Input: mpu3050 - configure the sampling method

This will improve the output of the sensor.

Signed-off-by: Heikki Krogerus <[e-mail]>
Signed-off-by: Kirill A. Shutemov <[e-mail]>
Signed-off-by: Alan Cox <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/misc/mpu3050.c

···
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
 
-#define MPU3050_CHIP_ID_REG	0x00
 #define MPU3050_CHIP_ID		0x69
-#define MPU3050_XOUT_H		0x1D
-#define MPU3050_PWR_MGM		0x3E
-#define MPU3050_PWR_MGM_POS	6
-#define MPU3050_PWR_MGM_MASK	0x40
 
 #define MPU3050_AUTO_DELAY	1000
 
 #define MPU3050_MIN_VALUE	-32768
 #define MPU3050_MAX_VALUE	32767
+
+#define MPU3050_DEFAULT_POLL_INTERVAL	200
+#define MPU3050_DEFAULT_FS_RANGE	3
+
+/* Register map */
+#define MPU3050_CHIP_ID_REG	0x00
+#define MPU3050_SMPLRT_DIV	0x15
+#define MPU3050_DLPF_FS_SYNC	0x16
+#define MPU3050_INT_CFG		0x17
+#define MPU3050_XOUT_H		0x1D
+#define MPU3050_PWR_MGM		0x3E
+#define MPU3050_PWR_MGM_POS	6
+
+/* Register bits */
+
+/* DLPF_FS_SYNC */
+#define MPU3050_EXT_SYNC_NONE		0x00
+#define MPU3050_EXT_SYNC_TEMP		0x20
+#define MPU3050_EXT_SYNC_GYROX		0x40
+#define MPU3050_EXT_SYNC_GYROY		0x60
+#define MPU3050_EXT_SYNC_GYROZ		0x80
+#define MPU3050_EXT_SYNC_ACCELX	0xA0
+#define MPU3050_EXT_SYNC_ACCELY	0xC0
+#define MPU3050_EXT_SYNC_ACCELZ	0xE0
+#define MPU3050_EXT_SYNC_MASK		0xE0
+#define MPU3050_FS_250DPS		0x00
+#define MPU3050_FS_500DPS		0x08
+#define MPU3050_FS_1000DPS		0x10
+#define MPU3050_FS_2000DPS		0x18
+#define MPU3050_FS_MASK		0x18
+#define MPU3050_DLPF_CFG_256HZ_NOLPF2	0x00
+#define MPU3050_DLPF_CFG_188HZ		0x01
+#define MPU3050_DLPF_CFG_98HZ		0x02
+#define MPU3050_DLPF_CFG_42HZ		0x03
+#define MPU3050_DLPF_CFG_20HZ		0x04
+#define MPU3050_DLPF_CFG_10HZ		0x05
+#define MPU3050_DLPF_CFG_5HZ		0x06
+#define MPU3050_DLPF_CFG_2100HZ_NOLPF	0x07
+#define MPU3050_DLPF_CFG_MASK		0x07
+/* INT_CFG */
+#define MPU3050_RAW_RDY_EN		0x01
+#define MPU3050_MPU_RDY_EN		0x02
+#define MPU3050_LATCH_INT_EN		0x04
+/* PWR_MGM */
+#define MPU3050_PWR_MGM_PLL_X		0x01
+#define MPU3050_PWR_MGM_PLL_Y		0x02
+#define MPU3050_PWR_MGM_PLL_Z		0x03
+#define MPU3050_PWR_MGM_CLKSEL		0x07
+#define MPU3050_PWR_MGM_STBY_ZG	0x08
+#define MPU3050_PWR_MGM_STBY_YG	0x10
+#define MPU3050_PWR_MGM_STBY_XG	0x20
+#define MPU3050_PWR_MGM_SLEEP		0x40
+#define MPU3050_PWR_MGM_RESET		0x80
+#define MPU3050_PWR_MGM_MASK		0x40
 
 struct axis_data {
 	s16 x;
···
 }
 
 /**
+ *	mpu3050_hw_init	-	initialize hardware
+ *	@sensor: the sensor
+ *
+ *	Called during device probe; configures the sampling method.
+ */
+static int __devinit mpu3050_hw_init(struct mpu3050_sensor *sensor)
+{
+	struct i2c_client *client = sensor->client;
+	int ret;
+	u8 reg;
+
+	/* Reset */
+	ret = i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM,
+					MPU3050_PWR_MGM_RESET);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(client, MPU3050_PWR_MGM);
+	if (ret < 0)
+		return ret;
+
+	ret &= ~MPU3050_PWR_MGM_CLKSEL;
+	ret |= MPU3050_PWR_MGM_PLL_Z;
+	ret = i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM, ret);
+	if (ret < 0)
+		return ret;
+
+	/* Output frequency divider. The poll interval */
+	ret = i2c_smbus_write_byte_data(client, MPU3050_SMPLRT_DIV,
+					MPU3050_DEFAULT_POLL_INTERVAL - 1);
+	if (ret < 0)
+		return ret;
+
+	/* Set low pass filter and full scale */
+	reg = MPU3050_DEFAULT_FS_RANGE;
+	reg |= MPU3050_DLPF_CFG_42HZ << 3;
+	reg |= MPU3050_EXT_SYNC_NONE << 5;
+	ret = i2c_smbus_write_byte_data(client, MPU3050_DLPF_FS_SYNC, reg);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+/**
  *	mpu3050_probe	-	device detection callback
  *	@client: i2c client of found device
  *	@id: id match information
···
 	input_set_drvdata(idev, sensor);
 
 	pm_runtime_set_active(&client->dev);
+
+	error = mpu3050_hw_init(sensor);
+	if (error)
+		goto err_pm_set_suspended;
 
 	error = request_threaded_irq(client->irq,
 				     NULL, mpu3050_interrupt_thread,