drm: atmel-hlcdc: add support for DSI output formats

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>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240424053351.589830-8-manikandan.m@microchip.com

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c

@@ -301,11 +301,60 @@ 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_xlcdc_connector_output_dsi(struct drm_encoder *encoder,
+					    struct drm_display_info *info)
+{
+	int j;
+	unsigned int supported_fmts = 0;
+
+	switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
+	case 0:
+		break;
+	case MEDIA_BUS_FMT_RGB565_1X16:
+		return ATMEL_HLCDC_DPI_RGB565C1_OUTPUT;
+	case MEDIA_BUS_FMT_RGB666_1X18:
+		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:
+		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;
+		}
+	}
+	return supported_fmts;
+}
 
 static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
 {
@@ -318,6 +367,13 @@ static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
 	encoder = state->best_encoder;
 	if (!encoder)
 		encoder = connector->encoder;
+	/*
+	 * atmel-hlcdc to support DSI formats with DSI video pipeline
+	 * when DRM_MODE_ENCODER_DSI type is set by
+	 * connector driver component.
+	 */
+	if (encoder->encoder_type == DRM_MODE_ENCODER_DSI)
+		return atmel_xlcdc_connector_output_dsi(encoder, info);
 
 	switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
 	case 0:
@@ -358,14 +414,16 @@ static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
 
 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;
 	int i;
 
 	crtc = drm_crtc_to_atmel_hlcdc_crtc(state->crtc);
+	output_fmts = crtc->dc->desc->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;