[RFC PATCH v2 1/3] drm: atmel-hlcdc: add support for 8-bit color lookup table mode

[Peter Rosin <peda@axentia.se>]

All layers of all supported chips support this, the only variable is the
base address of the lookup table in the register map.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c  |  5 +++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c    | 13 +++++++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h    | 16 ++++++++++++++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c | 29 +++++++++++++++++++++++++
 4 files changed, 63 insertions(+)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 5348985..694adcc 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -429,6 +429,8 @@ static const struct drm_crtc_funcs atmel_hlcdc_crtc_funcs = {
 	.atomic_destroy_state = atmel_hlcdc_crtc_destroy_state,
 	.enable_vblank = atmel_hlcdc_crtc_enable_vblank,
 	.disable_vblank = atmel_hlcdc_crtc_disable_vblank,
+	.set_property = drm_atomic_helper_crtc_set_property,
+	.gamma_set = drm_atomic_helper_legacy_gamma_set,
 };
 
 int atmel_hlcdc_crtc_create(struct drm_device *dev)
@@ -484,6 +486,9 @@ int atmel_hlcdc_crtc_create(struct drm_device *dev)
 	drm_crtc_helper_add(&crtc->base, &lcdc_crtc_helper_funcs);
 	drm_crtc_vblank_reset(&crtc->base);
 
+	drm_mode_crtc_set_gamma_size(&crtc->base, ATMEL_HLCDC_CLUT_SIZE);
+	drm_crtc_enable_color_mgmt(&crtc->base, 0, false, ATMEL_HLCDC_CLUT_SIZE);
+
 	dc->crtc = &crtc->base;
 
 	return 0;
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 30dbffd..4f6ef07 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -42,6 +42,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_at91sam9n12_layers[] = {
 			.default_color = 3,
 			.general_config = 4,
 		},
+		.clut_offset = 0x400,
 	},
 };
 
@@ -73,6 +74,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_at91sam9x5_layers[] = {
 			.disc_pos = 5,
 			.disc_size = 6,
 		},
+		.clut_offset = 0x400,
 	},
 	{
 		.name = "overlay1",
@@ -91,6 +93,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_at91sam9x5_layers[] = {
 			.chroma_key_mask = 8,
 			.general_config = 9,
 		},
+		.clut_offset = 0x800,
 	},
 	{
 		.name = "high-end-overlay",
@@ -112,6 +115,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_at91sam9x5_layers[] = {
 			.scaler_config = 13,
 			.csc = 14,
 		},
+		.clut_offset = 0x1000,
 	},
 	{
 		.name = "cursor",
@@ -131,6 +135,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_at91sam9x5_layers[] = {
 			.chroma_key_mask = 8,
 			.general_config = 9,
 		},
+		.clut_offset = 0x1400,
 	},
 };
 
@@ -162,6 +167,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d3_layers[] = {
 			.disc_pos = 5,
 			.disc_size = 6,
 		},
+		.clut_offset = 0x600,
 	},
 	{
 		.name = "overlay1",
@@ -180,6 +186,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d3_layers[] = {
 			.chroma_key_mask = 8,
 			.general_config = 9,
 		},
+		.clut_offset = 0xa00,
 	},
 	{
 		.name = "overlay2",
@@ -198,6 +205,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d3_layers[] = {
 			.chroma_key_mask = 8,
 			.general_config = 9,
 		},
+		.clut_offset = 0xe00,
 	},
 	{
 		.name = "high-end-overlay",
@@ -223,6 +231,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d3_layers[] = {
 			},
 			.csc = 14,
 		},
+		.clut_offset = 0x1200,
 	},
 	{
 		.name = "cursor",
@@ -244,6 +253,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d3_layers[] = {
 			.general_config = 9,
 			.scaler_config = 13,
 		},
+		.clut_offset = 0x1600,
 	},
 };
 
@@ -275,6 +285,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d4_layers[] = {
 			.disc_pos = 5,
 			.disc_size = 6,
 		},
+		.clut_offset = 0x600,
 	},
 	{
 		.name = "overlay1",
@@ -293,6 +304,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d4_layers[] = {
 			.chroma_key_mask = 8,
 			.general_config = 9,
 		},
+		.clut_offset = 0xa00,
 	},
 	{
 		.name = "overlay2",
@@ -336,6 +348,7 @@ static const struct atmel_hlcdc_layer_desc atmel_hlcdc_sama5d4_layers[] = {
 			},
 			.csc = 14,
 		},
+		.clut_offset = 0x1200,
 	},
 };
 
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
index b0596a8..709f7b9 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
@@ -88,6 +88,11 @@
 #define ATMEL_HLCDC_YUV422SWP			BIT(17)
 #define ATMEL_HLCDC_DSCALEOPT			BIT(20)
 
+#define ATMEL_HLCDC_C1_MODE			ATMEL_HLCDC_CLUT_MODE(0)
+#define ATMEL_HLCDC_C2_MODE			ATMEL_HLCDC_CLUT_MODE(1)
+#define ATMEL_HLCDC_C4_MODE			ATMEL_HLCDC_CLUT_MODE(2)
+#define ATMEL_HLCDC_C8_MODE			ATMEL_HLCDC_CLUT_MODE(3)
+
 #define ATMEL_HLCDC_XRGB4444_MODE		ATMEL_HLCDC_RGB_MODE(0)
 #define ATMEL_HLCDC_ARGB4444_MODE		ATMEL_HLCDC_RGB_MODE(1)
 #define ATMEL_HLCDC_RGBA4444_MODE		ATMEL_HLCDC_RGB_MODE(2)
@@ -142,6 +147,8 @@
 #define ATMEL_HLCDC_DMA_CHANNEL_DSCR_DONE	BIT(2)
 #define ATMEL_HLCDC_DMA_CHANNEL_DSCR_OVERRUN	BIT(3)
 
+#define ATMEL_HLCDC_CLUT_SIZE			256
+
 #define ATMEL_HLCDC_MAX_LAYERS			6
 
 /**
@@ -259,6 +266,7 @@ struct atmel_hlcdc_layer_desc {
 	int id;
 	int regs_offset;
 	int cfgs_offset;
+	int clut_offset;
 	struct atmel_hlcdc_formats *formats;
 	struct atmel_hlcdc_layer_cfg_layout layout;
 	int max_width;
@@ -414,6 +422,14 @@ static inline u32 atmel_hlcdc_layer_read_cfg(struct atmel_hlcdc_layer *layer,
 					  (cfgid * sizeof(u32)));
 }
 
+static inline void atmel_hlcdc_layer_write_clut(struct atmel_hlcdc_layer *layer,
+						unsigned int c, u32 val)
+{
+	atmel_hlcdc_layer_write_reg(layer,
+				    layer->desc->clut_offset + c * sizeof(u32),
+				    val);
+}
+
 static inline void atmel_hlcdc_layer_init(struct atmel_hlcdc_layer *layer,
 				const struct atmel_hlcdc_layer_desc *desc,
 				struct regmap *regmap)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
index 1124200..b5bd9b0 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
@@ -83,6 +83,7 @@ drm_plane_state_to_atmel_hlcdc_plane_state(struct drm_plane_state *s)
 #define SUBPIXEL_MASK			0xffff
 
 static uint32_t rgb_formats[] = {
+	DRM_FORMAT_C8,
 	DRM_FORMAT_XRGB4444,
 	DRM_FORMAT_ARGB4444,
 	DRM_FORMAT_RGBA4444,
@@ -100,6 +101,7 @@ struct atmel_hlcdc_formats atmel_hlcdc_plane_rgb_formats = {
 };
 
 static uint32_t rgb_and_yuv_formats[] = {
+	DRM_FORMAT_C8,
 	DRM_FORMAT_XRGB4444,
 	DRM_FORMAT_ARGB4444,
 	DRM_FORMAT_RGBA4444,
@@ -128,6 +130,9 @@ struct atmel_hlcdc_formats atmel_hlcdc_plane_rgb_and_yuv_formats = {
 static int atmel_hlcdc_format_to_plane_mode(u32 format, u32 *mode)
 {
 	switch (format) {
+	case DRM_FORMAT_C8:
+		*mode = ATMEL_HLCDC_C8_MODE;
+		break;
 	case DRM_FORMAT_XRGB4444:
 		*mode = ATMEL_HLCDC_XRGB4444_MODE;
 		break;
@@ -424,6 +429,29 @@ static void atmel_hlcdc_plane_update_format(struct atmel_hlcdc_plane *plane,
 				    ATMEL_HLCDC_LAYER_FORMAT_CFG, cfg);
 }
 
+static void atmel_hlcdc_plane_update_clut(struct atmel_hlcdc_plane *plane)
+{
+	struct drm_crtc *crtc = plane->base.crtc;
+	struct drm_color_lut *lut;
+	int idx;
+
+	if (!crtc || !crtc->state)
+		return;
+
+	if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
+		return;
+
+	lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
+
+	for (idx = 0; idx < ATMEL_HLCDC_CLUT_SIZE; idx++, lut++) {
+		u32 val = ((lut->red << 8) & 0xff0000) |
+			(lut->green & 0xff00) |
+			(lut->blue >> 8);
+
+		atmel_hlcdc_layer_write_clut(&plane->layer, idx, val);
+	}
+}
+
 static void atmel_hlcdc_plane_update_buffers(struct atmel_hlcdc_plane *plane,
 					struct atmel_hlcdc_plane_state *state)
 {
@@ -768,6 +796,7 @@ static void atmel_hlcdc_plane_atomic_update(struct drm_plane *p,
 	atmel_hlcdc_plane_update_pos_and_size(plane, state);
 	atmel_hlcdc_plane_update_general_settings(plane, state);
 	atmel_hlcdc_plane_update_format(plane, state);
+	atmel_hlcdc_plane_update_clut(plane);
 	atmel_hlcdc_plane_update_buffers(plane, state);
 	atmel_hlcdc_plane_update_disc_area(plane, state);
 
-- 
2.1.4