[PATCH v4 06/13] drm/bridge: lvds-codec: Add "lvds-decoder" support

[Fabrizio Castro]

Hi Laurent,

Thank you for your feedback!

> From: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Sent: 13 December 2019 17:11
> Subject: Re: [PATCH v4 06/13] drm/bridge: lvds-codec: Add "lvds-decoder" support
> 
> Hi Fabrizio,
> 
> On Wed, Nov 13, 2019 at 03:51:25PM +0000, Fabrizio Castro wrote:
> > Add support for transparent LVDS decoders by adding a new
> > compatible string ("lvds-decoder") to the driver.
> > This patch also adds member connector_type to struct lvds_codec,
> > and that's because LVDS decoders have a different connector type
> > from LVDS encoders. We fill this new member up with the data
> > matching the compatible string.
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro at bp.renesas.com>
> >
> > ---
> > v3->v4:
> > * New patch
> > ---
> >  drivers/gpu/drm/bridge/lvds-codec.c | 19 ++++++++++++++++---
> >  1 file changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> > index b5801a2..c32e125 100644
> > --- a/drivers/gpu/drm/bridge/lvds-codec.c
> > +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> > @@ -7,6 +7,7 @@
> >  #include <linux/gpio/consumer.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> > +#include <linux/of_device.h>
> >  #include <linux/of_graph.h>
> >  #include <linux/platform_device.h>
> >
> > @@ -17,6 +18,7 @@ struct lvds_codec {
> >  	struct drm_bridge bridge;
> >  	struct drm_bridge *panel_bridge;
> >  	struct gpio_desc *powerdown_gpio;
> > +	u32 connector_type;
> >  };
> >
> >  static int lvds_codec_attach(struct drm_bridge *bridge)
> > @@ -65,6 +67,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
> >  	if (!lvds_codec)
> >  		return -ENOMEM;
> >
> > +	lvds_codec->connector_type = (u32)of_device_get_match_data(&pdev->dev);
> 
> I'm now getting a compilation failure here:
> 
> drivers/gpu/drm/bridge/lvds-codec.c: In function ‘lvds_codec_probe’:
> drivers/gpu/drm/bridge/lvds-codec.c:68:31: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
>   lvds_codec->connector_type = (u32)of_device_get_match_data(&pdev->dev);
>                                ^
> 
> The fix should be simple:
> 
> 	lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
> 
> I'm bothered by the fact that I've compiled this before without any
> issue, so this really puzzles me. Do you get the same warning ?

The warning appears when compiling for arm64, understandably so.
We must have compiled this for arm only the first time around.

I think the right way to solve this is to either cast to (u32)(uintptr_t) or (u32)(unsigned long).

What's your preference?

Thanks,
Fab

> 
> >  	lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
> >  							     GPIOD_OUT_HIGH);
> >  	if (IS_ERR(lvds_codec->powerdown_gpio)) {
> > @@ -105,7 +108,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
> >
> >  	lvds_codec->panel_bridge =
> >  		devm_drm_panel_bridge_add_typed(dev, panel,
> > -						DRM_MODE_CONNECTOR_LVDS);
> > +						lvds_codec->connector_type);
> >  	if (IS_ERR(lvds_codec->panel_bridge))
> >  		return PTR_ERR(lvds_codec->panel_bridge);
> >
> > @@ -133,8 +136,18 @@ static int lvds_codec_remove(struct platform_device *pdev)
> >  }
> >
> >  static const struct of_device_id lvds_codec_match[] = {
> > -	{ .compatible = "lvds-encoder" },
> > -	{ .compatible = "thine,thc63lvdm83d" },
> > +	{
> > +		.compatible = "lvds-decoder",
> > +		.data = (void *)DRM_MODE_CONNECTOR_DPI,
> > +	},
> > +	{
> > +		.compatible = "lvds-encoder",
> > +		.data = (void *)DRM_MODE_CONNECTOR_LVDS,
> > +	},
> > +	{
> > +		.compatible = "thine,thc63lvdm83d",
> > +		.data = (void *)DRM_MODE_CONNECTOR_LVDS,
> > +	},
> >  	{},
> >  };
> >  MODULE_DEVICE_TABLE(of, lvds_codec_match);
> 
> --
> Regards,
> 
> Laurent Pinchart