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[v2,0/3] media: Add support for Cadence CSI2RX version 2.1

Message ID 20190905105601.27034-1-jank@cadence.com
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Series media: Add support for Cadence CSI2RX version 2.1 | expand

Message

Jan Kotas Sept. 5, 2019, 10:55 a.m. UTC
This patchset adds support for Cadence CSI2RX controller version 2.1.
It currently limits maximum amount of data lanes to 4.
Existing compatibility with v1.3 is maintained.

Jan Kotas (3):
  media: dt-bindings: Update bindings for Cadence CSI2RX
  media: Add lane checks for Cadence CSI2RX
  media: Add support for Cadence CSI2RX 2.1

 .../devicetree/bindings/media/cdns,csi2rx.txt      |   5 +-
 drivers/media/platform/cadence/cdns-csi2rx.c       | 152 +++++++++++++++++----
 2 files changed, 131 insertions(+), 26 deletions(-)

Comments

Maxime Ripard Sept. 5, 2019, 12:01 p.m. UTC | #1
On Thu, Sep 05, 2019 at 11:55:58AM +0100, Jan Kotas wrote:
> This patchset adds support for Cadence CSI2RX controller version 2.1.
> It currently limits maximum amount of data lanes to 4.
> Existing compatibility with v1.3 is maintained.

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Sakari Ailus Sept. 6, 2019, 7:54 a.m. UTC | #2
Hi Jan,

Thanks for the patchset.

On Thu, Sep 05, 2019 at 11:56:00AM +0100, Jan Kotas wrote:
> This patch adds lane checks for CSI2RX, to prevent clock lane
> being used as a data lane.
> 
> Signed-off-by: Jan Kotas <jank@cadence.com>
> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 31ace114e..97ec09e72 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -2,7 +2,7 @@
>  /*
>   * Driver for Cadence MIPI-CSI2 RX Controller v1.3
>   *
> - * Copyright (C) 2017 Cadence Design Systems Inc.
> + * Copyright (C) 2017-2019 Cadence Design Systems Inc.
>   */
>  
>  #include <linux/clk.h>
> @@ -364,7 +364,7 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
>  	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
>  	struct fwnode_handle *fwh;
>  	struct device_node *ep;
> -	int ret;
> +	int ret, i;
>  
>  	ep = of_graph_get_endpoint_by_regs(csi2rx->dev->of_node, 0, 0);
>  	if (!ep)
> @@ -395,6 +395,15 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
>  		return -EINVAL;
>  	}
>  
> +	for (i = 0; i < csi2rx->num_lanes; i++) {
> +		if (csi2rx->lanes[i] < 1) {

Do you need this? v4l2_fwnode_parse_endpoint() already has a more thorough
check for the lane numbers.

> +			dev_err(csi2rx->dev, "Invalid lane[%d] number: %u\n",
> +				i, csi2rx->lanes[i]);
> +			of_node_put(ep);
> +			return -EINVAL;
> +		}
> +	}
> +
>  	csi2rx->asd.match.fwnode = fwnode_graph_get_remote_port_parent(fwh);
>  	csi2rx->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
>  	of_node_put(ep);
Sakari Ailus Sept. 6, 2019, 8:01 a.m. UTC | #3
Hi Jan,

On Thu, Sep 05, 2019 at 11:56:01AM +0100, Jan Kotas wrote:
> This patch adds support for CSI2RX v2.1 version of the controller.
> 
> Signed-off-by: Jan Kotas <jank@cadence.com>
> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 139 ++++++++++++++++++++++-----
>  1 file changed, 116 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 97ec09e72..aa1d46111 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -1,6 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0+
>  /*
> - * Driver for Cadence MIPI-CSI2 RX Controller v1.3
> + * Driver for Cadence MIPI-CSI2 RX Controller
>   *
>   * Copyright (C) 2017-2019 Cadence Design Systems Inc.
>   */
> @@ -26,6 +26,9 @@
>  #define CSI2RX_SOFT_RESET_PROTOCOL			BIT(1)
>  #define CSI2RX_SOFT_RESET_FRONT				BIT(0)
>  
> +#define CSI2RX_V2_CORE_CTRL_REG			0x004
> +#define CSI2RX_V2_CORE_CTRL_START			BIT(0)
> +
>  #define CSI2RX_STATIC_CFG_REG			0x008
>  #define CSI2RX_STATIC_CFG_DLANE_MAP(llane, plane)	((plane) << (16 + (llane) * 4))
>  #define CSI2RX_STATIC_CFG_LANES_MASK			GENMASK(11, 8)
> @@ -54,6 +57,15 @@ enum csi2rx_pads {
>  	CSI2RX_PAD_MAX,
>  };
>  
> +struct csi2rx_priv;
> +
> +/* CSI2RX Variant Operations */
> +struct csi2rx_vops {
> +	void (*get_dev_cfg)(struct csi2rx_priv *csi2rx);
> +	void (*reset)(struct csi2rx_priv *csi2rx);
> +	void (*map_static)(struct csi2rx_priv *csi2rx);
> +};
> +
>  struct csi2rx_priv {
>  	struct device			*dev;
>  	unsigned int			count;
> @@ -69,6 +81,7 @@ struct csi2rx_priv {
>  	struct clk			*p_clk;
>  	struct clk			*pixel_clk[CSI2RX_STREAMS_MAX];
>  	struct phy			*dphy;
> +	struct csi2rx_vops		*vops;

const?

>  
>  	u8				lanes[CSI2RX_LANES_MAX];
>  	u8				num_lanes;
> @@ -92,6 +105,32 @@ struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
>  	return container_of(subdev, struct csi2rx_priv, subdev);
>  }
>  
> +static void csi2rx_get_dev_cfg(struct csi2rx_priv *csi2rx)
> +{
> +	u32 dev_cfg;
> +
> +	clk_prepare_enable(csi2rx->p_clk);
> +	dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> +	clk_disable_unprepare(csi2rx->p_clk);
> +
> +	csi2rx->max_lanes = dev_cfg & 7;
> +	csi2rx->max_streams = (dev_cfg >> 4) & 7;
> +	csi2rx->has_internal_dphy = dev_cfg & BIT(3) ? true : false;

Could you spell out these a little, by adding #defines for the register
bits? Same below.

> +}
> +
> +static void csi2rx_v2_get_dev_cfg(struct csi2rx_priv *csi2rx)
> +{
> +	u32 dev_cfg;
> +
> +	clk_prepare_enable(csi2rx->p_clk);
> +	dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> +	clk_disable_unprepare(csi2rx->p_clk);
> +
> +	csi2rx->max_lanes = dev_cfg & 0xF;
> +	csi2rx->max_streams = (dev_cfg >> 5) & 0xF;
> +	csi2rx->has_internal_dphy = dev_cfg & BIT(4) ? true : false;
> +}
> +
>  static void csi2rx_reset(struct csi2rx_priv *csi2rx)
>  {
>  	writel(CSI2RX_SOFT_RESET_PROTOCOL | CSI2RX_SOFT_RESET_FRONT,
> @@ -102,18 +141,21 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
>  	writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
>  }
>  
> -static int csi2rx_start(struct csi2rx_priv *csi2rx)
> +static void csi2rx_v2_reset(struct csi2rx_priv *csi2rx)
> +{
> +	writel(0, csi2rx->base + CSI2RX_V2_CORE_CTRL_REG);
> +
> +	udelay(10);
> +
> +	writel(CSI2RX_V2_CORE_CTRL_START,
> +	       csi2rx->base + CSI2RX_V2_CORE_CTRL_REG);
> +}
> +
> +static void csi2rx_map_static(struct csi2rx_priv *csi2rx)
>  {
>  	unsigned int i;
>  	unsigned long lanes_used = 0;
>  	u32 reg;
> -	int ret;
> -
> -	ret = clk_prepare_enable(csi2rx->p_clk);
> -	if (ret)
> -		return ret;
> -
> -	csi2rx_reset(csi2rx);
>  
>  	reg = csi2rx->num_lanes << 8;
>  	for (i = 0; i < csi2rx->num_lanes; i++) {
> @@ -135,6 +177,32 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  	}
>  
>  	writel(reg, csi2rx->base + CSI2RX_STATIC_CFG_REG);
> +}
> +
> +static void csi2rx_v2_map_static(struct csi2rx_priv *csi2rx)
> +{
> +	u32 reg;
> +
> +	reg = csi2rx->num_lanes << 4;
> +	writel(reg, csi2rx->base + CSI2RX_STATIC_CFG_REG);
> +}
> +
> +static int csi2rx_start(struct csi2rx_priv *csi2rx)
> +{
> +	unsigned int i;
> +	int ret;
> +
> +	ret = clk_prepare_enable(csi2rx->p_clk);
> +	if (ret)
> +		return ret;
> +
> +	if (csi2rx->vops) {
> +		if (csi2rx->vops->reset)
> +			csi2rx->vops->reset(csi2rx);
> +
> +		if (csi2rx->vops->map_static)
> +			csi2rx->vops->map_static(csi2rx);
> +	}
>  
>  	ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true);
>  	if (ret)
> @@ -282,7 +350,6 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
>  {
>  	struct resource *res;
>  	unsigned char i;
> -	u32 dev_cfg;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	csi2rx->base = devm_ioremap_resource(&pdev->dev, res);
> @@ -316,26 +383,25 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
>  		return -EINVAL;
>  	}
>  
> -	clk_prepare_enable(csi2rx->p_clk);
> -	dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> -	clk_disable_unprepare(csi2rx->p_clk);
> +	if (csi2rx->vops && csi2rx->vops->get_dev_cfg) {
> +		csi2rx->vops->get_dev_cfg(csi2rx);
> +	} else {
> +		dev_err(&pdev->dev, "Couldn't get device configuration\n");
> +		return -EINVAL;
> +	}
>  
> -	csi2rx->max_lanes = dev_cfg & 7;
>  	if (csi2rx->max_lanes > CSI2RX_LANES_MAX) {
>  		dev_err(&pdev->dev, "Invalid number of lanes: %u\n",
>  			csi2rx->max_lanes);
>  		return -EINVAL;
>  	}
>  
> -	csi2rx->max_streams = (dev_cfg >> 4) & 7;
>  	if (csi2rx->max_streams > CSI2RX_STREAMS_MAX) {
>  		dev_err(&pdev->dev, "Invalid number of streams: %u\n",
>  			csi2rx->max_streams);
>  		return -EINVAL;
>  	}
>  
> -	csi2rx->has_internal_dphy = dev_cfg & BIT(3) ? true : false;
> -
>  	/*
>  	 * FIXME: Once we'll have internal D-PHY support, the check
>  	 * will need to be removed.
> @@ -426,9 +492,39 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
>  	return ret;
>  }
>  
> +static const struct csi2rx_vops csi2rx_vops = {
> +	.get_dev_cfg = csi2rx_get_dev_cfg,
> +	.reset = csi2rx_reset,
> +	.map_static = csi2rx_map_static
> +};
> +
> +static const struct csi2rx_vops csi2rx_v2_vops = {
> +	.get_dev_cfg = csi2rx_v2_get_dev_cfg,
> +	.reset = csi2rx_v2_reset,
> +	.map_static = csi2rx_v2_map_static
> +};
> +
> +static const struct of_device_id csi2rx_of_table[] = {
> +	{
> +		.compatible = "cdns,csi2rx",
> +		.data = &csi2rx_vops
> +	},
> +	{
> +		.compatible = "cdns,csi2rx-1.3",
> +		.data = &csi2rx_vops
> +	},
> +	{
> +		.compatible = "cdns,csi2rx-2.1",
> +		.data = &csi2rx_v2_vops
> +	},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, csi2rx_of_table);
> +
>  static int csi2rx_probe(struct platform_device *pdev)
>  {
>  	struct csi2rx_priv *csi2rx;
> +	const struct of_device_id *of_id;
>  	unsigned int i;
>  	int ret;
>  
> @@ -439,6 +535,9 @@ static int csi2rx_probe(struct platform_device *pdev)
>  	csi2rx->dev = &pdev->dev;
>  	mutex_init(&csi2rx->lock);
>  
> +	of_id = of_match_node(csi2rx_of_table, pdev->dev.of_node);
> +	csi2rx->vops = (struct csi2rx_vops *)of_id->data;

The cast isn't needed, is it?

> +
>  	ret = csi2rx_get_resources(csi2rx, pdev);
>  	if (ret)
>  		goto err_free_priv;
> @@ -493,12 +592,6 @@ static int csi2rx_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static const struct of_device_id csi2rx_of_table[] = {
> -	{ .compatible = "cdns,csi2rx" },
> -	{ },
> -};
> -MODULE_DEVICE_TABLE(of, csi2rx_of_table);
> -
>  static struct platform_driver csi2rx_driver = {
>  	.probe	= csi2rx_probe,
>  	.remove	= csi2rx_remove,
Jan Kotas Sept. 9, 2019, 7:41 a.m. UTC | #4
Hello Sakari,

Thanks for your reply.
> On 6 Sep 2019, at 09:54, Sakari Ailus <sakari.ailus@iki.fi> wrote:
> 
> Hi Jan,
> 
> Thanks for the patchset.
> 
> On Thu, Sep 05, 2019 at 11:56:00AM +0100, Jan Kotas wrote:
>> /*
>>  * Driver for Cadence MIPI-CSI2 RX Controller v1.3
>>  *
>> - * Copyright (C) 2017 Cadence Design Systems Inc.
>> + * Copyright (C) 2017-2019 Cadence Design Systems Inc.
>>  */
>> 
>> +	for (i = 0; i < csi2rx->num_lanes; i++) {
>> +		if (csi2rx->lanes[i] < 1) {
> 
> Do you need this? v4l2_fwnode_parse_endpoint() already has a more thorough
> check for the lane numbers.

I looked at the source code of v4l2_fwnode_endpoint_parse_csi2_bus
and this particular case doesn’t seem to be checked.

> 
> -- 
> Regards,
> 
> Sakari Ailus

Regards,
Jan
Sakari Ailus Sept. 9, 2019, 7:51 a.m. UTC | #5
On Mon, Sep 09, 2019 at 07:41:21AM +0000, Jan Kotas wrote:
> 
> 
> Hello Sakari,
> 
> Thanks for your reply.
> > On 6 Sep 2019, at 09:54, Sakari Ailus <sakari.ailus@iki.fi> wrote:
> > 
> > Hi Jan,
> > 
> > Thanks for the patchset.
> > 
> > On Thu, Sep 05, 2019 at 11:56:00AM +0100, Jan Kotas wrote:
> >> /*
> >>  * Driver for Cadence MIPI-CSI2 RX Controller v1.3
> >>  *
> >> - * Copyright (C) 2017 Cadence Design Systems Inc.
> >> + * Copyright (C) 2017-2019 Cadence Design Systems Inc.
> >>  */
> >> 
> >> +	for (i = 0; i < csi2rx->num_lanes; i++) {
> >> +		if (csi2rx->lanes[i] < 1) {
> > 
> > Do you need this? v4l2_fwnode_parse_endpoint() already has a more thorough
> > check for the lane numbers.
> 
> I looked at the source code of v4l2_fwnode_endpoint_parse_csi2_bus
> and this particular case doesn’t seem to be checked.

Not specifically, since 0 is a valid lane number.

However, the driver only appears to be using the information on how many
lanes there are. If the hardware doesn't support lane routing, then this is
all you need. Otherwise additional checks should be added in case there are
limitations how the lanes can be routed.
Jan Kotas Sept. 9, 2019, 8:12 a.m. UTC | #6
> On 9 Sep 2019, at 09:51, Sakari Ailus <sakari.ailus@iki.fi> wrote:
> 
> 
> On Mon, Sep 09, 2019 at 07:41:21AM +0000, Jan Kotas wrote:
>> 
>> 
>> Hello Sakari,
>> 
>> Thanks for your reply.
>>> On 6 Sep 2019, at 09:54, Sakari Ailus <sakari.ailus@iki.fi> wrote:
>>> 
>>> Hi Jan,
>>> 
>>> Thanks for the patchset.
>>> 
>>> On Thu, Sep 05, 2019 at 11:56:00AM +0100, Jan Kotas wrote:
>>>> /*
>>>> * Driver for Cadence MIPI-CSI2 RX Controller v1.3
>>>> *
>>>> - * Copyright (C) 2017 Cadence Design Systems Inc.
>>>> + * Copyright (C) 2017-2019 Cadence Design Systems Inc.
>>>> */
>>>> 
>>>> +	for (i = 0; i < csi2rx->num_lanes; i++) {
>>>> +		if (csi2rx->lanes[i] < 1) {
>>> 
>>> Do you need this? v4l2_fwnode_parse_endpoint() already has a more thorough
>>> check for the lane numbers.
>> 
>> I looked at the source code of v4l2_fwnode_endpoint_parse_csi2_bus
>> and this particular case doesn’t seem to be checked.
> 
> Not specifically, since 0 is a valid lane number.
> 
> However, the driver only appears to be using the information on how many
> lanes there are. If the hardware doesn't support lane routing, then this is
> all you need. Otherwise additional checks should be added in case there are
> limitations how the lanes can be routed.

The CSI2RX v1.3 does support that (CSI2RX_STATIC_CFG_REG)
and assumes the first data lane has number 1.

Regrads,
Jan

> -- 
> Sakari Ailus
Jan Kotas Sept. 9, 2019, 9:24 a.m. UTC | #7
Hello Sakari,

Thanks for the review.

> On 6 Sep 2019, at 10:01, Sakari Ailus <sakari.ailus@iki.fi> wrote:
> 
> Hi Jan,
> 
> On Thu, Sep 05, 2019 at 11:56:01AM +0100, Jan Kotas wrote:
>> This patch adds support for CSI2RX v2.1 version of the controller.
>> 
>> Signed-off-by: Jan Kotas <jank@cadence.com>
>> ---
>> drivers/media/platform/cadence/cdns-csi2rx.c | 139 ++++++++++++++++++++++-----
>> 1 file changed, 116 insertions(+), 23 deletions(-)
>> 
>> struct csi2rx_priv {
>> 	struct device			*dev;
>> 	unsigned int			count;
>> @@ -69,6 +81,7 @@ struct csi2rx_priv {
>> 	struct clk			*p_clk;
>> 	struct clk			*pixel_clk[CSI2RX_STREAMS_MAX];
>> 	struct phy			*dphy;
>> +	struct csi2rx_vops		*vops;
> 
> const?

I’ll add it, thanks.

>> 
>> 	u8				lanes[CSI2RX_LANES_MAX];
>> 	u8				num_lanes;
>> @@ -92,6 +105,32 @@ struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
>> 	return container_of(subdev, struct csi2rx_priv, subdev);
>> }
>> 
>> +static void csi2rx_get_dev_cfg(struct csi2rx_priv *csi2rx)
>> +{
>> +	u32 dev_cfg;
>> +
>> +	clk_prepare_enable(csi2rx->p_clk);
>> +	dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
>> +	clk_disable_unprepare(csi2rx->p_clk);
>> +
>> +	csi2rx->max_lanes = dev_cfg & 7;
>> +	csi2rx->max_streams = (dev_cfg >> 4) & 7;
>> +	csi2rx->has_internal_dphy = dev_cfg & BIT(3) ? true : false;
> 
> Could you spell out these a little, by adding #defines for the register
> bits? Same below.

I tried to keep impact on the original code to the minimum, 
but you’re right. It’s a good opportunity for a cleanup. 

>> 
>> @@ -439,6 +535,9 @@ static int csi2rx_probe(struct platform_device *pdev)
>> 	csi2rx->dev = &pdev->dev;
>> 	mutex_init(&csi2rx->lock);
>> 
>> +	of_id = of_match_node(csi2rx_of_table, pdev->dev.of_node);
>> +	csi2rx->vops = (struct csi2rx_vops *)of_id->data;
> 
> The cast isn't needed, is it?

It’s not, but doesn’t make it more readable?

> -- 
> Kind regards,
> 
> Sakari Ailus

Regards,
Jan
Sakari Ailus Sept. 9, 2019, 9:40 a.m. UTC | #8
On Mon, Sep 09, 2019 at 08:12:54AM +0000, Jan Kotas wrote:
> 
> 
> > On 9 Sep 2019, at 09:51, Sakari Ailus <sakari.ailus@iki.fi> wrote:
> > 
> > 
> > On Mon, Sep 09, 2019 at 07:41:21AM +0000, Jan Kotas wrote:
> >> 
> >> 
> >> Hello Sakari,
> >> 
> >> Thanks for your reply.
> >>> On 6 Sep 2019, at 09:54, Sakari Ailus <sakari.ailus@iki.fi> wrote:
> >>> 
> >>> Hi Jan,
> >>> 
> >>> Thanks for the patchset.
> >>> 
> >>> On Thu, Sep 05, 2019 at 11:56:00AM +0100, Jan Kotas wrote:
> >>>> /*
> >>>> * Driver for Cadence MIPI-CSI2 RX Controller v1.3
> >>>> *
> >>>> - * Copyright (C) 2017 Cadence Design Systems Inc.
> >>>> + * Copyright (C) 2017-2019 Cadence Design Systems Inc.
> >>>> */
> >>>> 
> >>>> +	for (i = 0; i < csi2rx->num_lanes; i++) {
> >>>> +		if (csi2rx->lanes[i] < 1) {
> >>> 
> >>> Do you need this? v4l2_fwnode_parse_endpoint() already has a more thorough
> >>> check for the lane numbers.
> >> 
> >> I looked at the source code of v4l2_fwnode_endpoint_parse_csi2_bus
> >> and this particular case doesn’t seem to be checked.
> > 
> > Not specifically, since 0 is a valid lane number.
> > 
> > However, the driver only appears to be using the information on how many
> > lanes there are. If the hardware doesn't support lane routing, then this is
> > all you need. Otherwise additional checks should be added in case there are
> > limitations how the lanes can be routed.
> 
> The CSI2RX v1.3 does support that (CSI2RX_STATIC_CFG_REG)
> and assumes the first data lane has number 1.

Oh. I missed this. Thanks for pointing it out.

If the first data lane must be 1, then your check is still different: it
requires all the data lanes are greater than 1. Are there requireents for
the clock lane position? Looking at the driver, it seems it does not care
about the clock lane, and an educated guess gives 0 for the clock lane.

The DT binding documentation actually omits documenting the data-lanes
altogether. Please add it in a separate patch. I don't think "clock-lanes"
is needed _if_ zero is all you need, so please remove it also from the
examples.

It's actually nice to have more users for this feature. :-)
Sakari Ailus Sept. 9, 2019, 9:41 a.m. UTC | #9
Hi Jan,

On Mon, Sep 09, 2019 at 09:24:15AM +0000, Jan Kotas wrote:
> >> @@ -439,6 +535,9 @@ static int csi2rx_probe(struct platform_device *pdev)
> >> 	csi2rx->dev = &pdev->dev;
> >> 	mutex_init(&csi2rx->lock);
> >> 
> >> +	of_id = of_match_node(csi2rx_of_table, pdev->dev.of_node);
> >> +	csi2rx->vops = (struct csi2rx_vops *)of_id->data;
> > 
> > The cast isn't needed, is it?
> 
> It’s not, but doesn’t make it more readable?

If there's no need for it, please don't use explicit cast.