Hi Jacopo,
On 16/03/2020 20:27, Jacopo Mondi wrote:
> Parse the 'maxim,overlap-window' property value and cache its
> content to later program registers 0x63 and 0x64.
>
> As specified by the bindings documentation, the property is mandatory as
> long as a default value cannot be established to guarantee DTB backward
> compatibility.
Well, we don't yet have the DTB bindings 'in' I don't believe so I don't
think we need to worry about backwards compatibility yet...
Oh, or do you mean in the future it wouldn't have to be mandatory
perhaps ...
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> ---
> drivers/media/i2c/max9286.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index 06edd8bd3e82..0357515860b2 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -117,6 +117,9 @@
> #define MAX9286_REV_FLEN(n) ((n) - 20)
> /* Register 0x49 */
> #define MAX9286_VIDEO_DETECT_MASK 0x0f
> +/* Register 0x64 */
> +#define MAX9286_OVLP_WINDOWH_MASK GENMASK(4, 0)
> +
> /* Register 0x69 */
> #define MAX9286_LFLTBMONMASKED BIT(7)
> #define MAX9286_LOCKMONMASKED BIT(6)
> @@ -164,6 +167,8 @@ struct max9286_priv {
> unsigned int csi2_data_lanes;
> struct max9286_source sources[MAX9286_NUM_GMSL];
> struct v4l2_async_notifier notifier;
> +
> + u32 overlap_window;
> };
>
> static struct max9286_source *next_source(struct max9286_priv *priv,
> @@ -895,6 +900,11 @@ static int max9286_setup(struct max9286_priv *priv)
> max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
> MAX9286_FSYNCMETH_AUTO);
>
> + /* Configure overlap window. */
> + max9286_write(priv, 0x63, priv->overlap_window);
> + max9286_write(priv, 0x64, (priv->overlap_window >> 8) &
> + MAX9286_OVLP_WINDOWH_MASK);
> +
> /* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
> max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
> MAX9286_HVSRC_D14);
> @@ -1041,8 +1051,24 @@ static int max9286_parse_dt(struct max9286_priv *priv)
> struct device_node *i2c_mux;
> struct device_node *node = NULL;
> unsigned int i2c_mux_mask = 0;
> + int ret;
>
> of_node_get(dev->of_node);
> +
> + /*
> + * FIXM: Require overlap window value to be specified by DTS as long as
/FIXM/FIXME/
> + * the control function is not clarified. As soon as a default
> + * behaviour can be established drop this requirement, while older
/established/established,/
/requirement,/requirement/
> + * DTBs are guaranteed to be fully specified.
> + */
> + ret = of_property_read_u32(dev->of_node, "maxim,overlap-window",
> + &priv->overlap_window);
> + if (ret) {
> + dev_err(dev, "Missing property \"maxim,overlap-window\"\n");
> + of_node_put(dev->of_node);
> + return -EINVAL;
> + }
> +
Other wise, this looks fine except for my concerns and wondering if this
could be approached by defining a property of the requirements in the
serializer and parsing that in some form.
--
Kieran
> i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> if (!i2c_mux) {
> dev_err(dev, "Failed to find i2c-mux node\n");
>
