Re: [RFC 13/18] v4l: of: Read lane-polarity endpoint property

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Sakari,

Thank you for the patch.

On Saturday 07 March 2015 23:41:10 Sakari Ailus wrote:
> Add lane_polarity field to struct v4l2_of_bus_mipi_csi2 and write the
> contents of the lane polarity property to it. The field tells the polarity
> of the physical lanes starting from the first one. Any unused lanes are
> ignored, i.e. only the polarity of the used lanes is specified.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
> ---
>  drivers/media/v4l2-core/v4l2-of.c |   21 ++++++++++++++++-----
>  include/media/v4l2-of.h           |    3 +++
>  2 files changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-of.c
> b/drivers/media/v4l2-core/v4l2-of.c index b4ed9a9..a7a855e 100644
> --- a/drivers/media/v4l2-core/v4l2-of.c
> +++ b/drivers/media/v4l2-core/v4l2-of.c
> @@ -23,7 +23,6 @@ static void v4l2_of_parse_csi_bus(const struct device_node
> *node, struct v4l2_of_endpoint *endpoint)
>  {
>  	struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
> -	u32 data_lanes[ARRAY_SIZE(bus->data_lanes)];
>  	struct property *prop;
>  	bool have_clk_lane = false;
>  	unsigned int flags = 0;
> @@ -34,14 +33,26 @@ static void v4l2_of_parse_csi_bus(const struct
> device_node *node, const __be32 *lane = NULL;
>  		int i;
> 
> -		for (i = 0; i < ARRAY_SIZE(data_lanes); i++) {
> -			lane = of_prop_next_u32(prop, lane, &data_lanes[i]);
> +		for (i = 0; i < ARRAY_SIZE(bus->data_lanes); i++) {
> +			lane = of_prop_next_u32(prop, lane, &v);
>  			if (!lane)
>  				break;
> +			bus->data_lanes[i] = v;
>  		}
>  		bus->num_data_lanes = i;
> -		while (i--)
> -			bus->data_lanes[i] = data_lanes[i];
> +	}
> +
> +	prop = of_find_property(node, "lane-polarity", NULL);
> +	if (prop) {
> +		const __be32 *polarity = NULL;
> +		int i;

Could you please use unsigned int instead of int as the loop index can't have 
negative value ? Feel free to fix the index in the previous loop too :-)

> +
> +		for (i = 0; i < ARRAY_SIZE(bus->lane_polarity); i++) {
> +			polarity = of_prop_next_u32(prop, polarity, &v);
> +			if (!polarity)
> +				break;
> +			bus->lane_polarity[i] = v;
> +		}

Should we check that i == num_data_lines + 1 ?

>  	}
> 
>  	if (!of_property_read_u32(node, "clock-lanes", &v)) {
> diff --git a/include/media/v4l2-of.h b/include/media/v4l2-of.h
> index 70fa7b7..a70eb52 100644
> --- a/include/media/v4l2-of.h
> +++ b/include/media/v4l2-of.h
> @@ -29,12 +29,15 @@ struct device_node;
>   * @data_lanes: an array of physical data lane indexes
>   * @clock_lane: physical lane index of the clock lane
>   * @num_data_lanes: number of data lanes
> + * @lane_polarity: polarity of the lanes. The order is the same of
> + *		   the physical lanes.
>   */
>  struct v4l2_of_bus_mipi_csi2 {
>  	unsigned int flags;
>  	unsigned char data_lanes[4];
>  	unsigned char clock_lane;
>  	unsigned short num_data_lanes;
> +	bool lane_polarity[5];
>  };
> 
>  /**

-- 
Regards,

Laurent Pinchart