[PATCHv2 0/3] IIO: Add support for compass north usage attribute

[PATCHv2 0/3] IIO: Add support for compass north usage attribute

[Reyad Attiyat]

The following patches allow the hid-sensor-magn-3d driver to handle
the north usage attribute. It allows the driver to dynamically
create IIO channels depending on which HID reports are found.

Reyad Attiyat (3):
  IIO: Documentation: Add north attribute to ABI docs
  IIO: Add iio_chan modifier for True/Magnetic North HID usages
  IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID
    usages

 Documentation/ABI/testing/sysfs-bus-iio       |  76 ++++++++
 drivers/iio/industrialio-core.c               |   4 +
 drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271 +++++++++++++++++---------
 include/linux/iio/types.h                     |   4 +
 4 files changed, 261 insertions(+), 94 deletions(-)

-- 
1.9.3

[PATCHv2 1/3] IIO: Documentation: Add north attribute to ABI docs

[Reyad Attiyat]

Updated ABI documentation to inculde compass north usages.

Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
---
 Documentation/ABI/testing/sysfs-bus-iio | 76 +++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 6e02c50..251c2bb 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -165,6 +165,10 @@ Description:
 What:		/sys/bus/iio/devices/iio:deviceX/in_magn_x_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_magn_y_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_magn_z_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_tilt_comp_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_tilt_comp_raw
 KernelVersion:	2.6.35
 Contact:	linux-iio@vger.kernel.org
 Description:
@@ -249,6 +253,10 @@ What:		/sys/bus/iio/devices/iio:deviceX/in_magn_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_magn_x_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_magn_y_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_magn_z_scale
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_scale
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_scale
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_tilt_comp_scale
+What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_tilt_comp_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_pressureY_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_pressure_scale
 KernelVersion:	2.6.35
@@ -436,6 +444,14 @@ What:		/sys/.../iio:deviceX/events/in_magn_y_thresh_rising_en
 What:		/sys/.../iio:deviceX/events/in_magn_y_thresh_falling_en
 What:		/sys/.../iio:deviceX/events/in_magn_z_thresh_rising_en
 What:		/sys/.../iio:deviceX/events/in_magn_z_thresh_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_thresh_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_thresh_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_true_thresh_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_true_thresh_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_thresh_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_thresh_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_thresh_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_thresh_falling_en
 What:		/sys/.../iio:deviceX/events/in_voltageY_supply_thresh_rising_en
 What:		/sys/.../iio:deviceX/events/in_voltageY_supply_thresh_falling_en
 What:		/sys/.../iio:deviceX/events/in_voltageY_thresh_rising_en
@@ -481,6 +497,14 @@ What:		/sys/.../iio:deviceX/events/in_magn_y_roc_rising_en
 What:		/sys/.../iio:deviceX/events/in_magn_y_roc_falling_en
 What:		/sys/.../iio:deviceX/events/in_magn_z_roc_rising_en
 What:		/sys/.../iio:deviceX/events/in_magn_z_roc_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_roc_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_roc_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_true_roc_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_true_roc_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_roc_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_roc_falling_en
+What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_roc_rising_en
+What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_roc_falling_en
 What:		/sys/.../iio:deviceX/events/in_voltageY_supply_roc_rising_en
 What:		/sys/.../iio:deviceX/events/in_voltageY_supply_roc_falling_en
 What:		/sys/.../iio:deviceX/events/in_voltageY_roc_rising_en
@@ -527,6 +551,14 @@ What:		/sys/.../events/in_magn_y_raw_thresh_rising_value
 What:		/sys/.../events/in_magn_y_raw_thresh_falling_value
 What:		/sys/.../events/in_magn_z_raw_thresh_rising_value
 What:		/sys/.../events/in_magn_z_raw_thresh_falling_value
+What:		/sys/.../events/in_north_magnetic_raw_thresh_rising_value
+What:		/sys/.../events/in_north_magnetic_raw_thresh_falling_value
+What:		/sys/.../events/in_north_true_raw_thresh_rising_value
+What:		/sys/.../events/in_north_true_raw_thresh_falling_value
+What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_thresh_rising_value
+What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_thresh_falling_value
+What:		/sys/.../events/in_north_true_tilt_comp_raw_thresh_rising_value
+What:		/sys/.../events/in_north_true_tilt_comp_raw_thresh_falling_value
 What:		/sys/.../events/in_voltageY_supply_raw_thresh_rising_value
 What:		/sys/.../events/in_voltageY_supply_raw_thresh_falling_value
 What:		/sys/.../events/in_voltageY_raw_thresh_rising_value
@@ -577,6 +609,18 @@ What:		/sys/.../events/in_magn_y_thresh_either_hysteresis
 What:		/sys/.../events/in_magn_z_thresh_rising_hysteresis
 What:		/sys/.../events/in_magn_z_thresh_falling_hysteresis
 What:		/sys/.../events/in_magn_z_thresh_either_hysteresis
+What:		/sys/.../events/in_north_magnetic_thresh_rising_hysteresis
+What:		/sys/.../events/in_north_magnetic_thresh_falling_hysteresis
+What:		/sys/.../events/in_north_magnetic_thresh_either_hysteresis
+What:		/sys/.../events/in_north_true_thresh_rising_hysteresis
+What:		/sys/.../events/in_north_true_thresh_falling_hysteresis
+What:		/sys/.../events/in_north_true_thresh_either_hysteresis
+What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_rising_hysteresis
+What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_falling_hysteresis
+What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_either_hysteresis
+What:		/sys/.../events/in_north_true_tilt_comp_thresh_rising_hysteresis
+What:		/sys/.../events/in_north_true_tilt_comp_thresh_falling_hysteresis
+What:		/sys/.../events/in_north_true_tilt_comp_thresh_either_hysteresis
 What:		/sys/.../events/in_voltageY_thresh_rising_hysteresis
 What:		/sys/.../events/in_voltageY_thresh_falling_hysteresis
 What:		/sys/.../events/in_voltageY_thresh_either_hysteresis
@@ -624,6 +668,14 @@ What:		/sys/.../events/in_magn_y_raw_roc_rising_value
 What:		/sys/.../events/in_magn_y_raw_roc_falling_value
 What:		/sys/.../events/in_magn_z_raw_roc_rising_value
 What:		/sys/.../events/in_magn_z_raw_roc_falling_value
+What:		/sys/.../events/in_north_magnetic_raw_roc_rising_value
+What:		/sys/.../events/in_north_magnetic_raw_roc_falling_value
+What:		/sys/.../events/in_north_true_raw_roc_rising_value
+What:		/sys/.../events/in_north_true_raw_roc_falling_value
+What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_roc_rising_value
+What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_roc_falling_value
+What:		/sys/.../events/in_north_true_tilt_comp_raw_roc_rising_value
+What:		/sys/.../events/in_north_true_tilt_comp_raw_roc_falling_value
 What:		/sys/.../events/in_voltageY_supply_raw_roc_rising_value
 What:		/sys/.../events/in_voltageY_supply_raw_roc_falling_value
 What:		/sys/.../events/in_voltageY_raw_roc_rising_value
@@ -679,6 +731,22 @@ What:		/sys/.../events/in_magn_z_thresh_rising_period
 What:		/sys/.../events/in_magn_z_thresh_falling_period
 What:		/sys/.../events/in_magn_z_roc_rising_period
 What:		/sys/.../events/in_magn_z_roc_falling_period
+What:		/sys/.../events/in_north_magnetic_thresh_rising_period
+What:		/sys/.../events/in_north_magnetic_thresh_falling_period
+What:		/sys/.../events/in_north_magnetic_roc_rising_period
+What:		/sys/.../events/in_north_magnetic_roc_falling_period
+What:		/sys/.../events/in_north_true_thresh_rising_period
+What:		/sys/.../events/in_north_true_thresh_falling_period
+What:		/sys/.../events/in_north_true_roc_rising_period
+What:		/sys/.../events/in_north_true_roc_falling_period
+What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_rising_period
+What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_falling_period
+What:		/sys/.../events/in_north_magnetic_tilt_comp_roc_rising_period
+What:		/sys/.../events/in_north_magnetic_tilt_comp_roc_falling_period
+What:		/sys/.../events/in_north_true_tilt_comp_thresh_rising_period
+What:		/sys/.../events/in_north_true_tilt_comp_thresh_falling_period
+What:		/sys/.../events/in_north_true_tilt_comp_roc_rising_period
+What:		/sys/.../events/in_north_true_tilt_comp_roc_falling_period
 What:		/sys/.../events/in_voltageY_supply_thresh_rising_period
 What:		/sys/.../events/in_voltageY_supply_thresh_falling_period
 What:		/sys/.../events/in_voltageY_supply_roc_rising_period
@@ -776,6 +844,10 @@ What:		/sys/.../iio:deviceX/scan_elements/in_anglvel_z_en
 What:		/sys/.../iio:deviceX/scan_elements/in_magn_x_en
 What:		/sys/.../iio:deviceX/scan_elements/in_magn_y_en
 What:		/sys/.../iio:deviceX/scan_elements/in_magn_z_en
+What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_en
+What:		/sys/.../iio:deviceX/scan_elements/in_north_true_en
+What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_tilt_comp_en
+What:		/sys/.../iio:deviceX/scan_elements/in_north_true_tilt_comp_en
 What:		/sys/.../iio:deviceX/scan_elements/in_timestamp_en
 What:		/sys/.../iio:deviceX/scan_elements/in_voltageY_supply_en
 What:		/sys/.../iio:deviceX/scan_elements/in_voltageY_en
@@ -840,6 +912,10 @@ What:		/sys/.../iio:deviceX/scan_elements/in_anglvel_z_index
 What:		/sys/.../iio:deviceX/scan_elements/in_magn_x_index
 What:		/sys/.../iio:deviceX/scan_elements/in_magn_y_index
 What:		/sys/.../iio:deviceX/scan_elements/in_magn_z_index
+What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_index
+What:		/sys/.../iio:deviceX/scan_elements/in_north_true_index
+What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_tilt_comp_index
+What:		/sys/.../iio:deviceX/scan_elements/in_north_true_tilt_comp_index
 What:		/sys/.../iio:deviceX/scan_elements/in_incli_x_index
 What:		/sys/.../iio:deviceX/scan_elements/in_incli_y_index
 What:		/sys/.../iio:deviceX/scan_elements/in_timestamp_index
-- 
1.9.3

[PATCHv2 2/3] IIO: Add iio_chan modifier for True/Magnetic North HID usages

[Reyad Attiyat]

Updated iio modifier enum for compass north usages,
including magnetic/true north with tilt compensation.

Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
---
 drivers/iio/industrialio-core.c | 4 ++++
 include/linux/iio/types.h       | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index ede16aec..2f523b5 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -84,6 +84,10 @@ static const char * const iio_modifier_names[] = {
 	[IIO_MOD_LIGHT_RED] = "red",
 	[IIO_MOD_LIGHT_GREEN] = "green",
 	[IIO_MOD_LIGHT_BLUE] = "blue",
+	[IIO_MOD_NORTH_MAGN] = "north_magnetic",
+	[IIO_MOD_NORTH_TRUE] = "north_true",
+	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "north_magnetic_tilt_comp",
+	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "north_true_tilt_comp",
 };
 
 /* relies on pairs of these shared then separate */
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 084d882..5bf8847 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -53,6 +53,10 @@ enum iio_modifier {
 	IIO_MOD_LIGHT_RED,
 	IIO_MOD_LIGHT_GREEN,
 	IIO_MOD_LIGHT_BLUE,
+	IIO_MOD_NORTH_MAGN,
+	IIO_MOD_NORTH_TRUE,
+	IIO_MOD_NORTH_MAGN_TILT_COMP,
+	IIO_MOD_NORTH_TRUE_TILT_COMP
 };
 
 enum iio_event_type {
-- 
1.9.3

[PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Reyad Attiyat]

Updated magn_3d_channel enum for all possible north channels

Added functions to setup iio_chan_spec array depending on which hid usage reports are found

Renamed magn_val to iio_val to differentiate the index being used

Updated magn_3d_state struct to hold pointer array (magn_val_addr[]) which points to iio_val[]

Updated magn_3d_parse_report to scan for all compass usages and create iio channels for each

Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
---
 drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271 +++++++++++++++++---------
 1 file changed, 177 insertions(+), 94 deletions(-)

diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
index 6d162b7..32f4d90 100644
--- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
+++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
@@ -34,63 +34,54 @@ enum magn_3d_channel {
 	CHANNEL_SCAN_INDEX_X,
 	CHANNEL_SCAN_INDEX_Y,
 	CHANNEL_SCAN_INDEX_Z,
+	CHANNEL_SCAN_INDEX_NORTH_MAGN,
+	CHANNEL_SCAN_INDEX_NORTH_TRUE,
+	CHANNEL_SCAN_INDEX_NORTH_TILT_COMP,
+	CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
 	MAGN_3D_CHANNEL_MAX,
 };
 
+#define IIO_CHANNEL_MAX MAGN_3D_CHANNEL_MAX
+
 struct magn_3d_state {
 	struct hid_sensor_hub_callbacks callbacks;
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
-	u32 magn_val[MAGN_3D_CHANNEL_MAX];
-};
+	u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
 
-static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
-	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
-	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
-	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
+	u32 iio_val[IIO_CHANNEL_MAX];
+	int num_iio_channels;
 };
 
-/* Channel definitions */
-static const struct iio_chan_spec magn_3d_channels[] = {
-	{
-		.type = IIO_MAGN,
-		.modified = 1,
-		.channel2 = IIO_MOD_X,
-		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
-		BIT(IIO_CHAN_INFO_SCALE) |
-		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
-		BIT(IIO_CHAN_INFO_HYSTERESIS),
-		.scan_index = CHANNEL_SCAN_INDEX_X,
-	}, {
-		.type = IIO_MAGN,
-		.modified = 1,
-		.channel2 = IIO_MOD_Y,
-		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
-		BIT(IIO_CHAN_INFO_SCALE) |
-		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
-		BIT(IIO_CHAN_INFO_HYSTERESIS),
-		.scan_index = CHANNEL_SCAN_INDEX_Y,
-	}, {
-		.type = IIO_MAGN,
-		.modified = 1,
-		.channel2 = IIO_MOD_Z,
-		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
-		BIT(IIO_CHAN_INFO_SCALE) |
-		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
-		BIT(IIO_CHAN_INFO_HYSTERESIS),
-		.scan_index = CHANNEL_SCAN_INDEX_Z,
+/* Find index into magn_3d_state magn[] and magn_val_addr[] from HID Usage  */
+static int magn_3d_usage_id_to_chan_index(unsigned usage_id){
+	int offset = -1;
+
+	switch (usage_id) {
+	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
+		offset = CHANNEL_SCAN_INDEX_X;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
+		offset = CHANNEL_SCAN_INDEX_Y;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
+		offset = CHANNEL_SCAN_INDEX_Z;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
+		offset = CHANNEL_SCAN_INDEX_NORTH_TILT_COMP;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
+		offset = CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
+		offset = CHANNEL_SCAN_INDEX_NORTH_MAGN;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
+		offset = CHANNEL_SCAN_INDEX_NORTH_TRUE;
+		break;
 	}
-};
 
-/* Adjust channel real bits based on report descriptor */
-static void magn_3d_adjust_channel_bit_mask(struct iio_chan_spec *channels,
-						int channel, int size)
-{
-	channels[channel].scan_type.sign = 's';
-	/* Real storage bits will change based on the report desc. */
-	channels[channel].scan_type.realbits = size * 8;
-	/* Maximum size of a sample to capture is u32 */
-	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
+	return offset;
 }
 
 /* Channel read_raw handler */
@@ -101,21 +92,31 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
 {
 	struct magn_3d_state *magn_state = iio_priv(indio_dev);
 	int report_id = -1;
-	u32 address;
+	unsigned usage_id;
+	int chan_index = -1;
 	int ret;
 	int ret_type;
 
+	dev_dbg(&indio_dev->dev, "magn_3d_read_raw\n");
+
 	*val = 0;
 	*val2 = 0;
 	switch (mask) {
 	case 0:
+		/* We store the HID usage ID of the iio channel
+		 * in its address field
+		 */
+		usage_id = chan->address;
+		chan_index = magn_3d_usage_id_to_chan_index(usage_id);
+		if(chan_index < 0)
+			return -EINVAL;
+
 		report_id =
-			magn_state->magn[chan->scan_index].report_id;
-		address = magn_3d_addresses[chan->scan_index];
+			magn_state->magn[chan_index].report_id;
 		if (report_id >= 0)
 			*val = sensor_hub_input_attr_get_raw_value(
 				magn_state->common_attributes.hsdev,
-				HID_USAGE_SENSOR_COMPASS_3D, address,
+				HID_USAGE_SENSOR_COMPASS_3D, usage_id,
 				report_id);
 		else {
 			*val = 0;
@@ -202,12 +203,13 @@ static int magn_3d_proc_event(struct hid_sensor_hub_device *hsdev,
 				magn_state->common_attributes.data_ready);
 	if (magn_state->common_attributes.data_ready)
 		hid_sensor_push_data(indio_dev,
-				magn_state->magn_val,
-				sizeof(magn_state->magn_val));
+				&(magn_state->iio_val),
+				sizeof(magn_state->iio_val));
 
 	return 0;
 }
 
+
 /* Capture samples in local storage */
 static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
 				unsigned usage_id,
@@ -217,63 +219,143 @@ static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
 	struct magn_3d_state *magn_state = iio_priv(indio_dev);
 	int offset;
+	u32 *magn_val;
 	int ret = -EINVAL;
 
-	switch (usage_id) {
+	offset = magn_3d_usage_id_to_chan_index(usage_id);
+	if(offset < 0)
+		return ret;
+
+	magn_val = magn_state->magn_val_addr[offset];
+	if(!magn_val)
+		return ret;
+
+	*(magn_val) =  *(u32 *)raw_data;
+
+	return 0;
+}
+
+/* Setup the iio_chan_spec for HID Usage ID */
+static int magn_3d_setup_new_iio_chan(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				unsigned attr_usage_id,
+				struct iio_chan_spec *iio_chans,
+				struct magn_3d_state *st)
+{
+	int ret = -1;
+	int iio_index;
+	int magn_index;
+	struct iio_chan_spec *channel;
+
+	/* Setup magn_3d_state for new channel */
+	magn_index = magn_3d_usage_id_to_chan_index(attr_usage_id);
+	if(magn_index < 0 || magn_index >= MAGN_3D_CHANNEL_MAX){
+		return -1;
+	}
+
+	/* Check if usage attribute exists in the sensor hub device */
+	ret = sensor_hub_input_get_attribute_info(hsdev,
+		HID_INPUT_REPORT,
+		usage_id,
+		attr_usage_id,
+		&(st->magn[magn_index]));
+	if(ret != 0){
+		/* Usage not found. Nothing to setup.*/
+		return 0;
+	}
+
+	iio_index = st->num_iio_channels;
+	if(iio_index < 0 || iio_index >= IIO_CHANNEL_MAX){
+		return -2;
+	}
+
+	/* Check if this usage hasn't been setup */
+	if(st->magn_val_addr[magn_index] != NULL){
+		return -3;
+	}
+	st->magn_val_addr[magn_index] = &(st->iio_val[iio_index]);
+
+	/* Setup IIO Channel spec */
+	channel = &(iio_chans[iio_index]);
+
+	channel->type = IIO_MAGN;
+	channel->address = attr_usage_id;
+	channel->modified = 1;
+
+	switch (attr_usage_id){
+	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
+		channel->channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
+		channel->channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
+		channel->channel2 = IIO_MOD_NORTH_MAGN;
+		break;
+	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
+		channel->channel2 = IIO_MOD_NORTH_TRUE;
+		break;
 	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
+		channel->channel2 = IIO_MOD_X;
+		break;
 	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
+		channel->channel2 = IIO_MOD_Y;
+		break;
 	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
-		offset = usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
-		magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset] =
-						*(u32 *)raw_data;
-		ret = 0;
-	break;
-	default:
+		channel->channel2 = IIO_MOD_Z;
 		break;
+	default:
+		return -4;
 	}
 
+	channel->info_mask_shared_by_type =
+		BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS);
+
+	channel->scan_type.sign = 's';
+	/* Real storage bits will change based on the report desc. */
+	channel->scan_type.realbits = st->magn[magn_index].size * 8;
+	/* Maximum size of a sample to capture is u32 */
+	channel->scan_type.storagebits = sizeof(u32) * 8;
+
+	(st->num_iio_channels)++;
+	ret = 0;
+
 	return ret;
 }
 
-/* Parse report which is specific to an usage id*/
+/* Read the HID reports and setup IIO Channels */
 static int magn_3d_parse_report(struct platform_device *pdev,
 				struct hid_sensor_hub_device *hsdev,
-				struct iio_chan_spec *channels,
+				struct iio_chan_spec *iio_chans,
 				unsigned usage_id,
 				struct magn_3d_state *st)
 {
-	int ret;
+	int ret = 0;
 	int i;
 
-	for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
-		ret = sensor_hub_input_get_attribute_info(hsdev,
-				HID_INPUT_REPORT,
-				usage_id,
-				HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS + i,
-				&st->magn[CHANNEL_SCAN_INDEX_X + i]);
-		if (ret < 0)
-			break;
-		magn_3d_adjust_channel_bit_mask(channels,
-				CHANNEL_SCAN_INDEX_X + i,
-				st->magn[CHANNEL_SCAN_INDEX_X + i].size);
-	}
-	dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
-			st->magn[0].index,
-			st->magn[0].report_id,
-			st->magn[1].index, st->magn[1].report_id,
-			st->magn[2].index, st->magn[2].report_id);
-
-	/* Set Sensitivity field ids, when there is no individual modifier */
-	if (st->common_attributes.sensitivity.index < 0) {
-		sensor_hub_input_get_attribute_info(hsdev,
-			HID_FEATURE_REPORT, usage_id,
-			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
-			HID_USAGE_SENSOR_DATA_ORIENTATION,
-			&st->common_attributes.sensitivity);
-		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
-			st->common_attributes.sensitivity.index,
-			st->common_attributes.sensitivity.report_id);
-	}
+	dev_dbg(&pdev->dev, "magn_3d_parse_reports Usage ID: %x\n", usage_id);
+	for(i = HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
+	    i <= HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS && ret == 0;
+		i++)
+			ret = magn_3d_setup_new_iio_chan(hsdev,
+					usage_id,
+					i,
+					iio_chans,
+					st);
+
+	dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic axis. Returned: %d", st->num_iio_channels, ret);
+	for(i = HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH;
+	    i <= HID_USAGE_SENSOR_ORIENT_TRUE_NORTH && ret == 0;
+		i++)
+			ret = magn_3d_setup_new_iio_chan(hsdev,
+					usage_id,
+					i,
+					iio_chans,
+					st);
+	dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic channels. Returned: %d", st->num_iio_channels, ret);
 
 	return ret;
 }
@@ -307,10 +389,11 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	channels = kmemdup(magn_3d_channels, sizeof(magn_3d_channels),
-			   GFP_KERNEL);
+	channels = kcalloc(MAGN_3D_CHANNEL_MAX,
+			sizeof(struct iio_chan_spec),
+			GFP_KERNEL);
 	if (!channels) {
-		dev_err(&pdev->dev, "failed to duplicate channels\n");
+		dev_err(&pdev->dev, "failed to allocate memory for iio channel\n");
 		return -ENOMEM;
 	}
 
@@ -322,7 +405,7 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
 	}
 
 	indio_dev->channels = channels;
-	indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
+	indio_dev->num_channels = magn_state->num_iio_channels;
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &magn_3d_info;
 	indio_dev->name = name;
-- 
1.9.3

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Srinivas Pandruvada]

On 06/02/2014 04:14 PM, Reyad Attiyat wrote:
> Updated magn_3d_channel enum for all possible north channels
>
> Added functions to setup iio_chan_spec array depending on which hid usage reports are found
>
> Renamed magn_val to iio_val to differentiate the index being used
>
> Updated magn_3d_state struct to hold pointer array (magn_val_addr[]) which points to iio_val[]
>
> Updated magn_3d_parse_report to scan for all compass usages and create iio channels for each
>
> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
> ---
>   drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271 +++++++++++++++++---------
>   1 file changed, 177 insertions(+), 94 deletions(-)
>
> diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
> index 6d162b7..32f4d90 100644
> --- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
> +++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
> @@ -34,63 +34,54 @@ enum magn_3d_channel {
>   	CHANNEL_SCAN_INDEX_X,
>   	CHANNEL_SCAN_INDEX_Y,
>   	CHANNEL_SCAN_INDEX_Z,
> +	CHANNEL_SCAN_INDEX_NORTH_MAGN,
> +	CHANNEL_SCAN_INDEX_NORTH_TRUE,
> +	CHANNEL_SCAN_INDEX_NORTH_TILT_COMP,
> +	CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
>   	MAGN_3D_CHANNEL_MAX,
>   };
>
> +#define IIO_CHANNEL_MAX MAGN_3D_CHANNEL_MAX
> +
>   struct magn_3d_state {
>   	struct hid_sensor_hub_callbacks callbacks;
>   	struct hid_sensor_common common_attributes;
>   	struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
> -	u32 magn_val[MAGN_3D_CHANNEL_MAX];
> -};
> +	u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
>
> -static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
> -	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
> -	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
> -	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
> +	u32 iio_val[IIO_CHANNEL_MAX];
> +	int num_iio_channels;
>   };
>
> -/* Channel definitions */
> -static const struct iio_chan_spec magn_3d_channels[] = {
> -	{
> -		.type = IIO_MAGN,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_X,
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> -		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_HYSTERESIS),
> -		.scan_index = CHANNEL_SCAN_INDEX_X,
> -	}, {
> -		.type = IIO_MAGN,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_Y,
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> -		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_HYSTERESIS),
> -		.scan_index = CHANNEL_SCAN_INDEX_Y,
> -	}, {
> -		.type = IIO_MAGN,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_Z,
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> -		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_HYSTERESIS),
> -		.scan_index = CHANNEL_SCAN_INDEX_Z,

May be we should have a field in const struct iio_chan_spec, so that we
can dynamically enable disable channels. In this way we can statically 
define channels, but can be enabled/disabled dynamically.


> +/* Find index into magn_3d_state magn[] and magn_val_addr[] from HID Usage  */
> +static int magn_3d_usage_id_to_chan_index(unsigned usage_id){
> +	int offset = -1;
> +
> +	switch (usage_id) {
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
> +		offset = CHANNEL_SCAN_INDEX_X;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
> +		offset = CHANNEL_SCAN_INDEX_Y;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
> +		offset = CHANNEL_SCAN_INDEX_Z;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_MAGN;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_TRUE;
> +		break;
>   	}
> -};
>
> -/* Adjust channel real bits based on report descriptor */
> -static void magn_3d_adjust_channel_bit_mask(struct iio_chan_spec *channels,
> -						int channel, int size)
> -{
> -	channels[channel].scan_type.sign = 's';
> -	/* Real storage bits will change based on the report desc. */
> -	channels[channel].scan_type.realbits = size * 8;
> -	/* Maximum size of a sample to capture is u32 */
> -	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
> +	return offset;
>   }
>
>   /* Channel read_raw handler */
> @@ -101,21 +92,31 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
>   {
>   	struct magn_3d_state *magn_state = iio_priv(indio_dev);
>   	int report_id = -1;
> -	u32 address;
> +	unsigned usage_id;
> +	int chan_index = -1;
>   	int ret;
>   	int ret_type;
>
> +	dev_dbg(&indio_dev->dev, "magn_3d_read_raw\n");
> +
>   	*val = 0;
>   	*val2 = 0;
>   	switch (mask) {
>   	case 0:
> +		/* We store the HID usage ID of the iio channel
> +		 * in its address field
> +		 */
> +		usage_id = chan->address;
> +		chan_index = magn_3d_usage_id_to_chan_index(usage_id);
> +		if(chan_index < 0)
> +			return -EINVAL;
> +
>   		report_id =
> -			magn_state->magn[chan->scan_index].report_id;
> -		address = magn_3d_addresses[chan->scan_index];
> +			magn_state->magn[chan_index].report_id;
>   		if (report_id >= 0)
>   			*val = sensor_hub_input_attr_get_raw_value(
>   				magn_state->common_attributes.hsdev,
> -				HID_USAGE_SENSOR_COMPASS_3D, address,
> +				HID_USAGE_SENSOR_COMPASS_3D, usage_id,
>   				report_id);
>   		else {
>   			*val = 0;
> @@ -202,12 +203,13 @@ static int magn_3d_proc_event(struct hid_sensor_hub_device *hsdev,
>   				magn_state->common_attributes.data_ready);
>   	if (magn_state->common_attributes.data_ready)
>   		hid_sensor_push_data(indio_dev,
> -				magn_state->magn_val,
> -				sizeof(magn_state->magn_val));
> +				&(magn_state->iio_val),
> +				sizeof(magn_state->iio_val));
>
>   	return 0;
>   }
>
> +
>   /* Capture samples in local storage */
>   static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>   				unsigned usage_id,
> @@ -217,63 +219,143 @@ static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>   	struct iio_dev *indio_dev = platform_get_drvdata(priv);
>   	struct magn_3d_state *magn_state = iio_priv(indio_dev);
>   	int offset;
> +	u32 *magn_val;
>   	int ret = -EINVAL;
>
> -	switch (usage_id) {
> +	offset = magn_3d_usage_id_to_chan_index(usage_id);
> +	if(offset < 0)
> +		return ret;
> +
> +	magn_val = magn_state->magn_val_addr[offset];
> +	if(!magn_val)
> +		return ret;
> +
> +	*(magn_val) =  *(u32 *)raw_data;
> +
> +	return 0;
> +}
> +
> +/* Setup the iio_chan_spec for HID Usage ID */
> +static int magn_3d_setup_new_iio_chan(struct hid_sensor_hub_device *hsdev,
> +				unsigned usage_id,
> +				unsigned attr_usage_id,
> +				struct iio_chan_spec *iio_chans,
> +				struct magn_3d_state *st)
> +{
> +	int ret = -1;
> +	int iio_index;
> +	int magn_index;
> +	struct iio_chan_spec *channel;
> +
> +	/* Setup magn_3d_state for new channel */
> +	magn_index = magn_3d_usage_id_to_chan_index(attr_usage_id);
> +	if(magn_index < 0 || magn_index >= MAGN_3D_CHANNEL_MAX){
> +		return -1;
> +	}
> +
> +	/* Check if usage attribute exists in the sensor hub device */
> +	ret = sensor_hub_input_get_attribute_info(hsdev,
> +		HID_INPUT_REPORT,
> +		usage_id,
> +		attr_usage_id,
> +		&(st->magn[magn_index]));
> +	if(ret != 0){
> +		/* Usage not found. Nothing to setup.*/
> +		return 0;
> +	}
> +
> +	iio_index = st->num_iio_channels;
> +	if(iio_index < 0 || iio_index >= IIO_CHANNEL_MAX){
> +		return -2;
> +	}
> +
> +	/* Check if this usage hasn't been setup */
> +	if(st->magn_val_addr[magn_index] != NULL){
> +		return -3;
> +	}
> +	st->magn_val_addr[magn_index] = &(st->iio_val[iio_index]);
> +
> +	/* Setup IIO Channel spec */
> +	channel = &(iio_chans[iio_index]);
> +
> +	channel->type = IIO_MAGN;
> +	channel->address = attr_usage_id;
> +	channel->modified = 1;
> +
> +	switch (attr_usage_id){
> +	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_MAGN;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_TRUE;
> +		break;
>   	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
> +		channel->channel2 = IIO_MOD_X;
> +		break;
>   	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
> +		channel->channel2 = IIO_MOD_Y;
> +		break;
>   	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
> -		offset = usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
> -		magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset] =
> -						*(u32 *)raw_data;
> -		ret = 0;
> -	break;
> -	default:
> +		channel->channel2 = IIO_MOD_Z;
>   		break;
> +	default:
> +		return -4;
>   	}
>
> +	channel->info_mask_shared_by_type =
> +		BIT(IIO_CHAN_INFO_OFFSET) |
> +		BIT(IIO_CHAN_INFO_SCALE) |
> +		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> +		BIT(IIO_CHAN_INFO_HYSTERESIS);
> +
> +	channel->scan_type.sign = 's';
> +	/* Real storage bits will change based on the report desc. */
> +	channel->scan_type.realbits = st->magn[magn_index].size * 8;
> +	/* Maximum size of a sample to capture is u32 */
> +	channel->scan_type.storagebits = sizeof(u32) * 8;
> +
> +	(st->num_iio_channels)++;
> +	ret = 0;
> +
>   	return ret;
>   }
>
> -/* Parse report which is specific to an usage id*/
> +/* Read the HID reports and setup IIO Channels */
>   static int magn_3d_parse_report(struct platform_device *pdev,
>   				struct hid_sensor_hub_device *hsdev,
> -				struct iio_chan_spec *channels,
> +				struct iio_chan_spec *iio_chans,
>   				unsigned usage_id,
>   				struct magn_3d_state *st)
>   {
> -	int ret;
> +	int ret = 0;
>   	int i;
>
> -	for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
> -		ret = sensor_hub_input_get_attribute_info(hsdev,
> -				HID_INPUT_REPORT,
> -				usage_id,
> -				HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS + i,
> -				&st->magn[CHANNEL_SCAN_INDEX_X + i]);
> -		if (ret < 0)
> -			break;
> -		magn_3d_adjust_channel_bit_mask(channels,
> -				CHANNEL_SCAN_INDEX_X + i,
> -				st->magn[CHANNEL_SCAN_INDEX_X + i].size);
> -	}
> -	dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
> -			st->magn[0].index,
> -			st->magn[0].report_id,
> -			st->magn[1].index, st->magn[1].report_id,
> -			st->magn[2].index, st->magn[2].report_id);
> -
> -	/* Set Sensitivity field ids, when there is no individual modifier */
> -	if (st->common_attributes.sensitivity.index < 0) {
> -		sensor_hub_input_get_attribute_info(hsdev,
> -			HID_FEATURE_REPORT, usage_id,
> -			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
> -			HID_USAGE_SENSOR_DATA_ORIENTATION,
> -			&st->common_attributes.sensitivity);
> -		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> -			st->common_attributes.sensitivity.index,
> -			st->common_attributes.sensitivity.report_id);
> -	}
> +	dev_dbg(&pdev->dev, "magn_3d_parse_reports Usage ID: %x\n", usage_id);
> +	for(i = HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
> +	    i <= HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS && ret == 0;
> +		i++)
> +			ret = magn_3d_setup_new_iio_chan(hsdev,
> +					usage_id,
> +					i,
> +					iio_chans,
> +					st);
> +
> +	dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic axis. Returned: %d", st->num_iio_channels, ret);
> +	for(i = HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH;
> +	    i <= HID_USAGE_SENSOR_ORIENT_TRUE_NORTH && ret == 0;
> +		i++)
> +			ret = magn_3d_setup_new_iio_chan(hsdev,
> +					usage_id,
> +					i,
> +					iio_chans,
> +					st);
> +	dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic channels. Returned: %d", st->num_iio_channels, ret);
>
I think we need to present angle in radians. Are you basing change 
present in linux-next? This will automatically do in this function.

>   	return ret;
>   }
> @@ -307,10 +389,11 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
>   		return ret;
>   	}
>
> -	channels = kmemdup(magn_3d_channels, sizeof(magn_3d_channels),
> -			   GFP_KERNEL);
> +	channels = kcalloc(MAGN_3D_CHANNEL_MAX,
> +			sizeof(struct iio_chan_spec),
> +			GFP_KERNEL);

I don't see kfree. Try devm_kcalloc?

>   	if (!channels) {
> -		dev_err(&pdev->dev, "failed to duplicate channels\n");
> +		dev_err(&pdev->dev, "failed to allocate memory for iio channel\n");
>   		return -ENOMEM;
>   	}
>
> @@ -322,7 +405,7 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
>   	}
>
>   	indio_dev->channels = channels;
> -	indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
> +	indio_dev->num_channels = magn_state->num_iio_channels;
>   	indio_dev->dev.parent = &pdev->dev;
>   	indio_dev->info = &magn_3d_info;
>   	indio_dev->name = name;
>
Thanks,
Srinivas

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Reyad Attiyat]

Hey Srinivas,

On Tue, Jun 3, 2014 at 12:43 PM, Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:

>
> May be we should have a field in const struct iio_chan_spec, so that we
> can dynamically enable disable channels. In this way we can statically
> define channels, but can be enabled/disabled dynamically.
>
Would this require changing iio subsystem to create sysfs entries only
when enabled? Would we need to add functions to disable and enable
later on?
>
> I think we need to present angle in radians. Are you basing change present
> in linux-next? This will automatically do in this function.
>
I'll look into this. What function should I use to make the iio chanel
to report radians?
>
>
> I don't see kfree. Try devm_kcalloc?
>
I changed kmemdup to kcalloc so there is still a kfree in the exsiting
code. I can change this to devm_kcalloc but only if we don't go with
static channels that are enabled as found.

Thanks,
Reyad Attiyat

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Srinivas Pandruvada]

On 06/04/2014 08:23 AM, Reyad Attiyat wrote:
> Hey Srinivas,
>
> On Tue, Jun 3, 2014 at 12:43 PM, Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com> wrote:
>
>>
>> May be we should have a field in const struct iio_chan_spec, so that we
>> can dynamically enable disable channels. In this way we can statically
>> define channels, but can be enabled/disabled dynamically.
>>
> Would this require changing iio subsystem to create sysfs entries only
> when enabled? Would we need to add functions to disable and enable
> later on?

This is just a thought. You don't have to change it. I am sure Jonathan 
will have some opinion this.

>>
>> I think we need to present angle in radians. Are you basing change present
>> in linux-next? This will automatically do in this function.
>>
> I'll look into this. What function should I use to make the iio chanel
> to report radians?
I think it will work if the existing sequence is maintained
  st->scale_precision = hid_sensor_format_scale(
                                 HID_USAGE_SENSOR_COMPASS_3D,
                                 &st->magn[CHANNEL_SCAN_INDEX_X],
                                 &st->scale_pre_decml, 
&st->scale_post_decml);

So as long as you call this function, the scale value to user space will
be returned correctly.

>>
>>
>> I don't see kfree. Try devm_kcalloc?
>>
> I changed kmemdup to kcalloc so there is still a kfree in the exsiting
> code. I can change this to devm_kcalloc but only if we don't go with
> static channels that are enabled as found.
>
Since you are changing this part, devm_ calls are preferred, I think.

Thanks,
Srinivas


> Thanks,
> Reyad Attiyat
>

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Jonathan Cameron]

On 03/06/14 18:43, Srinivas Pandruvada wrote:
> On 06/02/2014 04:14 PM, Reyad Attiyat wrote:
>> Updated magn_3d_channel enum for all possible north channels
>>
>> Added functions to setup iio_chan_spec array depending on which hid usage reports are found
>>
>> Renamed magn_val to iio_val to differentiate the index being used
>>
>> Updated magn_3d_state struct to hold pointer array (magn_val_addr[]) which points to iio_val[]
>>
>> Updated magn_3d_parse_report to scan for all compass usages and create iio channels for each
>>
>> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
>> ---
>>   drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271 +++++++++++++++++---------
>>   1 file changed, 177 insertions(+), 94 deletions(-)
>>
>> diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> index 6d162b7..32f4d90 100644
>> --- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> +++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> @@ -34,63 +34,54 @@ enum magn_3d_channel {
>>       CHANNEL_SCAN_INDEX_X,
>>       CHANNEL_SCAN_INDEX_Y,
>>       CHANNEL_SCAN_INDEX_Z,
>> +    CHANNEL_SCAN_INDEX_NORTH_MAGN,
>> +    CHANNEL_SCAN_INDEX_NORTH_TRUE,
>> +    CHANNEL_SCAN_INDEX_NORTH_TILT_COMP,
>> +    CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
>>       MAGN_3D_CHANNEL_MAX,
>>   };
>>
>> +#define IIO_CHANNEL_MAX MAGN_3D_CHANNEL_MAX
>> +
>>   struct magn_3d_state {
>>       struct hid_sensor_hub_callbacks callbacks;
>>       struct hid_sensor_common common_attributes;
>>       struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
>> -    u32 magn_val[MAGN_3D_CHANNEL_MAX];
>> -};
>> +    u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
>>
>> -static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
>> -    HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
>> -    HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
>> -    HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
>> +    u32 iio_val[IIO_CHANNEL_MAX];
>> +    int num_iio_channels;
>>   };
>>
>> -/* Channel definitions */
>> -static const struct iio_chan_spec magn_3d_channels[] = {
>> -    {
>> -        .type = IIO_MAGN,
>> -        .modified = 1,
>> -        .channel2 = IIO_MOD_X,
>> -        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>> -        BIT(IIO_CHAN_INFO_SCALE) |
>> -        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> -        BIT(IIO_CHAN_INFO_HYSTERESIS),
>> -        .scan_index = CHANNEL_SCAN_INDEX_X,
>> -    }, {
>> -        .type = IIO_MAGN,
>> -        .modified = 1,
>> -        .channel2 = IIO_MOD_Y,
>> -        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>> -        BIT(IIO_CHAN_INFO_SCALE) |
>> -        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> -        BIT(IIO_CHAN_INFO_HYSTERESIS),
>> -        .scan_index = CHANNEL_SCAN_INDEX_Y,
>> -    }, {
>> -        .type = IIO_MAGN,
>> -        .modified = 1,
>> -        .channel2 = IIO_MOD_Z,
>> -        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>> -        BIT(IIO_CHAN_INFO_SCALE) |
>> -        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> -        BIT(IIO_CHAN_INFO_HYSTERESIS),
>> -        .scan_index = CHANNEL_SCAN_INDEX_Z,
>
> May be we should have a field in const struct iio_chan_spec, so that we
> can dynamically enable disable channels. In this way we can statically define channels, but can be enabled/disabled dynamically.
But then it's not const to you have to take a per instance copy.
Once you are doing that you might as well just pull out into the copy
those channels that are actually present, at which point the field
doesn't have any purpose.
>
>
>> +/* Find index into magn_3d_state magn[] and magn_val_addr[] from HID Usage  */
>> +static int magn_3d_usage_id_to_chan_index(unsigned usage_id){
>> +    int offset = -1;
>> +
>> +    switch (usage_id) {
>> +    case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
>> +        offset = CHANNEL_SCAN_INDEX_X;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
>> +        offset = CHANNEL_SCAN_INDEX_Y;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
>> +        offset = CHANNEL_SCAN_INDEX_Z;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
>> +        offset = CHANNEL_SCAN_INDEX_NORTH_TILT_COMP;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
>> +        offset = CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
>> +        offset = CHANNEL_SCAN_INDEX_NORTH_MAGN;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
>> +        offset = CHANNEL_SCAN_INDEX_NORTH_TRUE;
>> +        break;
>>       }
>> -};
>>
>> -/* Adjust channel real bits based on report descriptor */
>> -static void magn_3d_adjust_channel_bit_mask(struct iio_chan_spec *channels,
>> -                        int channel, int size)
>> -{
>> -    channels[channel].scan_type.sign = 's';
>> -    /* Real storage bits will change based on the report desc. */
>> -    channels[channel].scan_type.realbits = size * 8;
>> -    /* Maximum size of a sample to capture is u32 */
>> -    channels[channel].scan_type.storagebits = sizeof(u32) * 8;
>> +    return offset;
>>   }
>>
>>   /* Channel read_raw handler */
>> @@ -101,21 +92,31 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
>>   {
>>       struct magn_3d_state *magn_state = iio_priv(indio_dev);
>>       int report_id = -1;
>> -    u32 address;
>> +    unsigned usage_id;
>> +    int chan_index = -1;
>>       int ret;
>>       int ret_type;
>>
>> +    dev_dbg(&indio_dev->dev, "magn_3d_read_raw\n");
>> +
>>       *val = 0;
>>       *val2 = 0;
>>       switch (mask) {
>>       case 0:
>> +        /* We store the HID usage ID of the iio channel
>> +         * in its address field
>> +         */
>> +        usage_id = chan->address;
>> +        chan_index = magn_3d_usage_id_to_chan_index(usage_id);
>> +        if(chan_index < 0)
>> +            return -EINVAL;
>> +
>>           report_id =
>> -            magn_state->magn[chan->scan_index].report_id;
>> -        address = magn_3d_addresses[chan->scan_index];
>> +            magn_state->magn[chan_index].report_id;
>>           if (report_id >= 0)
>>               *val = sensor_hub_input_attr_get_raw_value(
>>                   magn_state->common_attributes.hsdev,
>> -                HID_USAGE_SENSOR_COMPASS_3D, address,
>> +                HID_USAGE_SENSOR_COMPASS_3D, usage_id,
>>                   report_id);
>>           else {
>>               *val = 0;
>> @@ -202,12 +203,13 @@ static int magn_3d_proc_event(struct hid_sensor_hub_device *hsdev,
>>                   magn_state->common_attributes.data_ready);
>>       if (magn_state->common_attributes.data_ready)
>>           hid_sensor_push_data(indio_dev,
>> -                magn_state->magn_val,
>> -                sizeof(magn_state->magn_val));
>> +                &(magn_state->iio_val),
>> +                sizeof(magn_state->iio_val));
>>
>>       return 0;
>>   }
>>
>> +
>>   /* Capture samples in local storage */
>>   static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>>                   unsigned usage_id,
>> @@ -217,63 +219,143 @@ static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>>       struct iio_dev *indio_dev = platform_get_drvdata(priv);
>>       struct magn_3d_state *magn_state = iio_priv(indio_dev);
>>       int offset;
>> +    u32 *magn_val;
>>       int ret = -EINVAL;
>>
>> -    switch (usage_id) {
>> +    offset = magn_3d_usage_id_to_chan_index(usage_id);
>> +    if(offset < 0)
>> +        return ret;
>> +
>> +    magn_val = magn_state->magn_val_addr[offset];
>> +    if(!magn_val)
>> +        return ret;
>> +
>> +    *(magn_val) =  *(u32 *)raw_data;
>> +
>> +    return 0;
>> +}
>> +
>> +/* Setup the iio_chan_spec for HID Usage ID */
>> +static int magn_3d_setup_new_iio_chan(struct hid_sensor_hub_device *hsdev,
>> +                unsigned usage_id,
>> +                unsigned attr_usage_id,
>> +                struct iio_chan_spec *iio_chans,
>> +                struct magn_3d_state *st)
>> +{
>> +    int ret = -1;
>> +    int iio_index;
>> +    int magn_index;
>> +    struct iio_chan_spec *channel;
>> +
>> +    /* Setup magn_3d_state for new channel */
>> +    magn_index = magn_3d_usage_id_to_chan_index(attr_usage_id);
>> +    if(magn_index < 0 || magn_index >= MAGN_3D_CHANNEL_MAX){
>> +        return -1;
>> +    }
>> +
>> +    /* Check if usage attribute exists in the sensor hub device */
>> +    ret = sensor_hub_input_get_attribute_info(hsdev,
>> +        HID_INPUT_REPORT,
>> +        usage_id,
>> +        attr_usage_id,
>> +        &(st->magn[magn_index]));
>> +    if(ret != 0){
>> +        /* Usage not found. Nothing to setup.*/
>> +        return 0;
>> +    }
>> +
>> +    iio_index = st->num_iio_channels;
>> +    if(iio_index < 0 || iio_index >= IIO_CHANNEL_MAX){
>> +        return -2;
>> +    }
>> +
>> +    /* Check if this usage hasn't been setup */
>> +    if(st->magn_val_addr[magn_index] != NULL){
>> +        return -3;
>> +    }
>> +    st->magn_val_addr[magn_index] = &(st->iio_val[iio_index]);
>> +
>> +    /* Setup IIO Channel spec */
>> +    channel = &(iio_chans[iio_index]);
>> +
>> +    channel->type = IIO_MAGN;
>> +    channel->address = attr_usage_id;
>> +    channel->modified = 1;
>> +
>> +    switch (attr_usage_id){
>> +    case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
>> +        channel->channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
>> +        channel->channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
>> +        channel->channel2 = IIO_MOD_NORTH_MAGN;
>> +        break;
>> +    case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
>> +        channel->channel2 = IIO_MOD_NORTH_TRUE;
>> +        break;
>>       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
>> +        channel->channel2 = IIO_MOD_X;
>> +        break;
>>       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
>> +        channel->channel2 = IIO_MOD_Y;
>> +        break;
>>       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
>> -        offset = usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
>> -        magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset] =
>> -                        *(u32 *)raw_data;
>> -        ret = 0;
>> -    break;
>> -    default:
>> +        channel->channel2 = IIO_MOD_Z;
>>           break;
>> +    default:
>> +        return -4;
>>       }
>>
>> +    channel->info_mask_shared_by_type =
>> +        BIT(IIO_CHAN_INFO_OFFSET) |
>> +        BIT(IIO_CHAN_INFO_SCALE) |
>> +        BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> +        BIT(IIO_CHAN_INFO_HYSTERESIS);
>> +
>> +    channel->scan_type.sign = 's';
>> +    /* Real storage bits will change based on the report desc. */
>> +    channel->scan_type.realbits = st->magn[magn_index].size * 8;
>> +    /* Maximum size of a sample to capture is u32 */
>> +    channel->scan_type.storagebits = sizeof(u32) * 8;
>> +
>> +    (st->num_iio_channels)++;
>> +    ret = 0;
>> +
>>       return ret;
>>   }
>>
>> -/* Parse report which is specific to an usage id*/
>> +/* Read the HID reports and setup IIO Channels */
>>   static int magn_3d_parse_report(struct platform_device *pdev,
>>                   struct hid_sensor_hub_device *hsdev,
>> -                struct iio_chan_spec *channels,
>> +                struct iio_chan_spec *iio_chans,
>>                   unsigned usage_id,
>>                   struct magn_3d_state *st)
>>   {
>> -    int ret;
>> +    int ret = 0;
>>       int i;
>>
>> -    for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
>> -        ret = sensor_hub_input_get_attribute_info(hsdev,
>> -                HID_INPUT_REPORT,
>> -                usage_id,
>> -                HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS + i,
>> -                &st->magn[CHANNEL_SCAN_INDEX_X + i]);
>> -        if (ret < 0)
>> -            break;
>> -        magn_3d_adjust_channel_bit_mask(channels,
>> -                CHANNEL_SCAN_INDEX_X + i,
>> -                st->magn[CHANNEL_SCAN_INDEX_X + i].size);
>> -    }
>> -    dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
>> -            st->magn[0].index,
>> -            st->magn[0].report_id,
>> -            st->magn[1].index, st->magn[1].report_id,
>> -            st->magn[2].index, st->magn[2].report_id);
>> -
>> -    /* Set Sensitivity field ids, when there is no individual modifier */
>> -    if (st->common_attributes.sensitivity.index < 0) {
>> -        sensor_hub_input_get_attribute_info(hsdev,
>> -            HID_FEATURE_REPORT, usage_id,
>> -            HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
>> -            HID_USAGE_SENSOR_DATA_ORIENTATION,
>> -            &st->common_attributes.sensitivity);
>> -        dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
>> -            st->common_attributes.sensitivity.index,
>> -            st->common_attributes.sensitivity.report_id);
>> -    }
>> +    dev_dbg(&pdev->dev, "magn_3d_parse_reports Usage ID: %x\n", usage_id);
>> +    for(i = HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
>> +        i <= HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS && ret == 0;
>> +        i++)
>> +            ret = magn_3d_setup_new_iio_chan(hsdev,
>> +                    usage_id,
>> +                    i,
>> +                    iio_chans,
>> +                    st);
>> +
>> +    dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic axis. Returned: %d", st->num_iio_channels, ret);
>> +    for(i = HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH;
>> +        i <= HID_USAGE_SENSOR_ORIENT_TRUE_NORTH && ret == 0;
>> +        i++)
>> +            ret = magn_3d_setup_new_iio_chan(hsdev,
>> +                    usage_id,
>> +                    i,
>> +                    iio_chans,
>> +                    st);
>> +    dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic channels. Returned: %d", st->num_iio_channels, ret);
>>
> I think we need to present angle in radians. Are you basing change present in linux-next? This will automatically do in this function.
Yes, angles need to be in radians.
>
>>       return ret;
>>   }
>> @@ -307,10 +389,11 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
>>           return ret;
>>       }
>>
>> -    channels = kmemdup(magn_3d_channels, sizeof(magn_3d_channels),
>> -               GFP_KERNEL);
>> +    channels = kcalloc(MAGN_3D_CHANNEL_MAX,
>> +            sizeof(struct iio_chan_spec),
>> +            GFP_KERNEL);
>
> I don't see kfree. Try devm_kcalloc?
>
>>       if (!channels) {
>> -        dev_err(&pdev->dev, "failed to duplicate channels\n");
>> +        dev_err(&pdev->dev, "failed to allocate memory for iio channel\n");
>>           return -ENOMEM;
>>       }
>>
>> @@ -322,7 +405,7 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
>>       }
>>
>>       indio_dev->channels = channels;
>> -    indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
>> +    indio_dev->num_channels = magn_state->num_iio_channels;
>>       indio_dev->dev.parent = &pdev->dev;
>>       indio_dev->info = &magn_3d_info;
>>       indio_dev->name = name;
>>
> Thanks,
> Srinivas
>

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Jonathan Cameron]

On 04/06/14 16:42, Srinivas Pandruvada wrote:
> On 06/04/2014 08:23 AM, Reyad Attiyat wrote:
>> Hey Srinivas,
>>
>> On Tue, Jun 3, 2014 at 12:43 PM, Srinivas Pandruvada
>> <srinivas.pandruvada@linux.intel.com> wrote:
>>
>>>
>>> May be we should have a field in const struct iio_chan_spec, so that we
>>> can dynamically enable disable channels. In this way we can statically
>>> define channels, but can be enabled/disabled dynamically.
>>>
>> Would this require changing iio subsystem to create sysfs entries only
>> when enabled? Would we need to add functions to disable and enable
>> later on?
>
> This is just a thought. You don't have to change it. I am sure Jonathan will have some opinion this.
Replied to earlier message.  If there is some common code we can factor out into
the core then I'm happy to do so, but I don't see an advantage in using
a field, rather than just tailoring the copy in the first place. e.g.

1) Pass whatever is needed to figure out how many channels are present.
2) Allocate space for that many channels.
3) Copy said channels from predefined versions, perhaps amending as necessary.

This is a reasonably common pattern in complex parts or those with hugely
variable numbers of channels...
>
>>>
>>> I think we need to present angle in radians. Are you basing change present
>>> in linux-next? This will automatically do in this function.
>>>
>> I'll look into this. What function should I use to make the iio chanel
>> to report radians?
> I think it will work if the existing sequence is maintained
>   st->scale_precision = hid_sensor_format_scale(
>                                  HID_USAGE_SENSOR_COMPASS_3D,
>                                  &st->magn[CHANNEL_SCAN_INDEX_X],
>                                  &st->scale_pre_decml, &st->scale_post_decml);
>
> So as long as you call this function, the scale value to user space will
> be returned correctly.
>
>>>
>>>
>>> I don't see kfree. Try devm_kcalloc?
>>>
>> I changed kmemdup to kcalloc so there is still a kfree in the exsiting
>> code. I can change this to devm_kcalloc but only if we don't go with
>> static channels that are enabled as found.
>>
> Since you are changing this part, devm_ calls are preferred, I think.
As long as it doesn't add complexity or possibility of race conditions,
devm calls are usually a good idea.
>
> Thanks,
> Srinivas
>
>
>> Thanks,
>> Reyad Attiyat
>>
>

Re: [PATCHv2 1/3] IIO: Documentation: Add north attribute to ABI docs

[Jonathan Cameron]

On 03/06/14 00:14, Reyad Attiyat wrote:
> Updated ABI documentation to inculde compass north usages.
>
> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
Amazing how many lines of documentation two small additions can make!

Anyhow, I'm keener on having these as as modifiers on a rotation rather than
there own type.

in_rot_from_north_magnetic_raw and friends (as per your suggestion elsewhere).

Otherwise, whilst obvious, perhaps a line or two in the main _raw attribute
description to state the obvious and say what this is...


J

> ---
>   Documentation/ABI/testing/sysfs-bus-iio | 76 +++++++++++++++++++++++++++++++++
>   1 file changed, 76 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index 6e02c50..251c2bb 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -165,6 +165,10 @@ Description:
>   What:		/sys/bus/iio/devices/iio:deviceX/in_magn_x_raw
>   What:		/sys/bus/iio/devices/iio:deviceX/in_magn_y_raw
>   What:		/sys/bus/iio/devices/iio:deviceX/in_magn_z_raw
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_raw
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_raw
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_tilt_comp_raw
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_tilt_comp_raw
>   KernelVersion:	2.6.35
>   Contact:	linux-iio@vger.kernel.org
>   Description:
> @@ -249,6 +253,10 @@ What:		/sys/bus/iio/devices/iio:deviceX/in_magn_scale
>   What:		/sys/bus/iio/devices/iio:deviceX/in_magn_x_scale
>   What:		/sys/bus/iio/devices/iio:deviceX/in_magn_y_scale
>   What:		/sys/bus/iio/devices/iio:deviceX/in_magn_z_scale
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_scale
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_scale
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_magnetic_tilt_comp_scale
> +What:		/sys/bus/iio/devices/iio:deviceX/in_north_true_tilt_comp_scale
>   What:		/sys/bus/iio/devices/iio:deviceX/in_pressureY_scale
>   What:		/sys/bus/iio/devices/iio:deviceX/in_pressure_scale
>   KernelVersion:	2.6.35
> @@ -436,6 +444,14 @@ What:		/sys/.../iio:deviceX/events/in_magn_y_thresh_rising_en
>   What:		/sys/.../iio:deviceX/events/in_magn_y_thresh_falling_en
>   What:		/sys/.../iio:deviceX/events/in_magn_z_thresh_rising_en
>   What:		/sys/.../iio:deviceX/events/in_magn_z_thresh_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_thresh_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_thresh_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_thresh_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_thresh_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_thresh_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_thresh_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_thresh_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_thresh_falling_en
>   What:		/sys/.../iio:deviceX/events/in_voltageY_supply_thresh_rising_en
>   What:		/sys/.../iio:deviceX/events/in_voltageY_supply_thresh_falling_en
>   What:		/sys/.../iio:deviceX/events/in_voltageY_thresh_rising_en
> @@ -481,6 +497,14 @@ What:		/sys/.../iio:deviceX/events/in_magn_y_roc_rising_en
>   What:		/sys/.../iio:deviceX/events/in_magn_y_roc_falling_en
>   What:		/sys/.../iio:deviceX/events/in_magn_z_roc_rising_en
>   What:		/sys/.../iio:deviceX/events/in_magn_z_roc_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_roc_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_roc_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_roc_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_roc_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_roc_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_magnetic_tilt_comp_roc_falling_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_roc_rising_en
> +What:		/sys/.../iio:deviceX/events/in_north_true_tilt_comp_roc_falling_en
>   What:		/sys/.../iio:deviceX/events/in_voltageY_supply_roc_rising_en
>   What:		/sys/.../iio:deviceX/events/in_voltageY_supply_roc_falling_en
>   What:		/sys/.../iio:deviceX/events/in_voltageY_roc_rising_en
> @@ -527,6 +551,14 @@ What:		/sys/.../events/in_magn_y_raw_thresh_rising_value
>   What:		/sys/.../events/in_magn_y_raw_thresh_falling_value
>   What:		/sys/.../events/in_magn_z_raw_thresh_rising_value
>   What:		/sys/.../events/in_magn_z_raw_thresh_falling_value
> +What:		/sys/.../events/in_north_magnetic_raw_thresh_rising_value
> +What:		/sys/.../events/in_north_magnetic_raw_thresh_falling_value
> +What:		/sys/.../events/in_north_true_raw_thresh_rising_value
> +What:		/sys/.../events/in_north_true_raw_thresh_falling_value
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_thresh_rising_value
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_thresh_falling_value
> +What:		/sys/.../events/in_north_true_tilt_comp_raw_thresh_rising_value
> +What:		/sys/.../events/in_north_true_tilt_comp_raw_thresh_falling_value
>   What:		/sys/.../events/in_voltageY_supply_raw_thresh_rising_value
>   What:		/sys/.../events/in_voltageY_supply_raw_thresh_falling_value
>   What:		/sys/.../events/in_voltageY_raw_thresh_rising_value
> @@ -577,6 +609,18 @@ What:		/sys/.../events/in_magn_y_thresh_either_hysteresis
>   What:		/sys/.../events/in_magn_z_thresh_rising_hysteresis
>   What:		/sys/.../events/in_magn_z_thresh_falling_hysteresis
>   What:		/sys/.../events/in_magn_z_thresh_either_hysteresis
> +What:		/sys/.../events/in_north_magnetic_thresh_rising_hysteresis
> +What:		/sys/.../events/in_north_magnetic_thresh_falling_hysteresis
> +What:		/sys/.../events/in_north_magnetic_thresh_either_hysteresis
> +What:		/sys/.../events/in_north_true_thresh_rising_hysteresis
> +What:		/sys/.../events/in_north_true_thresh_falling_hysteresis
> +What:		/sys/.../events/in_north_true_thresh_either_hysteresis
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_rising_hysteresis
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_falling_hysteresis
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_either_hysteresis
> +What:		/sys/.../events/in_north_true_tilt_comp_thresh_rising_hysteresis
> +What:		/sys/.../events/in_north_true_tilt_comp_thresh_falling_hysteresis
> +What:		/sys/.../events/in_north_true_tilt_comp_thresh_either_hysteresis
>   What:		/sys/.../events/in_voltageY_thresh_rising_hysteresis
>   What:		/sys/.../events/in_voltageY_thresh_falling_hysteresis
>   What:		/sys/.../events/in_voltageY_thresh_either_hysteresis
> @@ -624,6 +668,14 @@ What:		/sys/.../events/in_magn_y_raw_roc_rising_value
>   What:		/sys/.../events/in_magn_y_raw_roc_falling_value
>   What:		/sys/.../events/in_magn_z_raw_roc_rising_value
>   What:		/sys/.../events/in_magn_z_raw_roc_falling_value
> +What:		/sys/.../events/in_north_magnetic_raw_roc_rising_value
> +What:		/sys/.../events/in_north_magnetic_raw_roc_falling_value
> +What:		/sys/.../events/in_north_true_raw_roc_rising_value
> +What:		/sys/.../events/in_north_true_raw_roc_falling_value
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_roc_rising_value
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_raw_roc_falling_value
> +What:		/sys/.../events/in_north_true_tilt_comp_raw_roc_rising_value
> +What:		/sys/.../events/in_north_true_tilt_comp_raw_roc_falling_value
>   What:		/sys/.../events/in_voltageY_supply_raw_roc_rising_value
>   What:		/sys/.../events/in_voltageY_supply_raw_roc_falling_value
>   What:		/sys/.../events/in_voltageY_raw_roc_rising_value
> @@ -679,6 +731,22 @@ What:		/sys/.../events/in_magn_z_thresh_rising_period
>   What:		/sys/.../events/in_magn_z_thresh_falling_period
>   What:		/sys/.../events/in_magn_z_roc_rising_period
>   What:		/sys/.../events/in_magn_z_roc_falling_period
> +What:		/sys/.../events/in_north_magnetic_thresh_rising_period
> +What:		/sys/.../events/in_north_magnetic_thresh_falling_period
> +What:		/sys/.../events/in_north_magnetic_roc_rising_period
> +What:		/sys/.../events/in_north_magnetic_roc_falling_period
> +What:		/sys/.../events/in_north_true_thresh_rising_period
> +What:		/sys/.../events/in_north_true_thresh_falling_period
> +What:		/sys/.../events/in_north_true_roc_rising_period
> +What:		/sys/.../events/in_north_true_roc_falling_period
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_rising_period
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_thresh_falling_period
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_roc_rising_period
> +What:		/sys/.../events/in_north_magnetic_tilt_comp_roc_falling_period
> +What:		/sys/.../events/in_north_true_tilt_comp_thresh_rising_period
> +What:		/sys/.../events/in_north_true_tilt_comp_thresh_falling_period
> +What:		/sys/.../events/in_north_true_tilt_comp_roc_rising_period
> +What:		/sys/.../events/in_north_true_tilt_comp_roc_falling_period
>   What:		/sys/.../events/in_voltageY_supply_thresh_rising_period
>   What:		/sys/.../events/in_voltageY_supply_thresh_falling_period
>   What:		/sys/.../events/in_voltageY_supply_roc_rising_period
> @@ -776,6 +844,10 @@ What:		/sys/.../iio:deviceX/scan_elements/in_anglvel_z_en
>   What:		/sys/.../iio:deviceX/scan_elements/in_magn_x_en
>   What:		/sys/.../iio:deviceX/scan_elements/in_magn_y_en
>   What:		/sys/.../iio:deviceX/scan_elements/in_magn_z_en
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_en
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_true_en
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_tilt_comp_en
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_true_tilt_comp_en
>   What:		/sys/.../iio:deviceX/scan_elements/in_timestamp_en
>   What:		/sys/.../iio:deviceX/scan_elements/in_voltageY_supply_en
>   What:		/sys/.../iio:deviceX/scan_elements/in_voltageY_en
> @@ -840,6 +912,10 @@ What:		/sys/.../iio:deviceX/scan_elements/in_anglvel_z_index
>   What:		/sys/.../iio:deviceX/scan_elements/in_magn_x_index
>   What:		/sys/.../iio:deviceX/scan_elements/in_magn_y_index
>   What:		/sys/.../iio:deviceX/scan_elements/in_magn_z_index
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_index
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_true_index
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_magnetic_tilt_comp_index
> +What:		/sys/.../iio:deviceX/scan_elements/in_north_true_tilt_comp_index
>   What:		/sys/.../iio:deviceX/scan_elements/in_incli_x_index
>   What:		/sys/.../iio:deviceX/scan_elements/in_incli_y_index
>   What:		/sys/.../iio:deviceX/scan_elements/in_timestamp_index
>

Re: [PATCHv2 2/3] IIO: Add iio_chan modifier for True/Magnetic North HID usages

[Jonathan Cameron]

On 03/06/14 00:14, Reyad Attiyat wrote:
> Updated iio modifier enum for compass north usages,
> including magnetic/true north with tilt compensation.
>
> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
This looks fine.
> ---
>   drivers/iio/industrialio-core.c | 4 ++++
>   include/linux/iio/types.h       | 4 ++++
>   2 files changed, 8 insertions(+)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index ede16aec..2f523b5 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -84,6 +84,10 @@ static const char * const iio_modifier_names[] = {
>   	[IIO_MOD_LIGHT_RED] = "red",
>   	[IIO_MOD_LIGHT_GREEN] = "green",
>   	[IIO_MOD_LIGHT_BLUE] = "blue",
> +	[IIO_MOD_NORTH_MAGN] = "north_magnetic",
> +	[IIO_MOD_NORTH_TRUE] = "north_true",
> +	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "north_magnetic_tilt_comp",
> +	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "north_true_tilt_comp",
>   };
>
>   /* relies on pairs of these shared then separate */
> diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
> index 084d882..5bf8847 100644
> --- a/include/linux/iio/types.h
> +++ b/include/linux/iio/types.h
> @@ -53,6 +53,10 @@ enum iio_modifier {
>   	IIO_MOD_LIGHT_RED,
>   	IIO_MOD_LIGHT_GREEN,
>   	IIO_MOD_LIGHT_BLUE,
> +	IIO_MOD_NORTH_MAGN,
> +	IIO_MOD_NORTH_TRUE,
> +	IIO_MOD_NORTH_MAGN_TILT_COMP,
> +	IIO_MOD_NORTH_TRUE_TILT_COMP
>   };
>
>   enum iio_event_type {
>

Re: [PATCHv2 2/3] IIO: Add iio_chan modifier for True/Magnetic North HID usages

[Jonathan Cameron]

On 09/06/14 18:51, Jonathan Cameron wrote:
> On 03/06/14 00:14, Reyad Attiyat wrote:
>> Updated iio modifier enum for compass north usages,
>> including magnetic/true north with tilt compensation.
>>
>> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
> This looks fine.
gah. With the from_ prefix you suggested of course!
>> ---
>>   drivers/iio/industrialio-core.c | 4 ++++
>>   include/linux/iio/types.h       | 4 ++++
>>   2 files changed, 8 insertions(+)
>>
>> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
>> index ede16aec..2f523b5 100644
>> --- a/drivers/iio/industrialio-core.c
>> +++ b/drivers/iio/industrialio-core.c
>> @@ -84,6 +84,10 @@ static const char * const iio_modifier_names[] = {
>>       [IIO_MOD_LIGHT_RED] = "red",
>>       [IIO_MOD_LIGHT_GREEN] = "green",
>>       [IIO_MOD_LIGHT_BLUE] = "blue",
>> +    [IIO_MOD_NORTH_MAGN] = "north_magnetic",
>> +    [IIO_MOD_NORTH_TRUE] = "north_true",
>> +    [IIO_MOD_NORTH_MAGN_TILT_COMP] = "north_magnetic_tilt_comp",
>> +    [IIO_MOD_NORTH_TRUE_TILT_COMP] = "north_true_tilt_comp",
>>   };
>>
>>   /* relies on pairs of these shared then separate */
>> diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
>> index 084d882..5bf8847 100644
>> --- a/include/linux/iio/types.h
>> +++ b/include/linux/iio/types.h
>> @@ -53,6 +53,10 @@ enum iio_modifier {
>>       IIO_MOD_LIGHT_RED,
>>       IIO_MOD_LIGHT_GREEN,
>>       IIO_MOD_LIGHT_BLUE,
>> +    IIO_MOD_NORTH_MAGN,
>> +    IIO_MOD_NORTH_TRUE,
>> +    IIO_MOD_NORTH_MAGN_TILT_COMP,
>> +    IIO_MOD_NORTH_TRUE_TILT_COMP
>>   };
>>
>>   enum iio_event_type {
>>
>

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Jonathan Cameron]

On 03/06/14 00:14, Reyad Attiyat wrote:
> Updated magn_3d_channel enum for all possible north channels
>
> Added functions to setup iio_chan_spec array depending on which hid usage reports are found
>
> Renamed magn_val to iio_val to differentiate the index being used
>
> Updated magn_3d_state struct to hold pointer array (magn_val_addr[]) which points to iio_val[]
>
> Updated magn_3d_parse_report to scan for all compass usages and create iio channels for each
>
> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
Hi Reyad,

I've taken a rather quick look at this.  Will probably want to take
one more close look at a newer version.

Various bits and bobs inline - mostly fine!
Jonathan
> ---
>   drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271 +++++++++++++++++---------
>   1 file changed, 177 insertions(+), 94 deletions(-)
>
> diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
> index 6d162b7..32f4d90 100644
> --- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
> +++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
> @@ -34,63 +34,54 @@ enum magn_3d_channel {
>   	CHANNEL_SCAN_INDEX_X,
>   	CHANNEL_SCAN_INDEX_Y,
>   	CHANNEL_SCAN_INDEX_Z,
> +	CHANNEL_SCAN_INDEX_NORTH_MAGN,
> +	CHANNEL_SCAN_INDEX_NORTH_TRUE,
> +	CHANNEL_SCAN_INDEX_NORTH_TILT_COMP,
> +	CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
>   	MAGN_3D_CHANNEL_MAX,
>   };
>
> +#define IIO_CHANNEL_MAX MAGN_3D_CHANNEL_MAX
Please don't define a generic sounding name for a local
constant.  Why not use MAGN_3D_CHANNEL_MAX everywhere?
> +
>   struct magn_3d_state {
>   	struct hid_sensor_hub_callbacks callbacks;
>   	struct hid_sensor_common common_attributes;
>   	struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
> -	u32 magn_val[MAGN_3D_CHANNEL_MAX];
> -};
> +	u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
>
> -static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
> -	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
> -	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
> -	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
> +	u32 iio_val[IIO_CHANNEL_MAX];
> +	int num_iio_channels;
>   };
>
> -/* Channel definitions */
> -static const struct iio_chan_spec magn_3d_channels[] = {
> -	{
> -		.type = IIO_MAGN,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_X,
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> -		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_HYSTERESIS),
> -		.scan_index = CHANNEL_SCAN_INDEX_X,
> -	}, {
> -		.type = IIO_MAGN,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_Y,
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> -		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_HYSTERESIS),
> -		.scan_index = CHANNEL_SCAN_INDEX_Y,
> -	}, {
> -		.type = IIO_MAGN,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_Z,
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> -		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_HYSTERESIS),
> -		.scan_index = CHANNEL_SCAN_INDEX_Z,
> +/* Find index into magn_3d_state magn[] and magn_val_addr[] from HID Usage  */
> +static int magn_3d_usage_id_to_chan_index(unsigned usage_id){
> +	int offset = -1;
I'd personally prefer offset = -EINVAL and to have it assigned as
a default element in the switch statement rather that here.
> +
> +	switch (usage_id) {
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
> +		offset = CHANNEL_SCAN_INDEX_X;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
> +		offset = CHANNEL_SCAN_INDEX_Y;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
> +		offset = CHANNEL_SCAN_INDEX_Z;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_MAGN;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
> +		offset = CHANNEL_SCAN_INDEX_NORTH_TRUE;
> +		break;
>   	}
> -};
>
> -/* Adjust channel real bits based on report descriptor */
> -static void magn_3d_adjust_channel_bit_mask(struct iio_chan_spec *channels,
> -						int channel, int size)
> -{
> -	channels[channel].scan_type.sign = 's';
> -	/* Real storage bits will change based on the report desc. */
> -	channels[channel].scan_type.realbits = size * 8;
> -	/* Maximum size of a sample to capture is u32 */
> -	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
> +	return offset;
>   }
>
>   /* Channel read_raw handler */
> @@ -101,21 +92,31 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
>   {
>   	struct magn_3d_state *magn_state = iio_priv(indio_dev);
>   	int report_id = -1;
> -	u32 address;
> +	unsigned usage_id;
> +	int chan_index = -1;
>   	int ret;
>   	int ret_type;
>
> +	dev_dbg(&indio_dev->dev, "magn_3d_read_raw\n");
> +
>   	*val = 0;
>   	*val2 = 0;
>   	switch (mask) {
>   	case 0:
> +		/* We store the HID usage ID of the iio channel
> +		 * in its address field
> +		 */
> +		usage_id = chan->address;
> +		chan_index = magn_3d_usage_id_to_chan_index(usage_id);

> +		if(chan_index < 0)
> +			return -EINVAL;
> +
>   		report_id =
> -			magn_state->magn[chan->scan_index].report_id;
> -		address = magn_3d_addresses[chan->scan_index];
> +			magn_state->magn[chan_index].report_id;
>   		if (report_id >= 0)
>   			*val = sensor_hub_input_attr_get_raw_value(
>   				magn_state->common_attributes.hsdev,
> -				HID_USAGE_SENSOR_COMPASS_3D, address,
> +				HID_USAGE_SENSOR_COMPASS_3D, usage_id,
>   				report_id);
>   		else {
>   			*val = 0;
> @@ -202,12 +203,13 @@ static int magn_3d_proc_event(struct hid_sensor_hub_device *hsdev,
>   				magn_state->common_attributes.data_ready);
>   	if (magn_state->common_attributes.data_ready)
>   		hid_sensor_push_data(indio_dev,
> -				magn_state->magn_val,
> -				sizeof(magn_state->magn_val));
> +				&(magn_state->iio_val),
> +				sizeof(magn_state->iio_val));
>
>   	return 0;
>   }
>
> +
>   /* Capture samples in local storage */
>   static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>   				unsigned usage_id,
> @@ -217,63 +219,143 @@ static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>   	struct iio_dev *indio_dev = platform_get_drvdata(priv);
>   	struct magn_3d_state *magn_state = iio_priv(indio_dev);
>   	int offset;
> +	u32 *magn_val;
>   	int ret = -EINVAL;
>
> -	switch (usage_id) {
> +	offset = magn_3d_usage_id_to_chan_index(usage_id);
> +	if(offset < 0)
> +		return ret;
> +
> +	magn_val = magn_state->magn_val_addr[offset];
> +	if(!magn_val)
> +		return ret;
> +
> +	*(magn_val) =  *(u32 *)raw_data;
> +
> +	return 0;
> +}
> +
> +/* Setup the iio_chan_spec for HID Usage ID */
> +static int magn_3d_setup_new_iio_chan(struct hid_sensor_hub_device *hsdev,
> +				unsigned usage_id,
> +				unsigned attr_usage_id,
> +				struct iio_chan_spec *iio_chans,
> +				struct magn_3d_state *st)
> +{
> +	int ret = -1;
This is kind of backwards to normal practice for this sort of function.
Better to maintain ret in the correct state at all times.  Hence
start with it being 0 and set to negative when there is an error rather
than the other way around.
> +	int iio_index;
> +	int magn_index;
> +	struct iio_chan_spec *channel;
> +
> +	/* Setup magn_3d_state for new channel */
> +	magn_index = magn_3d_usage_id_to_chan_index(attr_usage_id);
> +	if(magn_index < 0 || magn_index >= MAGN_3D_CHANNEL_MAX){
> +		return -1;
> +	}
> +
> +	/* Check if usage attribute exists in the sensor hub device */
> +	ret = sensor_hub_input_get_attribute_info(hsdev,
> +		HID_INPUT_REPORT,
> +		usage_id,
> +		attr_usage_id,
> +		&(st->magn[magn_index]));
> +	if(ret != 0){
> +		/* Usage not found. Nothing to setup.*/
> +		return 0;
> +	}
> +
> +	iio_index = st->num_iio_channels;
> +	if(iio_index < 0 || iio_index >= IIO_CHANNEL_MAX){
I'd be tempted to allocate space dynamically but I guess this works.

> +		return -2;
> +	}
> +
> +	/* Check if this usage hasn't been setup */
> +	if(st->magn_val_addr[magn_index] != NULL){
Space before that bracket here and elsewhere.
Don't return your own error codes. Use standard ones.  I guess thees
are left from debugging.
> +		return -3;
> +	}
> +	st->magn_val_addr[magn_index] = &(st->iio_val[iio_index]);
> +
> +	/* Setup IIO Channel spec */
> +	channel = &(iio_chans[iio_index]);
Just pass this is in as a pointer in the first place?
That is a pointer to the current channel location, that may or may
not be filled by this function.
> +
> +	channel->type = IIO_MAGN;
> +	channel->address = attr_usage_id;
> +	channel->modified = 1;
> +
> +	switch (attr_usage_id){
> +	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_MAGN;
> +		break;
> +	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
> +		channel->channel2 = IIO_MOD_NORTH_TRUE;
> +		break;
>   	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
> +		channel->channel2 = IIO_MOD_X;
> +		break;
>   	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
> +		channel->channel2 = IIO_MOD_Y;
> +		break;
>   	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
> -		offset = usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
> -		magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset] =
> -						*(u32 *)raw_data;
> -		ret = 0;
> -	break;
> -	default:
> +		channel->channel2 = IIO_MOD_Z;
>   		break;
> +	default:
> +		return -4;
huh?  why -4. -EINVAL or -ENOSUP or something similar perhaps.
>   	}
>
> +	channel->info_mask_shared_by_type =
> +		BIT(IIO_CHAN_INFO_OFFSET) |
> +		BIT(IIO_CHAN_INFO_SCALE) |
> +		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> +		BIT(IIO_CHAN_INFO_HYSTERESIS);
> +
> +	channel->scan_type.sign = 's';
> +	/* Real storage bits will change based on the report desc. */
> +	channel->scan_type.realbits = st->magn[magn_index].size * 8;
> +	/* Maximum size of a sample to capture is u32 */
> +	channel->scan_type.storagebits = sizeof(u32) * 8;
> +
I'd keen num_iio_channels outside this function and increment it if
this function does not return an error.
> +	(st->num_iio_channels)++;
Don't do this. ret should have been valid throughout... if not something
odd is going on with your use of ret.

Hmm. I see it is in the original code :( feel free to clean this up.
> +	ret = 0;
> +
>   	return ret;
>   }
>
> -/* Parse report which is specific to an usage id*/
> +/* Read the HID reports and setup IIO Channels */
>   static int magn_3d_parse_report(struct platform_device *pdev,
>   				struct hid_sensor_hub_device *hsdev,
> -				struct iio_chan_spec *channels,
> +				struct iio_chan_spec *iio_chans,
>   				unsigned usage_id,
>   				struct magn_3d_state *st)
>   {
> -	int ret;
> +	int ret = 0;
>   	int i;
>
> -	for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
> -		ret = sensor_hub_input_get_attribute_info(hsdev,
> -				HID_INPUT_REPORT,
> -				usage_id,
> -				HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS + i,
> -				&st->magn[CHANNEL_SCAN_INDEX_X + i]);
> -		if (ret < 0)
> -			break;
> -		magn_3d_adjust_channel_bit_mask(channels,
> -				CHANNEL_SCAN_INDEX_X + i,
> -				st->magn[CHANNEL_SCAN_INDEX_X + i].size);
> -	}
> -	dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
> -			st->magn[0].index,
> -			st->magn[0].report_id,
> -			st->magn[1].index, st->magn[1].report_id,
> -			st->magn[2].index, st->magn[2].report_id);
> -
> -	/* Set Sensitivity field ids, when there is no individual modifier */
> -	if (st->common_attributes.sensitivity.index < 0) {
> -		sensor_hub_input_get_attribute_info(hsdev,
> -			HID_FEATURE_REPORT, usage_id,
> -			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
> -			HID_USAGE_SENSOR_DATA_ORIENTATION,
> -			&st->common_attributes.sensitivity);
> -		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> -			st->common_attributes.sensitivity.index,
> -			st->common_attributes.sensitivity.report_id);
> -	}
> +	dev_dbg(&pdev->dev, "magn_3d_parse_reports Usage ID: %x\n", usage_id);
> +	for(i = HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
> +	    i <= HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS && ret == 0;
> +		i++)
> +			ret = magn_3d_setup_new_iio_chan(hsdev,
> +					usage_id,
> +					i,
> +					iio_chans,
> +					st);
> +
> +	dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic axis. Returned: %d", st->num_iio_channels, ret);
> +	for(i = HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH;
> +	    i <= HID_USAGE_SENSOR_ORIENT_TRUE_NORTH && ret == 0;
> +		i++)
> +			ret = magn_3d_setup_new_iio_chan(hsdev,
> +					usage_id,
> +					i,
> +					iio_chans,
> +					st);
As stated above, I'd use whether this succeeds for a given channel to
increment the location in iio_chans and then pass in only the 'next' channel
location on each pass.  Moving the bounds checks out here as well would be
make for a cleaner magn_3d_setup_new_iio_chan function.

> +	dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic channels. Returned: %d", st->num_iio_channels, ret);
>
>   	return ret;
>   }
> @@ -307,10 +389,11 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
>   		return ret;
>   	}
>
> -	channels = kmemdup(magn_3d_channels, sizeof(magn_3d_channels),
> -			   GFP_KERNEL);
> +	channels = kcalloc(MAGN_3D_CHANNEL_MAX,
> +			sizeof(struct iio_chan_spec),
> +			GFP_KERNEL);
>   	if (!channels) {
> -		dev_err(&pdev->dev, "failed to duplicate channels\n");
> +		dev_err(&pdev->dev, "failed to allocate memory for iio channel\n");
>   		return -ENOMEM;
>   	}
>
> @@ -322,7 +405,7 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
>   	}
>
>   	indio_dev->channels = channels;
> -	indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
> +	indio_dev->num_channels = magn_state->num_iio_channels;
With a bit of rearranging it strikes me that you can fill num_channels
directly rather than having another copy of it....
>   	indio_dev->dev.parent = &pdev->dev;
>   	indio_dev->info = &magn_3d_info;
>   	indio_dev->name = name;
>

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Reyad Attiyat]

Hey Jonathan,

I will make the changes you suggested thanks for reviewing this. Any
conclusions on the naming, did you want me to change the sysfs name to
"in_rot_from_north_true/magnetic"?

On Mon, Jun 9, 2014 at 2:55 PM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 03/06/14 00:14, Reyad Attiyat wrote:
>>
>> Updated magn_3d_channel enum for all possible north channels
>>
>> Added functions to setup iio_chan_spec array depending on which hid usage
>> reports are found
>>
>> Renamed magn_val to iio_val to differentiate the index being used
>>
>> Updated magn_3d_state struct to hold pointer array (magn_val_addr[]) which
>> points to iio_val[]
>>
>> Updated magn_3d_parse_report to scan for all compass usages and create iio
>> channels for each
>>
>> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
>
> Hi Reyad,
>
> I've taken a rather quick look at this.  Will probably want to take
> one more close look at a newer version.
>
> Various bits and bobs inline - mostly fine!
> Jonathan
>
>> ---
>>   drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271
>> +++++++++++++++++---------
>>   1 file changed, 177 insertions(+), 94 deletions(-)
>>
>> diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> index 6d162b7..32f4d90 100644
>> --- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> +++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>> @@ -34,63 +34,54 @@ enum magn_3d_channel {
>>         CHANNEL_SCAN_INDEX_X,
>>         CHANNEL_SCAN_INDEX_Y,
>>         CHANNEL_SCAN_INDEX_Z,
>> +       CHANNEL_SCAN_INDEX_NORTH_MAGN,
>> +       CHANNEL_SCAN_INDEX_NORTH_TRUE,
>> +       CHANNEL_SCAN_INDEX_NORTH_TILT_COMP,
>> +       CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
>>         MAGN_3D_CHANNEL_MAX,
>>   };
>>
>> +#define IIO_CHANNEL_MAX MAGN_3D_CHANNEL_MAX
>
> Please don't define a generic sounding name for a local
> constant.  Why not use MAGN_3D_CHANNEL_MAX everywhere?
>
>> +
>>   struct magn_3d_state {
>>         struct hid_sensor_hub_callbacks callbacks;
>>         struct hid_sensor_common common_attributes;
>>         struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
>> -       u32 magn_val[MAGN_3D_CHANNEL_MAX];
>> -};
>> +       u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
>>
>> -static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
>> -       HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
>> -       HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
>> -       HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
>> +       u32 iio_val[IIO_CHANNEL_MAX];
>> +       int num_iio_channels;
>>   };
>>
>> -/* Channel definitions */
>> -static const struct iio_chan_spec magn_3d_channels[] = {
>> -       {
>> -               .type = IIO_MAGN,
>> -               .modified = 1,
>> -               .channel2 = IIO_MOD_X,
>> -               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>> -               BIT(IIO_CHAN_INFO_SCALE) |
>> -               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> -               BIT(IIO_CHAN_INFO_HYSTERESIS),
>> -               .scan_index = CHANNEL_SCAN_INDEX_X,
>> -       }, {
>> -               .type = IIO_MAGN,
>> -               .modified = 1,
>> -               .channel2 = IIO_MOD_Y,
>> -               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>> -               BIT(IIO_CHAN_INFO_SCALE) |
>> -               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> -               BIT(IIO_CHAN_INFO_HYSTERESIS),
>> -               .scan_index = CHANNEL_SCAN_INDEX_Y,
>> -       }, {
>> -               .type = IIO_MAGN,
>> -               .modified = 1,
>> -               .channel2 = IIO_MOD_Z,
>> -               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
>> -               BIT(IIO_CHAN_INFO_SCALE) |
>> -               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> -               BIT(IIO_CHAN_INFO_HYSTERESIS),
>> -               .scan_index = CHANNEL_SCAN_INDEX_Z,
>> +/* Find index into magn_3d_state magn[] and magn_val_addr[] from HID
>> Usage  */
>> +static int magn_3d_usage_id_to_chan_index(unsigned usage_id){
>> +       int offset = -1;
>
> I'd personally prefer offset = -EINVAL and to have it assigned as
> a default element in the switch statement rather that here.
>
>> +
>> +       switch (usage_id) {
>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
>> +               offset = CHANNEL_SCAN_INDEX_X;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
>> +               offset = CHANNEL_SCAN_INDEX_Y;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
>> +               offset = CHANNEL_SCAN_INDEX_Z;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
>> +               offset = CHANNEL_SCAN_INDEX_NORTH_TILT_COMP;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
>> +               offset = CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
>> +               offset = CHANNEL_SCAN_INDEX_NORTH_MAGN;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
>> +               offset = CHANNEL_SCAN_INDEX_NORTH_TRUE;
>> +               break;
>>         }
>> -};
>>
>> -/* Adjust channel real bits based on report descriptor */
>> -static void magn_3d_adjust_channel_bit_mask(struct iio_chan_spec
>> *channels,
>> -                                               int channel, int size)
>> -{
>> -       channels[channel].scan_type.sign = 's';
>> -       /* Real storage bits will change based on the report desc. */
>> -       channels[channel].scan_type.realbits = size * 8;
>> -       /* Maximum size of a sample to capture is u32 */
>> -       channels[channel].scan_type.storagebits = sizeof(u32) * 8;
>> +       return offset;
>>   }
>>
>>   /* Channel read_raw handler */
>> @@ -101,21 +92,31 @@ static int magn_3d_read_raw(struct iio_dev
>> *indio_dev,
>>   {
>>         struct magn_3d_state *magn_state = iio_priv(indio_dev);
>>         int report_id = -1;
>> -       u32 address;
>> +       unsigned usage_id;
>> +       int chan_index = -1;
>>         int ret;
>>         int ret_type;
>>
>> +       dev_dbg(&indio_dev->dev, "magn_3d_read_raw\n");
>> +
>>         *val = 0;
>>         *val2 = 0;
>>         switch (mask) {
>>         case 0:
>> +               /* We store the HID usage ID of the iio channel
>> +                * in its address field
>> +                */
>> +               usage_id = chan->address;
>> +               chan_index = magn_3d_usage_id_to_chan_index(usage_id);
>
>
>> +               if(chan_index < 0)
>> +                       return -EINVAL;
>> +
>>                 report_id =
>> -                       magn_state->magn[chan->scan_index].report_id;
>> -               address = magn_3d_addresses[chan->scan_index];
>> +                       magn_state->magn[chan_index].report_id;
>>                 if (report_id >= 0)
>>                         *val = sensor_hub_input_attr_get_raw_value(
>>                                 magn_state->common_attributes.hsdev,
>> -                               HID_USAGE_SENSOR_COMPASS_3D, address,
>> +                               HID_USAGE_SENSOR_COMPASS_3D, usage_id,
>>                                 report_id);
>>                 else {
>>                         *val = 0;
>> @@ -202,12 +203,13 @@ static int magn_3d_proc_event(struct
>> hid_sensor_hub_device *hsdev,
>>                                 magn_state->common_attributes.data_ready);
>>         if (magn_state->common_attributes.data_ready)
>>                 hid_sensor_push_data(indio_dev,
>> -                               magn_state->magn_val,
>> -                               sizeof(magn_state->magn_val));
>> +                               &(magn_state->iio_val),
>> +                               sizeof(magn_state->iio_val));
>>
>>         return 0;
>>   }
>>
>> +
>>   /* Capture samples in local storage */
>>   static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
>>                                 unsigned usage_id,
>> @@ -217,63 +219,143 @@ static int magn_3d_capture_sample(struct
>> hid_sensor_hub_device *hsdev,
>>         struct iio_dev *indio_dev = platform_get_drvdata(priv);
>>         struct magn_3d_state *magn_state = iio_priv(indio_dev);
>>         int offset;
>> +       u32 *magn_val;
>>         int ret = -EINVAL;
>>
>> -       switch (usage_id) {
>> +       offset = magn_3d_usage_id_to_chan_index(usage_id);
>> +       if(offset < 0)
>> +               return ret;
>> +
>> +       magn_val = magn_state->magn_val_addr[offset];
>> +       if(!magn_val)
>> +               return ret;
>> +
>> +       *(magn_val) =  *(u32 *)raw_data;
>> +
>> +       return 0;
>> +}
>> +
>> +/* Setup the iio_chan_spec for HID Usage ID */
>> +static int magn_3d_setup_new_iio_chan(struct hid_sensor_hub_device
>> *hsdev,
>> +                               unsigned usage_id,
>> +                               unsigned attr_usage_id,
>> +                               struct iio_chan_spec *iio_chans,
>> +                               struct magn_3d_state *st)
>> +{
>> +       int ret = -1;
>
> This is kind of backwards to normal practice for this sort of function.
> Better to maintain ret in the correct state at all times.  Hence
> start with it being 0 and set to negative when there is an error rather
> than the other way around.
>
>> +       int iio_index;
>> +       int magn_index;
>> +       struct iio_chan_spec *channel;
>> +
>> +       /* Setup magn_3d_state for new channel */
>> +       magn_index = magn_3d_usage_id_to_chan_index(attr_usage_id);
>> +       if(magn_index < 0 || magn_index >= MAGN_3D_CHANNEL_MAX){
>> +               return -1;
>> +       }
>> +
>> +       /* Check if usage attribute exists in the sensor hub device */
>> +       ret = sensor_hub_input_get_attribute_info(hsdev,
>> +               HID_INPUT_REPORT,
>> +               usage_id,
>> +               attr_usage_id,
>> +               &(st->magn[magn_index]));
>> +       if(ret != 0){
>> +               /* Usage not found. Nothing to setup.*/
>> +               return 0;
>> +       }
>> +
>> +       iio_index = st->num_iio_channels;
>> +       if(iio_index < 0 || iio_index >= IIO_CHANNEL_MAX){
>
> I'd be tempted to allocate space dynamically but I guess this works.
>
>
>> +               return -2;
>> +       }
>> +
>> +       /* Check if this usage hasn't been setup */
>> +       if(st->magn_val_addr[magn_index] != NULL){
>
> Space before that bracket here and elsewhere.
> Don't return your own error codes. Use standard ones.  I guess thees
> are left from debugging.
>
>> +               return -3;
>> +       }
>> +       st->magn_val_addr[magn_index] = &(st->iio_val[iio_index]);
>> +
>> +       /* Setup IIO Channel spec */
>> +       channel = &(iio_chans[iio_index]);
>
> Just pass this is in as a pointer in the first place?
> That is a pointer to the current channel location, that may or may
> not be filled by this function.
>
>> +
>> +       channel->type = IIO_MAGN;
>> +       channel->address = attr_usage_id;
>> +       channel->modified = 1;
>> +
>> +       switch (attr_usage_id){
>> +       case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
>> +               channel->channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
>> +               channel->channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
>> +               channel->channel2 = IIO_MOD_NORTH_MAGN;
>> +               break;
>> +       case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
>> +               channel->channel2 = IIO_MOD_NORTH_TRUE;
>> +               break;
>>         case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
>> +               channel->channel2 = IIO_MOD_X;
>> +               break;
>>         case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
>> +               channel->channel2 = IIO_MOD_Y;
>> +               break;
>>         case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
>> -               offset = usage_id -
>> HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
>> -               magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset] =
>> -                                               *(u32 *)raw_data;
>> -               ret = 0;
>> -       break;
>> -       default:
>> +               channel->channel2 = IIO_MOD_Z;
>>                 break;
>> +       default:
>> +               return -4;
>
> huh?  why -4. -EINVAL or -ENOSUP or something similar perhaps.
>
>>         }
>>
>> +       channel->info_mask_shared_by_type =
>> +               BIT(IIO_CHAN_INFO_OFFSET) |
>> +               BIT(IIO_CHAN_INFO_SCALE) |
>> +               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>> +               BIT(IIO_CHAN_INFO_HYSTERESIS);
>> +
>> +       channel->scan_type.sign = 's';
>> +       /* Real storage bits will change based on the report desc. */
>> +       channel->scan_type.realbits = st->magn[magn_index].size * 8;
>> +       /* Maximum size of a sample to capture is u32 */
>> +       channel->scan_type.storagebits = sizeof(u32) * 8;
>> +
>
> I'd keen num_iio_channels outside this function and increment it if
> this function does not return an error.
>>
>> +       (st->num_iio_channels)++;
>
> Don't do this. ret should have been valid throughout... if not something
> odd is going on with your use of ret.
>
> Hmm. I see it is in the original code :( feel free to clean this up.
>
>> +       ret = 0;
>> +
>>         return ret;
>>   }
>>
>> -/* Parse report which is specific to an usage id*/
>> +/* Read the HID reports and setup IIO Channels */
>>   static int magn_3d_parse_report(struct platform_device *pdev,
>>                                 struct hid_sensor_hub_device *hsdev,
>> -                               struct iio_chan_spec *channels,
>> +                               struct iio_chan_spec *iio_chans,
>>                                 unsigned usage_id,
>>                                 struct magn_3d_state *st)
>>   {
>> -       int ret;
>> +       int ret = 0;
>>         int i;
>>
>> -       for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
>> -               ret = sensor_hub_input_get_attribute_info(hsdev,
>> -                               HID_INPUT_REPORT,
>> -                               usage_id,
>> -                               HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS +
>> i,
>> -                               &st->magn[CHANNEL_SCAN_INDEX_X + i]);
>> -               if (ret < 0)
>> -                       break;
>> -               magn_3d_adjust_channel_bit_mask(channels,
>> -                               CHANNEL_SCAN_INDEX_X + i,
>> -                               st->magn[CHANNEL_SCAN_INDEX_X + i].size);
>> -       }
>> -       dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
>> -                       st->magn[0].index,
>> -                       st->magn[0].report_id,
>> -                       st->magn[1].index, st->magn[1].report_id,
>> -                       st->magn[2].index, st->magn[2].report_id);
>> -
>> -       /* Set Sensitivity field ids, when there is no individual modifier
>> */
>> -       if (st->common_attributes.sensitivity.index < 0) {
>> -               sensor_hub_input_get_attribute_info(hsdev,
>> -                       HID_FEATURE_REPORT, usage_id,
>> -                       HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
>> -                       HID_USAGE_SENSOR_DATA_ORIENTATION,
>> -                       &st->common_attributes.sensitivity);
>> -               dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
>> -                       st->common_attributes.sensitivity.index,
>> -                       st->common_attributes.sensitivity.report_id);
>> -       }
>> +       dev_dbg(&pdev->dev, "magn_3d_parse_reports Usage ID: %x\n",
>> usage_id);
>> +       for(i = HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
>> +           i <= HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS && ret == 0;
>> +               i++)
>> +                       ret = magn_3d_setup_new_iio_chan(hsdev,
>> +                                       usage_id,
>> +                                       i,
>> +                                       iio_chans,
>> +                                       st);
>> +
>> +       dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic
>> axis. Returned: %d", st->num_iio_channels, ret);
>> +       for(i = HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH;
>> +           i <= HID_USAGE_SENSOR_ORIENT_TRUE_NORTH && ret == 0;
>> +               i++)
>> +                       ret = magn_3d_setup_new_iio_chan(hsdev,
>> +                                       usage_id,
>> +                                       i,
>> +                                       iio_chans,
>> +                                       st);
>
> As stated above, I'd use whether this succeeds for a given channel to
> increment the location in iio_chans and then pass in only the 'next' channel
> location on each pass.  Moving the bounds checks out here as well would be
> make for a cleaner magn_3d_setup_new_iio_chan function.
>
>
>> +       dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n magnetic
>> channels. Returned: %d", st->num_iio_channels, ret);
>>
>>         return ret;
>>   }
>> @@ -307,10 +389,11 @@ static int hid_magn_3d_probe(struct platform_device
>> *pdev)
>>                 return ret;
>>         }
>>
>> -       channels = kmemdup(magn_3d_channels, sizeof(magn_3d_channels),
>> -                          GFP_KERNEL);
>> +       channels = kcalloc(MAGN_3D_CHANNEL_MAX,
>> +                       sizeof(struct iio_chan_spec),
>> +                       GFP_KERNEL);
>>         if (!channels) {
>> -               dev_err(&pdev->dev, "failed to duplicate channels\n");
>> +               dev_err(&pdev->dev, "failed to allocate memory for iio
>> channel\n");
>>                 return -ENOMEM;
>>         }
>>
>> @@ -322,7 +405,7 @@ static int hid_magn_3d_probe(struct platform_device
>> *pdev)
>>         }
>>
>>         indio_dev->channels = channels;
>> -       indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
>> +       indio_dev->num_channels = magn_state->num_iio_channels;
>
> With a bit of rearranging it strikes me that you can fill num_channels
> directly rather than having another copy of it....
>
>>         indio_dev->dev.parent = &pdev->dev;
>>         indio_dev->info = &magn_3d_info;
>>         indio_dev->name = name;
>>
>

Re: [PATCHv2 3/3] IIO: hid-sensor-magn-3d: Add in support for True/Magnetic North HID usages

[Jonathan Cameron]

On June 10, 2014 6:33:25 PM GMT+01:00, Reyad Attiyat <reyad.attiyat@gmail.com> wrote:
>Hey Jonathan,
>
>I will make the changes you suggested thanks for reviewing this. Any
>conclusions on the naming, did you want me to change the sysfs name to
>"in_rot_from_north_true/magnetic"?
Yes. I think that is the cleanest option from those we have considered!
>
>On Mon, Jun 9, 2014 at 2:55 PM, Jonathan Cameron <jic23@kernel.org>
>wrote:
>> On 03/06/14 00:14, Reyad Attiyat wrote:
>>>
>>> Updated magn_3d_channel enum for all possible north channels
>>>
>>> Added functions to setup iio_chan_spec array depending on which hid
>usage
>>> reports are found
>>>
>>> Renamed magn_val to iio_val to differentiate the index being used
>>>
>>> Updated magn_3d_state struct to hold pointer array (magn_val_addr[])
>which
>>> points to iio_val[]
>>>
>>> Updated magn_3d_parse_report to scan for all compass usages and
>create iio
>>> channels for each
>>>
>>> Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
>>
>> Hi Reyad,
>>
>> I've taken a rather quick look at this.  Will probably want to take
>> one more close look at a newer version.
>>
>> Various bits and bobs inline - mostly fine!
>> Jonathan
>>
>>> ---
>>>   drivers/iio/magnetometer/hid-sensor-magn-3d.c | 271
>>> +++++++++++++++++---------
>>>   1 file changed, 177 insertions(+), 94 deletions(-)
>>>
>>> diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>>> b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>>> index 6d162b7..32f4d90 100644
>>> --- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>>> +++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
>>> @@ -34,63 +34,54 @@ enum magn_3d_channel {
>>>         CHANNEL_SCAN_INDEX_X,
>>>         CHANNEL_SCAN_INDEX_Y,
>>>         CHANNEL_SCAN_INDEX_Z,
>>> +       CHANNEL_SCAN_INDEX_NORTH_MAGN,
>>> +       CHANNEL_SCAN_INDEX_NORTH_TRUE,
>>> +       CHANNEL_SCAN_INDEX_NORTH_TILT_COMP,
>>> +       CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
>>>         MAGN_3D_CHANNEL_MAX,
>>>   };
>>>
>>> +#define IIO_CHANNEL_MAX MAGN_3D_CHANNEL_MAX
>>
>> Please don't define a generic sounding name for a local
>> constant.  Why not use MAGN_3D_CHANNEL_MAX everywhere?
>>
>>> +
>>>   struct magn_3d_state {
>>>         struct hid_sensor_hub_callbacks callbacks;
>>>         struct hid_sensor_common common_attributes;
>>>         struct hid_sensor_hub_attribute_info
>magn[MAGN_3D_CHANNEL_MAX];
>>> -       u32 magn_val[MAGN_3D_CHANNEL_MAX];
>>> -};
>>> +       u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
>>>
>>> -static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
>>> -       HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
>>> -       HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
>>> -       HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
>>> +       u32 iio_val[IIO_CHANNEL_MAX];
>>> +       int num_iio_channels;
>>>   };
>>>
>>> -/* Channel definitions */
>>> -static const struct iio_chan_spec magn_3d_channels[] = {
>>> -       {
>>> -               .type = IIO_MAGN,
>>> -               .modified = 1,
>>> -               .channel2 = IIO_MOD_X,
>>> -               .info_mask_shared_by_type =
>BIT(IIO_CHAN_INFO_OFFSET) |
>>> -               BIT(IIO_CHAN_INFO_SCALE) |
>>> -               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>>> -               BIT(IIO_CHAN_INFO_HYSTERESIS),
>>> -               .scan_index = CHANNEL_SCAN_INDEX_X,
>>> -       }, {
>>> -               .type = IIO_MAGN,
>>> -               .modified = 1,
>>> -               .channel2 = IIO_MOD_Y,
>>> -               .info_mask_shared_by_type =
>BIT(IIO_CHAN_INFO_OFFSET) |
>>> -               BIT(IIO_CHAN_INFO_SCALE) |
>>> -               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>>> -               BIT(IIO_CHAN_INFO_HYSTERESIS),
>>> -               .scan_index = CHANNEL_SCAN_INDEX_Y,
>>> -       }, {
>>> -               .type = IIO_MAGN,
>>> -               .modified = 1,
>>> -               .channel2 = IIO_MOD_Z,
>>> -               .info_mask_shared_by_type =
>BIT(IIO_CHAN_INFO_OFFSET) |
>>> -               BIT(IIO_CHAN_INFO_SCALE) |
>>> -               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>>> -               BIT(IIO_CHAN_INFO_HYSTERESIS),
>>> -               .scan_index = CHANNEL_SCAN_INDEX_Z,
>>> +/* Find index into magn_3d_state magn[] and magn_val_addr[] from
>HID
>>> Usage  */
>>> +static int magn_3d_usage_id_to_chan_index(unsigned usage_id){
>>> +       int offset = -1;
>>
>> I'd personally prefer offset = -EINVAL and to have it assigned as
>> a default element in the switch statement rather that here.
>>
>>> +
>>> +       switch (usage_id) {
>>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
>>> +               offset = CHANNEL_SCAN_INDEX_X;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
>>> +               offset = CHANNEL_SCAN_INDEX_Y;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
>>> +               offset = CHANNEL_SCAN_INDEX_Z;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
>>> +               offset = CHANNEL_SCAN_INDEX_NORTH_TILT_COMP;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
>>> +               offset = CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
>>> +               offset = CHANNEL_SCAN_INDEX_NORTH_MAGN;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
>>> +               offset = CHANNEL_SCAN_INDEX_NORTH_TRUE;
>>> +               break;
>>>         }
>>> -};
>>>
>>> -/* Adjust channel real bits based on report descriptor */
>>> -static void magn_3d_adjust_channel_bit_mask(struct iio_chan_spec
>>> *channels,
>>> -                                               int channel, int
>size)
>>> -{
>>> -       channels[channel].scan_type.sign = 's';
>>> -       /* Real storage bits will change based on the report desc.
>*/
>>> -       channels[channel].scan_type.realbits = size * 8;
>>> -       /* Maximum size of a sample to capture is u32 */
>>> -       channels[channel].scan_type.storagebits = sizeof(u32) * 8;
>>> +       return offset;
>>>   }
>>>
>>>   /* Channel read_raw handler */
>>> @@ -101,21 +92,31 @@ static int magn_3d_read_raw(struct iio_dev
>>> *indio_dev,
>>>   {
>>>         struct magn_3d_state *magn_state = iio_priv(indio_dev);
>>>         int report_id = -1;
>>> -       u32 address;
>>> +       unsigned usage_id;
>>> +       int chan_index = -1;
>>>         int ret;
>>>         int ret_type;
>>>
>>> +       dev_dbg(&indio_dev->dev, "magn_3d_read_raw\n");
>>> +
>>>         *val = 0;
>>>         *val2 = 0;
>>>         switch (mask) {
>>>         case 0:
>>> +               /* We store the HID usage ID of the iio channel
>>> +                * in its address field
>>> +                */
>>> +               usage_id = chan->address;
>>> +               chan_index =
>magn_3d_usage_id_to_chan_index(usage_id);
>>
>>
>>> +               if(chan_index < 0)
>>> +                       return -EINVAL;
>>> +
>>>                 report_id =
>>> -                      
>magn_state->magn[chan->scan_index].report_id;
>>> -               address = magn_3d_addresses[chan->scan_index];
>>> +                       magn_state->magn[chan_index].report_id;
>>>                 if (report_id >= 0)
>>>                         *val = sensor_hub_input_attr_get_raw_value(
>>>                                 magn_state->common_attributes.hsdev,
>>> -                               HID_USAGE_SENSOR_COMPASS_3D,
>address,
>>> +                               HID_USAGE_SENSOR_COMPASS_3D,
>usage_id,
>>>                                 report_id);
>>>                 else {
>>>                         *val = 0;
>>> @@ -202,12 +203,13 @@ static int magn_3d_proc_event(struct
>>> hid_sensor_hub_device *hsdev,
>>>                                
>magn_state->common_attributes.data_ready);
>>>         if (magn_state->common_attributes.data_ready)
>>>                 hid_sensor_push_data(indio_dev,
>>> -                               magn_state->magn_val,
>>> -                               sizeof(magn_state->magn_val));
>>> +                               &(magn_state->iio_val),
>>> +                               sizeof(magn_state->iio_val));
>>>
>>>         return 0;
>>>   }
>>>
>>> +
>>>   /* Capture samples in local storage */
>>>   static int magn_3d_capture_sample(struct hid_sensor_hub_device
>*hsdev,
>>>                                 unsigned usage_id,
>>> @@ -217,63 +219,143 @@ static int magn_3d_capture_sample(struct
>>> hid_sensor_hub_device *hsdev,
>>>         struct iio_dev *indio_dev = platform_get_drvdata(priv);
>>>         struct magn_3d_state *magn_state = iio_priv(indio_dev);
>>>         int offset;
>>> +       u32 *magn_val;
>>>         int ret = -EINVAL;
>>>
>>> -       switch (usage_id) {
>>> +       offset = magn_3d_usage_id_to_chan_index(usage_id);
>>> +       if(offset < 0)
>>> +               return ret;
>>> +
>>> +       magn_val = magn_state->magn_val_addr[offset];
>>> +       if(!magn_val)
>>> +               return ret;
>>> +
>>> +       *(magn_val) =  *(u32 *)raw_data;
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +/* Setup the iio_chan_spec for HID Usage ID */
>>> +static int magn_3d_setup_new_iio_chan(struct hid_sensor_hub_device
>>> *hsdev,
>>> +                               unsigned usage_id,
>>> +                               unsigned attr_usage_id,
>>> +                               struct iio_chan_spec *iio_chans,
>>> +                               struct magn_3d_state *st)
>>> +{
>>> +       int ret = -1;
>>
>> This is kind of backwards to normal practice for this sort of
>function.
>> Better to maintain ret in the correct state at all times.  Hence
>> start with it being 0 and set to negative when there is an error
>rather
>> than the other way around.
>>
>>> +       int iio_index;
>>> +       int magn_index;
>>> +       struct iio_chan_spec *channel;
>>> +
>>> +       /* Setup magn_3d_state for new channel */
>>> +       magn_index = magn_3d_usage_id_to_chan_index(attr_usage_id);
>>> +       if(magn_index < 0 || magn_index >= MAGN_3D_CHANNEL_MAX){
>>> +               return -1;
>>> +       }
>>> +
>>> +       /* Check if usage attribute exists in the sensor hub device
>*/
>>> +       ret = sensor_hub_input_get_attribute_info(hsdev,
>>> +               HID_INPUT_REPORT,
>>> +               usage_id,
>>> +               attr_usage_id,
>>> +               &(st->magn[magn_index]));
>>> +       if(ret != 0){
>>> +               /* Usage not found. Nothing to setup.*/
>>> +               return 0;
>>> +       }
>>> +
>>> +       iio_index = st->num_iio_channels;
>>> +       if(iio_index < 0 || iio_index >= IIO_CHANNEL_MAX){
>>
>> I'd be tempted to allocate space dynamically but I guess this works.
>>
>>
>>> +               return -2;
>>> +       }
>>> +
>>> +       /* Check if this usage hasn't been setup */
>>> +       if(st->magn_val_addr[magn_index] != NULL){
>>
>> Space before that bracket here and elsewhere.
>> Don't return your own error codes. Use standard ones.  I guess thees
>> are left from debugging.
>>
>>> +               return -3;
>>> +       }
>>> +       st->magn_val_addr[magn_index] = &(st->iio_val[iio_index]);
>>> +
>>> +       /* Setup IIO Channel spec */
>>> +       channel = &(iio_chans[iio_index]);
>>
>> Just pass this is in as a pointer in the first place?
>> That is a pointer to the current channel location, that may or may
>> not be filled by this function.
>>
>>> +
>>> +       channel->type = IIO_MAGN;
>>> +       channel->address = attr_usage_id;
>>> +       channel->modified = 1;
>>> +
>>> +       switch (attr_usage_id){
>>> +       case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
>>> +               channel->channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
>>> +               channel->channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
>>> +               channel->channel2 = IIO_MOD_NORTH_MAGN;
>>> +               break;
>>> +       case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
>>> +               channel->channel2 = IIO_MOD_NORTH_TRUE;
>>> +               break;
>>>         case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
>>> +               channel->channel2 = IIO_MOD_X;
>>> +               break;
>>>         case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
>>> +               channel->channel2 = IIO_MOD_Y;
>>> +               break;
>>>         case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
>>> -               offset = usage_id -
>>> HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
>>> -               magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset]
>=
>>> -                                               *(u32 *)raw_data;
>>> -               ret = 0;
>>> -       break;
>>> -       default:
>>> +               channel->channel2 = IIO_MOD_Z;
>>>                 break;
>>> +       default:
>>> +               return -4;
>>
>> huh?  why -4. -EINVAL or -ENOSUP or something similar perhaps.
>>
>>>         }
>>>
>>> +       channel->info_mask_shared_by_type =
>>> +               BIT(IIO_CHAN_INFO_OFFSET) |
>>> +               BIT(IIO_CHAN_INFO_SCALE) |
>>> +               BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>>> +               BIT(IIO_CHAN_INFO_HYSTERESIS);
>>> +
>>> +       channel->scan_type.sign = 's';
>>> +       /* Real storage bits will change based on the report desc.
>*/
>>> +       channel->scan_type.realbits = st->magn[magn_index].size * 8;
>>> +       /* Maximum size of a sample to capture is u32 */
>>> +       channel->scan_type.storagebits = sizeof(u32) * 8;
>>> +
>>
>> I'd keen num_iio_channels outside this function and increment it if
>> this function does not return an error.
>>>
>>> +       (st->num_iio_channels)++;
>>
>> Don't do this. ret should have been valid throughout... if not
>something
>> odd is going on with your use of ret.
>>
>> Hmm. I see it is in the original code :( feel free to clean this up.
>>
>>> +       ret = 0;
>>> +
>>>         return ret;
>>>   }
>>>
>>> -/* Parse report which is specific to an usage id*/
>>> +/* Read the HID reports and setup IIO Channels */
>>>   static int magn_3d_parse_report(struct platform_device *pdev,
>>>                                 struct hid_sensor_hub_device *hsdev,
>>> -                               struct iio_chan_spec *channels,
>>> +                               struct iio_chan_spec *iio_chans,
>>>                                 unsigned usage_id,
>>>                                 struct magn_3d_state *st)
>>>   {
>>> -       int ret;
>>> +       int ret = 0;
>>>         int i;
>>>
>>> -       for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
>>> -               ret = sensor_hub_input_get_attribute_info(hsdev,
>>> -                               HID_INPUT_REPORT,
>>> -                               usage_id,
>>> -                              
>HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS +
>>> i,
>>> -                               &st->magn[CHANNEL_SCAN_INDEX_X +
>i]);
>>> -               if (ret < 0)
>>> -                       break;
>>> -               magn_3d_adjust_channel_bit_mask(channels,
>>> -                               CHANNEL_SCAN_INDEX_X + i,
>>> -                               st->magn[CHANNEL_SCAN_INDEX_X +
>i].size);
>>> -       }
>>> -       dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
>>> -                       st->magn[0].index,
>>> -                       st->magn[0].report_id,
>>> -                       st->magn[1].index, st->magn[1].report_id,
>>> -                       st->magn[2].index, st->magn[2].report_id);
>>> -
>>> -       /* Set Sensitivity field ids, when there is no individual
>modifier
>>> */
>>> -       if (st->common_attributes.sensitivity.index < 0) {
>>> -               sensor_hub_input_get_attribute_info(hsdev,
>>> -                       HID_FEATURE_REPORT, usage_id,
>>> -                      
>HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
>>> -                       HID_USAGE_SENSOR_DATA_ORIENTATION,
>>> -                       &st->common_attributes.sensitivity);
>>> -               dev_dbg(&pdev->dev, "Sensitivity index:report
>%d:%d\n",
>>> -                       st->common_attributes.sensitivity.index,
>>> -                      
>st->common_attributes.sensitivity.report_id);
>>> -       }
>>> +       dev_dbg(&pdev->dev, "magn_3d_parse_reports Usage ID: %x\n",
>>> usage_id);
>>> +       for(i = HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
>>> +           i <= HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS && ret ==
>0;
>>> +               i++)
>>> +                       ret = magn_3d_setup_new_iio_chan(hsdev,
>>> +                                       usage_id,
>>> +                                       i,
>>> +                                       iio_chans,
>>> +                                       st);
>>> +
>>> +       dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n
>magnetic
>>> axis. Returned: %d", st->num_iio_channels, ret);
>>> +       for(i = HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH;
>>> +           i <= HID_USAGE_SENSOR_ORIENT_TRUE_NORTH && ret == 0;
>>> +               i++)
>>> +                       ret = magn_3d_setup_new_iio_chan(hsdev,
>>> +                                       usage_id,
>>> +                                       i,
>>> +                                       iio_chans,
>>> +                                       st);
>>
>> As stated above, I'd use whether this succeeds for a given channel to
>> increment the location in iio_chans and then pass in only the 'next'
>channel
>> location on each pass.  Moving the bounds checks out here as well
>would be
>> make for a cleaner magn_3d_setup_new_iio_chan function.
>>
>>
>>> +       dev_dbg(&pdev->dev, "magn_3d_parse_reports Found %d\n
>magnetic
>>> channels. Returned: %d", st->num_iio_channels, ret);
>>>
>>>         return ret;
>>>   }
>>> @@ -307,10 +389,11 @@ static int hid_magn_3d_probe(struct
>platform_device
>>> *pdev)
>>>                 return ret;
>>>         }
>>>
>>> -       channels = kmemdup(magn_3d_channels,
>sizeof(magn_3d_channels),
>>> -                          GFP_KERNEL);
>>> +       channels = kcalloc(MAGN_3D_CHANNEL_MAX,
>>> +                       sizeof(struct iio_chan_spec),
>>> +                       GFP_KERNEL);
>>>         if (!channels) {
>>> -               dev_err(&pdev->dev, "failed to duplicate
>channels\n");
>>> +               dev_err(&pdev->dev, "failed to allocate memory for
>iio
>>> channel\n");
>>>                 return -ENOMEM;
>>>         }
>>>
>>> @@ -322,7 +405,7 @@ static int hid_magn_3d_probe(struct
>platform_device
>>> *pdev)
>>>         }
>>>
>>>         indio_dev->channels = channels;
>>> -       indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
>>> +       indio_dev->num_channels = magn_state->num_iio_channels;
>>
>> With a bit of rearranging it strikes me that you can fill
>num_channels
>> directly rather than having another copy of it....
>>
>>>         indio_dev->dev.parent = &pdev->dev;
>>>         indio_dev->info = &magn_3d_info;
>>>         indio_dev->name = name;
>>>
>>
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