Linux/AM3358: U-boot crashes on LCD clock enable

I'm using u-boot 2015.7 from SDK 2.00.00, so I don't know if the applies to the newer one.  So here is what I did:

Added to arch/arm/cpu/armv7/am33xx/clock_am33xx.c 
void enable_basic_clocks(void)
...
&cmper->lcdclkctrl,
&cmper->lcdcclkstctrl

board.c

#if defined(CONFIG_LCD) && defined(CONFIG_AM335X_LCD) && \
                !defined(CONFIG_SPL_BUILD)
void lcdbacklight(int on)
{
        gpio_request(GPIO_BACKLIGHT_EN, "backlight_en");
	gpio_request(GPIO_BACKLIGHT_ON, "backlight_on");
        if (on)
	{
                gpio_direction_output(GPIO_BACKLIGHT_EN, 1);
                gpio_direction_output(GPIO_BACKLIGHT_ON, 1);
	}
        else
	{
                gpio_direction_output(GPIO_BACKLIGHT_EN, 0);
		gpio_direction_output(GPIO_BACKLIGHT_ON, 0);
	}
}

int  load_lcdtiming(struct am335x_lcdpanel *panel)
{
        struct am335x_lcdpanel pnltmp;

        pnltmp.hactive = 800;
        pnltmp.vactive = 480;
        pnltmp.bpp = 16;
        pnltmp.hfp = 40;
        pnltmp.hbp = 40;
        pnltmp.hsw = 48;
        pnltmp.vfp = 13;
        pnltmp.vbp = 30;
        pnltmp.vsw = 3;
        pnltmp.pxl_clk_div = 2;
        pnltmp.pol = HSYNC_INVERT | VSYNC_INVERT | HSVS_CONTROL;
        pnltmp.pup_delay = 0;
        pnltmp.pon_delay = 0;
        panel_info.vl_rot = 0;

        memcpy((void *)panel, (void *)&pnltmp, sizeof(struct am335x_lcdpanel));

        return 0;
}

void lcdpower(int on)
{
        lcd_enable();
}

vidinfo_t       panel_info = {
                .vl_col = 800,
                .vl_row = 480,
                .vl_bpix = 4,
                .priv = 0
};

void lcd_ctrl_init(void *lcdbase)
{
        struct am335x_lcdpanel lcd_panel;

        memset(&lcd_panel, 0, sizeof(struct am335x_lcdpanel));
        if (load_lcdtiming(&lcd_panel) != 0)
                return;

        lcd_panel.panel_power_ctrl = &lcdpower;

        if (am335xfb_init(&lcd_panel) != 0)
                printf("ERROR: failed to initialize video!");

        /* Modify panel into to real resolution */
        panel_info.vl_col = lcd_panel.hactive;
        panel_info.vl_row = lcd_panel.vactive;

//      lcd_set_flush_dcache(1);
}

void lcd_enable(void)
{
        lcdbacklight(1);
}
#endif

mux.c

static struct module_pin_mux led_pin_mux[] = {
        {OFFSET(gpmc_a10), MODE(7) | PULLUP_EN | RXACTIVE},         /* GPIO1_26 */
        {OFFSET(gpmc_a11), MODE(7) | PULLUP_EN | RXACTIVE},         /* GPIO1_27 */
        {-1},
};

ifdef CONFIG_AM335X_LCD
static struct module_pin_mux lcd_pin_mux[] = {
        {OFFSET(lcd_data0), (MODE(0) | PULLUDDIS)},     /* LCD-Data(0) */
        {OFFSET(lcd_data1), (MODE(0) | PULLUDDIS)},     /* LCD-Data(1) */
        {OFFSET(lcd_data2), (MODE(0) | PULLUDDIS)},     /* LCD-Data(2) */
        {OFFSET(lcd_data3), (MODE(0) | PULLUDDIS)},     /* LCD-Data(3) */
        {OFFSET(lcd_data4), (MODE(0) | PULLUDDIS)},     /* LCD-Data(4) */
        {OFFSET(lcd_data5), (MODE(0) | PULLUDDIS)},     /* LCD-Data(5) */
        {OFFSET(lcd_data6), (MODE(0) | PULLUDDIS)},     /* LCD-Data(6) */
        {OFFSET(lcd_data7), (MODE(0) | PULLUDDIS)},     /* LCD-Data(7) */
        {OFFSET(lcd_data8), (MODE(0) | PULLUDDIS)},     /* LCD-Data(8) */
        {OFFSET(lcd_data9), (MODE(0) | PULLUDDIS)},     /* LCD-Data(9) */
        {OFFSET(lcd_data10), (MODE(0) | PULLUDDIS)},    /* LCD-Data(10) */
        {OFFSET(lcd_data11), (MODE(0) | PULLUDDIS)},    /* LCD-Data(11) */
        {OFFSET(lcd_data12), (MODE(0) | PULLUDDIS)},    /* LCD-Data(12) */
        {OFFSET(lcd_data13), (MODE(0) | PULLUDDIS)},    /* LCD-Data(13) */
        {OFFSET(lcd_data14), (MODE(0) | PULLUDDIS)},    /* LCD-Data(14) */
        {OFFSET(lcd_data15), (MODE(0) | PULLUDDIS)},    /* LCD-Data(15) */
        {OFFSET(lcd_vsync), (MODE(0) | PULLUDDIS)},     /* LCD-VSync */
        {OFFSET(lcd_hsync), (MODE(0) | PULLUDDIS)},     /* LCD-HSync */
        {OFFSET(lcd_ac_bias_en), (MODE(0) | PULLUDDIS)},/* LCD-DE */
        {OFFSET(lcd_pclk), (MODE(0) | PULLUDDIS)},      /* LCD-CLK */

        /* backlight */
        {OFFSET(xdma_event_intr0), (MODE(7) | PULLUDDIS)}, /* xdma_event_intr0_gpio0_19 */
	{OFFSET(spi0_sclk), (MODE(7) | PULLUDDIS)}, 	   /* spi0_sclk_gpio0_2 */

        {-1},
};
#endif

void enable_board_pin_mux(struct am335x_baseboard_id *header)
{
....
        configure_module_pin_mux(led_pin_mux);
#ifdef CONFIG_AM335X_LCD
        configure_module_pin_mux(lcd_pin_mux);
#endif
}

configs/am335x_evm_defconfig

CONFIG_SYS_EXTRA_OPTIONS="NAND" -> CONFIG_SYS_EXTRA_OPTIONS="NAND,SPLASH"

drivers/video/am335x-fb.c

static void disp_pll_clocks(void)
{
    u32 clkmode, clksel, div_m2;

    clkmode = readl(CM_CLKMODE_DPLL_DISP);
    clksel = readl(CM_CLKSEL_DPLL_DISP);
   // div_m2 = readl(CM_DIV_M2_DPLL_DISP);

    /* Set the PLL to bypass Mode */
    clkmode = (clkmode & 0xfffffff8) | 0x00000004;
    writel(clkmode, CM_CLKMODE_DPLL_DISP);
    while ((readl(CM_IDLEST_DPLL_DISP) & 0x00000100) != 0x00000100);

    clksel = clksel & (~0x7ffff);
    clksel = clksel | ((0x5 << 0x8) | 0x1);
    writel(clksel, CM_CLKSEL_DPLL_DISP);

    /*div_m2 = div_m2 & 0xFFFFFFE0;
    div_m2 = div_m2 | DISPPLL_M2;
    writel(div_m2, CM_DIV_M2_DPLL_DISP);*/

    clkmode = (clkmode & 0xfffffff8) | 0x7;
    writel(clkmode, CM_CLKMODE_DPLL_DISP);
    while ((readl(CM_IDLEST_DPLL_DISP) & 0x00000001) != 0x1);
}

int am335xfb_init(struct am335x_lcdpanel *panel)
 {
	disp_pll_clocks();
....
}



include/configs/am335x_evm.h


/* Splash scrren support */
#ifdef CONFIG_SPLASH
#define CONFIG_AM335X_LCD
#define CONFIG_LCD
#define CONFIG_LCD_NOSTDOUT
#define CONFIG_SYS_WHITE_ON_BLACK
#define LCD_BPP LCD_COLOR16

You have to change the values in display_pll_clocks to fit your display timings. I just checked that the values in these registers were in userspace and put the same values. And of course lcd timings has to be changed accordingly.

After that you can test the image, when you get to uboot and load the wanted image over tftp, with bmp display command.