Re: [PATCH v5 10/15] media: i2c: rdacm21: Power up OV10640 before OV490

From: Kieran Bingham
Date: Wed Jun 16 2021 - 19:47:46 EST


Hi Jacopo,

Hrm - this seems to be the only one in this series without my RB tag, so
lets take a look.


On 16/06/2021 13:46, Jacopo Mondi wrote:
> The current RDACM21 initialization routine powers up the OV10640 image
> sensor after the OV490 ISP. The ISP is programmed with a firmare loaded

s/firmare/firmware/

> from an embedded serial flash that (most probably) tries to interact and
> program also the image sensor connected to the ISP.
>
> As described in commit "media: i2c: rdacm21: Fix OV10640 powerup" the
> image sensor powerdown signal is kept high by an internal pull up
> resistor and occasionally fails to startup correctly if the powerdown
> line is not asserted explicitely. Failures in the OV10640 startup causes

s/explicitely/explicitly/


> the OV490 firmware to fail to boot correctly resulting in the camera
> module initialization to fail consequentially.
>
> Fix this by powering up the OV10640 image sensor before testing the
> OV490 firmware boot completion, by splitting the ov10640_initialize()
> function in an ov10640_power_up() one and an ov10640_check_id() one.
>
> Also make sure the OV10640 identification procedure gives enough time to
> the image sensor to resume after the programming phase performed by the
> OV490 firmware by repeating the ID read procedure.
>
> This commit fixes a sporadic start-up error triggered by a failure to
> detect the OV490 firmware boot completion:
> rdacm21 8-0054: Timeout waiting for firmware boot
>
> Fixes: a59f853b3b4b ("media: i2c: Add driver for RDACM21 camera module")
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>

> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/rdacm21.c | 46 ++++++++++++++++++++++++++-----------
> 1 file changed, 32 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
> index 7c0a4a84340a..43c41cb800a4 100644
> --- a/drivers/media/i2c/rdacm21.c
> +++ b/drivers/media/i2c/rdacm21.c
> @@ -69,6 +69,7 @@
> #define OV490_ISP_VSIZE_LOW 0x80820062
> #define OV490_ISP_VSIZE_HIGH 0x80820063
>
> +#define OV10640_PID_TIMEOUT 20
> #define OV10640_ID_HIGH 0xa6
> #define OV10640_CHIP_ID 0x300a
> #define OV10640_PIXEL_RATE 55000000
> @@ -329,10 +330,8 @@ static const struct v4l2_subdev_ops rdacm21_subdev_ops = {
> .pad = &rdacm21_subdev_pad_ops,
> };
>
> -static int ov10640_initialize(struct rdacm21_device *dev)
> +static void ov10640_power_up(struct rdacm21_device *dev)
> {
> - u8 val;
> -
> /* Enable GPIO0#0 (reset) and GPIO1#0 (pwdn) as output lines. */
> ov490_write_reg(dev, OV490_GPIO_SEL0, OV490_GPIO0);
> ov490_write_reg(dev, OV490_GPIO_SEL1, OV490_SPWDN0);
> @@ -347,18 +346,35 @@ static int ov10640_initialize(struct rdacm21_device *dev)
> usleep_range(1500, 3000);
> ov490_write_reg(dev, OV490_GPIO_OUTPUT_VALUE0, OV490_GPIO0);
> usleep_range(3000, 5000);
> +}
>
> - /* Read OV10640 ID to test communications. */
> - ov490_write_reg(dev, OV490_SCCB_SLAVE0_DIR, OV490_SCCB_SLAVE_READ);
> - ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_HIGH, OV10640_CHIP_ID >> 8);
> - ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, OV10640_CHIP_ID & 0xff);
> -
> - /* Trigger SCCB slave transaction and give it some time to complete. */
> - ov490_write_reg(dev, OV490_HOST_CMD, OV490_HOST_CMD_TRIGGER);
> - usleep_range(1000, 1500);
> +static int ov10640_check_id(struct rdacm21_device *dev)
> +{
> + unsigned int i;
> + u8 val;
>
> - ov490_read_reg(dev, OV490_SCCB_SLAVE0_DIR, &val);
> - if (val != OV10640_ID_HIGH) {
> + /* Read OV10640 ID to test communications. */
> + for (i = 0; i < OV10640_PID_TIMEOUT; ++i) {
> + ov490_write_reg(dev, OV490_SCCB_SLAVE0_DIR,
> + OV490_SCCB_SLAVE_READ);
> + ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_HIGH,
> + OV10640_CHIP_ID >> 8);
> + ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW,
> + OV10640_CHIP_ID & 0xff);
> +
> + /*
> + * Trigger SCCB slave transaction and give it some time
> + * to complete.
> + */
> + ov490_write_reg(dev, OV490_HOST_CMD, OV490_HOST_CMD_TRIGGER);
> + usleep_range(1000, 1500);
> +
> + ov490_read_reg(dev, OV490_SCCB_SLAVE0_DIR, &val);
> + if (val == OV10640_ID_HIGH)
> + break;
> + usleep_range(1000, 1500);
> + }
> + if (i == OV10640_PID_TIMEOUT) {
> dev_err(dev->dev, "OV10640 ID mismatch: (0x%02x)\n", val);
> return -ENODEV;
> }
> @@ -374,6 +390,8 @@ static int ov490_initialize(struct rdacm21_device *dev)
> unsigned int i;
> int ret;
>
> + ov10640_power_up(dev);
> +
> /*
> * Read OV490 Id to test communications. Give it up to 40msec to
> * exit from reset.
> @@ -411,7 +429,7 @@ static int ov490_initialize(struct rdacm21_device *dev)
> return -ENODEV;
> }
>
> - ret = ov10640_initialize(dev);
> + ret = ov10640_check_id(dev);
> if (ret)
> return ret;
>
>