media: i2c: imx500: Enable LED during SPI transfers

The Raspberry Pi 'AI Camera' is equipped with an LED. Enable this LED
during SPI transfers to indicate to the end-user that progress is being
made during large tramsfers.

Signed-off-by: Richard Oliver <richard.oliver@raspberrypi.com>

Author: roliver-rpi

arch/arm/boot/dts/overlays/imx500-overlay.dts

@@ -105,6 +105,7 @@
 
 &cam_node {
 	status = "okay";
+	led-gpios = <&spi_bridge 19 GPIO_ACTIVE_HIGH>;
 	reset-gpios = <&spi_bridge 20 GPIO_ACTIVE_HIGH>;
 	clocks = <&clk_aicam_gated>;
 	spi = <&spi_bridgedev0>;

arch/arm/boot/dts/overlays/imx500-pi5-overlay.dts

@@ -110,6 +110,7 @@
 
 &cam_node {
 	status = "okay";
+	led-gpios = <&spi_bridge 19 GPIO_ACTIVE_HIGH>;
 	reset-gpios = <&spi_bridge 20 GPIO_ACTIVE_HIGH>;
 	clocks = <&clk_aicam_gated>;
 	spi = <&spi_bridgedev0>;

drivers/media/i2c/imx500.c

@@ -965,6 +965,7 @@ struct imx500 {
 	struct clk *xclk;
 	u32 xclk_freq;
 
+	struct gpio_desc *led_gpio;
 	struct gpio_desc *reset_gpio;
 	struct regulator_bulk_data supplies[IMX500_NUM_SUPPLIES];
 
@@ -1990,7 +1991,10 @@ static int imx500_state_transition(struct imx500 *imx500, const u8 *fw,
 		}
 
 		/* Do SPI transfer */
+		gpiod_set_value_cansleep(imx500->led_gpio, 1);
 		ret = imx500_spi_write(imx500, data, size);
+		gpiod_set_value_cansleep(imx500->led_gpio, 0);
+
 		imx500->fw_progress += size;
 
 		if (ret < 0)
@@ -2670,6 +2674,8 @@ static int imx500_probe(struct i2c_client *client)
 		return ret;
 	}
 
+	imx500->led_gpio = devm_gpiod_get_optional(dev, "led", GPIOD_OUT_LOW);
+
 	imx500->reset_gpio =
 		devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);