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

[Anand Moon]

Hi Krzysztof,

On Mon, 1 Apr 2019 at 18:18, Krzysztof Kozlowski <krzk at kernel.org> wrote:
>
> 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?

Ideally usb start should be invoked while loading of the u-boot.
but some how this is missing I could not figure out this.

I have tried following in odroid.c but still no sign of usb to get
initialize usb,

int board_eth_init(bd_t *bis)
{
        printf("Registered USB_ETHER\n");
        exynos_usb_init();
        return 0;
}

Here is the debugging I tried to under stand before I tried to modify the code.
Before usb start is called.

Odroid # dm help
dm - Driver model low level access
...
 gpio        44  [   ]   gpio_exynos           |   |-- gpv3
 gpio        45  [   ]   gpio_exynos           |   `-- gpv4
 usb          0  [   ]   ehci_exynos           `-- ehci at 12580000

After usb start
Odroid # usb start
starting USB...
USB0:   USB EHCI 1.00
scanning bus 0 for devices... 4 USB Device(s) found
       scanning usb for storage devices... 1 Storage Device(s) found
       scanning usb for ethernet devices... 1 Ethernet Device(s) found
Odroid # dm tree

 gpio        45  [   ]   gpio_exynos           |   `-- gpv4
 usb          0  [ + ]   ehci_exynos           `-- ehci at 12580000
 usb_hub      0  [ + ]   usb_hub                   `-- usb_hub
 usb_dev_ge   0  [ + ]   usb_dev_generic_drv           |-- generic_bus_0_dev_2
 usb_hub      1  [ + ]   usb_hub                       `-- usb_hub
 usb_mass_s   0  [ + ]   usb_mass_storage                  `-- usb_mass_storage
 blk          2  [   ]   usb_storage_blk                       `--
usb_mass_storage.lun0

After the dm node register we can perform usb and ethernet operation on u-boot.

Any other input's I can try this out.

Best Regards
-Anand