drm/mxsfb: Update mxsfb with additional pixel formats

Since version 4 of eLCDIF, there are some registers that can do
transformations on the input data, like re-arranging the pixel
components. By doing that, we can support more pixel formats.
This patch adds support for X/ABGR and RGBX/A. Although, the local alpha
is not supported by eLCDIF, the alpha pixel formats were added to the
supported pixel formats but it will be ignored. This was necessary since
there are systems (like Android) that requires such pixel formats.

Also, add support for the following pixel formats:
            16 bpp: RG16 ,BG16, XR15, XB15, AR15, AB15

Set the bus format based on input from the user and panel
capabilities.
Save the bus format in crtc->mode.private_flags, so the bridge can
use it.

Signed-off-by: Robert Chiras <robert.chiras@nxp.com>
Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com>
Tested-by: Guido Günther <agx@sigxcpu.org>

1 files changed, 122 insertions, 25 deletions

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index 5e44f57b1458..1be29f584d2e 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -43,14 +43,17 @@ static u32 set_hsync_pulse_width(struct mxsfb_drm_private *mxsfb, u32 val)
 }
 
 /* Setup the MXSFB registers for decoding the pixels out of the framebuffer */
-static int mxsfb_set_pixel_fmt(struct mxsfb_drm_private *mxsfb)
+static int mxsfb_set_pixel_fmt(struct mxsfb_drm_private *mxsfb, bool update)
 {
 	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
 	struct drm_device *drm = crtc->dev;
 	const u32 format = crtc->primary->state->fb->format->format;
-	u32 ctrl, ctrl1;
+	u32 ctrl = 0, ctrl1 = 0;
+	bool bgr_format = true;
+	struct drm_format_name_buf format_name_buf;
 
-	ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER;
+	if (!update)
+		ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER;
 
 	/*
 	 * WARNING: The bus width, CTRL_SET_BUS_WIDTH(), is configured to
@@ -59,64 +62,158 @@ static int mxsfb_set_pixel_fmt(struct mxsfb_drm_private *mxsfb)
 	 * to arbitrary value. This limitation should not pose an issue.
 	 */
 
-	/* CTRL1 contains IRQ config and status bits, preserve those. */
-	ctrl1 = readl(mxsfb->base + LCDC_CTRL1);
-	ctrl1 &= CTRL1_CUR_FRAME_DONE_IRQ_EN | CTRL1_CUR_FRAME_DONE_IRQ;
+	if (!update) {
+		/* CTRL1 contains IRQ config and status bits, preserve those. */
+		ctrl1 = readl(mxsfb->base + LCDC_CTRL1);
+		ctrl1 &= CTRL1_CUR_FRAME_DONE_IRQ_EN | CTRL1_CUR_FRAME_DONE_IRQ;
+	}
+
+	DRM_DEV_DEBUG_DRIVER(drm->dev, "Setting up %s mode\n",
+			     drm_get_format_name(format, &format_name_buf));
+
+	/* Do some clean-up that we might have from a previous mode */
+	ctrl &= ~CTRL_SHIFT_DIR(1);
+	ctrl &= ~CTRL_SHIFT_NUM(0x3f);
+	if (mxsfb->devdata->ipversion >= 4)
+		writel(CTRL2_ODD_LINE_PATTERN(CTRL2_LINE_PATTERN_CLR) |
+		       CTRL2_EVEN_LINE_PATTERN(CTRL2_LINE_PATTERN_CLR),
+		       mxsfb->base + LCDC_V4_CTRL2 + REG_CLR);
 
 	switch (format) {
-	case DRM_FORMAT_RGB565:
-		dev_dbg(drm->dev, "Setting up RGB565 mode\n");
+	case DRM_FORMAT_BGR565: /* BG16 */
+		if (mxsfb->devdata->ipversion < 4)
+			goto err;
+		writel(CTRL2_ODD_LINE_PATTERN(CTRL2_LINE_PATTERN_BGR) |
+			CTRL2_EVEN_LINE_PATTERN(CTRL2_LINE_PATTERN_BGR),
+			mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
+		/* Fall through */
+	case DRM_FORMAT_RGB565: /* RG16 */
+		ctrl |= CTRL_SET_WORD_LENGTH(0);
+		ctrl &= ~CTRL_DF16;
+		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0xf);
+		break;
+	case DRM_FORMAT_XBGR1555: /* XB15 */
+	case DRM_FORMAT_ABGR1555: /* AB15 */
+		if (mxsfb->devdata->ipversion < 4)
+			goto err;
+		writel(CTRL2_ODD_LINE_PATTERN(CTRL2_LINE_PATTERN_BGR) |
+			CTRL2_EVEN_LINE_PATTERN(CTRL2_LINE_PATTERN_BGR),
+			mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
+		/* Fall through */
+	case DRM_FORMAT_XRGB1555: /* XR15 */
+	case DRM_FORMAT_ARGB1555: /* AR15 */
 		ctrl |= CTRL_SET_WORD_LENGTH(0);
+		ctrl |= CTRL_DF16;
 		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0xf);
 		break;
-	case DRM_FORMAT_XRGB8888:
-		dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
+	case DRM_FORMAT_RGBX8888: /* RX24 */
+	case DRM_FORMAT_RGBA8888: /* RA24 */
+		/* RGBX - > 0RGB */
+		ctrl |= CTRL_SHIFT_DIR(1);
+		ctrl |= CTRL_SHIFT_NUM(8);
+		bgr_format = false;
+		/* Fall through */
+	case DRM_FORMAT_XBGR8888: /* XB24 */
+	case DRM_FORMAT_ABGR8888: /* AB24 */
+		if (bgr_format) {
+			if (mxsfb->devdata->ipversion < 4)
+				goto err;
+			writel(CTRL2_ODD_LINE_PATTERN(CTRL2_LINE_PATTERN_BGR) |
+			       CTRL2_EVEN_LINE_PATTERN(CTRL2_LINE_PATTERN_BGR),
+			       mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
+		}
+		/* Fall through */
+	case DRM_FORMAT_XRGB8888: /* XR24 */
+	case DRM_FORMAT_ARGB8888: /* AR24 */
 		ctrl |= CTRL_SET_WORD_LENGTH(3);
 		/* Do not use packed pixels = one pixel per word instead. */
 		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0x7);
 		break;
 	default:
-		dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
-		return -EINVAL;
+		goto err;
 	}
 
-	writel(ctrl1, mxsfb->base + LCDC_CTRL1);
-	writel(ctrl, mxsfb->base + LCDC_CTRL);
+	if (update) {
+		writel(ctrl, mxsfb->base + LCDC_CTRL + REG_SET);
+		writel(ctrl1, mxsfb->base + LCDC_CTRL1 + REG_SET);
+	} else {
+		writel(ctrl, mxsfb->base + LCDC_CTRL);
+		writel(ctrl1, mxsfb->base + LCDC_CTRL1);
+	}
 
 	return 0;
+
+err:
+	DRM_DEV_ERROR(drm->dev, "Unhandled pixel format: %s\n",
+		      drm_get_format_name(format, &format_name_buf));
+
+	return -EINVAL;
+}
+
+static u32 get_bus_format_from_bpp(u32 bpp)
+{
+	switch (bpp) {
+	case 16:
+		return MEDIA_BUS_FMT_RGB565_1X16;
+	case 18:
+		return MEDIA_BUS_FMT_RGB666_1X18;
+	case 24:
+		return MEDIA_BUS_FMT_RGB888_1X24;
+	default:
+		return MEDIA_BUS_FMT_RGB888_1X24;
+	}
 }
 
 static void mxsfb_set_bus_fmt(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
+	unsigned int bits_per_pixel = crtc->primary->state->fb->format->depth;
 	struct drm_device *drm = crtc->dev;
 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
-	u32 reg;
-
-	reg = readl(mxsfb->base + LCDC_CTRL);
+	int num_bus_formats = mxsfb->connector->display_info.num_bus_formats;
+	const u32 *bus_formats = mxsfb->connector->display_info.bus_formats;
+	u32 reg = 0;
+	int i = 0;
+
+	/* match the user requested bus_format to one supported by the panel */
+	if (num_bus_formats) {
+		u32 user_bus_format = get_bus_format_from_bpp(bits_per_pixel);
+
+		bus_format = bus_formats[0];
+		for (i = 0; i < num_bus_formats; i++) {
+			if (user_bus_format == bus_formats[i]) {
+				bus_format = user_bus_format;
+				break;
+			}
+		}
+	}
 
-	if (mxsfb->connector->display_info.num_bus_formats)
-		bus_format = mxsfb->connector->display_info.bus_formats[0];
+	/*
+	 * CRTC will dictate the bus format via private_flags[16:1]
+	 * and private_flags[0] will signal a bus format change
+	 */
+	crtc->mode.private_flags &= ~0x1FFFF; /* clear bus format */
+	crtc->mode.private_flags |= (bus_format << 1); /* set bus format */
+	crtc->mode.private_flags |= 0x1; /* bus format change indication*/
 
 	DRM_DEV_DEBUG_DRIVER(drm->dev, "Using bus_format: 0x%08X\n",
 			     bus_format);
 
-	reg &= ~CTRL_BUS_WIDTH_MASK;
 	switch (bus_format) {
 	case MEDIA_BUS_FMT_RGB565_1X16:
-		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_16BIT);
+		reg = CTRL_SET_BUS_WIDTH(STMLCDIF_16BIT);
 		break;
 	case MEDIA_BUS_FMT_RGB666_1X18:
-		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_18BIT);
+		reg = CTRL_SET_BUS_WIDTH(STMLCDIF_18BIT);
 		break;
 	case MEDIA_BUS_FMT_RGB888_1X24:
-		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_24BIT);
+		reg = CTRL_SET_BUS_WIDTH(STMLCDIF_24BIT);
 		break;
 	default:
 		dev_err(drm->dev, "Unknown media bus format %d\n", bus_format);
 		break;
 	}
-	writel(reg, mxsfb->base + LCDC_CTRL);
+	writel(reg, mxsfb->base + LCDC_CTRL + REG_SET);
 }
 
 static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
@@ -238,7 +335,7 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 	/* Clear the FIFOs */
 	writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_SET);
 
-	err = mxsfb_set_pixel_fmt(mxsfb);
+	err = mxsfb_set_pixel_fmt(mxsfb, false);
 	if (err)
 		return;