iio: imu: st_lsm6dsx: enable drdy-mask if available

Enable drdy mask if available in order to mark invalid samples during
sensor bootstrap phase
Tested-by: Mario Tesi <mario.tesi@st.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h

@@ -245,6 +245,7 @@ struct st_lsm6dsx_ext_dev_settings {
  * @id: List of hw id/device name supported by the driver configuration.
  * @channels: IIO channels supported by the device.
  * @irq_config: interrupts related registers.
+ * @drdy_mask: register info for data-ready mask (addr + mask).
  * @odr_table: Hw sensors odr table (Hz + val).
  * @fs_table: Hw sensors gain table (gain + val).
  * @decimator: List of decimator register info (addr + mask).
@@ -277,6 +278,7 @@ struct st_lsm6dsx_settings {
 		struct st_lsm6dsx_reg hla;
 		struct st_lsm6dsx_reg od;
 	} irq_config;
+	struct st_lsm6dsx_reg drdy_mask;
 	struct st_lsm6dsx_odr_table_entry odr_table[2];
 	struct st_lsm6dsx_fs_table_entry fs_table[2];
 	struct st_lsm6dsx_reg decimator[ST_LSM6DSX_MAX_ID];

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c

@@ -450,13 +450,19 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
 	return read_len;
 }
 
+#define ST_LSM6DSX_INVALID_SAMPLE	0x7ffd
 static int
 st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw *hw, u8 tag,
 			    u8 *data, s64 ts)
 {
+	s16 val = le16_to_cpu(*(__le16 *)data);
 	struct st_lsm6dsx_sensor *sensor;
 	struct iio_dev *iio_dev;
 
+	/* invalid sample during bootstrap phase */
+	if (val >= ST_LSM6DSX_INVALID_SAMPLE)
+		return -EINVAL;
+
 	/*
 	 * EXT_TAG are managed in FIFO fashion so ST_LSM6DSX_EXT0_TAG
 	 * corresponds to the first enabled channel, ST_LSM6DSX_EXT1_TAG

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c

@@ -723,6 +723,10 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
 				.len = ARRAY_SIZE(st_lsm6dsx_gyro_channels),
 			},
 		},
+		.drdy_mask = {
+			.addr = 0x13,
+			.mask = BIT(3),
+		},
 		.odr_table = {
 			[ST_LSM6DSX_ID_ACC] = {
 				.reg = {
@@ -913,6 +917,10 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
 				.len = ARRAY_SIZE(st_lsm6dsx_gyro_channels),
 			},
 		},
+		.drdy_mask = {
+			.addr = 0x13,
+			.mask = BIT(3),
+		},
 		.odr_table = {
 			[ST_LSM6DSX_ID_ACC] = {
 				.reg = {
@@ -1080,6 +1088,10 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
 				.len = ARRAY_SIZE(st_lsm6dsx_gyro_channels),
 			},
 		},
+		.drdy_mask = {
+			.addr = 0x13,
+			.mask = BIT(3),
+		},
 		.odr_table = {
 			[ST_LSM6DSX_ID_ACC] = {
 				.reg = {
@@ -1943,6 +1955,15 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
 		}
 	}
 
+	/* enable drdy-mas if available */
+	if (hw->settings->drdy_mask.addr) {
+		reg = &hw->settings->drdy_mask;
+		err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
+					 ST_LSM6DSX_SHIFT_VAL(1, reg->mask));
+		if (err < 0)
+			return err;
+	}
+
 	err = st_lsm6dsx_init_shub(hw);
 	if (err < 0)
 		return err;