[U-Boot] [PATCH v4 07/16] tegra: Add LCD driver

[Marc Dietrich <marvin24@gmx.de>]

Simon,

I tried to adapt this for paz00. I only get backlight and an all white screen. 
On checking what's wrong I stumpled about something strange below...

Marc

On Thursday 27 September 2012 17:44:28 Simon Glass wrote:
> 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
> 
> Changes in v3:
> - Move some fdt decode code from LCD driver to SOC display driver
> - Rename fdt config structures
> - Use new pwm binding from pre-linux-next
> - Adjust LCD driver to use new SOC display driver structures
> 
> Changes in v4:
> - Rebase on top of new tegra common directory structure
> - Change LCD panel GPIOs to be entirely optional
> - Only indicate that LCD init is complete when all stages complete
> 
>  drivers/video/Makefile |    1 +
>  drivers/video/tegra.c  |  361
> ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 362
> insertions(+), 0 deletions(-)
>  create mode 100644 drivers/video/tegra.c
> 
> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
> index ebb6da8..78a7668 100644
> --- a/drivers/video/Makefile
> +++ b/drivers/video/Makefile
> @@ -49,6 +49,7 @@ COBJS-$(CONFIG_VIDEO_OMAP3) += omap3_dss.o
>  COBJS-$(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..9df2bd3
> --- /dev/null
> +++ b/drivers/video/tegra.c
> @@ -0,0 +1,361 @@
> +/*
> + * 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/pwm.h>
> +#include <asm/arch/display.h>
> +#include <asm/arch-tegra/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_PWM,
> +	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 */
> +
> +/* Our LCD config, set up in handle_stage() */
> +static struct fdt_panel_config config;
> +struct fdt_disp_config *disp_config;	/* Display controller config */
> +
> +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_disp_config *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;
> +
> +	assert(disp_config);
> +
> +	lcd_base = (void *)disp_config->frame_buffer;

this is always NULL, because it is defined in a circular manner (see 
arch/arm/cpu/armv7/tegra20/display.c:383) and ...

> +	/* Make sure that we can acommodate the selected LCD */
> +	assert(disp_config->width <= LCD_MAX_WIDTH);
> +	assert(disp_config->height <= LCD_MAX_HEIGHT);
> +	assert(disp_config->log2_bpp <= LCD_MAX_LOG2_BPP);
> +	if (disp_config->width <= LCD_MAX_WIDTH
> +			&& disp_config->height <= LCD_MAX_HEIGHT
> +			&& disp_config->log2_bpp <= LCD_MAX_LOG2_BPP)
> +		update_panel_size(disp_config);
> +	size = lcd_get_size(&line_length);
> +
> +	debug("LCD frame buffer at %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;
> +}
> +
> +/**
> + * Decode the panel information from the fdt.
> + *
> + * @param blob		fdt blob
> + * @param config	structure to store fdt config into
> + * @return 0 if ok, -ve on error
> + */
> +static int fdt_decode_lcd(const void *blob, struct fdt_panel_config
> *config) +{
> +	int display_node;
> +
> +	disp_config = tegra_display_get_config();
> +	if (!disp_config) {
> +		debug("%s: Display controller is not configured\n", __func__);
> +		return -1;
> +	}
> +	display_node = disp_config->panel_node;
> +	if (display_node < 0) {
> +		debug("%s: No panel configuration available\n", __func__);
> +		return -1;
> +	}
> +
> +	config->pwm_channel = pwm_request(blob, display_node, "nvidia,pwm");
> +	if (config->pwm_channel < 0) {
> +		debug("%s: Unable to request PWM channel\n", __func__);
> +		return -1;
> +	}
> +
> +	config->cache_type = fdtdec_get_int(blob, display_node,
> +					    "nvidia,cache-type",
> +					    FDT_LCD_CACHE_WRITE_BACK_FLUSH);
> +
> +	/* These GPIOs are all optional */
> +	fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-enable-gpios",
> +			    &config->backlight_en);
> +	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);
> +	fdtdec_decode_gpio(blob, display_node, "nvidia,panel-vdd-gpios",
> +			   &config->panel_vdd);
> +
> +	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:
> +		/* Initialize the Tegra display controller */
> +		if (tegra_display_probe(gd->fdt_blob, lcd_base)) {

.... here.

> +			printf("%s: Failed to probe display driver\n",
> +			__func__);
> +			return -1;
> +		}
> +
> +		/* get panel details */
> +		if (fdt_decode_lcd(blob, &config)) {
> +			printf("No valid 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.
> +		 */
> +		if (fdt_gpio_isvalid(&config.panel_vdd))
> +			gpio_direction_output(config.panel_vdd.gpio, 1);
> +		if (fdt_gpio_isvalid(&config.lvds_shutdown))
> +			gpio_direction_output(config.lvds_shutdown.gpio, 0);
> +		if (fdt_gpio_isvalid(&config.backlight_vdd))
> +			gpio_direction_output(config.backlight_vdd.gpio, 0);
> +		if (fdt_gpio_isvalid(&config.backlight_en))
> +			gpio_direction_output(config.backlight_en.gpio, 0);
> +		break;
> +	case STAGE_LVDS:
> +		if (fdt_gpio_isvalid(&config.lvds_shutdown))
> +			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_PWM:
> +		/* Enable PWM at 15/16 high, 32768 Hz with divider 1 */
> +		pinmux_set_func(PINGRP_GPU, PMUX_FUNC_PWM);
> +		pinmux_tristate_disable(PINGRP_GPU);
> +
> +		pwm_enable(config.pwm_channel, 32768, 0xdf, 1);
> +		break;
> +	case STAGE_BACKLIGHT_EN:
> +		if (fdt_gpio_isvalid(&config.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);
> +	if (stage == STAGE_DONE)
> +		debug("%s: LCD init complete\n", __func__);
> +
> +	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 (disp_config->log2_bpp != LCD_BPP) {
> +		printf("%s: Error: LCD depth configured in FDT (%d = %dbpp)"
> +			" must match setting of LCD_BPP (%d)\n", __func__,
> +		       disp_config->log2_bpp, disp_config->bpp, LCD_BPP);
> +	}
> +}