->version < 3) {
+ get_default_min_max_freq(state->resp->info.type,
+ &state->frequencies[1],
+ &state->frequencies[2]);
+ } else {
+ state->frequencies[1] =
+ state->resp->info_3.min_frequency;
+ state->frequencies[2] =
+ state->resp->info_3.max_frequency;
+ }
}

return 0;
@@ -461,6 +505,27 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);

+int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals,
+ int *type,
+ int *length,
+ long mask)
+{
+ struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *length = ARRAY_SIZE(state->frequencies);
+ *vals = (const int *)&state->frequencies;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read_avail);
+
int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
index 308ee6ff2e22..c62cb022b6bc 100644
--- a/drivers/iio/light/cros_ec_light_prox.c
+++ b/drivers/iio/light/cros_ec_light_prox.c
@@ -164,6 +164,7 @@ static int cros_ec_light_prox_write(struct iio_dev *indio_dev,
static const struct iio_info cros_ec_light_prox_info = {
.read_raw = &cros_ec_light_prox_read,
.write_raw = &cros_ec_light_prox_write,
+ .read_avail = &cros_ec_sensors_core_read_avail,
};

static int cros_ec_light_prox_probe(struct platform_device *pdev)
@@ -198,6 +199,8 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
channel->info_mask_shared_by_all =
BIT(IIO_CHAN_INFO_SAMP_FREQ) |
BIT(IIO_CHAN_INFO_FREQUENCY);
+ channel->info_mask_shared_by_all_available =
+ BIT(IIO_CHAN_INFO_SAMP_FREQ);
channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
channel->scan_type.shift = 0;
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index 0c636b9fe8d7..a9623111f7c9 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -70,6 +70,9 @@ struct cros_ec_sensors_core_state {
unsigned long scan_mask, s16 *data);

int curr_sampl_freq;
+
+ /* Table of known available frequencies : 0, Min and Max in mHz */
+ int frequencies[3];
};

/**
@@ -150,6 +153,24 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask);

+/**
+ * cros_ec_sensors_core_read_avail() - get available values
+ * @indio_dev: pointer to state information for device
+ * @chan: channel specification structure table
+ * @vals: list of available values
+ * @type: type of data returned
+ * @length: number of data returned in the array
+ * @mask: specifies which values to be requested
+ *
+ * Return: an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST
+ */
+int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals,
+ int *type,
+ int *length,
+ long mask);
+
/**
* cros_ec_sensors_core_write() - function to write a value to the sensor
* @st: pointer to state information for device
--
2.19.2