iio: imu: st_lsm6dsx: add i2c embedded controller support

i2c controller embedded in lsm6dx series can connect up to four
slave devices using accelerometer sensor as trigger for i2c
read/write operations.
Introduce sensor hub support for lsm6dso sensor. Add register map
for lis2mdl magnetometer sensor.
In order to perform single read/write operations st_lsm6dsx driver
relies on SLV0 channel (hw FIFO is not supported yet)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/st_lsm6dsx/Makefile

-st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o
+st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o \
+		st_lsm6dsx_shub.o
 
 obj-$(CONFIG_IIO_ST_LSM6DSX) += st_lsm6dsx.o
 obj-$(CONFIG_IIO_ST_LSM6DSX_I2C) += st_lsm6dsx_i2c.o

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h

@@ -43,6 +43,24 @@ enum st_lsm6dsx_hw_id {
 					 * ST_LSM6DSX_TAGGED_SAMPLE_SIZE)
 #define ST_LSM6DSX_SHIFT_VAL(val, mask)	(((val) << __ffs(mask)) & (mask))
 
+#define ST_LSM6DSX_CHANNEL(chan_type, addr, mod, scan_idx)		\
+{									\
+	.type = chan_type,						\
+	.address = addr,						\
+	.modified = 1,							\
+	.channel2 = mod,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
+			      BIT(IIO_CHAN_INFO_SCALE),			\
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+	.scan_index = scan_idx,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 16,						\
+		.storagebits = 16,					\
+		.endianness = IIO_LE,					\
+	},								\
+}
+
 struct st_lsm6dsx_reg {
 	u8 addr;
 	u8 mask;
@@ -50,6 +68,28 @@ struct st_lsm6dsx_reg {
 
 struct st_lsm6dsx_hw;
 
+struct st_lsm6dsx_odr {
+	u16 hz;
+	u8 val;
+};
+
+#define ST_LSM6DSX_ODR_LIST_SIZE	6
+struct st_lsm6dsx_odr_table_entry {
+	struct st_lsm6dsx_reg reg;
+	struct st_lsm6dsx_odr odr_avl[ST_LSM6DSX_ODR_LIST_SIZE];
+};
+
+struct st_lsm6dsx_fs {
+	u32 gain;
+	u8 val;
+};
+
+#define ST_LSM6DSX_FS_LIST_SIZE		4
+struct st_lsm6dsx_fs_table_entry {
+	struct st_lsm6dsx_reg reg;
+	struct st_lsm6dsx_fs fs_avl[ST_LSM6DSX_FS_LIST_SIZE];
+};
+
 /**
  * struct st_lsm6dsx_fifo_ops - ST IMU FIFO settings
  * @read_fifo: Read FIFO callback.
@@ -84,6 +124,66 @@ struct st_lsm6dsx_hw_ts_settings {
 	struct st_lsm6dsx_reg decimator;
 };
 
+/**
+ * struct st_lsm6dsx_shub_settings - ST IMU hw i2c controller settings
+ * @page_mux: register page mux info (addr + mask).
+ * @master_en: master config register info (addr + mask).
+ * @pullup_en: i2c controller pull-up register info (addr + mask).
+ * @aux_sens: aux sensor register info (addr + mask).
+ * @shub_out: sensor hub first output register info.
+ * @slv0_addr: slave0 address in secondary page.
+ * @dw_slv0_addr: slave0 write register address in secondary page.
+ */
+struct st_lsm6dsx_shub_settings {
+	struct st_lsm6dsx_reg page_mux;
+	struct st_lsm6dsx_reg master_en;
+	struct st_lsm6dsx_reg pullup_en;
+	struct st_lsm6dsx_reg aux_sens;
+	u8 shub_out;
+	u8 slv0_addr;
+	u8 dw_slv0_addr;
+};
+
+enum st_lsm6dsx_ext_sensor_id {
+	ST_LSM6DSX_ID_MAGN,
+};
+
+/**
+ * struct st_lsm6dsx_ext_dev_settings - i2c controller slave settings
+ * @i2c_addr: I2c slave address list.
+ * @wai: Wai address info.
+ * @id: external sensor id.
+ * @odr: Output data rate of the sensor [Hz].
+ * @gain: Configured sensor sensitivity.
+ * @temp_comp: Temperature compensation register info (addr + mask).
+ * @pwr_table: Power on register info (addr + mask).
+ * @off_canc: Offset cancellation register info (addr + mask).
+ * @bdu: Block data update register info (addr + mask).
+ * @out: Output register info.
+ */
+struct st_lsm6dsx_ext_dev_settings {
+	u8 i2c_addr[2];
+	struct {
+		u8 addr;
+		u8 val;
+	} wai;
+	enum st_lsm6dsx_ext_sensor_id id;
+	struct st_lsm6dsx_odr_table_entry odr_table;
+	struct st_lsm6dsx_fs_table_entry fs_table;
+	struct st_lsm6dsx_reg temp_comp;
+	struct {
+		struct st_lsm6dsx_reg reg;
+		u8 off_val;
+		u8 on_val;
+	} pwr_table;
+	struct st_lsm6dsx_reg off_canc;
+	struct st_lsm6dsx_reg bdu;
+	struct {
+		u8 addr;
+		u8 len;
+	} out;
+};
+
 /**
  * struct st_lsm6dsx_settings - ST IMU sensor settings
  * @wai: Sensor WhoAmI default value.
@@ -93,6 +193,7 @@ struct st_lsm6dsx_hw_ts_settings {
  * @batch: List of FIFO batching register info (addr + mask).
  * @fifo_ops: Sensor hw FIFO parameters.
  * @ts_settings: Hw timer related settings.
+ * @shub_settings: i2c controller related settings.
  */
 struct st_lsm6dsx_settings {
 	u8 wai;
@@ -102,6 +203,7 @@ struct st_lsm6dsx_settings {
 	struct st_lsm6dsx_reg batch[ST_LSM6DSX_MAX_ID];
 	struct st_lsm6dsx_fifo_ops fifo_ops;
 	struct st_lsm6dsx_hw_ts_settings ts_settings;
+	struct st_lsm6dsx_shub_settings shub_settings;
 };
 
 enum st_lsm6dsx_sensor_id {
@@ -129,6 +231,7 @@ enum st_lsm6dsx_fifo_mode {
  * @sip: Number of samples in a given pattern.
  * @decimator: FIFO decimation factor.
  * @ts_ref: Sensor timestamp reference for hw one.
+ * @ext_info: Sensor settings if it is connected to i2c controller
  */
 struct st_lsm6dsx_sensor {
 	char name[32];
@@ -142,6 +245,11 @@ struct st_lsm6dsx_sensor {
 	u8 sip;
 	u8 decimator;
 	s64 ts_ref;
+
+	struct {
+		const struct st_lsm6dsx_ext_dev_settings *settings;
+		u8 addr;
+	} ext_info;
 };
 
 /**
@@ -181,6 +289,7 @@ struct st_lsm6dsx_hw {
 	const struct st_lsm6dsx_settings *settings;
 };
 
+static const unsigned long st_lsm6dsx_available_scan_masks[] = {0x7, 0x0};
 extern const struct dev_pm_ops st_lsm6dsx_pm_ops;
 
 int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id, const char *name,
@@ -197,6 +306,9 @@ int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
 int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw);
 int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw);
 int st_lsm6dsx_check_odr(struct st_lsm6dsx_sensor *sensor, u16 odr, u8 *val);
+int st_lsm6dsx_shub_probe(struct st_lsm6dsx_hw *hw, const char *name);
+int st_lsm6dsx_shub_set_enable(struct st_lsm6dsx_sensor *sensor, bool enable);
+int st_lsm6dsx_set_page(struct st_lsm6dsx_hw *hw, bool enable);
 
 static inline int
 st_lsm6dsx_update_bits_locked(struct st_lsm6dsx_hw *hw, unsigned int addr,

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c

@@ -88,17 +88,6 @@
 #define ST_LSM6DSX_GYRO_FS_1000_GAIN		IIO_DEGREE_TO_RAD(35000)
 #define ST_LSM6DSX_GYRO_FS_2000_GAIN		IIO_DEGREE_TO_RAD(70000)
 
-struct st_lsm6dsx_odr {
-	u16 hz;
-	u8 val;
-};
-
-#define ST_LSM6DSX_ODR_LIST_SIZE	6
-struct st_lsm6dsx_odr_table_entry {
-	struct st_lsm6dsx_reg reg;
-	struct st_lsm6dsx_odr odr_avl[ST_LSM6DSX_ODR_LIST_SIZE];
-};
-
 static const struct st_lsm6dsx_odr_table_entry st_lsm6dsx_odr_table[] = {
 	[ST_LSM6DSX_ID_ACC] = {
 		.reg = {
@@ -126,17 +115,6 @@ static const struct st_lsm6dsx_odr_table_entry st_lsm6dsx_odr_table[] = {
 	}
 };
 
-struct st_lsm6dsx_fs {
-	u32 gain;
-	u8 val;
-};
-
-#define ST_LSM6DSX_FS_LIST_SIZE		4
-struct st_lsm6dsx_fs_table_entry {
-	struct st_lsm6dsx_reg reg;
-	struct st_lsm6dsx_fs fs_avl[ST_LSM6DSX_FS_LIST_SIZE];
-};
-
 static const struct st_lsm6dsx_fs_table_entry st_lsm6dsx_fs_table[] = {
 	[ST_LSM6DSX_ID_ACC] = {
 		.reg = {
@@ -342,27 +320,30 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
 				.mask = GENMASK(7, 6),
 			},
 		},
+		.shub_settings = {
+			.page_mux = {
+				.addr = 0x01,
+				.mask = BIT(6),
+			},
+			.master_en = {
+				.addr = 0x14,
+				.mask = BIT(2),
+			},
+			.pullup_en = {
+				.addr = 0x14,
+				.mask = BIT(3),
+			},
+			.aux_sens = {
+				.addr = 0x14,
+				.mask = GENMASK(1, 0),
+			},
+			.shub_out = 0x02,
+			.slv0_addr = 0x15,
+			.dw_slv0_addr = 0x21,
+		}
 	},
 };
 
-#define ST_LSM6DSX_CHANNEL(chan_type, addr, mod, scan_idx)		\
-{									\
-	.type = chan_type,						\
-	.address = addr,						\
-	.modified = 1,							\
-	.channel2 = mod,						\
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
-			      BIT(IIO_CHAN_INFO_SCALE),			\
-	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
-	.scan_index = scan_idx,						\
-	.scan_type = {							\
-		.sign = 's',						\
-		.realbits = 16,						\
-		.storagebits = 16,					\
-		.endianness = IIO_LE,					\
-	},								\
-}
-
 static const struct iio_chan_spec st_lsm6dsx_acc_channels[] = {
 	ST_LSM6DSX_CHANNEL(IIO_ACCEL, ST_LSM6DSX_REG_ACC_OUT_X_L_ADDR,
 			   IIO_MOD_X, 0),
@@ -383,6 +364,21 @@ static const struct iio_chan_spec st_lsm6dsx_gyro_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
+int st_lsm6dsx_set_page(struct st_lsm6dsx_hw *hw, bool enable)
+{
+	const struct st_lsm6dsx_shub_settings *hub_settings;
+	unsigned int data;
+	int err;
+
+	hub_settings = &hw->settings->shub_settings;
+	data = ST_LSM6DSX_SHIFT_VAL(enable, hub_settings->page_mux.mask);
+	err = regmap_update_bits(hw->regmap, hub_settings->page_mux.addr,
+				 hub_settings->page_mux.mask, data);
+	usleep_range(100, 150);
+
+	return err;
+}
+
 static int st_lsm6dsx_check_whoami(struct st_lsm6dsx_hw *hw, int id)
 {
 	int err, i, j, data;
@@ -736,8 +732,6 @@ static const struct iio_info st_lsm6dsx_gyro_info = {
 	.hwfifo_set_watermark = st_lsm6dsx_set_watermark,
 };
 
-static const unsigned long st_lsm6dsx_available_scan_masks[] = {0x7, 0x0};
-
 static int st_lsm6dsx_of_get_drdy_pin(struct st_lsm6dsx_hw *hw, int *drdy_pin)
 {
 	struct device_node *np = hw->dev->of_node;
@@ -776,6 +770,51 @@ static int st_lsm6dsx_get_drdy_reg(struct st_lsm6dsx_hw *hw, u8 *drdy_reg)
 	return err;
 }
 
+static int st_lsm6dsx_init_shub(struct st_lsm6dsx_hw *hw)
+{
+	const struct st_lsm6dsx_shub_settings *hub_settings;
+	struct device_node *np = hw->dev->of_node;
+	struct st_sensors_platform_data *pdata;
+	unsigned int data;
+	int err = 0;
+
+	hub_settings = &hw->settings->shub_settings;
+
+	pdata = (struct st_sensors_platform_data *)hw->dev->platform_data;
+	if ((np && of_property_read_bool(np, "st,pullups")) ||
+	    (pdata && pdata->pullups)) {
+		err = st_lsm6dsx_set_page(hw, true);
+		if (err < 0)
+			return err;
+
+		data = ST_LSM6DSX_SHIFT_VAL(1, hub_settings->pullup_en.mask);
+		err = regmap_update_bits(hw->regmap,
+					 hub_settings->pullup_en.addr,
+					 hub_settings->pullup_en.mask, data);
+
+		st_lsm6dsx_set_page(hw, false);
+
+		if (err < 0)
+			return err;
+	}
+
+	if (hub_settings->aux_sens.addr) {
+		/* configure aux sensors */
+		err = st_lsm6dsx_set_page(hw, true);
+		if (err < 0)
+			return err;
+
+		data = ST_LSM6DSX_SHIFT_VAL(3, hub_settings->aux_sens.mask);
+		err = regmap_update_bits(hw->regmap,
+					 hub_settings->aux_sens.addr,
+					 hub_settings->aux_sens.mask, data);
+
+		st_lsm6dsx_set_page(hw, false);
+	}
+
+	return err;
+}
+
 static int st_lsm6dsx_init_hw_timer(struct st_lsm6dsx_hw *hw)
 {
 	const struct st_lsm6dsx_hw_ts_settings *ts_settings;
@@ -856,6 +895,10 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
 	if (err < 0)
 		return err;
 
+	err = st_lsm6dsx_init_shub(hw);
+	if (err < 0)
+		return err;
+
 	return st_lsm6dsx_init_hw_timer(hw);
 }
 
@@ -909,6 +952,7 @@ static struct iio_dev *st_lsm6dsx_alloc_iiodev(struct st_lsm6dsx_hw *hw,
 int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id, const char *name,
 		     struct regmap *regmap)
 {
+	const struct st_lsm6dsx_shub_settings *hub_settings;
 	struct st_lsm6dsx_hw *hw;
 	int i, err;
 
@@ -944,6 +988,13 @@ int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id, const char *name,
 	if (err < 0)
 		return err;
 
+	hub_settings = &hw->settings->shub_settings;
+	if (hub_settings->master_en.addr) {
+		err = st_lsm6dsx_shub_probe(hw, name);
+		if (err < 0)
+			return err;
+	}
+
 	if (hw->irq > 0) {
 		err = st_lsm6dsx_fifo_setup(hw);
 		if (err < 0)

include/linux/platform_data/st_sensors_pdata.h

@@ -18,11 +18,13 @@
  *	Accelerometer DRDY on LSM330 available only on pin 1 (see datasheet).
  * @open_drain: set the interrupt line to be open drain if possible.
  * @spi_3wire: enable spi-3wire mode.
+ * @pullups: enable/disable i2c controller pullup resistors.
  */
 struct st_sensors_platform_data {
 	u8 drdy_int_pin;
 	bool open_drain;
 	bool spi_3wire;
+	bool pullups;
 };
 
 #endif /* ST_SENSORS_PDATA_H */