Hi Janusz,
On Sun, Oct 13, 2019 at 02:50:50PM +0200, Janusz Krzysztofik wrote:
> A hardcoded 12 MHz master clock frequency has been assumed since
> conversion of the driver from soc_camera sensor to a standalone V4L2
> subdevice by commit 23a52386fabe ("media: ov6650: convert to standalone
> v4l2 subdevice"). Fix it.
>
> Define a static table of supported master clock rates (fix misnamed
> symbol while being at it), then use v4l2_clk_get/set_rate() to obtain
> a clock rate matching one of those supported. On success, apply
> respective master clock hardware divisor provided by the matching
> element of the table.
>
> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx>
> ---
> drivers/media/i2c/ov6650.c | 64 ++++++++++++++++++++++++++++++++++----
> 1 file changed, 58 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/i2c/ov6650.c b/drivers/media/i2c/ov6650.c
> index f4723c0b5c70..13fd7c4699b2 100644
> --- a/drivers/media/i2c/ov6650.c
> +++ b/drivers/media/i2c/ov6650.c
> @@ -124,7 +124,7 @@
>
> #define DEF_AECH 0x4D
>
> -#define CLKRC_6MHz 0x00
> +#define CLKRC_8MHz 0x00
> #define CLKRC_12MHz 0x40
> #define CLKRC_16MHz 0x80
> #define CLKRC_24MHz 0xc0
> @@ -201,6 +201,29 @@ struct ov6650 {
> u32 code;
> };
>
> +struct ov6650_xclk {
> + unsigned long rate;
> + u8 clkrc;
> +};
> +
> +static const struct ov6650_xclk ov6650_xclk[] = {
> +{
> + .rate = 8000000,
> + .clkrc = CLKRC_8MHz,
> +},
> +{
> + .rate = 12000000,
> + .clkrc = CLKRC_12MHz,
> +},
> +{
> + .rate = 16000000,
> + .clkrc = CLKRC_16MHz,
> +},
> +{
> + .rate = 24000000,
> + .clkrc = CLKRC_24MHz,
> +},
> +};
>
> static u32 ov6650_codes[] = {
> MEDIA_BUS_FMT_YUYV8_2X8,
> @@ -774,7 +797,7 @@ static int ov6650_reset(struct i2c_client *client)
> }
>
> /* program default register values */
> -static int ov6650_prog_dflt(struct i2c_client *client)
> +static int ov6650_prog_dflt(struct i2c_client *client, u8 clkrc)
> {
> int ret;
>
> @@ -782,7 +805,7 @@ static int ov6650_prog_dflt(struct i2c_client *client)
>
> ret = ov6650_reg_write(client, REG_COMA, 0); /* ~COMA_RESET */
> if (!ret)
> - ret = ov6650_reg_write(client, REG_CLKRC, CLKRC_12MHz);
> + ret = ov6650_reg_write(client, REG_CLKRC, clkrc);
> if (!ret)
> ret = ov6650_reg_rmw(client, REG_COMB, 0, COMB_BAND_FILTER);
>
> @@ -793,8 +816,10 @@ static int ov6650_video_probe(struct v4l2_subdev *sd)
> {
> struct i2c_client *client = v4l2_get_subdevdata(sd);
> struct ov6650 *priv = to_ov6650(client);
> - u8 pidh, pidl, midh, midl;
> - int ret;
> + const struct ov6650_xclk *xclk;
> + unsigned long rate;
> + u8 pidh, pidl, midh, midl;
> + int i, ret;
>
> priv->clk = v4l2_clk_get(&client->dev, NULL);
> if (IS_ERR(priv->clk)) {
> @@ -803,6 +828,33 @@ static int ov6650_video_probe(struct v4l2_subdev *sd)
> return ret;
> }
>
> + rate = v4l2_clk_get_rate(priv->clk);
> + for (i = 0; rate && i < ARRAY_SIZE(ov6650_xclk); i++) {
> + if (rate != ov6650_xclk[i].rate)
> + continue;
> +
> + xclk = &ov6650_xclk[i];
> + dev_info(&client->dev, "using host default clock rate %lukHz\n",
> + rate / 1000);
> + break;
> + }
xclk is undefined unless it was set in the previous loop. Please initialise
to to NULL. I can fix that, too, while applying the patch.
> + for (i = 0; !xclk && i < ARRAY_SIZE(ov6650_xclk); i++) {
> + ret = v4l2_clk_set_rate(priv->clk, ov6650_xclk[i].rate);
> + if (ret || v4l2_clk_get_rate(priv->clk) != ov6650_xclk[i].rate)
> + continue;
> +
> + xclk = &ov6650_xclk[i];
> + dev_info(&client->dev, "using negotiated clock rate %lukHz\n",
> + xclk->rate / 1000);
> + break;
> + }
> + if (!xclk) {
> + dev_err(&client->dev, "unable to get supported clock rate\n");
> + if (!ret)
> + ret = -EINVAL;
> + goto eclkput;
> + }
> +
> ret = ov6650_s_power(sd, 1);
> if (ret < 0)
> goto eclkput;
> @@ -836,7 +888,7 @@ static int ov6650_video_probe(struct v4l2_subdev *sd)
>
> ret = ov6650_reset(client);
> if (!ret)
> - ret = ov6650_prog_dflt(client);
> + ret = ov6650_prog_dflt(client, xclk->clkrc);
> if (!ret) {
> struct v4l2_mbus_framefmt mf = ov6650_def_fmt;
>
--
Regards,
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxx
