driver: lsm6dso: Add support to LSM6DSO IMU

Added support to LSM6DSO IMU sensor.
Features included in this driver are:
 - Basic Sensor Read acc/gyro data
 - ODR and FS runtime configuration
 - FIFO water mark interrupt
 - Shared commons function with ST MEMs devices

BUG=none
BRANCH=master
TEST=Tested on discovery target BOARD with
LSM6DSO connected to EC i2c master bus and motion
sense task running.

Commands used to test LSM6DSO device are:
 - accelinit
 - accelrange
 - accelinfo

All basic features tested, including:
1) ODR change:
 - accelrate 0 [13000:208000]
 - accelrate 1 [13000:208000]

2) FS Range change:
 - accelrange 0 [2:16]
 - accelrange 1 [250:2000]

3) Interrupt on FIFO water mark

Signed-off-by: Mario Tesi <mario.tesi@st.com>

Change-Id: If2984f7d0d30b0ef475e0525aca2bc365aa4fe21
Signed-off-by: Mario Tesi <mario.tesi@st.com>
Reviewed-on: https://chromium-review.googlesource.com/1371364
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Enrico Granata <egranata@chromium.org>
Reviewed-by: Enrico Granata <egranata@chromium.org>

1 files changed, 233 insertions, 0 deletions

diff --git a/driver/accelgyro_lsm6dso.h b/driver/accelgyro_lsm6dso.h
new file mode 100644
index 0000000000..7748c7fe94
--- /dev/null
+++ b/driver/accelgyro_lsm6dso.h
@@ -0,0 +1,233 @@
+/* Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* LSM6DSO Accel and Gyro driver for Chrome EC */
+
+#ifndef __CROS_EC_ACCELGYRO_LSM6DSO_H
+#define __CROS_EC_ACCELGYRO_LSM6DSO_H
+
+#include "stm_mems_common.h"
+
+#define LSM6DSO_I2C_ADDR(__x)		(__x << 1)
+
+/*
+ * 7-bit address is 110101xb. Where 'x' is determined
+ * by the voltage on the ADDR pin
+ */
+#define LSM6DSO_ADDR0			LSM6DSO_I2C_ADDR(0x6a)
+#define LSM6DSO_ADDR1			LSM6DSO_I2C_ADDR(0x6b)
+
+/* Access to embedded sensor hub register bank */
+#define LSM6DSO_FUNC_CFG_ACC_ADDR	0x01
+#define LSM6DSO_FUNC_CFG_EN			0x80
+
+/* Who Am I */
+#define LSM6DSO_WHO_AM_I_REG		0x0f
+#define LSM6DSO_WHO_AM_I		0x6c
+
+/* Common defines for Acc and Gyro sensors */
+#define LSM6DSO_EN_BIT				0x01
+#define LSM6DSO_DIS_BIT				0x00
+
+#define LSM6DSO_GYRO_OUT_X_L_ADDR	0x22
+#define LSM6DSO_ACCEL_OUT_X_L_ADDR	0x28
+
+#define LSM6DSO_CTRL1_ADDR		0x10
+#define LSM6DSO_CTRL2_ADDR		0x11
+#define LSM6DSO_CTRL3_ADDR		0x12
+#define LSM6DSO_SW_RESET			0x01
+#define LSM6DSO_IF_INC				0x04
+#define LSM6DSO_PP_OD				0x10
+#define LSM6DSO_H_L_ACTIVE			0x20
+#define LSM6DSO_BDU				0x40
+
+#define LSM6DSO_CTRL4_ADDR		0x13
+#define LSM6DSO_INT2_ON_INT1_MASK		0x20
+
+#define LSM6DSO_CTRL5_ADDR		0x14
+#define LSM6DSO_CTRL6_ADDR		0x15
+#define LSM6DSO_CTRL7_ADDR		0x16
+#define LSM6DSO_CTRL8_ADDR		0x17
+#define LSM6DSO_CTRL9_ADDR		0x18
+
+#define LSM6DSO_CTRL10_ADDR		0x19
+#define LSM6DSO_TIMESTAMP_EN    		0x20
+
+#define LSM6DSO_STATUS_REG		0x1e
+
+/* Output data rate registers and masks */
+#define LSM6DSO_ODR_REG(_sensor) \
+	(LSM6DSO_CTRL1_ADDR + (_sensor))
+#define LSM6DSO_ODR_MASK			0xf0
+
+/* Hardware FIFO size in byte */
+#define LSM6DSO_MAX_FIFO_SIZE		4096
+#define LSM6DSO_MAX_FIFO_LENGTH	(LSM6DSO_MAX_FIFO_SIZE / OUT_XYZ_SIZE)
+
+/* FIFO decimator registers and bitmask */
+#define LSM6DSO_FIFO_CTRL1_ADDR		0x07
+#define LSM6DSO_FIFO_CTRL2_ADDR		0x08
+
+#define LSM6DSO_FIFO_CTRL3_ADDR		0x09
+#define LSM6DSO_FIFO_ODR_XL_MASK		0x0f
+#define LSM6DSO_FIFO_ODR_G_MASK			0xf0
+
+#define LSM6DSO_FIFO_CTRL4_ADDR		0x0a
+#define LSM6DSO_FIFO_MODE_MASK			0x07
+
+#define LSM6DSO_INT1_CTRL		0x0d
+#define LSM6DSO_INT2_CTRL		0x0e
+#define LSM6DSO_INT_FIFO_TH			0x08
+#define LSM6DSO_INT_FIFO_OVR			0x10
+#define LSM6DSO_INT_FIFO_FULL			0x20
+
+#define LSM6DSO_FIFO_STS1_ADDR		0x3a
+#define LSM6DSO_FIFO_STS2_ADDR		0x3b
+#define LSM6DSO_FIFO_DIFF_MASK			0x07ff
+#define LSM6DSO_FIFO_FULL			0x2000
+#define LSM6DSO_FIFO_DATA_OVR			0x4000
+#define LSM6DSO_FIFO_WATERMARK			0x8000
+
+/* Out FIFO data register */
+#define LSM6DSO_FIFO_DATA_ADDR_TAG	0x78
+
+/* Registers value for supported FIFO mode */
+#define LSM6DSO_FIFO_MODE_BYPASS_VAL	0x00
+#define LSM6DSO_FIFO_MODE_CONTINUOUS_VAL	0x06
+
+/* Define device available in FIFO pattern */
+enum lsm6dso_dev_fifo {
+	LSM6DSO_FIFO_DEV_INVALID = -1,
+	LSM6DSO_FIFO_DEV_GYRO = 0,
+	LSM6DSO_FIFO_DEV_ACCEL,
+	LSM6DSO_FIFO_DEV_NUM,
+};
+
+/* Define FIFO data pattern, tag and len */
+#define LSM6DSO_SAMPLE_SIZE		6
+#define LSM6DSO_TS_SAMPLE_SIZE		4
+#define LSM6DSO_TAG_SIZE		1
+#define LSM6DSO_FIFO_SAMPLE_SIZE	LSM6DSO_SAMPLE_SIZE + LSM6DSO_TAG_SIZE
+#define LSM6DSO_MAX_FIFO_DEPTH		416
+
+enum lsm6dso_tag_fifo {
+	LSM6DSO_GYRO_TAG = 0x01,
+	LSM6DSO_ACC_TAG = 0x02,
+};
+
+struct lsm6dso_fstatus {
+	uint16_t len;
+	uint16_t pattern;
+};
+
+/* Absolute maximum rate for Acc and Gyro sensors */
+#define LSM6DSO_ODR_MIN_VAL		13000
+#define LSM6DSO_ODR_MAX_VAL \
+	MOTION_MAX_SENSOR_FREQUENCY(416000, 13000)
+
+/* ODR reg value from selected data rate in mHz */
+#define LSM6DSO_ODR_TO_REG(_odr) (__fls(_odr / LSM6DSO_ODR_MIN_VAL) + 1)
+
+#define LSM6DSO_FIFO_ODR_TO_REG(_s) \
+	(_s->type == MOTIONSENSE_TYPE_ACCEL ? LSM6DSO_FIFO_ODR_XL_MASK : \
+	 LSM6DSO_FIFO_ODR_G_MASK)
+
+/* Normalized ODR values from selected data rate in mHz */
+#define LSM6DSO_REG_TO_ODR(_reg) (LSM6DSO_ODR_MIN_VAL << (_reg - 1))
+
+/* Full Scale ranges value and gain for Acc */
+#define LSM6DSO_FS_LIST_NUM		4
+
+#define LSM6DSO_ACCEL_FS_ADDR		0x10
+#define LSM6DSO_ACCEL_FS_MASK			0x0c
+
+#define LSM6DSO_ACCEL_FS_2G_VAL		0x00
+#define LSM6DSO_ACCEL_FS_4G_VAL		0x02
+#define LSM6DSO_ACCEL_FS_8G_VAL		0x03
+#define LSM6DSO_ACCEL_FS_16G_VAL	0x01
+
+#define LSM6DSO_ACCEL_FS_MAX_VAL	16
+
+/* Accel reg value from Full Scale range */
+static inline uint8_t lsm6dso_accel_fs_reg(int fs)
+{
+	uint8_t ret;
+
+	switch(fs) {
+	case 2:
+		ret = LSM6DSO_ACCEL_FS_2G_VAL;
+		break;
+	case 16:
+		ret = LSM6DSO_ACCEL_FS_16G_VAL;
+		break;
+	default:
+		ret = __fls(fs);
+		break;
+	}
+
+	return ret;
+}
+
+/* Accel normalized FS value from Full Scale */
+#define LSM6DSO_ACCEL_NORMALIZE_FS(_fs) (1 << __fls(_fs))
+
+/* Full Scale range value and gain for Gyro */
+#define LSM6DSO_GYRO_FS_ADDR		0x11
+#define LSM6DSO_GYRO_FS_MASK			0x0c
+
+/* Minimal Gyro range in mDPS */
+#define LSM6DSO_GYRO_FS_MIN_VAL_MDPS ((8750 << 15) / 1000)
+#define LSM6DSO_GYRO_FS_MAX_REG_VAL 3
+
+/* Gyro reg value for Full Scale selection in DPS */
+#define LSM6DSO_GYRO_FS_REG(_fs) \
+	__fls(MAX(1, (_fs * 1000) / LSM6DSO_GYRO_FS_MIN_VAL_MDPS))
+
+/* Gyro normalized FS value (in DPS) from Full Scale register */
+#define LSM6DSO_GYRO_NORMALIZE_FS(_reg) \
+	((LSM6DSO_GYRO_FS_MIN_VAL_MDPS << (_reg)) / 1000)
+
+/* FS register address/mask for Acc/Gyro sensors */
+#define LSM6DSO_RANGE_REG(_sensor)  	(LSM6DSO_ACCEL_FS_ADDR + (_sensor))
+#define LSM6DSO_RANGE_MASK  			0x0c
+
+/* Status register bit for Acc/Gyro data ready */
+enum lsm6dso_status {
+	LSM6DSO_STS_DOWN = 0x00,
+	LSM6DSO_STS_XLDA_UP = 0x01,
+	LSM6DSO_STS_GDA_UP = 0x02
+};
+
+/* Status register bitmask for Acc/Gyro data ready */
+#define LSM6DSO_STS_XLDA_MASK			0x01
+#define LSM6DSO_STS_GDA_MASK			0x02
+
+/* Sensor resolution in number of bits: fixed 16 bit */
+#define LSM6DSO_RESOLUTION      	16
+
+/* Aggregate private data for all supported sensor (Acc, Gyro) */
+struct lsm6dso_data {
+	struct stprivate_data st_data[LSM6DSO_FIFO_DEV_NUM];
+};
+
+/*
+ * Note: The specific number of samples to discard depends on the filters
+ * configured for the chip, as well as the ODR being set. For most of our
+ * allowed ODRs, 3 should suffice.
+ * See: ST's LSM6DSO application notes (AN5192) Tables 12 and 18 for details
+ */
+#define LSM6DSO_DISCARD_SAMPLES 3
+
+#define LSM6DSO_GET_DATA(_s) ((struct stprivate_data *)((_s)->drv_data))
+
+/* Macro to initialize motion_sensors structure */
+#define LSM6DSO_ST_DATA(g, type) (&(&(g))->st_data[(type)])
+#define LSM6DSO_MAIN_SENSOR(_s) ((_s) - (_s)->type)
+
+extern const struct accelgyro_drv lsm6dso_drv;
+
+void lsm6dso_interrupt(enum gpio_signal signal);
+
+#endif /* __CROS_EC_ACCELGYRO_LSM6DSO_H */