[U-Boot] [PATCH 4/5] cm-t35: add support for user defined lcd parameters

[Jeroen Hofstee <jeroen@myspectrum.nl>]

On 12/23/2012 08:03 AM, Nikita Kiryanov wrote:
> Add support for user defined lcd parameters for cm-t35 splash screen.
>
> Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
> Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
> ---
>   board/cm_t35/display.c |  213 +++++++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 210 insertions(+), 3 deletions(-)
>
> diff --git a/board/cm_t35/display.c b/board/cm_t35/display.c
> index 11b8ed9..7b09bce 100644
> --- a/board/cm_t35/display.c
> +++ b/board/cm_t35/display.c
> @@ -3,6 +3,8 @@
>    *
>    * Authors: Nikita Kiryanov <nikita@compulab.co.il>
>    *
> + * Parsing code based on linux/drivers/video/pxafb.c
> + *
>    * See file CREDITS for list of people who contributed to this
>    * project.
>    *
> @@ -33,6 +35,7 @@ DECLARE_GLOBAL_DATA_PTR;
>   enum display_type {
>   	NONE,
>   	DVI,
> +	DVI_CUSTOM,
>   };
>   
>   /*
> @@ -138,6 +141,205 @@ static enum display_type set_dvi_preset(const struct panel_config preset,
>   }
>   
>   /*
> + * parse_mode() - parse the mode parameter of custom lcd settings
> + *
> + * @mode:	<res_x>x<res_y>
> + *
> + * Returns -1 on error, 0 on success.
> + */
> +static int parse_mode(const char *mode)
> +{
> +	unsigned int modelen = strlen(mode);
> +	int res_specified = 0;
> +	unsigned int xres = 0, yres = 0;
> +	int yres_specified = 0;
> +	int i;
> +
> +	for (i = modelen - 1; i >= 0; i--) {
> +		switch (mode[i]) {
> +		case 'x':
> +			if (!yres_specified) {
> +				yres = simple_strtoul(&mode[i + 1], NULL, 0);
> +				yres_specified = 1;
> +			} else {
> +				goto done_parsing;
> +			}
> +
> +			break;
> +		case '0' ... '9':
> +			break;
> +		default:
> +			goto done_parsing;
> +		}
> +	}
> +
> +	if (i < 0 && yres_specified) {
> +		xres = simple_strtoul(mode, NULL, 0);
> +		res_specified = 1;
> +	}
> +
> +done_parsing:
> +	if (res_specified) {
> +		set_resolution_params(xres, yres);
> +	} else {
> +		printf("LCD: invalid mode: %s\n", mode);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +#define PIXEL_CLK_NUMERATOR (26 * 432 / 39)
> +/*
> + * parse_pixclock() - Parse the pixclock parameter of custom lcd settings
> + *
> + * @pixclock:	the desired pixel clock
> + *
> + * Returns -1 on error, 0 on success.
> + *
> + * Handling the pixel_clock:
> + *
> + * Pixel clock is defined in the OMAP35x TRM as follows:
> + * pixel_clock =
> + * (SYS_CLK * 2 * PRCM.CM_CLKSEL2_PLL[18:8]) /
> + * (DSS.DISPC_DIVISOR[23:16] * DSS.DISPC_DIVISOR[6:0] *
> + * PRCM.CM_CLKSEL_DSS[4:0] * (PRCM.CM_CLKSEL2_PLL[6:0] + 1))
> + *
> + * In practice, this means that in order to set the
> + * divisor for the desired pixel clock one needs to
> + * solve the following equation:
> + *
> + * 26 * 432 / (39 * <pixel_clock>) = DSS.DISPC_DIVISOR[6:0]
> + *
> + * NOTE: the explicit equation above is reduced. Do not
> + * try to infer anything from these numbers.
> + */
> +static int parse_pixclock(char *pixclock)
> +{
> +	int divisor, pixclock_val;
> +	char *pixclk_start = pixclock;
> +
> +	pixclock_val = simple_strtoul(pixclock, &pixclock, 10);
> +	divisor = DIV_ROUND_UP(PIXEL_CLK_NUMERATOR, pixclock_val);
> +	/* 0 and 1 are illegal values for PCD */
> +	if (divisor <= 1)
> +		divisor = 2;
> +
> +	panel_cfg.divisor = divisor | (1 << 16);
> +	if (pixclock[0] != '\0') {
> +		printf("LCD: invalid value for pixclock:%s\n", pixclk_start);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * parse_setting() - parse a single setting of custom lcd parameters
> + *
> + * @setting:	The custom lcd setting <name>:<value>
> + *
> + * Returns -1 on failure, 0 on success.
> + */
> +static int parse_setting(char *setting)
> +{
> +	int num_val;
> +	char *setting_start = setting;
> +
> +	if (!strncmp(setting, "mode:", 5)) {
> +		return parse_mode(setting + 5);
> +	} else if (!strncmp(setting, "pixclock:", 9)) {
> +		return parse_pixclock(setting + 9);
> +	} else if (!strncmp(setting, "left:", 5)) {
> +		num_val = simple_strtoul(setting + 5, &setting, 0);
> +		panel_cfg.timing_h |= DSS_HBP(num_val);
> +	} else if (!strncmp(setting, "right:", 6)) {
> +		num_val = simple_strtoul(setting + 6, &setting, 0);
> +		panel_cfg.timing_h |= DSS_HFP(num_val);
> +	} else if (!strncmp(setting, "upper:", 6)) {
> +		num_val = simple_strtoul(setting + 6, &setting, 0);
> +		panel_cfg.timing_v |= DSS_VBP(num_val);
> +	} else if (!strncmp(setting, "lower:", 6)) {
> +		num_val = simple_strtoul(setting + 6, &setting, 0);
> +		panel_cfg.timing_v |= DSS_VFP(num_val);
> +	} else if (!strncmp(setting, "hsynclen:", 9)) {
> +		num_val = simple_strtoul(setting + 9, &setting, 0);
> +		panel_cfg.timing_h |= DSS_HSW(num_val);
> +	} else if (!strncmp(setting, "vsynclen:", 9)) {
> +		num_val = simple_strtoul(setting + 9, &setting, 0);
> +		panel_cfg.timing_v |= DSS_VSW(num_val);
> +	} else if (!strncmp(setting, "hsync:", 6)) {
> +		if (simple_strtoul(setting + 6, &setting, 0) == 0)
> +			panel_cfg.pol_freq |= DSS_IHS;
> +		else
> +			panel_cfg.pol_freq &= ~DSS_IHS;
> +	} else if (!strncmp(setting, "vsync:", 6)) {
> +		if (simple_strtoul(setting + 6, &setting, 0) == 0)
> +			panel_cfg.pol_freq |= DSS_IVS;
> +		else
> +			panel_cfg.pol_freq &= ~DSS_IVS;
> +	} else if (!strncmp(setting, "outputen:", 9)) {
> +		if (simple_strtoul(setting + 9, &setting, 0) == 0)
> +			panel_cfg.pol_freq |= DSS_IEO;
> +		else
> +			panel_cfg.pol_freq &= ~DSS_IEO;
> +	} else if (!strncmp(setting, "pixclockpol:", 12)) {
> +		if (simple_strtoul(setting + 12, &setting, 0) == 0)
> +			panel_cfg.pol_freq |= DSS_IPC;
> +		else
> +			panel_cfg.pol_freq &= ~DSS_IPC;
> +	} else if (!strncmp(setting, "active", 6)) {
> +		panel_cfg.panel_type = ACTIVE_DISPLAY;
> +		return 0; /* Avoid sanity check below */
> +	} else if (!strncmp(setting, "passive", 7)) {
> +		panel_cfg.panel_type = PASSIVE_DISPLAY;
> +		return 0; /* Avoid sanity check below */
> +	} else if (!strncmp(setting, "display:", 8)) {
> +		if (!strncmp(setting + 8, "dvi", 3)) {
> +			lcd_def = DVI_CUSTOM;
> +			return 0; /* Avoid sanity check below */
> +		}
> +	} else {
> +		printf("LCD: unknown option %s\n", setting_start);
> +		return -1;
> +	}
> +
> +	if (setting[0] != '\0') {
> +		printf("LCD: invalid value for %s\n", setting_start);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * env_parse_customlcd() - parse custom lcd params from an environment variable.
> + *
> + * @custom_lcd_params:	The environment variable containing the lcd params.
> + *
> + * Returns -1 on failure, 0 on success.
> + */
> +static int parse_customlcd(char *custom_lcd_params)
> +{
> +	char params_cpy[160];
> +	char *setting;
> +
> +	strncpy(params_cpy, custom_lcd_params, 160);
I fail to understand why you want to copy this.
> +	setting = strtok(params_cpy, ",");
> +	while (setting) {
> +		if (parse_setting(setting) < 0)
> +			return -1;
> +
> +		setting = strtok(NULL, ",");
> +	}
> +
> +	/* Currently we don't support changing this via custom lcd params */
> +	panel_cfg.data_lines = LCD_INTERFACE_24_BIT;
> +
again, if you only support 24 panels, why not drive them as such?
> +	return 0;
> +}
> +
Is above really board specific or should it be in omap_videomodes.c or 
whatever?
> +/*
>    * env_parse_displaytype() - parse display type.
>    *
>    * Parses the environment variable "displaytype", which contains the
> @@ -176,14 +378,19 @@ void lcd_ctrl_init(void *lcdbase)
>   {
>   	struct dispc_regs *dispc = (struct dispc_regs *)OMAP3_DISPC_BASE;
>   	struct prcm *prcm = (struct prcm *)PRCM_BASE;
> +	char *custom_lcd;
>   	char *displaytype = getenv("displaytype");
>   
>   	if (displaytype == NULL)
>   		return;
>   
>   	lcd_def = env_parse_displaytype(displaytype);
> -	if (lcd_def == NONE)
> -		return;
> +	/* If we did not recognize the preset, check if it's an env variable */
> +	if (lcd_def == NONE) {
> +		custom_lcd = getenv(displaytype);
> +		if (custom_lcd == NULL || parse_customlcd(custom_lcd) < 0)
> +			return;
> +	}
>   
>   	panel_cfg.frame_buffer = lcdbase;
>   	omap3_dss_panel_config(&panel_cfg);
> @@ -204,7 +411,7 @@ void lcd_ctrl_init(void *lcdbase)
>   
>   void lcd_enable(void)
>   {
> -	if (lcd_def == DVI) {
> +	if (lcd_def == DVI || lcd_def == DVI_CUSTOM) {
>   		gpio_direction_output(54, 0); /* Turn on DVI */
>   		omap3_dss_enable();
>   	}
Regards,
Jeroen