[U-Boot] [PATCH 12/18] arm: mx6: add support for Compulab cm-fx6 CoM

[Tim Harvey]

On Sun, Aug 3, 2014 at 12:34 AM, Nikita Kiryanov <nikita at compulab.co.il> wrote:
> Add initial support for Compulab CM-FX6 CoM.
> Support includes MMC, SPI flash, and SPL with dynamic DRAM detection.
>
<snip>
> +
> +static void spl_mx6s_dram_init(enum ddr_config dram_config, int reset)
> +{
> +       struct mx6_mmdc_calibration calib;
> +       struct mx6_ddr_sysinfo sysinfo;
> +       struct mx6_ddr3_cfg ddr3_cfg;
> +
> +       if (reset)
> +               ((struct mmdc_p_regs *)MX6_MMDC_P0_MDCTL)->mdmisc = 2;
> +
> +       calib.p0_mpwldectrl0    = 0x005B0061;
> +       calib.p0_mpwldectrl1    = 0x004F0055;
> +       calib.p0_mpdgctrl0      = 0x0314030C;
> +       calib.p0_mpdgctrl1      = 0x025C0268;
> +       calib.p0_mprddlctl      = 0x42464646;
> +       calib.p0_mpwrdlctl      = 0x36322C34;
> +       ddr3_cfg.mem_speed      = 800;
> +       ddr3_cfg.density        = 4;
> +       ddr3_cfg.rowaddr        = 14;
> +       ddr3_cfg.coladdr        = 10;
> +       ddr3_cfg.pagesz         = 2;
> +       ddr3_cfg.trcd           = 1800;
> +       ddr3_cfg.trcmin         = 5200;
> +       ddr3_cfg.trasmin        = 3600;
> +       ddr3_cfg.SRT            = 0;
> +       sysinfo.cs1_mirror      = 1;
> +       sysinfo.cs_density      = 16;
> +       sysinfo.bi_on           = 1;
> +       sysinfo.rtt_nom         = 1;
> +       sysinfo.rtt_wr          = 0;
> +       sysinfo.ralat           = 5;
> +       sysinfo.walat           = 1;
> +       sysinfo.mif3_mode       = 3;
> +       sysinfo.rst_to_cke      = 0x23;
> +       sysinfo.sde_to_rst      = 0x10;
> +       switch (dram_config) {
> +       case DDR_16BIT_256MB:
> +               sysinfo.dsize = 0;
> +               sysinfo.ncs = 1;
> +               break;
> +       case DDR_32BIT_512MB:
> +               sysinfo.dsize = 1;
> +               sysinfo.ncs = 1;
> +               break;
> +       case DDR_32BIT_1GB:
> +               sysinfo.dsize = 1;
> +               sysinfo.ncs = 2;
> +               break;
> +       default:
> +               puts("Tried to setup invalid DDR configuration\n");
> +               hang();
> +       }
> +
> +       mx6_dram_cfg(&sysinfo, &calib, &ddr3_cfg);
> +       udelay(100);
> +}

Nikita,

I'm curious why you add an extra udelay(100) here? There is an
mdelay(1) before the return of mx6_dram_cfg() to wait for auto-ZQ
calibration to complete (I never found a way to determine when it was
complete via registers).

Regards,

Tim