drm/mediatek: Add support for AR30 and BA30 overlays

Add the ability for the Mediatek DRM driver to control
the bit depth register. If the DTS indicates the device supports
10-bit overlays and the current format has a fourcc of AR30, BA30,
or RA30, we set the bit depth register to 10 bit.

The next patch in the series actually enables 10-bit overlays for
MT8195 devices, but this current patch should be a no-op. This
patch was tested by simply running Chrome on an MT8195 and looking
for regressions.

Signed-off-by: Justin Green <greenjustin@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20230309210623.1167567-1-greenjustin@chromium.org/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_disp_ovl.c

@@ -42,6 +42,7 @@
 #define DISP_REG_OVL_RDMA_CTRL(n)		(0x00c0 + 0x20 * (n))
 #define DISP_REG_OVL_RDMA_GMC(n)		(0x00c8 + 0x20 * (n))
 #define DISP_REG_OVL_ADDR_MT2701		0x0040
+#define DISP_REG_OVL_CLRFMT_EXT			0x02D0
 #define DISP_REG_OVL_ADDR_MT8173		0x0f40
 #define DISP_REG_OVL_ADDR(ovl, n)		((ovl)->data->addr + 0x20 * (n))
 #define DISP_REG_OVL_HDR_ADDR(ovl, n)		((ovl)->data->addr + 0x20 * (n) + 0x04)
@@ -62,6 +63,10 @@
 					0 : OVL_CON_CLRFMT_RGB)
 #define OVL_CON_CLRFMT_RGB888(ovl)	((ovl)->data->fmt_rgb565_is_0 ? \
 					OVL_CON_CLRFMT_RGB : 0)
+#define OVL_CON_CLRFMT_BIT_DEPTH_MASK(ovl)	(0xFF << 4 * (ovl))
+#define OVL_CON_CLRFMT_BIT_DEPTH(depth, ovl)	(depth << 4 * (ovl))
+#define OVL_CON_CLRFMT_8_BIT			0x00
+#define OVL_CON_CLRFMT_10_BIT			0x01
 #define	OVL_CON_AEN		BIT(8)
 #define	OVL_CON_ALPHA		0xff
 #define	OVL_CON_VIRT_FLIP	BIT(9)
@@ -90,6 +95,7 @@ struct mtk_disp_ovl_data {
 	bool supports_afbc;
 	const u32 *formats;
 	size_t num_formats;
+	bool supports_clrfmt_ext;
 };
 
 /*
@@ -219,6 +225,30 @@ static void mtk_ovl_set_afbc(struct mtk_disp_ovl *ovl, struct cmdq_pkt *cmdq_pkt
 			   DISP_REG_OVL_DATAPATH_CON, OVL_LAYER_AFBC_EN(idx));
 }
 
+static void mtk_ovl_set_bit_depth(struct device *dev, int idx, u32 format,
+				  struct cmdq_pkt *cmdq_pkt)
+{
+	struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
+	unsigned int reg;
+	unsigned int bit_depth = OVL_CON_CLRFMT_8_BIT;
+
+	if (!ovl->data->supports_clrfmt_ext)
+		return;
+
+	reg = readl(ovl->regs + DISP_REG_OVL_CLRFMT_EXT);
+	reg &= ~OVL_CON_CLRFMT_BIT_DEPTH_MASK(idx);
+
+	if (format == DRM_FORMAT_RGBA1010102 ||
+	    format == DRM_FORMAT_BGRA1010102 ||
+	    format == DRM_FORMAT_ARGB2101010)
+		bit_depth = OVL_CON_CLRFMT_10_BIT;
+
+	reg |= OVL_CON_CLRFMT_BIT_DEPTH(bit_depth, idx);
+
+	mtk_ddp_write(cmdq_pkt, reg, &ovl->cmdq_reg,
+		      ovl->regs, DISP_REG_OVL_CLRFMT_EXT);
+}
+
 void mtk_ovl_config(struct device *dev, unsigned int w,
 		    unsigned int h, unsigned int vrefresh,
 		    unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
@@ -333,9 +363,11 @@ static unsigned int ovl_fmt_convert(struct mtk_disp_ovl *ovl, unsigned int fmt)
 		return OVL_CON_CLRFMT_ARGB8888;
 	case DRM_FORMAT_BGRX8888:
 	case DRM_FORMAT_BGRA8888:
+	case DRM_FORMAT_BGRA1010102:
 		return OVL_CON_CLRFMT_ARGB8888 | OVL_CON_BYTE_SWAP;
 	case DRM_FORMAT_XRGB8888:
 	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_ARGB2101010:
 		return OVL_CON_CLRFMT_RGBA8888;
 	case DRM_FORMAT_XBGR8888:
 	case DRM_FORMAT_ABGR8888:
@@ -419,6 +451,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
 				      &ovl->cmdq_reg, ovl->regs, DISP_REG_OVL_PITCH_MSB(idx));
 	}
 
+	mtk_ovl_set_bit_depth(dev, idx, fmt, cmdq_pkt);
 	mtk_ovl_layer_on(dev, idx, cmdq_pkt);
 }