V4L/DVB (10015): gspca - m5602: Add initial read sensor implementation

Signed-off-by: Erik Andrén <erik.andren@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/m5602/m5602_bridge.h

@@ -136,4 +136,7 @@ int m5602_write_bridge(
 int m5602_write_sensor(struct sd *sd, const u8 address,
 		       u8 *i2c_data, const u8 len);
 
+int m5602_read_sensor(struct sd *sd, const u8 address,
+		      u8 *i2c_data, const u8 len);
+
 #endif

drivers/media/video/gspca/m5602/m5602_core.c

@@ -80,6 +80,42 @@ int m5602_write_bridge(struct sd *sd, u8 address, u8 i2c_data)
 	return (err < 0) ? err : 0;
 }
 
+int m5602_read_sensor(struct sd *sd, const u8 address,
+		       u8 *i2c_data, const u8 len)
+{
+	int err, i;
+
+	do {
+		err = m5602_read_bridge(sd, M5602_XB_I2C_STATUS, i2c_data);
+	} while ((*i2c_data & I2C_BUSY) && !err);
+
+	err = m5602_write_bridge(sd, M5602_XB_I2C_DEV_ADDR,
+				 sd->sensor->i2c_slave_id);
+	if (err < 0)
+		goto out;
+
+	err = m5602_write_bridge(sd, M5602_XB_I2C_REG_ADDR, address);
+	if (err < 0)
+		goto out;
+
+	err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 0x10 + len);
+	if (err < 0)
+		goto out;
+
+	err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 0x08);
+	if (err < 0)
+		goto out;
+
+	for (i = 0; (i < len) && !err; i++) {
+		err = m5602_read_bridge(sd, M5602_XB_I2C_DATA, &(i2c_data[i]));
+
+		PDEBUG(D_CONF, "Reading sensor register "
+			       "0x%x containing 0x%x ", address, *i2c_data);
+	}
+out:
+	return err;
+}
+
 int m5602_write_sensor(struct sd *sd, const u8 address,
 			u8 *i2c_data, const u8 len)
 {