Re: [PATCH 1/3] i2c: adv748x: store number of CSI-2 lanes described in device tree

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

Hi Niklas,

Thank you for the patch.

On Tuesday, 18 September 2018 04:45:07 EEST Niklas Söderlund wrote:
> The adv748x CSI-2 transmitters TXA and TXB can use different number of
> lines to transmit data on. In order to be able configure the device

s/lines/lanes/
s/data on/data/
s/able configure/able to configure/

> correctly this information need to be parsed from device tree and stored
> in each TX private data structure.
> 
> TXA supports 1, 2 and 4 lanes while TXB supports 1 lane.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>  drivers/media/i2c/adv748x/adv748x-core.c | 49 ++++++++++++++++++++++++
>  drivers/media/i2c/adv748x/adv748x.h      |  1 +
>  2 files changed, 50 insertions(+)
> 
> diff --git a/drivers/media/i2c/adv748x/adv748x-core.c
> b/drivers/media/i2c/adv748x/adv748x-core.c index
> 85c027bdcd56748d..a93f8ea89a228474 100644
> --- a/drivers/media/i2c/adv748x/adv748x-core.c
> +++ b/drivers/media/i2c/adv748x/adv748x-core.c
> @@ -23,6 +23,7 @@
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-device.h>
>  #include <media/v4l2-dv-timings.h>
> +#include <media/v4l2-fwnode.h>
>  #include <media/v4l2-ioctl.h>
> 
>  #include "adv748x.h"
> @@ -561,11 +562,54 @@ void adv748x_subdev_init(struct v4l2_subdev *sd,
> struct adv748x_state *state, sd->entity.ops = &adv748x_media_ops;
>  }
> 
> +static int adv748x_parse_csi2_lanes(struct adv748x_state *state,
> +				    unsigned int port,
> +				    struct device_node *ep)
> +{
> +	struct v4l2_fwnode_endpoint vep;
> +	unsigned int num_lanes;
> +	int ret;
> +
> +	if (port != ADV748X_PORT_TXA && port != ADV748X_PORT_TXB)
> +		return 0;
> +
> +	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &vep);
> +	if (ret)
> +		return ret;
> +
> +	num_lanes = vep.bus.mipi_csi2.num_data_lanes;
> +
> +	if (vep.base.port == ADV748X_PORT_TXA) {
> +		if (num_lanes != 1 && num_lanes != 2 && num_lanes != 4) {
> +			adv_err(state, "TXA: Invalid number (%d) of lanes\n",

%u for unsigned int (and below as well).

> +				num_lanes);
> +			return -EINVAL;
> +		}
> +
> +		state->txa.num_lanes = num_lanes;
> +		adv_dbg(state, "TXA: using %d lanes\n", state->txa.num_lanes);

I wonder if the debug message is really needed.

Apart from that,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	}
> +
> +	if (vep.base.port == ADV748X_PORT_TXB) {
> +		if (num_lanes != 1) {
> +			adv_err(state, "TXB: Invalid number (%d) of lanes\n",
> +				num_lanes);
> +			return -EINVAL;
> +		}
> +
> +		state->txb.num_lanes = num_lanes;
> +		adv_dbg(state, "TXB: using %d lanes\n", state->txb.num_lanes);
> +	}
> +
> +	return 0;
> +}
> +
>  static int adv748x_parse_dt(struct adv748x_state *state)
>  {
>  	struct device_node *ep_np = NULL;
>  	struct of_endpoint ep;
>  	bool found = false;
> +	int ret;
> 
>  	for_each_endpoint_of_node(state->dev->of_node, ep_np) {
>  		of_graph_parse_endpoint(ep_np, &ep);
> @@ -589,6 +633,11 @@ static int adv748x_parse_dt(struct adv748x_state
> *state) state->endpoints[ep.port] = ep_np;
> 
>  		found = true;
> +
> +		/* Store number of CSI-2 lanes used for TXA and TXB. */
> +		ret = adv748x_parse_csi2_lanes(state, ep.port, ep_np);
> +		if (ret)
> +			return ret;
>  	}
> 
>  	return found ? 0 : -ENODEV;
> diff --git a/drivers/media/i2c/adv748x/adv748x.h
> b/drivers/media/i2c/adv748x/adv748x.h index
> c9016acaba34aff2..88ad06a3045c5427 100644
> --- a/drivers/media/i2c/adv748x/adv748x.h
> +++ b/drivers/media/i2c/adv748x/adv748x.h
> @@ -78,6 +78,7 @@ struct adv748x_csi2 {
>  	struct adv748x_state *state;
>  	struct v4l2_mbus_framefmt format;
>  	unsigned int page;
> +	unsigned int num_lanes;
> 
>  	struct media_pad pads[ADV748X_CSI2_NR_PADS];
>  	struct v4l2_ctrl_handler ctrl_hdl;

-- 
Regards,

Laurent Pinchart