iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub.

Add the core functions to be able to support the sensors attached behind
the ChromeOS Embedded Controller and used by other IIO cros-ec sensor
drivers.

The cros_ec_sensor_core driver matches with current driver in ChromeOS
4.4 tree, so it includes all the fixes at the moment. The support for
this driver was made by Gwendal Grignou. The original patch and all the
fixes has been squashed and rebased on top of mainline.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
[eballetbo: split, squash and rebase on top of mainline the patches
found in ChromeOS tree]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

2 files changed, 103 insertions, 5 deletions

diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 76f7ef4..1f85b7a 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -148,6 +148,15 @@ struct cros_ec_device {
 	int event_size;
 };
 
+/**
+ * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information
+ *
+ * @sensor_num: Id of the sensor, as reported by the EC.
+ */
+struct cros_ec_sensor_platform {
+	u8 sensor_num;
+};
+
 /* struct cros_ec_platform - ChromeOS EC platform information
  *
  * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index 76728ff..8826e0f 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -1315,6 +1315,24 @@ enum motionsense_command {
 	 */
 	MOTIONSENSE_CMD_KB_WAKE_ANGLE = 5,
 
+	/*
+	 * Returns a single sensor data.
+	 */
+	MOTIONSENSE_CMD_DATA = 6,
+
+	/*
+	 * Perform low level calibration.. On sensors that support it, ask to
+	 * do offset calibration.
+	 */
+	MOTIONSENSE_CMD_PERFORM_CALIB = 10,
+
+	/*
+	 * Sensor Offset command is a setter/getter command for the offset used
+	 * for calibration. The offsets can be calculated by the host, or via
+	 * PERFORM_CALIB command.
+	 */
+	MOTIONSENSE_CMD_SENSOR_OFFSET = 11,
+
 	/* Number of motionsense sub-commands. */
 	MOTIONSENSE_NUM_CMDS
 };
@@ -1335,12 +1353,18 @@ enum motionsensor_id {
 enum motionsensor_type {
 	MOTIONSENSE_TYPE_ACCEL = 0,
 	MOTIONSENSE_TYPE_GYRO = 1,
+	MOTIONSENSE_TYPE_MAG = 2,
+	MOTIONSENSE_TYPE_PROX = 3,
+	MOTIONSENSE_TYPE_LIGHT = 4,
+	MOTIONSENSE_TYPE_ACTIVITY = 5,
+	MOTIONSENSE_TYPE_MAX
 };
 
 /* List of motion sensor locations. */
 enum motionsensor_location {
 	MOTIONSENSE_LOC_BASE = 0,
 	MOTIONSENSE_LOC_LID = 1,
+	MOTIONSENSE_LOC_MAX,
 };
 
 /* List of motion sensor chips. */
@@ -1361,6 +1385,31 @@ enum motionsensor_chip {
  */
 #define EC_MOTION_SENSE_NO_VALUE -1
 
+#define EC_MOTION_SENSE_INVALID_CALIB_TEMP 0x8000
+
+/* Set Calibration information */
+#define MOTION_SENSE_SET_OFFSET	1
+
+struct ec_response_motion_sensor_data {
+	/* Flags for each sensor. */
+	uint8_t flags;
+	/* Sensor number the data comes from */
+	uint8_t sensor_num;
+	/* Each sensor is up to 3-axis. */
+	union {
+		int16_t             data[3];
+		struct {
+			uint16_t    rsvd;
+			uint32_t    timestamp;
+		} __packed;
+		struct {
+			uint8_t     activity; /* motionsensor_activity */
+			uint8_t     state;
+			int16_t     add_info[2];
+		};
+	};
+} __packed;
+
 struct ec_params_motion_sense {
 	uint8_t cmd;
 	union {
@@ -1378,9 +1427,37 @@ struct ec_params_motion_sense {
 			int16_t data;
 		} ec_rate, kb_wake_angle;
 
+		/* Used for MOTIONSENSE_CMD_SENSOR_OFFSET */
+		struct {
+			uint8_t sensor_num;
+
+			/*
+			 * bit 0: If set (MOTION_SENSE_SET_OFFSET), set
+			 * the calibration information in the EC.
+			 * If unset, just retrieve calibration information.
+			 */
+			uint16_t flags;
+
+			/*
+			 * Temperature at calibration, in units of 0.01 C
+			 * 0x8000: invalid / unknown.
+			 * 0x0: 0C
+			 * 0x7fff: +327.67C
+			 */
+			int16_t temp;
+
+			/*
+			 * Offset for calibration.
+			 * Unit:
+			 * Accelerometer: 1/1024 g
+			 * Gyro:          1/1024 deg/s
+			 * Compass:       1/16 uT
+			 */
+			int16_t offset[3];
+		} __packed sensor_offset;
+
 		/* Used for MOTIONSENSE_CMD_INFO. */
 		struct {
-			/* Should be element of enum motionsensor_id. */
 			uint8_t sensor_num;
 		} info;
 
@@ -1410,11 +1487,14 @@ struct ec_response_motion_sense {
 			/* Flags representing the motion sensor module. */
 			uint8_t module_flags;
 
-			/* Flags for each sensor in enum motionsensor_id. */
-			uint8_t sensor_flags[EC_MOTION_SENSOR_COUNT];
+			/* Number of sensors managed directly by the EC. */
+			uint8_t sensor_count;
 
-			/* Array of all sensor data. Each sensor is 3-axis. */
-			int16_t data[3*EC_MOTION_SENSOR_COUNT];
+			/*
+			 * Sensor data is truncated if response_max is too small
+			 * for holding all the data.
+			 */
+			struct ec_response_motion_sensor_data sensor[0];
 		} dump;
 
 		/* Used for MOTIONSENSE_CMD_INFO. */
@@ -1429,6 +1509,9 @@ struct ec_response_motion_sense {
 			uint8_t chip;
 		} info;
 
+		/* Used for MOTIONSENSE_CMD_DATA */
+		struct ec_response_motion_sensor_data data;
+
 		/*
 		 * Used for MOTIONSENSE_CMD_EC_RATE, MOTIONSENSE_CMD_SENSOR_ODR,
 		 * MOTIONSENSE_CMD_SENSOR_RANGE, and
@@ -1438,6 +1521,12 @@ struct ec_response_motion_sense {
 			/* Current value of the parameter queried. */
 			int32_t ret;
 		} ec_rate, sensor_odr, sensor_range, kb_wake_angle;
+
+		/* Used for MOTIONSENSE_CMD_SENSOR_OFFSET */
+		struct {
+			int16_t temp;
+			int16_t offset[3];
+		} sensor_offset, perform_calib;
 	};
 } __packed;