iio: imu: add support to lsm6dsx driver
authorLorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Tue, 10 Jan 2017 21:55:18 +0000 (22:55 +0100)
committerJonathan Cameron <jic23@kernel.org>
Sat, 14 Jan 2017 12:40:37 +0000 (12:40 +0000)
Add support to STM LSM6DS3-LSM6DSM 6-axis (acc + gyro) Mems sensor

http://www.st.com/resource/en/datasheet/lsm6ds3.pdf
http://www.st.com/resource/en/datasheet/lsm6dsm.pdf

- continuous mode support
- i2c support
- spi support
- sw fifo mode support
- supported devices: lsm6ds3, lsm6dsm

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/imu/Kconfig
drivers/iio/imu/Makefile
drivers/iio/imu/st_lsm6dsx/Kconfig [new file with mode: 0644]
drivers/iio/imu/st_lsm6dsx/Makefile [new file with mode: 0644]
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h [new file with mode: 0644]
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c [new file with mode: 0644]
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c [new file with mode: 0644]
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c [new file with mode: 0644]
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c [new file with mode: 0644]

index 1f1ad41ef881faa468b8a290b441dcf980dd6519..156630a216960bba56d8e16fc208d80345fd15b2 100644 (file)
@@ -39,6 +39,7 @@ config KMX61
          be called kmx61.
 
 source "drivers/iio/imu/inv_mpu6050/Kconfig"
+source "drivers/iio/imu/st_lsm6dsx/Kconfig"
 
 endmenu
 
index c71bcd30dc38ae487f895d288df56d775c846341..8b563c3323b572926217b54094a1b23a3f815857 100644 (file)
@@ -17,3 +17,5 @@ obj-y += bmi160/
 obj-y += inv_mpu6050/
 
 obj-$(CONFIG_KMX61) += kmx61.o
+
+obj-y += st_lsm6dsx/
diff --git a/drivers/iio/imu/st_lsm6dsx/Kconfig b/drivers/iio/imu/st_lsm6dsx/Kconfig
new file mode 100644 (file)
index 0000000..935d4cd
--- /dev/null
@@ -0,0 +1,22 @@
+
+config IIO_ST_LSM6DSX
+       tristate "ST_LSM6DSx driver for STM 6-axis IMU MEMS sensors"
+       depends on (I2C || SPI)
+       select IIO_BUFFER
+       select IIO_KFIFO_BUF
+       select IIO_ST_LSM6DSX_I2C if (I2C)
+       select IIO_ST_LSM6DSX_SPI if (SPI_MASTER)
+       help
+         Say yes here to build support for STMicroelectronics LSM6DSx imu
+         sensor. Supported devices: lsm6ds3, lsm6dsm
+
+         To compile this driver as a module, choose M here: the module
+         will be called st_lsm6dsx.
+
+config IIO_ST_LSM6DSX_I2C
+       tristate
+       depends on IIO_ST_LSM6DSX
+
+config IIO_ST_LSM6DSX_SPI
+       tristate
+       depends on IIO_ST_LSM6DSX
diff --git a/drivers/iio/imu/st_lsm6dsx/Makefile b/drivers/iio/imu/st_lsm6dsx/Makefile
new file mode 100644 (file)
index 0000000..35919fe
--- /dev/null
@@ -0,0 +1,5 @@
+st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o
+
+obj-$(CONFIG_IIO_ST_LSM6DSX) += st_lsm6dsx.o
+obj-$(CONFIG_IIO_ST_LSM6DSX_I2C) += st_lsm6dsx_i2c.o
+obj-$(CONFIG_IIO_ST_LSM6DSX_SPI) += st_lsm6dsx_spi.o
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
new file mode 100644 (file)
index 0000000..69deafe
--- /dev/null
@@ -0,0 +1,141 @@
+/*
+ * STMicroelectronics st_lsm6dsx sensor driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_LSM6DSX_H
+#define ST_LSM6DSX_H
+
+#include <linux/device.h>
+
+#define ST_LSM6DS3_DEV_NAME    "lsm6ds3"
+#define ST_LSM6DSM_DEV_NAME    "lsm6dsm"
+
+enum st_lsm6dsx_hw_id {
+       ST_LSM6DS3_ID,
+       ST_LSM6DSM_ID,
+};
+
+#define ST_LSM6DSX_CHAN_SIZE           2
+#define ST_LSM6DSX_SAMPLE_SIZE         6
+#define ST_LSM6DSX_SAMPLE_DEPTH                (ST_LSM6DSX_SAMPLE_SIZE / \
+                                        ST_LSM6DSX_CHAN_SIZE)
+
+#if defined(CONFIG_SPI_MASTER)
+#define ST_LSM6DSX_RX_MAX_LENGTH       256
+#define ST_LSM6DSX_TX_MAX_LENGTH       8
+
+struct st_lsm6dsx_transfer_buffer {
+       u8 rx_buf[ST_LSM6DSX_RX_MAX_LENGTH];
+       u8 tx_buf[ST_LSM6DSX_TX_MAX_LENGTH] ____cacheline_aligned;
+};
+#endif /* CONFIG_SPI_MASTER */
+
+struct st_lsm6dsx_transfer_function {
+       int (*read)(struct device *dev, u8 addr, int len, u8 *data);
+       int (*write)(struct device *dev, u8 addr, int len, u8 *data);
+};
+
+struct st_lsm6dsx_reg {
+       u8 addr;
+       u8 mask;
+};
+
+struct st_lsm6dsx_settings {
+       u8 wai;
+       u16 max_fifo_size;
+       enum st_lsm6dsx_hw_id id;
+};
+
+enum st_lsm6dsx_sensor_id {
+       ST_LSM6DSX_ID_ACC,
+       ST_LSM6DSX_ID_GYRO,
+       ST_LSM6DSX_ID_MAX,
+};
+
+enum st_lsm6dsx_fifo_mode {
+       ST_LSM6DSX_FIFO_BYPASS = 0x0,
+       ST_LSM6DSX_FIFO_CONT = 0x6,
+};
+
+/**
+ * struct st_lsm6dsx_sensor - ST IMU sensor instance
+ * @id: Sensor identifier.
+ * @hw: Pointer to instance of struct st_lsm6dsx_hw.
+ * @gain: Configured sensor sensitivity.
+ * @odr: Output data rate of the sensor [Hz].
+ * @watermark: Sensor watermark level.
+ * @sip: Number of samples in a given pattern.
+ * @decimator: FIFO decimation factor.
+ * @decimator_mask: Sensor mask for decimation register.
+ * @delta_ts: Delta time between two consecutive interrupts.
+ * @ts: Latest timestamp from the interrupt handler.
+ */
+struct st_lsm6dsx_sensor {
+       enum st_lsm6dsx_sensor_id id;
+       struct st_lsm6dsx_hw *hw;
+
+       u32 gain;
+       u16 odr;
+
+       u16 watermark;
+       u8 sip;
+       u8 decimator;
+       u8 decimator_mask;
+
+       s64 delta_ts;
+       s64 ts;
+};
+
+/**
+ * struct st_lsm6dsx_hw - ST IMU MEMS hw instance
+ * @dev: Pointer to instance of struct device (I2C or SPI).
+ * @irq: Device interrupt line (I2C or SPI).
+ * @lock: Mutex to protect read and write operations.
+ * @fifo_lock: Mutex to prevent concurrent access to the hw FIFO.
+ * @fifo_mode: FIFO operating mode supported by the device.
+ * @enable_mask: Enabled sensor bitmask.
+ * @sip: Total number of samples (acc/gyro) in a given pattern.
+ * @iio_devs: Pointers to acc/gyro iio_dev instances.
+ * @settings: Pointer to the specific sensor settings in use.
+ * @tf: Transfer function structure used by I/O operations.
+ * @tb: Transfer buffers used by SPI I/O operations.
+ */
+struct st_lsm6dsx_hw {
+       struct device *dev;
+       int irq;
+
+       struct mutex lock;
+       struct mutex fifo_lock;
+
+       enum st_lsm6dsx_fifo_mode fifo_mode;
+       u8 enable_mask;
+       u8 sip;
+
+       struct iio_dev *iio_devs[ST_LSM6DSX_ID_MAX];
+
+       const struct st_lsm6dsx_settings *settings;
+
+       const struct st_lsm6dsx_transfer_function *tf;
+#if defined(CONFIG_SPI_MASTER)
+       struct st_lsm6dsx_transfer_buffer tb;
+#endif /* CONFIG_SPI_MASTER */
+};
+
+int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
+                    const struct st_lsm6dsx_transfer_function *tf_ops);
+int st_lsm6dsx_sensor_enable(struct st_lsm6dsx_sensor *sensor);
+int st_lsm6dsx_sensor_disable(struct st_lsm6dsx_sensor *sensor);
+int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw);
+int st_lsm6dsx_write_with_mask(struct st_lsm6dsx_hw *hw, u8 addr, u8 mask,
+                              u8 val);
+int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor,
+                               u16 watermark);
+
+#endif /* ST_LSM6DSX_H */
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
new file mode 100644 (file)
index 0000000..78532ce
--- /dev/null
@@ -0,0 +1,454 @@
+/*
+ * STMicroelectronics st_lsm6dsx FIFO buffer library driver
+ *
+ * LSM6DS3/LSM6DSM: The FIFO buffer can be configured to store data
+ * from gyroscope and accelerometer. Samples are queued without any tag
+ * according to a specific pattern based on 'FIFO data sets' (6 bytes each):
+ *  - 1st data set is reserved for gyroscope data
+ *  - 2nd data set is reserved for accelerometer data
+ * The FIFO pattern changes depending on the ODRs and decimation factors
+ * assigned to the FIFO data sets. The first sequence of data stored in FIFO
+ * buffer contains the data of all the enabled FIFO data sets
+ * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated depending on the
+ * value of the decimation factor and ODR set for each FIFO data set.
+ * FIFO supported modes:
+ *  - BYPASS: FIFO disabled
+ *  - CONTINUOUS: FIFO enabled. When the buffer is full, the FIFO index
+ *    restarts from the beginning and the oldest sample is overwritten
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+
+#include "st_lsm6dsx.h"
+
+#define ST_LSM6DSX_REG_FIFO_THL_ADDR           0x06
+#define ST_LSM6DSX_REG_FIFO_THH_ADDR           0x07
+#define ST_LSM6DSX_FIFO_TH_MASK                        GENMASK(11, 0)
+#define ST_LSM6DSX_REG_FIFO_DEC_GXL_ADDR       0x08
+#define ST_LSM6DSX_REG_FIFO_MODE_ADDR          0x0a
+#define ST_LSM6DSX_FIFO_MODE_MASK              GENMASK(2, 0)
+#define ST_LSM6DSX_FIFO_ODR_MASK               GENMASK(6, 3)
+#define ST_LSM6DSX_REG_FIFO_DIFFL_ADDR         0x3a
+#define ST_LSM6DSX_FIFO_DIFF_MASK              GENMASK(11, 0)
+#define ST_LSM6DSX_FIFO_EMPTY_MASK             BIT(12)
+#define ST_LSM6DSX_REG_FIFO_OUTL_ADDR          0x3e
+
+#define ST_LSM6DSX_MAX_FIFO_ODR_VAL            0x08
+
+struct st_lsm6dsx_decimator_entry {
+       u8 decimator;
+       u8 val;
+};
+
+static const
+struct st_lsm6dsx_decimator_entry st_lsm6dsx_decimator_table[] = {
+       {  0, 0x0 },
+       {  1, 0x1 },
+       {  2, 0x2 },
+       {  3, 0x3 },
+       {  4, 0x4 },
+       {  8, 0x5 },
+       { 16, 0x6 },
+       { 32, 0x7 },
+};
+
+static int st_lsm6dsx_get_decimator_val(u8 val)
+{
+       const int max_size = ARRAY_SIZE(st_lsm6dsx_decimator_table);
+       int i;
+
+       for (i = 0; i < max_size; i++)
+               if (st_lsm6dsx_decimator_table[i].decimator == val)
+                       break;
+
+       return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
+}
+
+static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw,
+                                      u16 *max_odr, u16 *min_odr)
+{
+       struct st_lsm6dsx_sensor *sensor;
+       int i;
+
+       *max_odr = 0, *min_odr = ~0;
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               sensor = iio_priv(hw->iio_devs[i]);
+
+               if (!(hw->enable_mask & BIT(sensor->id)))
+                       continue;
+
+               *max_odr = max_t(u16, *max_odr, sensor->odr);
+               *min_odr = min_t(u16, *min_odr, sensor->odr);
+       }
+}
+
+static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
+{
+       struct st_lsm6dsx_sensor *sensor;
+       u16 max_odr, min_odr, sip = 0;
+       int err, i;
+       u8 data;
+
+       st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr);
+
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               sensor = iio_priv(hw->iio_devs[i]);
+
+               /* update fifo decimators and sample in pattern */
+               if (hw->enable_mask & BIT(sensor->id)) {
+                       sensor->sip = sensor->odr / min_odr;
+                       sensor->decimator = max_odr / sensor->odr;
+                       data = st_lsm6dsx_get_decimator_val(sensor->decimator);
+               } else {
+                       sensor->sip = 0;
+                       sensor->decimator = 0;
+                       data = 0;
+               }
+
+               err = st_lsm6dsx_write_with_mask(hw,
+                                       ST_LSM6DSX_REG_FIFO_DEC_GXL_ADDR,
+                                       sensor->decimator_mask, data);
+               if (err < 0)
+                       return err;
+
+               sip += sensor->sip;
+       }
+       hw->sip = sip;
+
+       return 0;
+}
+
+static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
+                                   enum st_lsm6dsx_fifo_mode fifo_mode)
+{
+       u8 data;
+       int err;
+
+       switch (fifo_mode) {
+       case ST_LSM6DSX_FIFO_BYPASS:
+               data = fifo_mode;
+               break;
+       case ST_LSM6DSX_FIFO_CONT:
+               data = (ST_LSM6DSX_MAX_FIFO_ODR_VAL <<
+                       __ffs(ST_LSM6DSX_FIFO_ODR_MASK)) | fifo_mode;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       err = hw->tf->write(hw->dev, ST_LSM6DSX_REG_FIFO_MODE_ADDR,
+                           sizeof(data), &data);
+       if (err < 0)
+               return err;
+
+       hw->fifo_mode = fifo_mode;
+
+       return 0;
+}
+
+int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark)
+{
+       u16 fifo_watermark = ~0, cur_watermark, sip = 0;
+       struct st_lsm6dsx_hw *hw = sensor->hw;
+       struct st_lsm6dsx_sensor *cur_sensor;
+       __le16 wdata;
+       int i, err;
+       u8 data;
+
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               cur_sensor = iio_priv(hw->iio_devs[i]);
+
+               if (!(hw->enable_mask & BIT(cur_sensor->id)))
+                       continue;
+
+               cur_watermark = (cur_sensor == sensor) ? watermark
+                                                      : cur_sensor->watermark;
+
+               fifo_watermark = min_t(u16, fifo_watermark, cur_watermark);
+               sip += cur_sensor->sip;
+       }
+
+       if (!sip)
+               return 0;
+
+       fifo_watermark = max_t(u16, fifo_watermark, sip);
+       fifo_watermark = (fifo_watermark / sip) * sip;
+       fifo_watermark = fifo_watermark * ST_LSM6DSX_SAMPLE_DEPTH;
+
+       mutex_lock(&hw->lock);
+
+       err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_FIFO_THH_ADDR,
+                          sizeof(data), &data);
+       if (err < 0)
+               goto out;
+
+       fifo_watermark = ((data & ~ST_LSM6DSX_FIFO_TH_MASK) << 8) |
+                         (fifo_watermark & ST_LSM6DSX_FIFO_TH_MASK);
+
+       wdata = cpu_to_le16(fifo_watermark);
+       err = hw->tf->write(hw->dev, ST_LSM6DSX_REG_FIFO_THL_ADDR,
+                           sizeof(wdata), (u8 *)&wdata);
+out:
+       mutex_unlock(&hw->lock);
+
+       return err < 0 ? err : 0;
+}
+
+/**
+ * st_lsm6dsx_read_fifo() - LSM6DS3-LSM6DSM read FIFO routine
+ * @hw: Pointer to instance of struct st_lsm6dsx_hw.
+ *
+ * Read samples from the hw FIFO and push them to IIO buffers.
+ *
+ * Return: Number of bytes read from the FIFO
+ */
+static int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
+{
+       u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
+       int err, acc_sip, gyro_sip, read_len, samples, offset;
+       struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor;
+       s64 acc_ts, acc_delta_ts, gyro_ts, gyro_delta_ts;
+       u8 iio_buff[ALIGN(ST_LSM6DSX_SAMPLE_SIZE, sizeof(s64)) + sizeof(s64)];
+       u8 buff[pattern_len];
+       __le16 fifo_status;
+
+       err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_FIFO_DIFFL_ADDR,
+                          sizeof(fifo_status), (u8 *)&fifo_status);
+       if (err < 0)
+               return err;
+
+       if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
+               return 0;
+
+       fifo_len = (le16_to_cpu(fifo_status) & ST_LSM6DSX_FIFO_DIFF_MASK) *
+                  ST_LSM6DSX_CHAN_SIZE;
+       samples = fifo_len / ST_LSM6DSX_SAMPLE_SIZE;
+       fifo_len = (fifo_len / pattern_len) * pattern_len;
+
+       /*
+        * compute delta timestamp between two consecutive samples
+        * in order to estimate queueing time of data generated
+        * by the sensor
+        */
+       acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
+       acc_ts = acc_sensor->ts - acc_sensor->delta_ts;
+       acc_delta_ts = div_s64(acc_sensor->delta_ts * acc_sensor->decimator,
+                              samples);
+
+       gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
+       gyro_ts = gyro_sensor->ts - gyro_sensor->delta_ts;
+       gyro_delta_ts = div_s64(gyro_sensor->delta_ts * gyro_sensor->decimator,
+                               samples);
+
+       for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
+               err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_FIFO_OUTL_ADDR,
+                                  sizeof(buff), buff);
+               if (err < 0)
+                       return err;
+
+               /*
+                * Data are written to the FIFO with a specific pattern
+                * depending on the configured ODRs. The first sequence of data
+                * stored in FIFO contains the data of all enabled sensors
+                * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated
+                * depending on the value of the decimation factor set for each
+                * sensor.
+                *
+                * Supposing the FIFO is storing data from gyroscope and
+                * accelerometer at different ODRs:
+                *   - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz
+                * Since the gyroscope ODR is twice the accelerometer one, the
+                * following pattern is repeated every 9 samples:
+                *   - Gx, Gy, Gz, Ax, Ay, Az, Gx, Gy, Gz
+                */
+               gyro_sip = gyro_sensor->sip;
+               acc_sip = acc_sensor->sip;
+               offset = 0;
+
+               while (acc_sip > 0 || gyro_sip > 0) {
+                       if (gyro_sip-- > 0) {
+                               memcpy(iio_buff, &buff[offset],
+                                      ST_LSM6DSX_SAMPLE_SIZE);
+                               iio_push_to_buffers_with_timestamp(
+                                       hw->iio_devs[ST_LSM6DSX_ID_GYRO],
+                                       iio_buff, gyro_ts);
+                               offset += ST_LSM6DSX_SAMPLE_SIZE;
+                               gyro_ts += gyro_delta_ts;
+                       }
+
+                       if (acc_sip-- > 0) {
+                               memcpy(iio_buff, &buff[offset],
+                                      ST_LSM6DSX_SAMPLE_SIZE);
+                               iio_push_to_buffers_with_timestamp(
+                                       hw->iio_devs[ST_LSM6DSX_ID_ACC],
+                                       iio_buff, acc_ts);
+                               offset += ST_LSM6DSX_SAMPLE_SIZE;
+                               acc_ts += acc_delta_ts;
+                       }
+               }
+       }
+
+       return read_len;
+}
+
+static int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw)
+{
+       int err;
+
+       mutex_lock(&hw->fifo_lock);
+
+       st_lsm6dsx_read_fifo(hw);
+       err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS);
+
+       mutex_unlock(&hw->fifo_lock);
+
+       return err;
+}
+
+static int st_lsm6dsx_update_fifo(struct iio_dev *iio_dev, bool enable)
+{
+       struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+       struct st_lsm6dsx_hw *hw = sensor->hw;
+       int err;
+
+       if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS) {
+               err = st_lsm6dsx_flush_fifo(hw);
+               if (err < 0)
+                       return err;
+       }
+
+       if (enable) {
+               err = st_lsm6dsx_sensor_enable(sensor);
+               if (err < 0)
+                       return err;
+       } else {
+               err = st_lsm6dsx_sensor_disable(sensor);
+               if (err < 0)
+                       return err;
+       }
+
+       err = st_lsm6dsx_update_decimators(hw);
+       if (err < 0)
+               return err;
+
+       err = st_lsm6dsx_update_watermark(sensor, sensor->watermark);
+       if (err < 0)
+               return err;
+
+       if (hw->enable_mask) {
+               err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
+               if (err < 0)
+                       return err;
+
+               /*
+                * store enable buffer timestamp as reference to compute
+                * first delta timestamp
+                */
+               sensor->ts = iio_get_time_ns(iio_dev);
+       }
+
+       return 0;
+}
+
+static irqreturn_t st_lsm6dsx_handler_irq(int irq, void *private)
+{
+       struct st_lsm6dsx_hw *hw = (struct st_lsm6dsx_hw *)private;
+       struct st_lsm6dsx_sensor *sensor;
+       int i;
+
+       if (!hw->sip)
+               return IRQ_NONE;
+
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               sensor = iio_priv(hw->iio_devs[i]);
+
+               if (sensor->sip > 0) {
+                       s64 timestamp;
+
+                       timestamp = iio_get_time_ns(hw->iio_devs[i]);
+                       sensor->delta_ts = timestamp - sensor->ts;
+                       sensor->ts = timestamp;
+               }
+       }
+
+       return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private)
+{
+       struct st_lsm6dsx_hw *hw = (struct st_lsm6dsx_hw *)private;
+       int count;
+
+       mutex_lock(&hw->fifo_lock);
+       count = st_lsm6dsx_read_fifo(hw);
+       mutex_unlock(&hw->fifo_lock);
+
+       return !count ? IRQ_NONE : IRQ_HANDLED;
+}
+
+static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
+{
+       return st_lsm6dsx_update_fifo(iio_dev, true);
+}
+
+static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev)
+{
+       return st_lsm6dsx_update_fifo(iio_dev, false);
+}
+
+static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
+       .preenable = st_lsm6dsx_buffer_preenable,
+       .postdisable = st_lsm6dsx_buffer_postdisable,
+};
+
+int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
+{
+       struct iio_buffer *buffer;
+       unsigned long irq_type;
+       int i, err;
+
+       irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
+
+       switch (irq_type) {
+       case IRQF_TRIGGER_HIGH:
+       case IRQF_TRIGGER_RISING:
+               break;
+       default:
+               dev_info(hw->dev, "mode %lx unsupported\n", irq_type);
+               return -EINVAL;
+       }
+
+       err = devm_request_threaded_irq(hw->dev, hw->irq,
+                                       st_lsm6dsx_handler_irq,
+                                       st_lsm6dsx_handler_thread,
+                                       irq_type | IRQF_ONESHOT,
+                                       "lsm6dsx", hw);
+       if (err) {
+               dev_err(hw->dev, "failed to request trigger irq %d\n",
+                       hw->irq);
+               return err;
+       }
+
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               buffer = devm_iio_kfifo_allocate(hw->dev);
+               if (!buffer)
+                       return -ENOMEM;
+
+               iio_device_attach_buffer(hw->iio_devs[i], buffer);
+               hw->iio_devs[i]->modes |= INDIO_BUFFER_SOFTWARE;
+               hw->iio_devs[i]->setup_ops = &st_lsm6dsx_buffer_ops;
+       }
+
+       return 0;
+}
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
new file mode 100644 (file)
index 0000000..01e002c
--- /dev/null
@@ -0,0 +1,673 @@
+/*
+ * STMicroelectronics st_lsm6dsx sensor driver
+ *
+ * The ST LSM6DSx IMU MEMS series consists of 3D digital accelerometer
+ * and 3D digital gyroscope system-in-package with a digital I2C/SPI serial
+ * interface standard output.
+ * LSM6DSx IMU MEMS series has a dynamic user-selectable full-scale
+ * acceleration range of +-2/+-4/+-8/+-16 g and an angular rate range of
+ * +-125/+-245/+-500/+-1000/+-2000 dps
+ * LSM6DSx series has an integrated First-In-First-Out (FIFO) buffer
+ * allowing dynamic batching of sensor data.
+ *
+ * Supported sensors:
+ * - LSM6DS3:
+ *   - Accelerometer/Gyroscope supported ODR [Hz]: 13, 26, 52, 104, 208, 416
+ *   - Accelerometer supported full-scale [g]: +-2/+-4/+-8/+-16
+ *   - Gyroscope supported full-scale [dps]: +-125/+-245/+-500/+-1000/+-2000
+ *   - FIFO size: 8KB
+ *
+ * - LSM6DSM:
+ *   - Accelerometer/Gyroscope supported ODR [Hz]: 13, 26, 52, 104, 208, 416
+ *   - Accelerometer supported full-scale [g]: +-2/+-4/+-8/+-16
+ *   - Gyroscope supported full-scale [dps]: +-125/+-245/+-500/+-1000/+-2000
+ *   - FIFO size: 4KB
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include "st_lsm6dsx.h"
+
+#define ST_LSM6DSX_REG_ACC_DEC_MASK            GENMASK(2, 0)
+#define ST_LSM6DSX_REG_GYRO_DEC_MASK           GENMASK(5, 3)
+#define ST_LSM6DSX_REG_INT1_ADDR               0x0d
+#define ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK       BIT(3)
+#define ST_LSM6DSX_REG_WHOAMI_ADDR             0x0f
+#define ST_LSM6DSX_REG_RESET_ADDR              0x12
+#define ST_LSM6DSX_REG_RESET_MASK              BIT(0)
+#define ST_LSM6DSX_REG_BDU_ADDR                        0x12
+#define ST_LSM6DSX_REG_BDU_MASK                        BIT(6)
+#define ST_LSM6DSX_REG_INT2_ON_INT1_ADDR       0x13
+#define ST_LSM6DSX_REG_INT2_ON_INT1_MASK       BIT(5)
+#define ST_LSM6DSX_REG_ROUNDING_ADDR           0x16
+#define ST_LSM6DSX_REG_ROUNDING_MASK           BIT(2)
+#define ST_LSM6DSX_REG_LIR_ADDR                        0x58
+#define ST_LSM6DSX_REG_LIR_MASK                        BIT(0)
+
+#define ST_LSM6DSX_REG_ACC_ODR_ADDR            0x10
+#define ST_LSM6DSX_REG_ACC_ODR_MASK            GENMASK(7, 4)
+#define ST_LSM6DSX_REG_ACC_FS_ADDR             0x10
+#define ST_LSM6DSX_REG_ACC_FS_MASK             GENMASK(3, 2)
+#define ST_LSM6DSX_REG_ACC_OUT_X_L_ADDR                0x28
+#define ST_LSM6DSX_REG_ACC_OUT_Y_L_ADDR                0x2a
+#define ST_LSM6DSX_REG_ACC_OUT_Z_L_ADDR                0x2c
+
+#define ST_LSM6DSX_REG_GYRO_ODR_ADDR           0x11
+#define ST_LSM6DSX_REG_GYRO_ODR_MASK           GENMASK(7, 4)
+#define ST_LSM6DSX_REG_GYRO_FS_ADDR            0x11
+#define ST_LSM6DSX_REG_GYRO_FS_MASK            GENMASK(3, 2)
+#define ST_LSM6DSX_REG_GYRO_OUT_X_L_ADDR       0x22
+#define ST_LSM6DSX_REG_GYRO_OUT_Y_L_ADDR       0x24
+#define ST_LSM6DSX_REG_GYRO_OUT_Z_L_ADDR       0x26
+
+#define ST_LSM6DS3_WHOAMI                      0x69
+#define ST_LSM6DSM_WHOAMI                      0x6a
+
+#define ST_LSM6DS3_MAX_FIFO_SIZE               8192
+#define ST_LSM6DSM_MAX_FIFO_SIZE               4096
+
+#define ST_LSM6DSX_ACC_FS_2G_GAIN              IIO_G_TO_M_S_2(61)
+#define ST_LSM6DSX_ACC_FS_4G_GAIN              IIO_G_TO_M_S_2(122)
+#define ST_LSM6DSX_ACC_FS_8G_GAIN              IIO_G_TO_M_S_2(244)
+#define ST_LSM6DSX_ACC_FS_16G_GAIN             IIO_G_TO_M_S_2(488)
+
+#define ST_LSM6DSX_GYRO_FS_245_GAIN            IIO_DEGREE_TO_RAD(4375)
+#define ST_LSM6DSX_GYRO_FS_500_GAIN            IIO_DEGREE_TO_RAD(8750)
+#define ST_LSM6DSX_GYRO_FS_1000_GAIN           IIO_DEGREE_TO_RAD(17500)
+#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 = {
+                       .addr = ST_LSM6DSX_REG_ACC_ODR_ADDR,
+                       .mask = ST_LSM6DSX_REG_ACC_ODR_MASK,
+               },
+               .odr_avl[0] = {  13, 0x01 },
+               .odr_avl[1] = {  26, 0x02 },
+               .odr_avl[2] = {  52, 0x03 },
+               .odr_avl[3] = { 104, 0x04 },
+               .odr_avl[4] = { 208, 0x05 },
+               .odr_avl[5] = { 416, 0x06 },
+       },
+       [ST_LSM6DSX_ID_GYRO] = {
+               .reg = {
+                       .addr = ST_LSM6DSX_REG_GYRO_ODR_ADDR,
+                       .mask = ST_LSM6DSX_REG_GYRO_ODR_MASK,
+               },
+               .odr_avl[0] = {  13, 0x01 },
+               .odr_avl[1] = {  26, 0x02 },
+               .odr_avl[2] = {  52, 0x03 },
+               .odr_avl[3] = { 104, 0x04 },
+               .odr_avl[4] = { 208, 0x05 },
+               .odr_avl[5] = { 416, 0x06 },
+       }
+};
+
+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 = {
+                       .addr = ST_LSM6DSX_REG_ACC_FS_ADDR,
+                       .mask = ST_LSM6DSX_REG_ACC_FS_MASK,
+               },
+               .fs_avl[0] = {  ST_LSM6DSX_ACC_FS_2G_GAIN, 0x0 },
+               .fs_avl[1] = {  ST_LSM6DSX_ACC_FS_4G_GAIN, 0x2 },
+               .fs_avl[2] = {  ST_LSM6DSX_ACC_FS_8G_GAIN, 0x3 },
+               .fs_avl[3] = { ST_LSM6DSX_ACC_FS_16G_GAIN, 0x1 },
+       },
+       [ST_LSM6DSX_ID_GYRO] = {
+               .reg = {
+                       .addr = ST_LSM6DSX_REG_GYRO_FS_ADDR,
+                       .mask = ST_LSM6DSX_REG_GYRO_FS_MASK,
+               },
+               .fs_avl[0] = {  ST_LSM6DSX_GYRO_FS_245_GAIN, 0x0 },
+               .fs_avl[1] = {  ST_LSM6DSX_GYRO_FS_500_GAIN, 0x1 },
+               .fs_avl[2] = { ST_LSM6DSX_GYRO_FS_1000_GAIN, 0x2 },
+               .fs_avl[3] = { ST_LSM6DSX_GYRO_FS_2000_GAIN, 0x3 },
+       }
+};
+
+static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
+       {
+               .wai = ST_LSM6DS3_WHOAMI,
+               .max_fifo_size = ST_LSM6DS3_MAX_FIFO_SIZE,
+               .id = ST_LSM6DS3_ID,
+       },
+       {
+               .wai = ST_LSM6DSM_WHOAMI,
+               .max_fifo_size = ST_LSM6DSM_MAX_FIFO_SIZE,
+               .id = ST_LSM6DSM_ID,
+       },
+};
+
+#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),
+       ST_LSM6DSX_CHANNEL(IIO_ACCEL, ST_LSM6DSX_REG_ACC_OUT_Y_L_ADDR,
+                          IIO_MOD_Y, 1),
+       ST_LSM6DSX_CHANNEL(IIO_ACCEL, ST_LSM6DSX_REG_ACC_OUT_Z_L_ADDR,
+                          IIO_MOD_Z, 2),
+       IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const struct iio_chan_spec st_lsm6dsx_gyro_channels[] = {
+       ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, ST_LSM6DSX_REG_GYRO_OUT_X_L_ADDR,
+                          IIO_MOD_X, 0),
+       ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, ST_LSM6DSX_REG_GYRO_OUT_Y_L_ADDR,
+                          IIO_MOD_Y, 1),
+       ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, ST_LSM6DSX_REG_GYRO_OUT_Z_L_ADDR,
+                          IIO_MOD_Z, 2),
+       IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+int st_lsm6dsx_write_with_mask(struct st_lsm6dsx_hw *hw, u8 addr, u8 mask,
+                              u8 val)
+{
+       u8 data;
+       int err;
+
+       mutex_lock(&hw->lock);
+
+       err = hw->tf->read(hw->dev, addr, sizeof(data), &data);
+       if (err < 0) {
+               dev_err(hw->dev, "failed to read %02x register\n", addr);
+               goto out;
+       }
+
+       data = (data & ~mask) | ((val << __ffs(mask)) & mask);
+
+       err = hw->tf->write(hw->dev, addr, sizeof(data), &data);
+       if (err < 0)
+               dev_err(hw->dev, "failed to write %02x register\n", addr);
+
+out:
+       mutex_unlock(&hw->lock);
+
+       return err;
+}
+
+static int st_lsm6dsx_check_whoami(struct st_lsm6dsx_hw *hw, int id)
+{
+       int err, i;
+       u8 data;
+
+       for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_sensor_settings); i++) {
+               if (id == st_lsm6dsx_sensor_settings[i].id)
+                       break;
+       }
+
+       if (i == ARRAY_SIZE(st_lsm6dsx_sensor_settings)) {
+               dev_err(hw->dev, "unsupported hw id [%02x]\n", id);
+               return -ENODEV;
+       }
+
+       err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_WHOAMI_ADDR, sizeof(data),
+                          &data);
+       if (err < 0) {
+               dev_err(hw->dev, "failed to read whoami register\n");
+               return err;
+       }
+
+       if (data != st_lsm6dsx_sensor_settings[i].wai) {
+               dev_err(hw->dev, "unsupported whoami [%02x]\n", data);
+               return -ENODEV;
+       }
+
+       hw->settings = &st_lsm6dsx_sensor_settings[i];
+
+       return 0;
+}
+
+static int st_lsm6dsx_set_full_scale(struct st_lsm6dsx_sensor *sensor,
+                                    u32 gain)
+{
+       enum st_lsm6dsx_sensor_id id = sensor->id;
+       int i, err;
+       u8 val;
+
+       for (i = 0; i < ST_LSM6DSX_FS_LIST_SIZE; i++)
+               if (st_lsm6dsx_fs_table[id].fs_avl[i].gain == gain)
+                       break;
+
+       if (i == ST_LSM6DSX_FS_LIST_SIZE)
+               return -EINVAL;
+
+       val = st_lsm6dsx_fs_table[id].fs_avl[i].val;
+       err = st_lsm6dsx_write_with_mask(sensor->hw,
+                                        st_lsm6dsx_fs_table[id].reg.addr,
+                                        st_lsm6dsx_fs_table[id].reg.mask,
+                                        val);
+       if (err < 0)
+               return err;
+
+       sensor->gain = gain;
+
+       return 0;
+}
+
+static int st_lsm6dsx_set_odr(struct st_lsm6dsx_sensor *sensor, u16 odr)
+{
+       enum st_lsm6dsx_sensor_id id = sensor->id;
+       int i, err;
+       u8 val;
+
+       for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++)
+               if (st_lsm6dsx_odr_table[id].odr_avl[i].hz == odr)
+                       break;
+
+       if (i == ST_LSM6DSX_ODR_LIST_SIZE)
+               return -EINVAL;
+
+       val = st_lsm6dsx_odr_table[id].odr_avl[i].val;
+       err = st_lsm6dsx_write_with_mask(sensor->hw,
+                                        st_lsm6dsx_odr_table[id].reg.addr,
+                                        st_lsm6dsx_odr_table[id].reg.mask,
+                                        val);
+       if (err < 0)
+               return err;
+
+       sensor->odr = odr;
+
+       return 0;
+}
+
+int st_lsm6dsx_sensor_enable(struct st_lsm6dsx_sensor *sensor)
+{
+       int err;
+
+       err = st_lsm6dsx_set_odr(sensor, sensor->odr);
+       if (err < 0)
+               return err;
+
+       sensor->hw->enable_mask |= BIT(sensor->id);
+
+       return 0;
+}
+
+int st_lsm6dsx_sensor_disable(struct st_lsm6dsx_sensor *sensor)
+{
+       enum st_lsm6dsx_sensor_id id = sensor->id;
+       int err;
+
+       err = st_lsm6dsx_write_with_mask(sensor->hw,
+                                        st_lsm6dsx_odr_table[id].reg.addr,
+                                        st_lsm6dsx_odr_table[id].reg.mask, 0);
+       if (err < 0)
+               return err;
+
+       sensor->hw->enable_mask &= ~BIT(id);
+
+       return 0;
+}
+
+static int st_lsm6dsx_read_oneshot(struct st_lsm6dsx_sensor *sensor,
+                                  u8 addr, int *val)
+{
+       int err, delay;
+       __le16 data;
+
+       err = st_lsm6dsx_sensor_enable(sensor);
+       if (err < 0)
+               return err;
+
+       delay = 1000000 / sensor->odr;
+       usleep_range(delay, 2 * delay);
+
+       err = sensor->hw->tf->read(sensor->hw->dev, addr, sizeof(data),
+                                  (u8 *)&data);
+       if (err < 0)
+               return err;
+
+       st_lsm6dsx_sensor_disable(sensor);
+
+       *val = (s16)data;
+
+       return IIO_VAL_INT;
+}
+
+static int st_lsm6dsx_read_raw(struct iio_dev *iio_dev,
+                              struct iio_chan_spec const *ch,
+                              int *val, int *val2, long mask)
+{
+       struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+       int ret;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               ret = iio_device_claim_direct_mode(iio_dev);
+               if (ret)
+                       break;
+
+               ret = st_lsm6dsx_read_oneshot(sensor, ch->address, val);
+               iio_device_release_direct_mode(iio_dev);
+               break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *val = sensor->odr;
+               ret = IIO_VAL_INT;
+               break;
+       case IIO_CHAN_INFO_SCALE:
+               *val = 0;
+               *val2 = sensor->gain;
+               ret = IIO_VAL_INT_PLUS_MICRO;
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static int st_lsm6dsx_write_raw(struct iio_dev *iio_dev,
+                               struct iio_chan_spec const *chan,
+                               int val, int val2, long mask)
+{
+       struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+       int err;
+
+       err = iio_device_claim_direct_mode(iio_dev);
+       if (err)
+               return err;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_SCALE:
+               err = st_lsm6dsx_set_full_scale(sensor, val2);
+               break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               err = st_lsm6dsx_set_odr(sensor, val);
+               break;
+       default:
+               err = -EINVAL;
+               break;
+       }
+
+       iio_device_release_direct_mode(iio_dev);
+
+       return err;
+}
+
+static int st_lsm6dsx_set_watermark(struct iio_dev *iio_dev, unsigned int val)
+{
+       struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+       struct st_lsm6dsx_hw *hw = sensor->hw;
+       int err, max_fifo_len;
+
+       max_fifo_len = hw->settings->max_fifo_size / ST_LSM6DSX_SAMPLE_SIZE;
+       if (val < 1 || val > max_fifo_len)
+               return -EINVAL;
+
+       err = st_lsm6dsx_update_watermark(sensor, val);
+       if (err < 0)
+               return err;
+
+       sensor->watermark = val;
+
+       return 0;
+}
+
+static ssize_t
+st_lsm6dsx_sysfs_sampling_frequency_avail(struct device *dev,
+                                         struct device_attribute *attr,
+                                         char *buf)
+{
+       struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
+       enum st_lsm6dsx_sensor_id id = sensor->id;
+       int i, len = 0;
+
+       for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++)
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
+                                st_lsm6dsx_odr_table[id].odr_avl[i].hz);
+       buf[len - 1] = '\n';
+
+       return len;
+}
+
+static ssize_t st_lsm6dsx_sysfs_scale_avail(struct device *dev,
+                                           struct device_attribute *attr,
+                                           char *buf)
+{
+       struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
+       enum st_lsm6dsx_sensor_id id = sensor->id;
+       int i, len = 0;
+
+       for (i = 0; i < ST_LSM6DSX_FS_LIST_SIZE; i++)
+               len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
+                                st_lsm6dsx_fs_table[id].fs_avl[i].gain);
+       buf[len - 1] = '\n';
+
+       return len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(st_lsm6dsx_sysfs_sampling_frequency_avail);
+static IIO_DEVICE_ATTR(in_accel_scale_available, 0444,
+                      st_lsm6dsx_sysfs_scale_avail, NULL, 0);
+static IIO_DEVICE_ATTR(in_anglvel_scale_available, 0444,
+                      st_lsm6dsx_sysfs_scale_avail, NULL, 0);
+
+static struct attribute *st_lsm6dsx_acc_attributes[] = {
+       &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+       &iio_dev_attr_in_accel_scale_available.dev_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group st_lsm6dsx_acc_attribute_group = {
+       .attrs = st_lsm6dsx_acc_attributes,
+};
+
+static const struct iio_info st_lsm6dsx_acc_info = {
+       .driver_module = THIS_MODULE,
+       .attrs = &st_lsm6dsx_acc_attribute_group,
+       .read_raw = st_lsm6dsx_read_raw,
+       .write_raw = st_lsm6dsx_write_raw,
+       .hwfifo_set_watermark = st_lsm6dsx_set_watermark,
+};
+
+static struct attribute *st_lsm6dsx_gyro_attributes[] = {
+       &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+       &iio_dev_attr_in_anglvel_scale_available.dev_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group st_lsm6dsx_gyro_attribute_group = {
+       .attrs = st_lsm6dsx_gyro_attributes,
+};
+
+static const struct iio_info st_lsm6dsx_gyro_info = {
+       .driver_module = THIS_MODULE,
+       .attrs = &st_lsm6dsx_gyro_attribute_group,
+       .read_raw = st_lsm6dsx_read_raw,
+       .write_raw = st_lsm6dsx_write_raw,
+       .hwfifo_set_watermark = st_lsm6dsx_set_watermark,
+};
+
+static const unsigned long st_lsm6dsx_available_scan_masks[] = {0x7, 0x0};
+
+static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
+{
+       int err;
+       u8 data;
+
+       data = ST_LSM6DSX_REG_RESET_MASK;
+       err = hw->tf->write(hw->dev, ST_LSM6DSX_REG_RESET_ADDR, sizeof(data),
+                           &data);
+       if (err < 0)
+               return err;
+
+       msleep(200);
+
+       /* latch interrupts */
+       err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_LIR_ADDR,
+                                        ST_LSM6DSX_REG_LIR_MASK, 1);
+       if (err < 0)
+               return err;
+
+       /* enable Block Data Update */
+       err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_BDU_ADDR,
+                                        ST_LSM6DSX_REG_BDU_MASK, 1);
+       if (err < 0)
+               return err;
+
+       err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_ROUNDING_ADDR,
+                                        ST_LSM6DSX_REG_ROUNDING_MASK, 1);
+       if (err < 0)
+               return err;
+
+       /* enable FIFO watermak interrupt */
+       err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_INT1_ADDR,
+                                        ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK, 1);
+       if (err < 0)
+               return err;
+
+       /* redirect INT2 on INT1 */
+       return st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_INT2_ON_INT1_ADDR,
+                                         ST_LSM6DSX_REG_INT2_ON_INT1_MASK, 1);
+}
+
+static struct iio_dev *st_lsm6dsx_alloc_iiodev(struct st_lsm6dsx_hw *hw,
+                                              enum st_lsm6dsx_sensor_id id)
+{
+       struct st_lsm6dsx_sensor *sensor;
+       struct iio_dev *iio_dev;
+
+       iio_dev = devm_iio_device_alloc(hw->dev, sizeof(*sensor));
+       if (!iio_dev)
+               return NULL;
+
+       iio_dev->modes = INDIO_DIRECT_MODE;
+       iio_dev->dev.parent = hw->dev;
+       iio_dev->available_scan_masks = st_lsm6dsx_available_scan_masks;
+
+       sensor = iio_priv(iio_dev);
+       sensor->id = id;
+       sensor->hw = hw;
+       sensor->odr = st_lsm6dsx_odr_table[id].odr_avl[0].hz;
+       sensor->gain = st_lsm6dsx_fs_table[id].fs_avl[0].gain;
+       sensor->watermark = 1;
+
+       switch (id) {
+       case ST_LSM6DSX_ID_ACC:
+               iio_dev->channels = st_lsm6dsx_acc_channels;
+               iio_dev->num_channels = ARRAY_SIZE(st_lsm6dsx_acc_channels);
+               iio_dev->name = "lsm6dsx_accel";
+               iio_dev->info = &st_lsm6dsx_acc_info;
+
+               sensor->decimator_mask = ST_LSM6DSX_REG_ACC_DEC_MASK;
+               break;
+       case ST_LSM6DSX_ID_GYRO:
+               iio_dev->channels = st_lsm6dsx_gyro_channels;
+               iio_dev->num_channels = ARRAY_SIZE(st_lsm6dsx_gyro_channels);
+               iio_dev->name = "lsm6dsx_gyro";
+               iio_dev->info = &st_lsm6dsx_gyro_info;
+
+               sensor->decimator_mask = ST_LSM6DSX_REG_GYRO_DEC_MASK;
+               break;
+       default:
+               return NULL;
+       }
+
+       return iio_dev;
+}
+
+int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
+                    const struct st_lsm6dsx_transfer_function *tf_ops)
+{
+       struct st_lsm6dsx_hw *hw;
+       int i, err;
+
+       hw = devm_kzalloc(dev, sizeof(*hw), GFP_KERNEL);
+       if (!hw)
+               return -ENOMEM;
+
+       dev_set_drvdata(dev, (void *)hw);
+
+       mutex_init(&hw->lock);
+       mutex_init(&hw->fifo_lock);
+
+       hw->dev = dev;
+       hw->irq = irq;
+       hw->tf = tf_ops;
+
+       err = st_lsm6dsx_check_whoami(hw, hw_id);
+       if (err < 0)
+               return err;
+
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               hw->iio_devs[i] = st_lsm6dsx_alloc_iiodev(hw, i);
+               if (!hw->iio_devs[i])
+                       return -ENOMEM;
+       }
+
+       err = st_lsm6dsx_init_device(hw);
+       if (err < 0)
+               return err;
+
+       if (hw->irq > 0) {
+               err = st_lsm6dsx_fifo_setup(hw);
+               if (err < 0)
+                       return err;
+       }
+
+       for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+               err = devm_iio_device_register(hw->dev, hw->iio_devs[i]);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(st_lsm6dsx_probe);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c
new file mode 100644 (file)
index 0000000..ea30411
--- /dev/null
@@ -0,0 +1,101 @@
+/*
+ * STMicroelectronics st_lsm6dsx i2c driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "st_lsm6dsx.h"
+
+static int st_lsm6dsx_i2c_read(struct device *dev, u8 addr, int len, u8 *data)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct i2c_msg msg[2];
+
+       msg[0].addr = client->addr;
+       msg[0].flags = client->flags;
+       msg[0].len = 1;
+       msg[0].buf = &addr;
+
+       msg[1].addr = client->addr;
+       msg[1].flags = client->flags | I2C_M_RD;
+       msg[1].len = len;
+       msg[1].buf = data;
+
+       return i2c_transfer(client->adapter, msg, 2);
+}
+
+static int st_lsm6dsx_i2c_write(struct device *dev, u8 addr, int len, u8 *data)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct i2c_msg msg;
+       u8 send[len + 1];
+
+       send[0] = addr;
+       memcpy(&send[1], data, len * sizeof(u8));
+
+       msg.addr = client->addr;
+       msg.flags = client->flags;
+       msg.len = len + 1;
+       msg.buf = send;
+
+       return i2c_transfer(client->adapter, &msg, 1);
+}
+
+static const struct st_lsm6dsx_transfer_function st_lsm6dsx_transfer_fn = {
+       .read = st_lsm6dsx_i2c_read,
+       .write = st_lsm6dsx_i2c_write,
+};
+
+static int st_lsm6dsx_i2c_probe(struct i2c_client *client,
+                               const struct i2c_device_id *id)
+{
+       return st_lsm6dsx_probe(&client->dev, client->irq,
+                               (int)id->driver_data,
+                               &st_lsm6dsx_transfer_fn);
+}
+
+static const struct of_device_id st_lsm6dsx_i2c_of_match[] = {
+       {
+               .compatible = "st,lsm6ds3",
+               .data = (void *)ST_LSM6DS3_ID,
+       },
+       {
+               .compatible = "st,lsm6dsm",
+               .data = (void *)ST_LSM6DSM_ID,
+       },
+       {},
+};
+MODULE_DEVICE_TABLE(of, st_lsm6dsx_i2c_of_match);
+
+static const struct i2c_device_id st_lsm6dsx_i2c_id_table[] = {
+       { ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID },
+       { ST_LSM6DSM_DEV_NAME, ST_LSM6DSM_ID },
+       {},
+};
+MODULE_DEVICE_TABLE(i2c, st_lsm6dsx_i2c_id_table);
+
+static struct i2c_driver st_lsm6dsx_driver = {
+       .driver = {
+               .name = "st_lsm6dsx_i2c",
+               .of_match_table = of_match_ptr(st_lsm6dsx_i2c_of_match),
+       },
+       .probe = st_lsm6dsx_i2c_probe,
+       .id_table = st_lsm6dsx_i2c_id_table,
+};
+module_i2c_driver(st_lsm6dsx_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx i2c driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c
new file mode 100644 (file)
index 0000000..fbe7247
--- /dev/null
@@ -0,0 +1,118 @@
+/*
+ * STMicroelectronics st_lsm6dsx spi driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "st_lsm6dsx.h"
+
+#define SENSORS_SPI_READ       BIT(7)
+
+static int st_lsm6dsx_spi_read(struct device *dev, u8 addr, int len,
+                              u8 *data)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct st_lsm6dsx_hw *hw = spi_get_drvdata(spi);
+       int err;
+
+       struct spi_transfer xfers[] = {
+               {
+                       .tx_buf = hw->tb.tx_buf,
+                       .bits_per_word = 8,
+                       .len = 1,
+               },
+               {
+                       .rx_buf = hw->tb.rx_buf,
+                       .bits_per_word = 8,
+                       .len = len,
+               }
+       };
+
+       hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
+
+       err = spi_sync_transfer(spi, xfers,  ARRAY_SIZE(xfers));
+       if (err < 0)
+               return err;
+
+       memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
+
+       return len;
+}
+
+static int st_lsm6dsx_spi_write(struct device *dev, u8 addr, int len,
+                               u8 *data)
+{
+       struct st_lsm6dsx_hw *hw;
+       struct spi_device *spi;
+
+       if (len >= ST_LSM6DSX_TX_MAX_LENGTH)
+               return -ENOMEM;
+
+       spi = to_spi_device(dev);
+       hw = spi_get_drvdata(spi);
+
+       hw->tb.tx_buf[0] = addr;
+       memcpy(&hw->tb.tx_buf[1], data, len);
+
+       return spi_write(spi, hw->tb.tx_buf, len + 1);
+}
+
+static const struct st_lsm6dsx_transfer_function st_lsm6dsx_transfer_fn = {
+       .read = st_lsm6dsx_spi_read,
+       .write = st_lsm6dsx_spi_write,
+};
+
+static int st_lsm6dsx_spi_probe(struct spi_device *spi)
+{
+       const struct spi_device_id *id = spi_get_device_id(spi);
+
+       return st_lsm6dsx_probe(&spi->dev, spi->irq,
+                               (int)id->driver_data,
+                               &st_lsm6dsx_transfer_fn);
+}
+
+static const struct of_device_id st_lsm6dsx_spi_of_match[] = {
+       {
+               .compatible = "st,lsm6ds3",
+               .data = (void *)ST_LSM6DS3_ID,
+       },
+       {
+               .compatible = "st,lsm6dsm",
+               .data = (void *)ST_LSM6DSM_ID,
+       },
+       {},
+};
+MODULE_DEVICE_TABLE(of, st_lsm6dsx_spi_of_match);
+
+static const struct spi_device_id st_lsm6dsx_spi_id_table[] = {
+       { ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID },
+       { ST_LSM6DSM_DEV_NAME, ST_LSM6DSM_ID },
+       {},
+};
+MODULE_DEVICE_TABLE(spi, st_lsm6dsx_spi_id_table);
+
+static struct spi_driver st_lsm6dsx_driver = {
+       .driver = {
+               .name = "st_lsm6dsx_spi",
+               .of_match_table = of_match_ptr(st_lsm6dsx_spi_of_match),
+       },
+       .probe = st_lsm6dsx_spi_probe,
+       .id_table = st_lsm6dsx_spi_id_table,
+};
+module_spi_driver(st_lsm6dsx_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx spi driver");
+MODULE_LICENSE("GPL v2");