drivers/aspeed/common: Add support for high resolution framebuffer

* Implement reading EDID over software I2C.
* Fall back to VGA if no monitor connected for BMC KVM
* Copy the linux kernel code and add a bunch of wrapper structs to make it
  compile.
* Convert the EDID to a drm_display_mode, which is understood by the
  driver.
* Properly select HAVE_LINEAR_FRAMEBUFFER and HAVE_VGA_TEXT_FRAMEBUFFER

Tested on Supermicro X11SSH-TF using FullHD VGA monitor.
Initializes the graphics in about 1 second, which is twice as fast as the
VGA Option ROM.

The framebuffer is advertised and working in tianocore.

Change-Id: I7803566b64158405efc04a39f80a0ec98b44e646
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35726
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 256 insertions, 0 deletions

diff --git a/src/drivers/aspeed/common/ast_mode_corebootfb.c b/src/drivers/aspeed/common/ast_mode_corebootfb.c
new file mode 100644
index 0000000000..2ec85ac31f
--- /dev/null
+++ b/src/drivers/aspeed/common/ast_mode_corebootfb.c
@@ -0,0 +1,256 @@
+/*
+ * Copied from Linux drivers/gpu/drm/ast/ast_mode.c
+ *
+ * Copyright 2012 Red Hat Inc.
+ * Parts based on xf86-video-ast
+ * Copyright (c) 2005 ASPEED Technology Inc.
+ * Copyright Dave Airlie <airlied@redhat.com>
+ * Copyright 2019 9Elements Agency GmbH <patrick.rudolph@9elements.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ */
+
+#include <edid.h>
+
+#include "ast_drv.h"
+
+/*
+ * Set framebuffer MMIO address, which must fall into BAR0 MMIO window.
+ *
+ * Complete reimplementation as the original expects multiple kernel internal
+ * subsystems to be present.
+ */
+int ast_crtc_do_set_base(struct drm_crtc *crtc)
+{
+	struct ast_private *ast = crtc->dev->dev_private;
+	struct drm_framebuffer *fb = crtc->primary->fb;
+
+	/* PCI BAR 0 */
+	struct resource *res = find_resource(crtc->dev->pdev, 0x10);
+	if (!res) {
+		printk(BIOS_ERR, "BAR0 resource not found.\n");
+		return -EIO;
+	}
+
+	if (res->size < fb->pitches[0] * crtc->mode.vdisplay) {
+		dev_err(dev->pdev, "Framebuffer doesn't fit into BAR0 MMIO window\n");
+		return -ENOMEM;
+	}
+
+	fb->mmio_addr = (u32)res2mmio(res, 4095, 4095);
+
+	ast_set_offset_reg(crtc);
+	ast_set_start_address_crt1(ast, fb->mmio_addr);
+
+	return 0;
+}
+
+static void ast_edid_to_drmmode(struct edid *edid, struct drm_display_mode *mode)
+{
+	memset(mode, 0, sizeof(*mode));
+
+	mode->hdisplay = edid->mode.ha;
+	mode->vdisplay = edid->mode.va;
+	mode->crtc_hdisplay = edid->mode.ha;
+	mode->crtc_vdisplay = edid->mode.va;
+
+	/* EDID clock is in 10kHz, but drm clock is in KHz */
+	mode->clock = edid->mode.pixel_clock * 10;
+	mode->vrefresh = edid->mode.refresh;
+
+	mode->crtc_hblank_start = edid->mode.ha;
+	mode->crtc_hblank_end = edid->mode.ha + edid->mode.hbl;
+	mode->crtc_hsync_start = edid->mode.ha + edid->mode.hso;
+	mode->crtc_hsync_end = edid->mode.ha + edid->mode.hso + edid->mode.hspw;
+	mode->crtc_htotal = mode->crtc_hblank_end;
+
+	mode->crtc_vblank_start = edid->mode.va;
+	mode->crtc_vblank_end = edid->mode.va + edid->mode.vbl;
+	mode->crtc_vsync_start = edid->mode.va + edid->mode.vso;
+	mode->crtc_vsync_end = edid->mode.va + edid->mode.vso + edid->mode.vspw;
+	mode->crtc_vtotal = mode->crtc_vblank_end;
+
+	mode->flags = 0;
+	if (edid->mode.phsync == '+')
+		mode->flags |= DRM_MODE_FLAG_PHSYNC;
+	else
+		mode->flags |= DRM_MODE_FLAG_NHSYNC;
+
+	if (edid->mode.pvsync == '+')
+		mode->flags |= DRM_MODE_FLAG_PVSYNC;
+	else
+		mode->flags |= DRM_MODE_FLAG_NVSYNC;
+}
+
+static int ast_select_mode(struct drm_connector *connector,
+			   struct edid *edid)
+{
+	struct ast_private *ast = connector->dev->dev_private;
+	bool widescreen;
+	u8 raw[128];
+	bool flags = false;
+
+	if (ast->tx_chip_type == AST_TX_DP501) {
+		ast->dp501_maxclk = 0xff;
+		flags = ast_dp501_read_edid(connector->dev, (u8 *)raw);
+		if (flags)
+			ast->dp501_maxclk = ast_get_dp501_max_clk(connector->dev);
+		else
+			dev_err(dev->pdev, "I2C transmission error\n");
+	}
+
+	if (!flags)
+		ast_software_i2c_read(ast, raw);
+
+	if (decode_edid(raw, sizeof(raw), edid) != EDID_CONFORMANT) {
+		dev_err(dev->pdev, "Failed to decode EDID\n");
+		printk(BIOS_DEBUG, "Assuming VGA for KVM\n");
+
+		memset(edid, 0, sizeof(*edid));
+
+		edid->mode.pixel_clock = 6411;
+		edid->mode.refresh = 60;
+		edid->mode.ha = 1024;
+		edid->mode.hspw = 4;
+		edid->mode.hso = 56;
+		edid->mode.hbl = 264;
+		edid->mode.phsync = '-';
+
+		edid->mode.va = 768;
+		edid->mode.vspw = 3;
+		edid->mode.vso = 1;
+		edid->mode.vbl = 26;
+		edid->mode.pvsync = '+';
+	}
+
+	printk(BIOS_DEBUG, "AST: Display has %dpx x %dpx\n", edid->mode.ha, edid->mode.va);
+
+	widescreen = !!(((edid->mode.ha * 4) % (edid->mode.va * 3)));
+
+	while (ast_mode_valid(connector, edid->mode.ha, edid->mode.va) != MODE_OK) {
+		/* Select a compatible smaller mode */
+		if (edid->mode.ha > 1920 && widescreen) {
+			edid->mode.ha = 1920;
+			edid->mode.va = 1080;
+		} else if (edid->mode.ha >= 1920 && widescreen) {
+			edid->mode.ha = 1680;
+			edid->mode.va = 1050;
+		} else if (edid->mode.ha >= 1680 && widescreen) {
+			edid->mode.ha = 1600;
+			edid->mode.va = 900;
+		} else if (edid->mode.ha >= 1680 && !widescreen) {
+			edid->mode.ha = 1600;
+			edid->mode.va = 1200;
+		} else if (edid->mode.ha >= 1600 && widescreen) {
+			edid->mode.ha = 1440;
+			edid->mode.va = 900;
+		} else if (edid->mode.ha >= 1440 && widescreen) {
+			edid->mode.ha = 1360;
+			edid->mode.va = 768;
+		} else if (edid->mode.ha >= 1360 && widescreen) {
+			edid->mode.ha = 1280;
+			edid->mode.va = 800;
+		} else if (edid->mode.ha >= 1360 && !widescreen) {
+			edid->mode.ha = 1280;
+			edid->mode.va = 1024;
+		} else if (edid->mode.ha >= 1280) {
+			edid->mode.ha = 1024;
+			edid->mode.va = 768;
+		} else if (edid->mode.ha >= 1024) {
+			edid->mode.ha = 800;
+			edid->mode.va = 600;
+		} else if (edid->mode.ha >= 800) {
+			edid->mode.ha = 640;
+			edid->mode.va = 480;
+		} else {
+			dev_err(dev->pdev, "No compatible mode found.\n");
+
+			return -EIO;
+		}
+	};
+
+	return 0;
+}
+
+int ast_driver_framebuffer_init(struct drm_device *dev, int flags)
+{
+	struct drm_display_mode adjusted_mode;
+	struct drm_crtc crtc;
+	struct drm_format format;
+	struct drm_primary primary;
+	struct drm_framebuffer fb;
+	struct drm_connector connector;
+	struct edid edid;
+	int ret;
+
+	/* Init wrapper structs */
+	connector.dev = dev;
+
+	format.cpp[0] = 4; /* 32 BPP */
+	fb.format = &format;
+
+	primary.fb = &fb;
+
+	crtc.dev = dev;
+	crtc.primary = &primary;
+
+	/* Read EDID and find mode */
+	ret = ast_select_mode(&connector, &edid);
+	if (ret) {
+		dev_err(dev->pdev, "Failed to select mode.\n");
+		return ret;
+	}
+
+	/* Updated edid for set_vbe_mode_info_valid */
+	edid.x_resolution = edid.mode.ha;
+	edid.y_resolution = edid.mode.va;
+	edid.framebuffer_bits_per_pixel = format.cpp[0] * 8;
+	edid.bytes_per_line = ALIGN_UP(edid.x_resolution * format.cpp[0], 8);
+
+	/* Updated framebuffer info for ast_crtc_mode_set */
+	fb.pitches[0] = edid.bytes_per_line;
+
+	printk(BIOS_DEBUG, "Using framebuffer %dpx x %dpx pitch %d @ %d BPP\n",
+	       edid.x_resolution, edid.y_resolution, edid.bytes_per_line,
+	       edid.framebuffer_bits_per_pixel);
+
+	/* Convert EDID to AST DRM mode */
+	ast_edid_to_drmmode(&edid, &crtc.mode);
+
+	memcpy(&adjusted_mode, &crtc.mode, sizeof(crtc.mode));
+
+	ret = ast_crtc_mode_set(&crtc, &crtc.mode, &adjusted_mode);
+	if (ret) {
+		dev_err(dev->pdev, "Failed to set mode.\n");
+		return ret;
+	}
+
+	ast_hide_cursor(&crtc);
+
+	/* Advertise new mode */
+	set_vbe_mode_info_valid(&edid, fb.mmio_addr);
+
+	/* Clear display */
+	memset((void *)fb.mmio_addr, 0, edid.bytes_per_line * edid.y_resolution);
+
+	return 0;
+}