media: i2c: imx258: Issue reset before starting streaming

Whilst not documented, register 0x0103 bit 0 is the soft
reset for the sensor, so send it before trying to configure
the sensor.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

Author: 6by9

drivers/media/i2c/imx258.c

@@ -20,6 +20,8 @@
 #define IMX258_MODE_STANDBY		0x00
 #define IMX258_MODE_STREAMING		0x01
 
+#define IMX258_REG_RESET		0x0103
+
 /* Chip ID */
 #define IMX258_REG_CHIP_ID		0x0016
 #define IMX258_CHIP_ID			0x0258
@@ -1319,6 +1321,14 @@ static int imx258_start_streaming(struct imx258 *imx258)
 	const struct imx258_link_freq_config *link_freq_cfg;
 	int ret, link_freq_index;
 
+	ret = imx258_write_reg(imx258, IMX258_REG_RESET, IMX258_REG_VALUE_08BIT,
+			       0x01);
+	if (ret) {
+		dev_err(&client->dev, "%s failed to reset sensor\n", __func__);
+		return ret;
+	}
+	usleep_range(10000, 15000);
+
 	/* Setup PLL */
 	link_freq_index = imx258->cur_mode->link_freq_index;
 	link_freq_cfg = &imx258->link_freq_configs[link_freq_index];