[U-Boot] [PATCH v2 1/2] sunxi: video: Add lcd output support

Siarhei Siamashka siarhei.siamashka at gmail.com
Thu Jan 1 21:21:51 CET 2015


On Wed, 31 Dec 2014 13:07:20 +0100
Hans de Goede <hdegoede at redhat.com> wrote:

> Add lcd output support, see the new Kconfig entries and doc/README.video for
> how to enable / configure this.
> 
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
> Changes in v2:
> -Do not request backlight gpio twices
> -Fix some spelling errors in comments
> -Fix some no longer accurate comments
> ---
>  arch/arm/include/asm/arch-sunxi/display.h |  25 ++++-
>  arch/arm/include/asm/arch-sunxi/gpio.h    |   2 +
>  board/sunxi/Kconfig                       |  43 ++++++-
>  doc/README.video                          |  50 +++++++--
>  drivers/video/sunxi_display.c             | 179 ++++++++++++++++++++++++++++--
>  5 files changed, 272 insertions(+), 27 deletions(-)
> 
> diff --git a/arch/arm/include/asm/arch-sunxi/display.h b/arch/arm/include/asm/arch-sunxi/display.h
> index 00e3466..dcb2fe4 100644
> --- a/arch/arm/include/asm/arch-sunxi/display.h
> +++ b/arch/arm/include/asm/arch-sunxi/display.h
> @@ -57,14 +57,13 @@ struct sunxi_lcdc_reg {
>  	u32 int0;			/* 0x04 */
>  	u32 int1;			/* 0x08 */
>  	u8 res0[0x04];			/* 0x0c */
> -	u32 frame_ctrl;			/* 0x10 */
> -	u8 res1[0x2c];			/* 0x14 */
> +	u32 frame_ctrl[12];		/* 0x10 */
>  	u32 tcon0_ctrl;			/* 0x40 */
>  	u32 tcon0_dclk;			/* 0x44 */
> -	u32 tcon0_basic_timing0;	/* 0x48 */
> -	u32 tcon0_basic_timing1;	/* 0x4c */
> -	u32 tcon0_basic_timing2;	/* 0x50 */
> -	u32 tcon0_basic_timing3;	/* 0x54 */
> +	u32 tcon0_timing_active;	/* 0x48 */
> +	u32 tcon0_timing_h;		/* 0x4c */
> +	u32 tcon0_timing_v;		/* 0x50 */
> +	u32 tcon0_timing_sync;		/* 0x54 */
>  	u32 tcon0_hv_intf;		/* 0x58 */
>  	u8 res2[0x04];			/* 0x5c */
>  	u32 tcon0_cpu_intf;		/* 0x60 */
> @@ -179,7 +178,21 @@ struct sunxi_hdmi_reg {
>  #define SUNXI_LCDC_CTRL_IO_MAP_TCON0		(0 << 0)
>  #define SUNXI_LCDC_CTRL_IO_MAP_TCON1		(1 << 0)
>  #define SUNXI_LCDC_CTRL_TCON_ENABLE		(1 << 31)
> +#define SUNXI_LCDC_FRAME_CTRL0_RGB666		((1 << 31) | (0 << 4))
> +#define SUNXI_LCDC_FRAME_CTRL0_RGB656		((1 << 31) | (5 << 4))

This would be probably SUNXI_LCDC_FRAME_CTRL0_RGB565 according to
the Allwinner documentation of the TCON0_FRM_CTL_REG register:

 0: 6bit frm output
 1: 5bit frm output

Since we have 5 there (101 bit pattern), it simply means RGB565.

> +#define SUNXI_LCDC_FRAME_CTRL_DITHER0		0x11111111
> +#define SUNXI_LCDC_FRAME_CTRL_DITHER1		0x01010000
> +#define SUNXI_LCDC_FRAME_CTRL_DITHER2		0x15151111
> +#define SUNXI_LCDC_FRAME_CTRL_DITHER3		0x57575555
> +#define SUNXI_LCDC_FRAME_CTRL_DITHER4		0x7f7f7777
> +#define SUNXI_LCDC_TCON0_CTRL_CLK_DELAY(n)	(((n) & 0x1f) << 4)
> +#define SUNXI_LCDC_TCON0_CTRL_ENABLE		(1 << 31)
> +#define SUNXI_LCDC_TCON0_DCLK_DIV(n)		((n) << 0)
>  #define SUNXI_LCDC_TCON0_DCLK_ENABLE		(0xf << 28)
> +#define SUNXI_LCDC_TCON0_TIMING_H_BP(n)		(((n) - 1) << 0)
> +#define SUNXI_LCDC_TCON0_TIMING_H_TOTAL(n)	(((n) - 1) << 16)
> +#define SUNXI_LCDC_TCON0_TIMING_V_BP(n)		(((n) - 1) << 0)
> +#define SUNXI_LCDC_TCON0_TIMING_V_TOTAL(n)	(((n) * 2) << 16)
>  #define SUNXI_LCDC_TCON1_CTRL_CLK_DELAY(n)	(((n) & 0x1f) << 4)
>  #define SUNXI_LCDC_TCON1_CTRL_ENABLE		(1 << 31)
>  #define SUNXI_LCDC_TCON1_TIMING_H_BP(n)		(((n) - 1) << 0)
> diff --git a/arch/arm/include/asm/arch-sunxi/gpio.h b/arch/arm/include/asm/arch-sunxi/gpio.h
> index 32941cb..9438f5a 100644
> --- a/arch/arm/include/asm/arch-sunxi/gpio.h
> +++ b/arch/arm/include/asm/arch-sunxi/gpio.h
> @@ -150,6 +150,8 @@ enum sunxi_gpio_number {
>  
>  #define SUNXI_GPC6_SDC2		3
>  
> +#define SUNXI_GPD0_LCD0		2
> +
>  #define SUNXI_GPF0_SDC0		2
>  
>  #define SUNXI_GPF2_SDC0		2
> diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
> index 72c0165..6f2377d 100644
> --- a/board/sunxi/Kconfig
> +++ b/board/sunxi/Kconfig
> @@ -281,17 +281,52 @@ config USB2_VBUS_PIN
>  	See USB1_VBUS_PIN help text.
>  
>  config VIDEO
> -	boolean "Enable graphical uboot console on HDMI"
> +	boolean "Enable graphical uboot console on HDMI, LCD or VGA"
>  	default y
>  	---help---
> -	Say Y here to add support for using a cfb console on the HDMI output
> -	found on most sunxi devices.
> +	Say Y here to add support for using a cfb console on the HDMI, LCD
> +	or VGA output found on most sunxi devices. See doc/README.video for
> +	info on how to select the video output and mode.
> +
> +config VIDEO_LCD_MODE
> +	string "LCD panel timing details"
> +	depends on VIDEO
> +	default ""
> +	---help---
> +	LCD panel timing details string, leave empty if there is no LCD panel.
> +	This is in drivers/video/videomodes.c: video_get_params() format, e.g.
> +	x:800,y:480,depth:18,pclk_khz:33000,le:16,ri:209,up:22,lo:22,hs:30,vs:1,sync:0,vmode:0
> +
> +config VIDEO_LCD_POWER
> +	string "LCD panel power enable pin"
> +	depends on VIDEO
> +	default ""
> +	---help---
> +	Set the power enable pin for the LCD panel. This takes a string in the
> +	format understood by sunxi_name_to_gpio, e.g. PH1 for pin 1 of port H.
> +
> +config VIDEO_LCD_BL_EN
> +	string "LCD panel backlight enable pin"
> +	depends on VIDEO
> +	default ""
> +	---help---
> +	Set the backlight enable pin for the LCD panel. This takes a string in the
> +	the format understood by sunxi_name_to_gpio, e.g. PH1 for pin 1 of
> +	port H.
> +
> +config VIDEO_LCD_BL_PWM
> +	string "LCD panel backlight pwm pin"
> +	depends on VIDEO
> +	default ""
> +	---help---
> +	Set the backlight pwm pin for the LCD panel. This takes a string in the
> +	format understood by sunxi_name_to_gpio, e.g. PH1 for pin 1 of port H.
>  
>  config USB_KEYBOARD
>  	boolean "Enable USB keyboard support"
>  	default y
>  	---help---
>  	Say Y here to add support for using a USB keyboard (typically used
> -	in combination with a graphical console on HDMI).
> +	in combination with a graphical console).
>  
>  endif
> diff --git a/doc/README.video b/doc/README.video
> index dadbfcd..cfe6318 100644
> --- a/doc/README.video
> +++ b/doc/README.video
> @@ -5,15 +5,8 @@
>   * SPDX-License-Identifier:	GPL-2.0+
>   */
>  
> -U-Boot MPC8xx video controller driver
> -======================================
> -
> -The driver has been tested with the following configurations:
> -
> -- MPC823FADS with AD7176 on a PAL TV (YCbYCr)	- arsenio at tin.it
> -
>  "video-mode" environment variable
> -===============================
> +=================================
>  
>  The 'video-mode' environment variable can be used to enable and configure
>  some video drivers.  The format matches the video= command-line option used
> @@ -28,4 +21,45 @@ for Linux:
>  	<freq>		The frequency (in Hz) to use.
>  	<options>	A comma-separated list of device-specific options
>  
> +
> +U-Boot MPC8xx video controller driver
> +=====================================
> +
> +The driver has been tested with the following configurations:
> +
> +- MPC823FADS with AD7176 on a PAL TV (YCbYCr)	- arsenio at tin.it
> +
>  Example: video-mode=fslfb:1280x1024-32 at 60,monitor=dvi
> +
> +
> +U-boot sunxi video controller driver
> +====================================
> +
> +U-boot supports hdmi and lcd output on Allwinner sunxi SoCs, lcd output
> +requires the CONFIG_VIDEO_LCD_MODE Kconfig value to be set.
> +
> +The sunxi u-boot driver supports the following video-mode options:
> +
> +- monitor=[none|dvi|hdmi|lcd] - Select the video output to use
> + none:     Disable video output.
> + dvi/hdmi: Selects output over the hdmi connector with dvi resp. hdmi output
> +           format, if edid is used the format is automatically selected.
> + lcd:      Selects video output to a LCD screen.
> + vga:      Selects bideo output over the VGA connector.
> + Defaults to monitor=dvi.
> +
> +- hpd=[0|1] - Enable use of the hdmi HotPlug Detect feature
> + 0: Disabled. Configure dvi/hdmi output even if no cable is detected
> + 1: Enabled. If a LCD has been configured fallback to the LCD when no cable is
> +    detected, if no LCD is configured, disable video ouput.
> + Defaults to hpd=1.
> +
> +- edid=[0|1] - Enable use of DDC + EDID to get monitor info
> + 0: Disabled.
> + 1: Enabled. If valid EDID info was read from the monitor the EDID info will
> +    overrides the xres, yres and refresh from the video-mode env. variable.
> + Defaults to edid=1.
> +
> +For example to always use the hdmi connector, even if no cable is inserted,
> +using edid info when available and otherwise initalizing it at 1024x768 at 60Hz,
> +use: video-mode=sunxi:1024x768-24 at 60,monitor=dvi,hpd=0,edid=1 .
> diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c
> index ad38f16..fee1474 100644
> --- a/drivers/video/sunxi_display.c
> +++ b/drivers/video/sunxi_display.c
> @@ -11,7 +11,9 @@
>  
>  #include <asm/arch/clock.h>
>  #include <asm/arch/display.h>
> +#include <asm/arch/gpio.h>
>  #include <asm/global_data.h>
> +#include <asm/gpio.h>
>  #include <asm/io.h>
>  #include <errno.h>
>  #include <fdtdec.h>
> @@ -34,6 +36,7 @@ struct sunxi_display {
>  	GraphicDevice graphic_device;
>  	bool enabled;
>  	enum sunxi_monitor monitor;
> +	unsigned int depth;
>  } sunxi_display;
>  
>  /*
> @@ -435,6 +438,133 @@ static void sunxi_lcdc_enable(void)
>  	setbits_le32(&lcdc->ctrl, SUNXI_LCDC_CTRL_TCON_ENABLE);
>  }
>  
> +static void sunxi_lcdc_panel_enable(void)
> +{
> +	int pin;
> +
> +	/*
> +	 * Start with backlight disabled to avoid the screen flashing to
> +	 * white while the lcd inits.
> +	 */
> +	pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_BL_EN);
> +	if (pin != -1) {
> +		gpio_request(pin, "lcd_backlight_enable");
> +		gpio_direction_output(pin, 0);
> +	}
> +
> +	pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_BL_PWM);
> +	if (pin != -1) {
> +		gpio_request(pin, "lcd_backlight_pwm");
> +		/* backlight pwm is inverted, set to 1 to disable backlight */
> +		gpio_direction_output(pin, 1);
> +	}
> +
> +	/* Give the backlight some time to turn off and power up the panel. */
> +	mdelay(40);
> +	pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_POWER);
> +	if (pin != -1) {
> +		gpio_request(pin, "lcd_power");
> +		gpio_direction_output(pin, 1);
> +	}
> +}
> +
> +static void sunxi_lcdc_backlight_enable(void)
> +{
> +	int pin;
> +
> +	/*
> +	 * We want to have scanned out at least one frame before enabling the
> +	 * backlight to avoid the screen flashing to white when we enable it.
> +	 */
> +	mdelay(40);
> +
> +	pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_BL_EN);
> +	if (pin != -1)
> +		gpio_direction_output(pin, 1);
> +
> +	pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_BL_PWM);
> +	if (pin != -1) {
> +		/* backlight pwm is inverted, set to 0 to enable backlight */
> +		gpio_direction_output(pin, 0);
> +	}
> +}
> +
> +static int sunxi_lcdc_get_clk_delay(const struct ctfb_res_modes *mode)
> +{
> +	int delay;
> +
> +	delay = mode->lower_margin + mode->vsync_len + mode->upper_margin - 2;
> +	return (delay > 30) ? 30 : delay;
> +}
> +
> +static void sunxi_lcdc_tcon0_mode_set(const struct ctfb_res_modes *mode)
> +{
> +	struct sunxi_lcdc_reg * const lcdc =
> +		(struct sunxi_lcdc_reg *)SUNXI_LCD0_BASE;
> +	int bp, clk_delay, clk_div, clk_double, pin, total;
> +
> +	for (pin = SUNXI_GPD(0); pin <= SUNXI_GPD(27); pin++)
> +		sunxi_gpio_set_cfgpin(pin, SUNXI_GPD0_LCD0);
> +
> +	sunxi_lcdc_pll_set(0, mode->pixclock_khz, &clk_div, &clk_double);
> +
> +	/* Use tcon0 */
> +	clrsetbits_le32(&lcdc->ctrl, SUNXI_LCDC_CTRL_IO_MAP_MASK,
> +			SUNXI_LCDC_CTRL_IO_MAP_TCON0);
> +
> +	clk_delay = sunxi_lcdc_get_clk_delay(mode);
> +	writel(SUNXI_LCDC_TCON0_CTRL_ENABLE |
> +	       SUNXI_LCDC_TCON0_CTRL_CLK_DELAY(clk_delay), &lcdc->tcon0_ctrl);
> +
> +	writel(SUNXI_LCDC_TCON0_DCLK_ENABLE |
> +	       SUNXI_LCDC_TCON0_DCLK_DIV(clk_div), &lcdc->tcon0_dclk);
> +
> +	writel(SUNXI_LCDC_X(mode->xres) | SUNXI_LCDC_Y(mode->yres),
> +	       &lcdc->tcon0_timing_active);
> +
> +	bp = mode->hsync_len + mode->left_margin;
> +	total = mode->xres + mode->right_margin + bp;
> +	writel(SUNXI_LCDC_TCON0_TIMING_H_TOTAL(total) |
> +	       SUNXI_LCDC_TCON0_TIMING_H_BP(bp), &lcdc->tcon0_timing_h);
> +
> +	bp = mode->vsync_len + mode->upper_margin;
> +	total = mode->yres + mode->lower_margin + bp;
> +	writel(SUNXI_LCDC_TCON0_TIMING_V_TOTAL(total) |
> +	       SUNXI_LCDC_TCON0_TIMING_V_BP(bp), &lcdc->tcon0_timing_v);
> +
> +	writel(SUNXI_LCDC_X(mode->hsync_len) | SUNXI_LCDC_Y(mode->vsync_len),
> +	       &lcdc->tcon0_timing_sync);
> +
> +	/* We only support hv-sync parallel lcd-s for now */
> +	writel(0, &lcdc->tcon0_hv_intf);
> +	writel(0, &lcdc->tcon0_cpu_intf);
> +
> +	if (sunxi_display.depth == 18 || sunxi_display.depth == 17) {

Here 17 is not quite correct for RGB565.

Also these are dithering settings, and this code just unconditionally
enables the right dithering for 16-bit LCD displays (this seems to
be never used in any real device from the sunxi-boards repository) or
18-bit LCD displays, which are very common.

Because 32-bit framebuffers support more colors than the 18-bit LCD
hardware can show, dithering is needed and used:
    http://en.wikipedia.org/wiki/Frame_rate_control

Do we want to have a separate option to enable/disable dithering? Or
just keep it always enabled until somebody complains?

A simple program for testing dithering effects/usefulness can be found
here:
    http://lists.denx.de/pipermail/u-boot/2015-January/200031.html

> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER0, &lcdc->frame_ctrl[1]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER0, &lcdc->frame_ctrl[2]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER0, &lcdc->frame_ctrl[3]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER0, &lcdc->frame_ctrl[4]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER0, &lcdc->frame_ctrl[5]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER0, &lcdc->frame_ctrl[6]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER1, &lcdc->frame_ctrl[7]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER2, &lcdc->frame_ctrl[8]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER3, &lcdc->frame_ctrl[9]);
> +		writel(SUNXI_LCDC_FRAME_CTRL_DITHER4, &lcdc->frame_ctrl[10]);
> +		writel(((sunxi_display.depth == 18) ?
> +			SUNXI_LCDC_FRAME_CTRL0_RGB666 :
> +			SUNXI_LCDC_FRAME_CTRL0_RGB656),
> +		       &lcdc->frame_ctrl[0]);
> +	}
> +
> +	/*
> +	 * Bit 24 and 25 of tcon0_io_polarity can be used to invert hsync /
> +	 * vsync polarity, but this leads to noise problems, so we always
> +	 * keep the polarity positive.
> +	 */
> +	writel(0, &lcdc->tcon0_io_polarity);
> +	writel(0, &lcdc->tcon0_io_tristate);
> +}
> +
>  static void sunxi_lcdc_tcon1_mode_set(const struct ctfb_res_modes *mode,
>  				      int *clk_div, int *clk_double)
>  {
> @@ -618,7 +748,12 @@ static void sunxi_mode_set(const struct ctfb_res_modes *mode,
>  		}
>  		break;
>  	case sunxi_monitor_lcd:
> -		/* TODO */
> +		sunxi_lcdc_panel_enable();
> +		sunxi_composer_mode_set(mode, address);
> +		sunxi_lcdc_tcon0_mode_set(mode);
> +		sunxi_composer_enable();
> +		sunxi_lcdc_enable();
> +		sunxi_lcdc_backlight_enable();
>  		break;
>  	case sunxi_monitor_vga:
>  		break;
> @@ -641,11 +776,11 @@ void *video_hw_init(void)
>  {
>  	static GraphicDevice *graphic_device = &sunxi_display.graphic_device;
>  	const struct ctfb_res_modes *mode;
> -	struct ctfb_res_modes edid_mode;
> +	struct ctfb_res_modes custom;
>  	const char *options;
> -	unsigned int depth;
>  	int i, ret, hpd, edid;
>  	char mon[16];
> +	char *lcd_mode = CONFIG_VIDEO_LCD_MODE;
>  
>  	memset(&sunxi_display, 0, sizeof(struct sunxi_display));
>  
> @@ -653,7 +788,8 @@ void *video_hw_init(void)
>  	       CONFIG_SUNXI_FB_SIZE >> 10);
>  	gd->fb_base = gd->ram_top;
>  
> -	video_get_ctfb_res_modes(RES_MODE_1024x768, 24, &mode, &depth, &options);
> +	video_get_ctfb_res_modes(RES_MODE_1024x768, 24, &mode,
> +				 &sunxi_display.depth, &options);
>  	hpd = video_get_option_int(options, "hpd", 1);
>  	edid = video_get_option_int(options, "edid", 1);
>  	sunxi_display.monitor = sunxi_monitor_dvi;
> @@ -678,16 +814,26 @@ void *video_hw_init(void)
>  		ret = sunxi_hdmi_hpd_detect();
>  		if (ret) {
>  			printf("HDMI connected: ");
> -			if (edid && sunxi_hdmi_edid_get_mode(&edid_mode) == 0)
> -				mode = &edid_mode;
> +			if (edid && sunxi_hdmi_edid_get_mode(&custom) == 0)
> +				mode = &custom;
>  			break;
>  		}
>  		if (!hpd)
>  			break; /* User has requested to ignore hpd */
>  
>  		sunxi_hdmi_shutdown();
> -		return NULL;
> +
> +		if (lcd_mode[0] == 0)
> +			return NULL; /* No LCD, bail */
> +
> +		/* Fall back / through to LCD */
> +		sunxi_display.monitor = sunxi_monitor_lcd;
>  	case sunxi_monitor_lcd:
> +		if (lcd_mode[0]) {
> +			sunxi_display.depth = video_get_params(&custom, lcd_mode);
> +			mode = &custom;
> +			break;
> +		}
>  		printf("LCD not supported on this board\n");
>  		return NULL;
>  	case sunxi_monitor_vga:
> @@ -729,16 +875,31 @@ int sunxi_simplefb_setup(void *blob)
>  {
>  	static GraphicDevice *graphic_device = &sunxi_display.graphic_device;
>  	int offset, ret;
> +	const char *pipeline = NULL;
>  
>  	if (!sunxi_display.enabled)
>  		return 0;
>  
> -	/* Find a framebuffer node, with pipeline == "de_be0-lcd0-hdmi" */
> +	switch (sunxi_display.monitor) {
> +	case sunxi_monitor_none:
> +		return 0;
> +	case sunxi_monitor_dvi:
> +	case sunxi_monitor_hdmi:
> +		pipeline = "de_be0-lcd0-hdmi";
> +		break;
> +	case sunxi_monitor_lcd:
> +		pipeline = "de_be0-lcd0";
> +		break;
> +	case sunxi_monitor_vga:
> +		break;
> +	}
> +
> +	/* Find a prefilled simpefb node, matching out pipeline config */
>  	offset = fdt_node_offset_by_compatible(blob, -1,
>  					       "allwinner,simple-framebuffer");
>  	while (offset >= 0) {
>  		ret = fdt_find_string(blob, offset, "allwinner,pipeline",
> -				      "de_be0-lcd0-hdmi");
> +				      pipeline);
>  		if (ret == 0)
>  			break;
>  		offset = fdt_node_offset_by_compatible(blob, offset,



-- 
Best regards,
Siarhei Siamashka


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