iio: imu: inv_mpu6050: rewrite power and engine management

Rewrite clock management to use automatic clock switching
present since MPU6500.
Sensors engine management can now turn on or off a batch of
sensors which simplifies usage a lot.
Temperature sensor is now turned on/off depending on usage.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

@@ -83,11 +83,22 @@ enum inv_devices {
 	INV_NUM_PARTS
 };
 
+/* chip sensors mask: accelerometer, gyroscope, temperature, magnetometer */
+#define INV_MPU6050_SENSOR_ACCL		BIT(0)
+#define INV_MPU6050_SENSOR_GYRO		BIT(1)
+#define INV_MPU6050_SENSOR_TEMP		BIT(2)
+#define INV_MPU6050_SENSOR_MAGN		BIT(3)
+
 /**
  *  struct inv_mpu6050_chip_config - Cached chip configuration data.
+ *  @clk:		selected chip clock
  *  @fsr:		Full scale range.
  *  @lpf:		Digital low pass filter frequency.
  *  @accl_fs:		accel full scale range.
+ *  @accl_en:		accel engine enabled
+ *  @gyro_en:		gyro engine enabled
+ *  @temp_en:		temperature sensor enabled
+ *  @magn_en:		magn engine (i2c master) enabled
  *  @accl_fifo_enable:	enable accel data output
  *  @gyro_fifo_enable:	enable gyro data output
  *  @temp_fifo_enable:	enable temp data output
@@ -95,9 +106,14 @@ enum inv_devices {
  *  @divider:		chip sample rate divider (sample rate divider - 1)
  */
 struct inv_mpu6050_chip_config {
+	unsigned int clk:3;
 	unsigned int fsr:2;
 	unsigned int lpf:3;
 	unsigned int accl_fs:2;
+	unsigned int accl_en:1;
+	unsigned int gyro_en:1;
+	unsigned int temp_en:1;
+	unsigned int magn_en:1;
 	unsigned int accl_fifo_enable:1;
 	unsigned int gyro_fifo_enable:1;
 	unsigned int temp_fifo_enable:1;
@@ -262,6 +278,7 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_REG_PWR_MGMT_1          0x6B
 #define INV_MPU6050_BIT_H_RESET             0x80
 #define INV_MPU6050_BIT_SLEEP               0x40
+#define INV_MPU6050_BIT_TEMP_DIS            0x08
 #define INV_MPU6050_BIT_CLK_MASK            0x7
 
 #define INV_MPU6050_REG_PWR_MGMT_2          0x6C
@@ -292,7 +309,9 @@ struct inv_mpu6050_state {
 /* delay time in milliseconds */
 #define INV_MPU6050_POWER_UP_TIME            100
 #define INV_MPU6050_TEMP_UP_TIME             100
-#define INV_MPU6050_SENSOR_UP_TIME           30
+#define INV_MPU6050_ACCEL_UP_TIME            20
+#define INV_MPU6050_GYRO_UP_TIME             35
+#define INV_MPU6050_GYRO_DOWN_TIME           150
 
 /* delay time in microseconds */
 #define INV_MPU6050_REG_UP_TIME_MIN          5000
@@ -417,7 +436,8 @@ enum inv_mpu6050_clock_sel_e {
 irqreturn_t inv_mpu6050_read_fifo(int irq, void *p);
 int inv_mpu6050_probe_trigger(struct iio_dev *indio_dev, int irq_type);
 int inv_reset_fifo(struct iio_dev *indio_dev);
-int inv_mpu6050_switch_engine(struct inv_mpu6050_state *st, bool en, u32 mask);
+int inv_mpu6050_switch_engine(struct inv_mpu6050_state *st, bool en,
+			      unsigned int mask);
 int inv_mpu6050_write_reg(struct inv_mpu6050_state *st, int reg, u8 val);
 int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on);
 int inv_mpu_acpi_create_mux_client(struct i2c_client *client);

drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c

@@ -316,9 +316,9 @@ int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st)
  *
  * Returns 0 on success, a negative error code otherwise
  */
-int inv_mpu_magn_read(const struct inv_mpu6050_state *st, int axis, int *val)
+int inv_mpu_magn_read(struct inv_mpu6050_state *st, int axis, int *val)
 {
-	unsigned int user_ctrl, status;
+	unsigned int status;
 	__be16 data;
 	uint8_t addr;
 	unsigned int freq_hz, period_ms;
@@ -350,16 +350,14 @@ int inv_mpu_magn_read(const struct inv_mpu6050_state *st, int axis, int *val)
 		freq_hz = INV_MPU_MAGN_FREQ_HZ_MAX;
 	period_ms = 1000 / freq_hz;
 
-	/* start i2c master, wait for xfer, stop */
-	user_ctrl = st->chip_config.user_ctrl | INV_MPU6050_BIT_I2C_MST_EN;
-	ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
+	ret = inv_mpu6050_switch_engine(st, true, INV_MPU6050_SENSOR_MAGN);
 	if (ret)
 		return ret;
 
 	/* need to wait 2 periods + half-period margin */
 	msleep(period_ms * 2 + period_ms / 2);
-	user_ctrl = st->chip_config.user_ctrl;
-	ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
+
+	ret = inv_mpu6050_switch_engine(st, false, INV_MPU6050_SENSOR_MAGN);
 	if (ret)
 		return ret;
 

drivers/iio/imu/inv_mpu6050/inv_mpu_magn.h

@@ -31,6 +31,6 @@ int inv_mpu_magn_set_rate(const struct inv_mpu6050_state *st, int fifo_rate);
 
 int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st);
 
-int inv_mpu_magn_read(const struct inv_mpu6050_state *st, int axis, int *val);
+int inv_mpu_magn_read(struct inv_mpu6050_state *st, int axis, int *val);
 
 #endif		/* INV_MPU_MAGN_H_ */

drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c

@@ -5,9 +5,10 @@
 
 #include "inv_mpu_iio.h"
 
-static void inv_scan_query_mpu6050(struct iio_dev *indio_dev)
+static unsigned int inv_scan_query_mpu6050(struct iio_dev *indio_dev)
 {
 	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+	unsigned int mask;
 
 	st->chip_config.gyro_fifo_enable =
 		test_bit(INV_MPU6050_SCAN_GYRO_X,
@@ -27,17 +28,28 @@ static void inv_scan_query_mpu6050(struct iio_dev *indio_dev)
 
 	st->chip_config.temp_fifo_enable =
 		test_bit(INV_MPU6050_SCAN_TEMP, indio_dev->active_scan_mask);
+
+	mask = 0;
+	if (st->chip_config.gyro_fifo_enable)
+		mask |= INV_MPU6050_SENSOR_GYRO;
+	if (st->chip_config.accl_fifo_enable)
+		mask |= INV_MPU6050_SENSOR_ACCL;
+	if (st->chip_config.temp_fifo_enable)
+		mask |= INV_MPU6050_SENSOR_TEMP;
+
+	return mask;
 }
 
-static void inv_scan_query_mpu9x50(struct iio_dev *indio_dev)
+static unsigned int inv_scan_query_mpu9x50(struct iio_dev *indio_dev)
 {
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	unsigned int mask;
 
-	inv_scan_query_mpu6050(indio_dev);
+	mask = inv_scan_query_mpu6050(indio_dev);
 
 	/* no magnetometer if i2c auxiliary bus is used */
 	if (st->magn_disabled)
-		return;
+		return mask;
 
 	st->chip_config.magn_fifo_enable =
 		test_bit(INV_MPU9X50_SCAN_MAGN_X,
@@ -46,9 +58,13 @@ static void inv_scan_query_mpu9x50(struct iio_dev *indio_dev)
 			 indio_dev->active_scan_mask) ||
 		test_bit(INV_MPU9X50_SCAN_MAGN_Z,
 			 indio_dev->active_scan_mask);
+	if (st->chip_config.magn_fifo_enable)
+		mask |= INV_MPU6050_SENSOR_MAGN;
+
+	return mask;
 }
 
-static void inv_scan_query(struct iio_dev *indio_dev)
+static unsigned int inv_scan_query(struct iio_dev *indio_dev)
 {
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
 
@@ -92,62 +108,40 @@ static unsigned int inv_compute_skip_samples(const struct inv_mpu6050_state *st)
 static int inv_mpu6050_set_enable(struct iio_dev *indio_dev, bool enable)
 {
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
-	uint8_t d;
+	unsigned int scan;
 	int result;
 
+	scan = inv_scan_query(indio_dev);
+
 	if (enable) {
 		result = inv_mpu6050_set_power_itg(st, true);
 		if (result)
 			return result;
-		inv_scan_query(indio_dev);
-		if (st->chip_config.gyro_fifo_enable) {
-			result = inv_mpu6050_switch_engine(st, true,
-					INV_MPU6050_BIT_PWR_GYRO_STBY);
-			if (result)
-				goto error_power_off;
-		}
-		if (st->chip_config.accl_fifo_enable) {
-			result = inv_mpu6050_switch_engine(st, true,
-					INV_MPU6050_BIT_PWR_ACCL_STBY);
-			if (result)
-				goto error_gyro_off;
-		}
-		if (st->chip_config.magn_fifo_enable) {
-			d = st->chip_config.user_ctrl |
-					INV_MPU6050_BIT_I2C_MST_EN;
-			result = regmap_write(st->map, st->reg->user_ctrl, d);
-			if (result)
-				goto error_accl_off;
-			st->chip_config.user_ctrl = d;
-		}
+		result = inv_mpu6050_switch_engine(st, true, scan);
+		if (result)
+			goto error_power_off;
 		st->skip_samples = inv_compute_skip_samples(st);
 		result = inv_reset_fifo(indio_dev);
 		if (result)
-			goto error_magn_off;
+			goto error_sensors_off;
 	} else {
 		result = regmap_write(st->map, st->reg->fifo_en, 0);
 		if (result)
-			goto error_magn_off;
+			goto error_fifo_off;
 
 		result = regmap_write(st->map, st->reg->int_enable, 0);
 		if (result)
-			goto error_magn_off;
-
-		d = st->chip_config.user_ctrl & ~INV_MPU6050_BIT_I2C_MST_EN;
-		result = regmap_write(st->map, st->reg->user_ctrl, d);
-		if (result)
-			goto error_magn_off;
-		st->chip_config.user_ctrl = d;
+			goto error_fifo_off;
 
-		result = inv_mpu6050_switch_engine(st, false,
-					INV_MPU6050_BIT_PWR_ACCL_STBY);
+		/* restore user_ctrl for disabling FIFO reading */
+		result = regmap_write(st->map, st->reg->user_ctrl,
+				      st->chip_config.user_ctrl);
 		if (result)
-			goto error_accl_off;
+			goto error_sensors_off;
 
-		result = inv_mpu6050_switch_engine(st, false,
-					INV_MPU6050_BIT_PWR_GYRO_STBY);
+		result = inv_mpu6050_switch_engine(st, false, scan);
 		if (result)
-			goto error_gyro_off;
+			goto error_power_off;
 
 		result = inv_mpu6050_set_power_itg(st, false);
 		if (result)
@@ -156,18 +150,11 @@ static int inv_mpu6050_set_enable(struct iio_dev *indio_dev, bool enable)
 
 	return 0;
 
-error_magn_off:
+error_fifo_off:
 	/* always restore user_ctrl to disable fifo properly */
-	st->chip_config.user_ctrl &= ~INV_MPU6050_BIT_I2C_MST_EN;
 	regmap_write(st->map, st->reg->user_ctrl, st->chip_config.user_ctrl);
-error_accl_off:
-	if (st->chip_config.accl_fifo_enable)
-		inv_mpu6050_switch_engine(st, false,
-					  INV_MPU6050_BIT_PWR_ACCL_STBY);
-error_gyro_off:
-	if (st->chip_config.gyro_fifo_enable)
-		inv_mpu6050_switch_engine(st, false,
-					  INV_MPU6050_BIT_PWR_GYRO_STBY);
+error_sensors_off:
+	inv_mpu6050_switch_engine(st, false, scan);
 error_power_off:
 	inv_mpu6050_set_power_itg(st, false);
 	return result;