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Message-ID: <d78559db-65c4-4a1b-9921-4c0217b5e2f7@tuxon.dev>
Date: Sat, 3 Feb 2024 15:00:56 +0200
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Subject: Re: [PATCH RESEND v7 7/7] drm: atmel-hlcdc: add support for DSI
 output formats
Content-Language: en-US
To: Manikandan Muralidharan <manikandan.m@microchip.com>, sam@ravnborg.org,
 bbrezillon@kernel.org, airlied@gmail.com, daniel@ffwll.ch,
 nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com, lee@kernel.org,
 dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org
Cc: Hari.PrasathGE@microchip.com, Balamanikandan.Gunasundar@microchip.com,
 Durai.ManickamKR@microchip.com, Nayabbasha.Sayed@microchip.com,
 Dharma.B@microchip.com, Varshini.Rajendran@microchip.com,
 Balakrishnan.S@microchip.com
References: <20240129092319.199365-1-manikandan.m@microchip.com>
 <20240129092319.199365-8-manikandan.m@microchip.com>
From: claudiu beznea <claudiu.beznea@tuxon.dev>
In-Reply-To: <20240129092319.199365-8-manikandan.m@microchip.com>
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On 29.01.2024 11:23, Manikandan Muralidharan wrote:
> Add support for the following DPI mode if the encoder type
> is DSI as per the XLCDC IP datasheet:
> - 16BPPCFG1
> - 16BPPCFG2
> - 16BPPCFG3
> - 18BPPCFG1
> - 18BPPCFG2
> - 24BPP
> 
> Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
> [durai.manickamkr@microchip.com: update output format using is_xlcdc flag]
> Signed-off-by: Durai Manickam KR <durai.manickamkr@microchip.com>
> ---
>  .../gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c    | 123 +++++++++++++-----
>  1 file changed, 88 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
> index 1899be2eb6a3..6f529769b036 100644
> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
> @@ -295,11 +295,18 @@ static void atmel_hlcdc_crtc_atomic_enable(struct drm_crtc *c,
>  
>  }
>  
> -#define ATMEL_HLCDC_RGB444_OUTPUT	BIT(0)
> -#define ATMEL_HLCDC_RGB565_OUTPUT	BIT(1)
> -#define ATMEL_HLCDC_RGB666_OUTPUT	BIT(2)
> -#define ATMEL_HLCDC_RGB888_OUTPUT	BIT(3)
> -#define ATMEL_HLCDC_OUTPUT_MODE_MASK	GENMASK(3, 0)
> +#define ATMEL_HLCDC_RGB444_OUTPUT		BIT(0)
> +#define ATMEL_HLCDC_RGB565_OUTPUT		BIT(1)
> +#define ATMEL_HLCDC_RGB666_OUTPUT		BIT(2)
> +#define ATMEL_HLCDC_RGB888_OUTPUT		BIT(3)
> +#define ATMEL_HLCDC_DPI_RGB565C1_OUTPUT		BIT(4)
> +#define ATMEL_HLCDC_DPI_RGB565C2_OUTPUT		BIT(5)
> +#define ATMEL_HLCDC_DPI_RGB565C3_OUTPUT		BIT(6)
> +#define ATMEL_HLCDC_DPI_RGB666C1_OUTPUT		BIT(7)
> +#define ATMEL_HLCDC_DPI_RGB666C2_OUTPUT		BIT(8)
> +#define ATMEL_HLCDC_DPI_RGB888_OUTPUT		BIT(9)
> +#define ATMEL_HLCDC_OUTPUT_MODE_MASK		GENMASK(3, 0)
> +#define ATMEL_XLCDC_OUTPUT_MODE_MASK		GENMASK(9, 0)
>  
>  static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
>  {
> @@ -313,53 +320,99 @@ static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
>  	if (!encoder)
>  		encoder = connector->encoder;
>  
> -	switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
> -	case 0:
> -		break;
> -	case MEDIA_BUS_FMT_RGB444_1X12:
> -		return ATMEL_HLCDC_RGB444_OUTPUT;
> -	case MEDIA_BUS_FMT_RGB565_1X16:
> -		return ATMEL_HLCDC_RGB565_OUTPUT;
> -	case MEDIA_BUS_FMT_RGB666_1X18:
> -		return ATMEL_HLCDC_RGB666_OUTPUT;
> -	case MEDIA_BUS_FMT_RGB888_1X24:
> -		return ATMEL_HLCDC_RGB888_OUTPUT;
> -	default:
> -		return -EINVAL;
> -	}
> -
> -	for (j = 0; j < info->num_bus_formats; j++) {
> -		switch (info->bus_formats[j]) {
> -		case MEDIA_BUS_FMT_RGB444_1X12:
> -			supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT;

To generate less diff here and have a cleaner code you can move all this
DSI specific code in a different function and have here something like:

	if (encoder->encoder_type == DRM_MODE_ENCODER_DSI)
		return atmel_hlcdc_connector_output_dsi();

> +	if (encoder->encoder_type == DRM_MODE_ENCODER_DSI) {
> +		/*
> +		 * atmel-hlcdc to support DSI formats with DSI video pipeline
> +		 * when DRM_MODE_ENCODER_DSI type is set by
> +		 * connector driver component.
> +		 */
> +		switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
> +		case 0:
>  			break;
>  		case MEDIA_BUS_FMT_RGB565_1X16:
> -			supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT;
> -			break;
> +			return ATMEL_HLCDC_DPI_RGB565C1_OUTPUT;
>  		case MEDIA_BUS_FMT_RGB666_1X18:
> -			supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT;
> -			break;
> +			return ATMEL_HLCDC_DPI_RGB666C1_OUTPUT;
> +		case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
> +			return ATMEL_HLCDC_DPI_RGB666C2_OUTPUT;
>  		case MEDIA_BUS_FMT_RGB888_1X24:
> -			supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT;
> -			break;
> +			return ATMEL_HLCDC_DPI_RGB888_OUTPUT;
>  		default:
> +			return -EINVAL;
> +		}
> +
> +		for (j = 0; j < info->num_bus_formats; j++) {
> +			switch (info->bus_formats[j]) {
> +			case MEDIA_BUS_FMT_RGB565_1X16:
> +				supported_fmts |=
> +					ATMEL_HLCDC_DPI_RGB565C1_OUTPUT;
> +				break;
> +			case MEDIA_BUS_FMT_RGB666_1X18:
> +				supported_fmts |=
> +					ATMEL_HLCDC_DPI_RGB666C1_OUTPUT;
> +				break;
> +			case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
> +				supported_fmts |=
> +					ATMEL_HLCDC_DPI_RGB666C2_OUTPUT;
> +				break;
> +			case MEDIA_BUS_FMT_RGB888_1X24:
> +				supported_fmts |=
> +					ATMEL_HLCDC_DPI_RGB888_OUTPUT;
> +				break;
> +			default:
> +				break;
> +			}
> +		}
> +	} else {
> +		switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
> +		case 0:
>  			break;
> +		case MEDIA_BUS_FMT_RGB444_1X12:
> +			return ATMEL_HLCDC_RGB444_OUTPUT;
> +		case MEDIA_BUS_FMT_RGB565_1X16:
> +			return ATMEL_HLCDC_RGB565_OUTPUT;
> +		case MEDIA_BUS_FMT_RGB666_1X18:
> +			return ATMEL_HLCDC_RGB666_OUTPUT;
> +		case MEDIA_BUS_FMT_RGB888_1X24:
> +			return ATMEL_HLCDC_RGB888_OUTPUT;
> +		default:
> +			return -EINVAL;
>  		}
> -	}
>  
> +		for (j = 0; j < info->num_bus_formats; j++) {
> +			switch (info->bus_formats[j]) {
> +			case MEDIA_BUS_FMT_RGB444_1X12:
> +				supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT;
> +				break;
> +			case MEDIA_BUS_FMT_RGB565_1X16:
> +				supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT;
> +				break;
> +			case MEDIA_BUS_FMT_RGB666_1X18:
> +				supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT;
> +				break;
> +			case MEDIA_BUS_FMT_RGB888_1X24:
> +				supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT;
> +				break;
> +			default:
> +				break;
> +			}
> +		}
> +	}
>  	return supported_fmts;
>  }
>  
>  static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state)
>  {
> -	unsigned int output_fmts = ATMEL_HLCDC_OUTPUT_MODE_MASK;
> +	unsigned int output_fmts;
>  	struct atmel_hlcdc_crtc_state *hstate;
>  	struct drm_connector_state *cstate;
>  	struct drm_connector *connector;
> -	struct atmel_hlcdc_crtc *crtc;
> +	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(state->crtc);

Previous code uses reverse christmass tree order for variable, thus, try to
keep it the same.

>  	int i;
> +	bool is_xlcdc = crtc->dc->desc->is_xlcdc;
>  
> -	crtc = drm_crtc_to_atmel_hlcdc_crtc(state->crtc);
> +	output_fmts = is_xlcdc ? ATMEL_XLCDC_OUTPUT_MODE_MASK :
> +		      ATMEL_HLCDC_OUTPUT_MODE_MASK;
>  
>  	for_each_new_connector_in_state(state->state, connector, cstate, i) {
>  		unsigned int supported_fmts = 0;
> @@ -380,7 +433,7 @@ static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state)
>  
>  	hstate = drm_crtc_state_to_atmel_hlcdc_crtc_state(state);
>  	hstate->output_mode = fls(output_fmts) - 1;
> -	if (crtc->dc->desc->is_xlcdc) {
> +	if (is_xlcdc) {
>  		/* check if MIPI DPI bit needs to be set */
>  		if (fls(output_fmts) > 3) {
>  			hstate->output_mode -= 4;