sunxi: video: Add cfb console driver for sunxi

This adds a fixed mode hdmi driver for the sunxi platform. The fixed
mode is a relatively safe 1024x768, more complete EDID handling is
currently not provided. Only HDMI is supported today.

This code is enabled when HPD detects an attached monitor.

Current config is such that 8MB is shaved off at the top of the RAM.
This avoids several memory handling issues, most significant is the fact
that on linux on ARM you are not allowed to remap known RAM as IO. A
clued in display driver will be able to recycle this reserved RAM in
future though.

cfbconsole was chosen as it provides the most important functionality: a
working u-boot console, allowing for the debugging of certain issues
without the need for a UART.

Signed-off-by: Luc Verhaegen <libv@skynet.be>
[hdegoede@redhat.com: Major cleanups and some small bugfixes]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

2 files changed, 381 insertions, 0 deletions

diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 14a6781..7301be3 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_VIDEO_SANDBOX_SDL) += sandbox_sdl.o
 obj-$(CONFIG_VIDEO_SED13806) += sed13806.o
 obj-$(CONFIG_VIDEO_SM501) += sm501.o
 obj-$(CONFIG_VIDEO_SMI_LYNXEM) += smiLynxEM.o videomodes.o
+obj-$(CONFIG_VIDEO_SUNXI) += sunxi_display.o
 obj-$(CONFIG_VIDEO_TEGRA) += tegra.o
 obj-$(CONFIG_VIDEO_VCXK) += bus_vcxk.o
 obj-$(CONFIG_FORMIKE) += formike.o
diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c
new file mode 100644
index 0000000..82229d7
--- /dev/null
+++ b/drivers/video/sunxi_display.c
@@ -0,0 +1,380 @@
+/*
+ * Display driver for Allwinner SoCs.
+ *
+ * (C) Copyright 2013-2014 Luc Verhaegen <libv@skynet.be>
+ * (C) Copyright 2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch/display.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+#include <linux/fb.h>
+#include <video_fb.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sunxi_display {
+	GraphicDevice graphic_device;
+	bool enabled;
+} sunxi_display;
+
+static int sunxi_hdmi_hpd_detect(void)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	struct sunxi_hdmi_reg * const hdmi =
+		(struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE;
+
+	/* Set pll3 to 300MHz */
+	clock_set_pll3(300000000);
+
+	/* Set hdmi parent to pll3 */
+	clrsetbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_PLL_MASK,
+			CCM_HDMI_CTRL_PLL3);
+
+	/* Set ahb gating to pass */
+	setbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_HDMI);
+
+	/* Clock on */
+	setbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_GATE);
+
+	writel(SUNXI_HDMI_CTRL_ENABLE, &hdmi->ctrl);
+	writel(SUNXI_HDMI_PAD_CTRL0_HDP, &hdmi->pad_ctrl0);
+
+	udelay(1000);
+
+	if (readl(&hdmi->hpd) & SUNXI_HDMI_HPD_DETECT)
+		return 1;
+
+	/* No need to keep these running */
+	clrbits_le32(&hdmi->ctrl, SUNXI_HDMI_CTRL_ENABLE);
+	clrbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_GATE);
+	clrbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_HDMI);
+	clock_set_pll3(0);
+
+	return 0;
+}
+
+/*
+ * This is the entity that mixes and matches the different layers and inputs.
+ * Allwinner calls it the back-end, but i like composer better.
+ */
+static void sunxi_composer_init(void)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	struct sunxi_de_be_reg * const de_be =
+		(struct sunxi_de_be_reg *)SUNXI_DE_BE0_BASE;
+	int i;
+
+	/* Clocks on */
+	setbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_DE_BE0);
+	setbits_le32(&ccm->dram_clk_gate, 1 << CCM_DRAM_GATE_OFFSET_DE_BE0);
+	clock_set_de_mod_clock(&ccm->be0_clk_cfg, 300000000);
+
+	/* Engine bug, clear registers after reset */
+	for (i = 0x0800; i < 0x1000; i += 4)
+		writel(0, SUNXI_DE_BE0_BASE + i);
+
+	setbits_le32(&de_be->mode, SUNXI_DE_BE_MODE_ENABLE);
+}
+
+static void sunxi_composer_mode_set(struct fb_videomode *mode,
+				    unsigned int address)
+{
+	struct sunxi_de_be_reg * const de_be =
+		(struct sunxi_de_be_reg *)SUNXI_DE_BE0_BASE;
+
+	writel(SUNXI_DE_BE_HEIGHT(mode->yres) | SUNXI_DE_BE_WIDTH(mode->xres),
+	       &de_be->disp_size);
+	writel(SUNXI_DE_BE_HEIGHT(mode->yres) | SUNXI_DE_BE_WIDTH(mode->xres),
+	       &de_be->layer0_size);
+	writel(SUNXI_DE_BE_LAYER_STRIDE(mode->xres), &de_be->layer0_stride);
+	writel(address << 3, &de_be->layer0_addr_low32b);
+	writel(address >> 29, &de_be->layer0_addr_high4b);
+	writel(SUNXI_DE_BE_LAYER_ATTR1_FMT_XRGB8888, &de_be->layer0_attr1_ctrl);
+
+	setbits_le32(&de_be->mode, SUNXI_DE_BE_MODE_LAYER0_ENABLE);
+}
+
+/*
+ * LCDC, what allwinner calls a CRTC, so timing controller and serializer.
+ */
+static void sunxi_lcdc_pll_set(int dotclock, int *clk_div, int *clk_double)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	int value, n, m, diff;
+	int best_n = 0, best_m = 0, best_diff = 0x0FFFFFFF;
+	int best_double = 0;
+
+	/*
+	 * Find the lowest divider resulting in a matching clock, if there
+	 * is no match, pick the closest lower clock, as monitors tend to
+	 * not sync to higher frequencies.
+	 */
+	for (m = 15; m > 0; m--) {
+		n = (m * dotclock) / 3000;
+
+		if ((n >= 9) && (n <= 127)) {
+			value = (3000 * n) / m;
+			diff = dotclock - value;
+			if (diff < best_diff) {
+				best_diff = diff;
+				best_m = m;
+				best_n = n;
+				best_double = 0;
+			}
+		}
+
+		/* These are just duplicates */
+		if (!(m & 1))
+			continue;
+
+		n = (m * dotclock) / 6000;
+		if ((n >= 9) && (n <= 127)) {
+			value = (6000 * n) / m;
+			diff = dotclock - value;
+			if (diff < best_diff) {
+				best_diff = diff;
+				best_m = m;
+				best_n = n;
+				best_double = 1;
+			}
+		}
+	}
+
+	debug("dotclock: %dkHz = %dkHz: (%d * 3MHz * %d) / %d\n",
+	      dotclock, (best_double + 1) * 3000 * best_n / best_m,
+	      best_double + 1, best_n, best_m);
+
+	clock_set_pll3(best_n * 3000000);
+
+	writel(CCM_LCD_CH1_CTRL_GATE |
+	    (best_double ? CCM_LCD_CH1_CTRL_PLL3_2X : CCM_LCD_CH1_CTRL_PLL3) |
+	    CCM_LCD_CH1_CTRL_M(best_m), &ccm->lcd0_ch1_clk_cfg);
+
+	*clk_div = best_m;
+	*clk_double = best_double;
+}
+
+static void sunxi_lcdc_init(void)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	struct sunxi_lcdc_reg * const lcdc =
+		(struct sunxi_lcdc_reg *)SUNXI_LCD0_BASE;
+
+	/* Reset off */
+	setbits_le32(&ccm->lcd0_ch0_clk_cfg, CCM_LCD_CH0_CTRL_RST);
+
+	/* Clock on */
+	setbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_LCD0);
+
+	/* Init lcdc */
+	writel(0, &lcdc->ctrl); /* Disable tcon */
+	writel(0, &lcdc->int0); /* Disable all interrupts */
+
+	/* Disable tcon0 dot clock */
+	clrbits_le32(&lcdc->tcon0_dclk, SUNXI_LCDC_TCON0_DCLK_ENABLE);
+
+	/* Set all io lines to tristate */
+	writel(0xffffffff, &lcdc->tcon0_io_tristate);
+	writel(0xffffffff, &lcdc->tcon1_io_tristate);
+}
+
+static void sunxi_lcdc_mode_set(struct fb_videomode *mode,
+				int *clk_div, int *clk_double)
+{
+	struct sunxi_lcdc_reg * const lcdc =
+		(struct sunxi_lcdc_reg *)SUNXI_LCD0_BASE;
+	int bp, total;
+
+	/* Use tcon1 */
+	clrsetbits_le32(&lcdc->ctrl, SUNXI_LCDC_CTRL_IO_MAP_MASK,
+			SUNXI_LCDC_CTRL_IO_MAP_TCON1);
+
+	/* Enabled, 0x1e start delay */
+	writel(SUNXI_LCDC_TCON1_CTRL_ENABLE |
+	       SUNXI_LCDC_TCON1_CTRL_CLK_DELAY(0x1e), &lcdc->tcon1_ctrl);
+
+	writel(SUNXI_LCDC_X(mode->xres) | SUNXI_LCDC_Y(mode->yres),
+	       &lcdc->tcon1_timing_source);
+	writel(SUNXI_LCDC_X(mode->xres) | SUNXI_LCDC_Y(mode->yres),
+	       &lcdc->tcon1_timing_scale);
+	writel(SUNXI_LCDC_X(mode->xres) | SUNXI_LCDC_Y(mode->yres),
+	       &lcdc->tcon1_timing_out);
+
+	bp = mode->hsync_len + mode->left_margin;
+	total = mode->xres + mode->right_margin + bp;
+	writel(SUNXI_LCDC_TCON1_TIMING_H_TOTAL(total) |
+	       SUNXI_LCDC_TCON1_TIMING_H_BP(bp), &lcdc->tcon1_timing_h);
+
+	bp = mode->vsync_len + mode->upper_margin;
+	total = mode->yres + mode->lower_margin + bp;
+	writel(SUNXI_LCDC_TCON1_TIMING_V_TOTAL(total) |
+	       SUNXI_LCDC_TCON1_TIMING_V_BP(bp), &lcdc->tcon1_timing_v);
+
+	writel(SUNXI_LCDC_X(mode->hsync_len) | SUNXI_LCDC_Y(mode->vsync_len),
+	       &lcdc->tcon1_timing_sync);
+
+	sunxi_lcdc_pll_set(mode->pixclock, clk_div, clk_double);
+}
+
+static void sunxi_hdmi_mode_set(struct fb_videomode *mode,
+				int clk_div, int clk_double)
+{
+	struct sunxi_hdmi_reg * const hdmi =
+		(struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE;
+	int x, y;
+
+	/* Write clear interrupt status bits */
+	writel(SUNXI_HDMI_IRQ_STATUS_BITS, &hdmi->irq);
+
+	/* Init various registers, select pll3 as clock source */
+	writel(SUNXI_HDMI_VIDEO_POL_TX_CLK, &hdmi->video_polarity);
+	writel(SUNXI_HDMI_PAD_CTRL0_RUN, &hdmi->pad_ctrl0);
+	writel(SUNXI_HDMI_PAD_CTRL1, &hdmi->pad_ctrl1);
+	writel(SUNXI_HDMI_PLL_CTRL, &hdmi->pll_ctrl);
+	writel(SUNXI_HDMI_PLL_DBG0_PLL3, &hdmi->pll_dbg0);
+
+	/* Setup clk div and doubler */
+	clrsetbits_le32(&hdmi->pll_ctrl, SUNXI_HDMI_PLL_CTRL_DIV_MASK,
+			SUNXI_HDMI_PLL_CTRL_DIV(clk_div));
+	if (!clk_double)
+		setbits_le32(&hdmi->pad_ctrl1, SUNXI_HDMI_PAD_CTRL1_HALVE);
+
+	/* Setup timing registers */
+	writel(SUNXI_HDMI_Y(mode->yres) | SUNXI_HDMI_X(mode->xres),
+	       &hdmi->video_size);
+
+	x = mode->hsync_len + mode->left_margin;
+	y = mode->vsync_len + mode->upper_margin;
+	writel(SUNXI_HDMI_Y(y) | SUNXI_HDMI_X(x), &hdmi->video_bp);
+
+	x = mode->right_margin;
+	y = mode->lower_margin;
+	writel(SUNXI_HDMI_Y(y) | SUNXI_HDMI_X(x), &hdmi->video_fp);
+
+	x = mode->hsync_len;
+	y = mode->vsync_len;
+	writel(SUNXI_HDMI_Y(y) | SUNXI_HDMI_X(x), &hdmi->video_spw);
+
+	if (mode->sync & FB_SYNC_HOR_HIGH_ACT)
+		setbits_le32(&hdmi->video_polarity, SUNXI_HDMI_VIDEO_POL_HOR);
+
+	if (mode->sync & FB_SYNC_VERT_HIGH_ACT)
+		setbits_le32(&hdmi->video_polarity, SUNXI_HDMI_VIDEO_POL_VER);
+}
+
+static void sunxi_engines_init(void)
+{
+	sunxi_composer_init();
+	sunxi_lcdc_init();
+}
+
+static void sunxi_mode_set(struct fb_videomode *mode, unsigned int address)
+{
+	struct sunxi_de_be_reg * const de_be =
+		(struct sunxi_de_be_reg *)SUNXI_DE_BE0_BASE;
+	struct sunxi_lcdc_reg * const lcdc =
+		(struct sunxi_lcdc_reg *)SUNXI_LCD0_BASE;
+	struct sunxi_hdmi_reg * const hdmi =
+		(struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE;
+	int clk_div, clk_double;
+	int retries = 3;
+
+retry:
+	clrbits_le32(&hdmi->video_ctrl, SUNXI_HDMI_VIDEO_CTRL_ENABLE);
+	clrbits_le32(&lcdc->ctrl, SUNXI_LCDC_CTRL_TCON_ENABLE);
+	clrbits_le32(&de_be->mode, SUNXI_DE_BE_MODE_START);
+
+	sunxi_composer_mode_set(mode, address);
+	sunxi_lcdc_mode_set(mode, &clk_div, &clk_double);
+	sunxi_hdmi_mode_set(mode, clk_div, clk_double);
+
+	setbits_le32(&de_be->reg_ctrl, SUNXI_DE_BE_REG_CTRL_LOAD_REGS);
+	setbits_le32(&de_be->mode, SUNXI_DE_BE_MODE_START);
+
+	udelay(1000000 / mode->refresh + 500);
+
+	setbits_le32(&lcdc->ctrl, SUNXI_LCDC_CTRL_TCON_ENABLE);
+
+	udelay(1000000 / mode->refresh + 500);
+
+	setbits_le32(&hdmi->video_ctrl, SUNXI_HDMI_VIDEO_CTRL_ENABLE);
+
+	udelay(1000000 / mode->refresh + 500);
+
+	/*
+	 * Sometimes the display pipeline does not sync up properly, if
+	 * this happens the hdmi fifo underrun or overrun bits are set.
+	 */
+	if (readl(&hdmi->irq) &
+	    (SUNXI_HDMI_IRQ_STATUS_FIFO_UF | SUNXI_HDMI_IRQ_STATUS_FIFO_OF)) {
+		if (retries--)
+			goto retry;
+		printf("HDMI fifo under or overrun\n");
+	}
+}
+
+void *video_hw_init(void)
+{
+	static GraphicDevice *graphic_device = &sunxi_display.graphic_device;
+	/*
+	 * Vesa standard 1024x768@60
+	 * 65.0  1024 1048 1184 1344  768 771 777 806  -hsync -vsync
+	 */
+	struct fb_videomode mode = {
+		.name = "1024x768",
+		.refresh = 60,
+		.xres = 1024,
+		.yres = 768,
+		.pixclock = 65000,
+		.left_margin = 160,
+		.right_margin = 24,
+		.upper_margin = 29,
+		.lower_margin = 3,
+		.hsync_len = 136,
+		.vsync_len = 6,
+		.sync = 0,
+		.vmode = 0,
+		.flag = 0,
+	};
+	int ret;
+
+	memset(&sunxi_display, 0, sizeof(struct sunxi_display));
+
+	printf("Reserved %dkB of RAM for Framebuffer.\n",
+	       CONFIG_SUNXI_FB_SIZE >> 10);
+	gd->fb_base = gd->ram_top;
+
+	ret = sunxi_hdmi_hpd_detect();
+	if (!ret)
+		return NULL;
+
+	printf("HDMI connected.\n");
+	sunxi_display.enabled = true;
+
+	printf("Setting up a %s console.\n", mode.name);
+	sunxi_engines_init();
+	sunxi_mode_set(&mode, gd->fb_base - CONFIG_SYS_SDRAM_BASE);
+
+	/*
+	 * These are the only members of this structure that are used. All the
+	 * others are driver specific. There is nothing to decribe pitch or
+	 * stride, but we are lucky with our hw.
+	 */
+	graphic_device->frameAdrs = gd->fb_base;
+	graphic_device->gdfIndex = GDF_32BIT_X888RGB;
+	graphic_device->gdfBytesPP = 4;
+	graphic_device->winSizeX = mode.xres;
+	graphic_device->winSizeY = mode.yres;
+
+	return graphic_device;
+}