[U-Boot] [PATCH 1/3] samsung: board: support eMMC reset using DT

[Simon Glass]

Hi Joonyoung,

On 7 January 2015 at 22:44, Joonyoung Shim <jy0922.shim at samsung.com> wrote:
> Some exynos boards require special handling of SD4_nRESET_OUT line for
> eMMC memory to perform complete reboot e.g. Odroid X2/U3/XU3 boards.
>
> This will support eMMC reset using DT from reset_misc of samsung common
> board file and each board files can support eMMC reset on non DT case.
>
> Signed-off-by: Joonyoung Shim <jy0922.shim at samsung.com>
> ---
>  board/samsung/common/board.c                   | 27 ++++++++++++++++++++++++++
>  board/samsung/odroid/odroid.c                  |  2 +-
>  doc/device-tree-bindings/exynos/emmc-reset.txt | 15 ++++++++++++++
>  3 files changed, 43 insertions(+), 1 deletion(-)
>  create mode 100644 doc/device-tree-bindings/exynos/emmc-reset.txt
>
> diff --git a/board/samsung/common/board.c b/board/samsung/common/board.c
> index c04ab3c..3218463 100644
> --- a/board/samsung/common/board.c
> +++ b/board/samsung/common/board.c
> @@ -40,6 +40,8 @@ __weak int exynos_power_init(void)
>         return 0;
>  }
>
> +__weak void exynos_reset_misc(void) {}
> +
>  #if defined CONFIG_EXYNOS_TMU
>  /* Boot Time Thermal Analysis for SoC temperature threshold breach */
>  static void boot_temp_check(void)
> @@ -400,3 +402,28 @@ int misc_init_r(void)
>         return 0;
>  }
>  #endif
> +
> +void reset_misc(void)
> +{
> +#ifdef CONFIG_OF_CONTROL

I think all Samsung boards have this defined, so this #ifdef can be removed.

> +       struct gpio_desc gpio = {};
> +       int node;
> +
> +       node = fdt_node_offset_by_compatible(gd->fdt_blob, 0,
> +                       "samsung,emmc-reset");
> +       if (node < 0)
> +               return;
> +
> +       gpio_request_by_name_nodev(gd->fdt_blob, node, "reset-gpio", 0, &gpio,
> +                                  GPIOD_IS_OUT);
> +
> +       if (dm_gpio_is_valid(&gpio)) {
> +               /* Reset eMMC*/
> +               dm_gpio_set_value(&gpio, 0);
> +               mdelay(10);

That's a very long reset! Is that what it needs?

> +               dm_gpio_set_value(&gpio, 1);
> +       }
> +#else
> +       exynos_reset_misc();

So I don't think you need this function.

> +#endif
> +}
> diff --git a/board/samsung/odroid/odroid.c b/board/samsung/odroid/odroid.c
> index 3f43e17..db35945 100644
> --- a/board/samsung/odroid/odroid.c
> +++ b/board/samsung/odroid/odroid.c
> @@ -516,7 +516,7 @@ int board_usb_init(int index, enum usb_init_type init)
>  }
>  #endif
>
> -void reset_misc(void)
> +void exynos_reset_misc(void)
>  {
>         /* Reset eMMC*/
>         gpio_set_value(EXYNOS4X12_GPIO_K12, 0);
> diff --git a/doc/device-tree-bindings/exynos/emmc-reset.txt b/doc/device-tree-bindings/exynos/emmc-reset.txt
> new file mode 100644
> index 0000000..e48e508
> --- /dev/null
> +++ b/doc/device-tree-bindings/exynos/emmc-reset.txt
> @@ -0,0 +1,15 @@
> +* Samsung eMMC reset
> +
> +Some exynos boards require special handling of SD4_nRESET_OUT line for eMMC
> +memory to perform complete reboot.
> +
> +Required properties:
> +- compatible: should be "samsung,emmc-reset"
> +- reset-gpio: gpio chip for eMMC reset.
> +
> +Example:
> +
> +emmc-reset {
> +        compatible = "samsung,emmc-reset";
> +        reset-gpio = <&gpk1 2 0>;
> +};
> --
> 1.9.1
>

Regards,
Simon