[U-Boot] [RFC 1/6] odroid: exynos: USB initialization on the U3/X2

[Krzysztof Kozlowski]

On Mon, 1 Apr 2019 at 13:52, Anand Moon <linux.amoon at gmail.com> wrote:
>
> From: Tobias Jakobi <tjakobi at math.uni-bielefeld.de>
>
> Rename board_usb_init() to exynos_usb_init() and call it
> early in the Exynos EHCI driver when probing.
>
> This kind of works. After a 'usb start; usb stop; usb start'
> cycle the attached devices are recognized.
>
> Add small delay between gpio_direction_output to stable
> initialization of usb gpio pins.
>
> Signed-off-by: Tobias Jakobi <tjakobi at math.uni-bielefeld.de>
> Signed-off-by: Anand Moon <linux.amoon at gmail.com>
> ---
> Reoder the exynos_usb_init so that "usb start" command initialization
> correcly.
> ---
> ---
>  board/samsung/odroid/odroid.c  | 14 +++++++++-----
>  drivers/usb/host/ehci-exynos.c |  7 +++++++
>  2 files changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/board/samsung/odroid/odroid.c b/board/samsung/odroid/odroid.c
> index 3e594fd850..79d14ead01 100644
> --- a/board/samsung/odroid/odroid.c
> +++ b/board/samsung/odroid/odroid.c
> @@ -468,8 +468,6 @@ struct dwc2_plat_otg_data s5pc210_otg_data = {
>  };
>  #endif
>
> -#if defined(CONFIG_USB_GADGET) || defined(CONFIG_CMD_USB)
> -
>  static void set_usb3503_ref_clk(void)
>  {
>  #ifdef CONFIG_BOARD_TYPES
> @@ -490,9 +488,8 @@ static void set_usb3503_ref_clk(void)
>  #endif /* CONFIG_BOARD_TYPES */
>  }
>
> -int board_usb_init(int index, enum usb_init_type init)
> +int exynos_usb_init(void)
>  {
> -#ifdef CONFIG_CMD_USB
>         struct udevice *dev;
>         int ret;
>
> @@ -501,6 +498,7 @@ int board_usb_init(int index, enum usb_init_type init)
>         /* Disconnect, Reset, Connect */
>         gpio_direction_output(EXYNOS4X12_GPIO_X34, 0);
>         gpio_direction_output(EXYNOS4X12_GPIO_X35, 0);
> +       sdelay(200000);

This should be a separate patch with its own explanation.

>         gpio_direction_output(EXYNOS4X12_GPIO_X35, 1);
>         gpio_direction_output(EXYNOS4X12_GPIO_X34, 1);
>
> @@ -530,7 +528,13 @@ int board_usb_init(int index, enum usb_init_type init)
>                 pr_err("Regulator %s value setting error: %d\n", dev->name, ret);
>                 return ret;
>         }
> -#endif
> +
> +       return 0;
> +}
> +
> +#ifdef CONFIG_USB_GADGET
> +int board_usb_init(int index, enum usb_init_type init)
> +{
>         debug("USB_udc_probe\n");
>         return dwc2_udc_probe(&s5pc210_otg_data);
>  }
> diff --git a/drivers/usb/host/ehci-exynos.c b/drivers/usb/host/ehci-exynos.c
> index fabc662eb6..b0f7bd4936 100644
> --- a/drivers/usb/host/ehci-exynos.c
> +++ b/drivers/usb/host/ehci-exynos.c
> @@ -31,6 +31,8 @@ struct exynos_ehci_platdata {
>         struct gpio_desc vbus_gpio;
>  };
>
> +extern int exynos_usb_init(void);
> +
>  /**
>   * Contains pointers to register base addresses
>   * for the usb controller.
> @@ -152,6 +154,11 @@ static void exynos4412_setup_usb_phy(struct exynos4412_usb_phy *usb)
>         setbits_le32(&usb->usbphyrstcon, (RSTCON_HOSTPHY_SWRST | RSTCON_SWRST));
>         udelay(10);
>         clrbits_le32(&usb->usbphyrstcon, (RSTCON_HOSTPHY_SWRST | RSTCON_SWRST));
> +
> +       /*
> +        * "usb start" initialize the usb driver
> +        */
> +       exynos_usb_init();

It should be something more generic like
CONFIG_SYS_USB_OHCI_BOARD_INIT which calls board_usb_init()... but it
still will be calling board code from the driver. Why do you need this
in the first place?

Best regards,
Krzysztof