[U-Boot] [PATCH 3/4] mmc: exynos dwmmc: check boot mode before init dwmmc

[Simon Glass]

Hi Przemyslaw,

On 17 February 2015 at 06:09, Przemyslaw Marczak <p.marczak at samsung.com> wrote:
> Before this commit, the mmc devices were always registered
> in the same order. So dwmmc channel 0 was registered as mmc 0,
> channel 1 as mmc 1, etc.
> In case of possibility to boot from more then one device,
> the CONFIG_SYS_MMC_ENV_DEV should always point to right mmc device.
>
> This can be achieved by init boot device as first, so it will be
> always registered as mmc 0. Thanks to this, the 'saveenv' command
> will work fine for all mmc boot devices.
>
> Exynos based boards usually uses mmc host channels configuration:
> - 0, or 0+1 for 8 bit  - as a default boot device (usually eMMC)
> - 2 for 4bit - as an optional boot device (usually SD card slot)
>
> And usually the boot order is defined by OM pin configuration,
> which can be changed in a few ways, eg.
> - Odroid U3     - eMMC card insertion -> first boot from eMMC
> - Odroid X2/XU3 - boot priority jumper
>
> By this commit, Exynos dwmmc driver will check the OM pin configuration,
> and then try to init the boot device and register it as mmc 0.

I think a better way to do this would be to make
CONFIG_SYS_MMC_ENV_DEV support an option where the device can be
selected at run-time.

However that would probably be better done when the drive rmodel
conversion is complete.

So this seems a reasonable patch given where we are.

Reviewed-by: Simon Glass <sjg at chromium.org>

>
> Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
> Cc: Minkyu Kang <mk7.kang at samsung.com>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> Cc: Pantelis Antoniou <panto at intracom.gr>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Akshay Saraswat <akshay.s at samsung.com>
> ---
>  drivers/mmc/exynos_dw_mmc.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/exynos_dw_mmc.c b/drivers/mmc/exynos_dw_mmc.c
> index dfa209b..91f0163 100644
> --- a/drivers/mmc/exynos_dw_mmc.c
> +++ b/drivers/mmc/exynos_dw_mmc.c
> @@ -13,6 +13,7 @@
>  #include <asm/arch/dwmmc.h>
>  #include <asm/arch/clk.h>
>  #include <asm/arch/pinmux.h>
> +#include <asm/arch/power.h>
>  #include <asm/gpio.h>
>  #include <asm-generic/errno.h>
>
> @@ -166,7 +167,6 @@ static int exynos_dwmci_get_config(const void *blob, int node,
>         if (host->dev_index == host->dev_id)
>                 host->dev_index = host->dev_id - PERIPH_ID_SDMMC0;
>
> -
>         /* Get the bus width from the device node */
>         host->buswidth = fdtdec_get_int(blob, node, "samsung,bus-width", 0);
>         if (host->buswidth <= 0) {
> @@ -229,12 +229,21 @@ int exynos_dwmmc_init(const void *blob)
>  {
>         int compat_id;
>         int node_list[DWMMC_MAX_CH_NUM];
> +       int boot_dev_node;
>         int err = 0, count;
>
>         compat_id = COMPAT_SAMSUNG_EXYNOS_DWMMC;
>
>         count = fdtdec_find_aliases_for_id(blob, "mmc",
>                                 compat_id, node_list, DWMMC_MAX_CH_NUM);
> +
> +       /* For DWMMC always set boot device as mmc 0 */
> +       if (count >= 3 && get_boot_mode() == BOOT_MODE_SD) {
> +               boot_dev_node = node_list[2];
> +               node_list[2] = node_list[0];
> +               node_list[0] = boot_dev_node;
> +       }
> +
>         err = exynos_dwmci_process_node(blob, node_list, count);
>
>         return err;
> --
> 1.9.1
>

Regards,
Simon