[PATCH v8 09/14] drm: bridge: samsung-dsim: Add atomic_get_input_bus_fmts

[Marek Szyprowski]

On 10.11.2022 19:38, Jagan Teki wrote:
> Finding the right input bus format throughout the pipeline is hard
> so add atomic_get_input_bus_fmts callback and initialize with the
> proper input format from list of supported output formats.
>
> This format can be used in pipeline for negotiating bus format between
> the DSI-end of this bridge and the other component closer to pipeline
> components.
>
> List of Pixel formats are taken from,
> AN13573 i.MX 8/RT MIPI DSI/CSI-2, Rev. 0, 21 March 2022
> 3.7.4 Pixel formats
> Table 14. DSI pixel packing formats
>
> v8:
> * added pixel formats supported by NXP AN13573 i.MX 8/RT MIPI DSI/CSI-2
>
> v7, v6, v5, v4:
> * none
>
> v3:
> * include media-bus-format.h
>
> v2:
> * none
>
> v1:
> * new patch
>
> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> ---
>   drivers/gpu/drm/bridge/samsung-dsim.c | 53 +++++++++++++++++++++++++++
>   1 file changed, 53 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 0fe153b29e4f..33e5ae9c865f 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -15,6 +15,7 @@
>   #include <linux/clk.h>
>   #include <linux/delay.h>
>   #include <linux/irq.h>
> +#include <linux/media-bus-format.h>
>   #include <linux/of_device.h>
>   #include <linux/phy/phy.h>
>   
> @@ -1321,6 +1322,57 @@ static void samsung_dsim_atomic_post_disable(struct drm_bridge *bridge,
>   	pm_runtime_put_sync(dsi->dev);
>   }
>   
> +/*
> + * This pixel output formats list referenced from,
> + * AN13573 i.MX 8/RT MIPI DSI/CSI-2, Rev. 0, 21 March 2022
> + * 3.7.4 Pixel formats
> + * Table 14. DSI pixel packing formats
> + */
> +static const u32 samsung_dsim_pixel_output_fmts[] = {
> +	MEDIA_BUS_FMT_UYVY8_1X16,
> +	MEDIA_BUS_FMT_RGB101010_1X30,
> +	MEDIA_BUS_FMT_RGB121212_1X36,
> +	MEDIA_BUS_FMT_RGB565_1X16,
> +	MEDIA_BUS_FMT_RGB666_1X18,
> +	MEDIA_BUS_FMT_RGB888_1X24,
> +};
> +
> +static bool samsung_dsim_pixel_output_fmt_supported(u32 fmt)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(samsung_dsim_pixel_output_fmts); i++) {
> +		if (samsung_dsim_pixel_output_fmts[i] == fmt)
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +static u32 *
> +samsung_dsim_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> +				       struct drm_bridge_state *bridge_state,
> +				       struct drm_crtc_state *crtc_state,
> +				       struct drm_connector_state *conn_state,
> +				       u32 output_fmt,
> +				       unsigned int *num_input_fmts)
> +{
> +	u32 *input_fmts;
> +
> +	if (!samsung_dsim_pixel_output_fmt_supported(output_fmt))
> +		return NULL;


Please add support for MEDIA_BUS_FMT_FIXED and maybe default to 
MEDIA_BUS_FMT_RGB888_1X24 if requested format is not matched.

Otherwise the above check breaks all current clients of the Samsung 
DSIM/Exynos DSI. I didn't dig into the bus matching code yet, but all 
DSI panels requests such format on my test systems...


> +
> +	*num_input_fmts = 1;
> +
> +	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
> +	if (!input_fmts)
> +		return NULL;
> +
> +	input_fmts[0] = output_fmt;
> +
> +	return input_fmts;
> +}
> +
>   static int samsung_dsim_atomic_check(struct drm_bridge *bridge,
>   				     struct drm_bridge_state *bridge_state,
>   				     struct drm_crtc_state *crtc_state,
> @@ -1385,6 +1437,7 @@ static const struct drm_bridge_funcs samsung_dsim_bridge_funcs = {
>   	.atomic_duplicate_state		= drm_atomic_helper_bridge_duplicate_state,
>   	.atomic_destroy_state		= drm_atomic_helper_bridge_destroy_state,
>   	.atomic_reset			= drm_atomic_helper_bridge_reset,
> +	.atomic_get_input_bus_fmts	= samsung_dsim_atomic_get_input_bus_fmts,
>   	.atomic_check			= samsung_dsim_atomic_check,
>   	.atomic_pre_enable		= samsung_dsim_atomic_pre_enable,
>   	.atomic_enable			= samsung_dsim_atomic_enable,

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland