[U-Boot] [PATCH v2 10/19] tegra: Add LCD driver

[Simon Glass <sjg@chromium.org>]

This driver supports driving a single LCD and providing a U-Boot console
on it.

Signed-off-by: Simon Glass <sjg@chromium.org>
---
Changes in v2:
- Update LCD driver to deal with new fdt bindings

 drivers/video/Makefile |    1 +
 drivers/video/tegra.c  |  383 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/fdtdec.h       |    1 +
 lib/fdtdec.c           |    1 +
 4 files changed, 386 insertions(+), 0 deletions(-)
 create mode 100644 drivers/video/tegra.c

diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 4fad20d..d7518c4 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -46,6 +46,7 @@ COBJS-$(CONFIG_VIDEO_OMAP3) += omap3_dss.o videomodes.o
 COBJS-$(CONFIG_VIDEO_SED13806) += sed13806.o
 COBJS-$(CONFIG_VIDEO_SM501) += sm501.o
 COBJS-$(CONFIG_VIDEO_SMI_LYNXEM) += smiLynxEM.o videomodes.o
+COBJS-$(CONFIG_VIDEO_TEGRA) += tegra.o
 COBJS-$(CONFIG_VIDEO_VCXK) += bus_vcxk.o
 
 COBJS	:= $(sort $(COBJS-y))
diff --git a/drivers/video/tegra.c b/drivers/video/tegra.c
new file mode 100644
index 0000000..12518b2
--- /dev/null
+++ b/drivers/video/tegra.c
@@ -0,0 +1,383 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <lcd.h>
+
+#include <asm/system.h>
+#include <asm/gpio.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch/funcmux.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/pwfm.h>
+#include <asm/arch/display.h>
+#include <asm/arch/timer.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* These are the stages we go throuh in enabling the LCD */
+enum stage_t {
+	STAGE_START,
+	STAGE_LVDS,
+	STAGE_BACKLIGHT_VDD,
+	STAGE_PWFM,
+	STAGE_BACKLIGHT_EN,
+	STAGE_DONE,
+};
+
+static enum stage_t stage;	/* Current stage we are at */
+static unsigned long timer_next; /* Time we can move onto next stage */
+static struct fdt_lcd config;	/* Our LCD config, set up in handle_stage() */
+
+enum {
+	/* Maximum LCD size we support */
+	LCD_MAX_WIDTH		= 1366,
+	LCD_MAX_HEIGHT		= 768,
+	LCD_MAX_LOG2_BPP	= 4,		/* 2^4 = 16 bpp */
+};
+
+int lcd_line_length;
+int lcd_color_fg;
+int lcd_color_bg;
+
+void *lcd_base;			/* Start of framebuffer memory	*/
+void *lcd_console_address;	/* Start of console buffer	*/
+
+short console_col;
+short console_row;
+
+vidinfo_t panel_info = {
+	/* Insert a value here so that we don't end up in the BSS */
+	.vl_col = -1,
+};
+
+char lcd_cursor_enabled;
+
+ushort lcd_cursor_width;
+ushort lcd_cursor_height;
+
+#ifndef CONFIG_OF_CONTROL
+#error "You must enable CONFIG_OF_CONTROL to get Tegra LCD support"
+#endif
+
+void lcd_cursor_size(ushort width, ushort height)
+{
+	lcd_cursor_width = width;
+	lcd_cursor_height = height;
+}
+
+void lcd_toggle_cursor(void)
+{
+	ushort x, y;
+	uchar *dest;
+	ushort row;
+
+	x = console_col * lcd_cursor_width;
+	y = console_row * lcd_cursor_height;
+	dest = (uchar *)(lcd_base + y * lcd_line_length + x * (1 << LCD_BPP) /
+			8);
+
+	for (row = 0; row < lcd_cursor_height; ++row, dest += lcd_line_length) {
+		ushort *d = (ushort *)dest;
+		ushort color;
+		int i;
+
+		for (i = 0; i < lcd_cursor_width; ++i) {
+			color = *d;
+			color ^= lcd_color_fg;
+			*d = color;
+			++d;
+		}
+	}
+}
+
+void lcd_cursor_on(void)
+{
+	lcd_cursor_enabled = 1;
+	lcd_toggle_cursor();
+}
+void lcd_cursor_off(void)
+{
+	lcd_cursor_enabled = 0;
+	lcd_toggle_cursor();
+}
+
+char lcd_is_cursor_enabled(void)
+{
+	return lcd_cursor_enabled;
+}
+
+static void update_panel_size(struct fdt_lcd *config)
+{
+	panel_info.vl_col = config->width;
+	panel_info.vl_row = config->height;
+	panel_info.vl_bpix = config->log2_bpp;
+}
+
+/*
+ *  Main init function called by lcd driver.
+ *  Inits and then prints test pattern if required.
+ */
+
+void lcd_ctrl_init(void *lcdbase)
+{
+	int line_length, size;
+
+	/*
+	 * The framebuffer address should be specified in the device tree.
+	 * This FDT value should be the same as the one defined in Linux kernel;
+	 * otherwise, it causes screen flicker. The FDT value overrides the
+	 * framebuffer allocated at the top of memory by board_init_f().
+	 *
+	 * If the framebuffer address is not defined in the FDT, falls back to
+	 * use the address allocated by board_init_f().
+	 */
+	if (config.frame_buffer != FDT_ADDR_T_NONE) {
+		gd->fb_base = config.frame_buffer;
+		lcd_base = (void *)(gd->fb_base);
+	} else {
+		config.frame_buffer = (u32)lcd_base;
+	}
+
+	/* Make sure that we can acommodate the selected LCD */
+	assert(config.width <= LCD_MAX_WIDTH);
+	assert(config.height <= LCD_MAX_HEIGHT);
+	assert(config.log2_bpp <= LCD_MAX_LOG2_BPP);
+	if (config.width <= LCD_MAX_WIDTH && config.height <= LCD_MAX_HEIGHT &&
+			config.log2_bpp <= LCD_MAX_LOG2_BPP)
+		update_panel_size(&config);
+	size = lcd_get_size(&line_length);
+
+	/* Initialize the Tegra display controller */
+	if (tegra2_display_register(&config)) {
+		printf("%s: Failed to register with display driver\n",
+		       __func__);
+		return;
+	}
+
+	debug("LCD frame buffer@%p\n", lcd_base);
+}
+
+ulong calc_fbsize(void)
+{
+	return (panel_info.vl_col * panel_info.vl_row *
+		NBITS(panel_info.vl_bpix)) / 8;
+}
+
+void lcd_setcolreg(ushort regno, ushort red, ushort green, ushort blue)
+{
+}
+
+void tegra_lcd_early_init(const void *blob)
+{
+	/*
+	 * Go with the maximum size for now. We will fix this up after
+	 * relocation. These values are only used for memory alocation.
+	 */
+	panel_info.vl_col = LCD_MAX_WIDTH;
+	panel_info.vl_row = LCD_MAX_HEIGHT;
+	panel_info.vl_bpix = LCD_MAX_LOG2_BPP;
+}
+
+int fdt_decode_lcd(const void *blob, struct fdt_lcd *config)
+{
+	int err, bpp, bit;
+	int lcd_node, display_node;
+
+	display_node = fdtdec_next_compatible(gd->fdt_blob, 0,
+				      COMPAT_NVIDIA_TEGRA20_DISPLAY);
+	if (display_node < 0)
+		return display_node;
+
+	lcd_node = fdt_next_node(blob, display_node, NULL);
+	if (lcd_node < 0)
+		return lcd_node;
+
+	config->width = fdtdec_get_int(blob, lcd_node, "nvidia,width", -1);
+	config->height = fdtdec_get_int(blob, lcd_node, "nvidia,height", -1);
+	bpp = fdtdec_get_int(blob, lcd_node, "nvidia,bits-per-pixel", -1);
+	bit = ffs(bpp) - 1;
+	if (bpp == (1 << bit))
+		config->log2_bpp = bit;
+	else
+		config->log2_bpp = bpp;
+	config->bpp = bpp;
+	config->pixel_clock = fdtdec_get_int(blob, lcd_node,
+					     "nvidia,pixel-clock", 0);
+	if (!config->pixel_clock || bpp == -1 ||
+			config->width == -1 || config->height == -1)
+		return -FDT_ERR_NOTFOUND;
+	err = fdtdec_get_int_array(blob, lcd_node, "nvidia,horiz-timing",
+			config->horiz_timing, FDT_LCD_TIMING_COUNT);
+	if (!err)
+		err = fdtdec_get_int_array(blob, lcd_node, "nvidia,vert-timing",
+				config->vert_timing, FDT_LCD_TIMING_COUNT);
+	if (err)
+		return err;
+
+	config->disp = (struct disp_ctlr *)fdtdec_get_addr(blob,
+						display_node, "reg");
+	config->pwfm = fdtdec_lookup_phandle_reg(blob, display_node,
+						 "nvidia,pwfm");
+	if ((fdt_addr_t)config->disp == FDT_ADDR_T_NONE ||
+			(fdt_addr_t)config->pwfm == FDT_ADDR_T_NONE)
+		return -1;
+	config->cache_type = fdtdec_get_int(blob, display_node,
+					    "nvidia,cache-type",
+					    FDT_LCD_CACHE_WRITE_BACK_FLUSH);
+	config->frame_buffer = fdtdec_get_addr(blob, display_node,
+					       "nvidia,frame-buffer");
+
+	err |= fdtdec_decode_gpio(blob, display_node,
+				  "nvidia,backlight-enable-gpios",
+				  &config->backlight_en);
+	err |= fdtdec_decode_gpio(blob, display_node,
+			"nvidia,lvds-shutdown-gpios", &config->lvds_shutdown);
+	fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-vdd-gpios",
+			   &config->backlight_vdd);
+	err |= fdtdec_decode_gpio(blob, display_node, "nvidia,panel-vdd-gpios",
+				  &config->panel_vdd);
+	if (err)
+		return -FDT_ERR_NOTFOUND;
+
+	return fdtdec_get_int_array(blob, display_node, "nvidia,panel-timings",
+			config->panel_timings, FDT_LCD_TIMINGS);
+}
+
+/**
+ * Handle the next stage of device init
+ */
+static int handle_stage(const void *blob)
+{
+	debug("%s: stage %d\n", __func__, stage);
+
+	/* do the things for this stage */
+	switch (stage) {
+	case STAGE_START:
+		/* get panel details */
+		if (fdt_decode_lcd(blob, &config)) {
+			printf("No LCD information in device tree\n");
+			return -1;
+		}
+
+		/*
+		 * It is possible that the FDT has requested that the LCD be
+		 * disabled. We currently don't support this. It would require
+		 * changes to U-Boot LCD subsystem to have LCD support
+		 * compiled in but not used. An easier option might be to
+		 * still have a frame buffer, but leave the backlight off and
+		 * remove all mention of lcd in the stdout environment
+		 * variable.
+		 */
+
+		funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT);
+
+		fdtdec_setup_gpio(&config.panel_vdd);
+		fdtdec_setup_gpio(&config.lvds_shutdown);
+		fdtdec_setup_gpio(&config.backlight_vdd);
+		fdtdec_setup_gpio(&config.backlight_en);
+
+		/*
+		 * TODO: If fdt includes output flag we can omit this code
+		 * since fdtdec_setup_gpio will do it for us.
+		 */
+		gpio_direction_output(config.panel_vdd.gpio, 1);
+		gpio_direction_output(config.lvds_shutdown.gpio, 0);
+		gpio_direction_output(config.backlight_vdd.gpio, 0);
+		gpio_direction_output(config.backlight_en.gpio, 0);
+		break;
+
+	case STAGE_LVDS:
+		gpio_set_value(config.lvds_shutdown.gpio, 1);
+		break;
+
+	case STAGE_BACKLIGHT_VDD:
+		if (fdt_gpio_isvalid(&config.backlight_vdd))
+			gpio_set_value(config.backlight_vdd.gpio, 1);
+		break;
+
+	case STAGE_PWFM:
+		/* Enable PWM at 15/16 high, 32768 Hz with divider 1 */
+		pinmux_set_func(PINGRP_GPU, PMUX_FUNC_PWM);
+		pinmux_tristate_disable(PINGRP_GPU);
+		pwfm_enable(config.pwfm, 32768, 0xdf, 1);
+		break;
+
+	case STAGE_BACKLIGHT_EN:
+		gpio_set_value(config.backlight_en.gpio, 1);
+		break;
+
+	case STAGE_DONE:
+		break;
+	}
+
+	/* set up timer for next stage */
+	timer_next = timer_get_us() + config.panel_timings[stage] * 1000;
+
+	/* move to next stage */
+	stage++;
+	return 0;
+}
+
+int tegra_lcd_check_next_stage(const void *blob, int wait)
+{
+	if (stage == STAGE_DONE)
+		return 0;
+
+	do {
+		/* wait if we need to */
+		debug("%s: stage %d\n", __func__, stage);
+		if (stage != STAGE_START) {
+			int delay = timer_next - timer_get_us();
+
+			if (delay > 0) {
+				if (wait)
+					udelay(delay);
+				else
+					return 0;
+			}
+		}
+
+		if (handle_stage(blob))
+			return -1;
+	} while (wait && stage != STAGE_DONE);
+	return 0;
+}
+
+void lcd_enable(void)
+{
+	/*
+	 * Backlight and power init will be done separately in
+	 * tegra_lcd_check_next_stage(), which should be called in
+	 * board_late_init().
+	 *
+	 * U-Boot code supports only colour depth, selected at compile time.
+	 * The device tree setting should match this. Otherwise the display
+	 * will not look right, and U-Boot may crash.
+	 */
+	if (config.log2_bpp != LCD_BPP) {
+		printf("%s: Error: LCD depth configured in FDT (%d = %dbpp)"
+			" must match setting of LCD_BPP (%d)\n", __func__,
+		       config.log2_bpp, config.bpp, LCD_BPP);
+	}
+}
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 627d077..c1aad5c 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -65,6 +65,7 @@ enum fdt_compat_id {
 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra2 memory controller */
 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra2 memory timing table */
 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra2 Keyboard */
+	COMPAT_NVIDIA_TEGRA20_DISPLAY,	/* Tegra 2 Display controller */
 
 	COMPAT_COUNT,
 };
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 8185d8f..2d68c17 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -43,6 +43,7 @@ static const char * const compat_names[COMPAT_COUNT] = {
 	COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"),
 	COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"),
 	COMPAT(NVIDIA_TEGRA20_KBC, "nvidia,tegra20-kbc"),
+	COMPAT(NVIDIA_TEGRA20_DISPLAY, "nvidia,tegra20-display"),
 };
 
 const char *fdtdec_get_compatible(enum fdt_compat_id id)
-- 
1.7.7.3