[U-Boot] [PATCH V2] usb: ehci-mx6: Fix bus enumeration for DM case

[Lukasz Majewski]

Hi Marek,

> The EHCI iMX6 driver is only partly converted to DT probing and
> still uses a tremendous amount of hard-coded addresses. Worse,
> the driver uses hard-coded SoC-model-specific base addresses, which
> are derived from values protected by SoC-specific macros, hence the
> driver is also compiled for a specific SoC model. Even worse, the
> driver depends on specific sequential indexing of the controllers,
> from which it derives offsets in the PHY and ANATOP register sets.

Indexes and offsets two biggest problems with DT/DTS conversion.

> 
> However, when the driver is probed from DT, the indexing is not
> correct. In fact, each controller has index 0. This patch derives
> the index for DT probing case from the controller base addresses,
> which is not the way this should be done, however it is the least
> intrusive approach, favorable this close to release.
> 
> The necessary steps to convert this driver fully to DT probing are
> described inside the patch, however this should be done in the next
> release and depends on iMX clock driver patches.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Abel Vesa <abel.vesa at nxp.com>
> Cc: Adam Ford <aford173 at gmail.com>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Ludwig Zenz <lzenz at dh-electronics.com>
> Cc: Lukasz Majewski <lukma at denx.de>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Stefano Babic <sbabic at denx.de>
> Cc: Vagrant Cascadian <vagrant at debian.org>
> ---
> V2: Derive the controller index from it's base address
> ---
>  drivers/usb/host/ehci-mx6.c | 37
> +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/usb/host/ehci-mx6.c b/drivers/usb/host/ehci-mx6.c
> index 33abfeada0..e9e6ed596d 100644
> --- a/drivers/usb/host/ehci-mx6.c
> +++ b/drivers/usb/host/ehci-mx6.c
> @@ -503,6 +503,42 @@ static int ehci_usb_ofdata_to_platdata(struct
> udevice *dev) return 0;
>  }
>  
> +static int ehci_usb_bind(struct udevice *dev)
> +{
> +	/*
> +	 * TODO:
> +	 * This driver is only partly converted to DT probing and
> still uses
> +	 * a tremendous amount of hard-coded addresses. To make
> things worse,
> +	 * the driver depends on specific sequential indexing of
> controllers,
> +	 * from which it derives offsets in the PHY and ANATOP
> register sets.
> +	 *
> +	 * Here we attempt to calculate these indexes from DT
> information as
> +	 * well as we can. The USB controllers on all existing
> iMX6/iMX7 SoCs
> +	 * are placed next to each other, at addresses incremented
> by 0x200.
> +	 * Thus, the index is derived from the multiple of 0x200
> offset from
> +	 * the first controller address.
> +	 *
> +	 * However, to complete conversion of this driver to DT
> probing, the
> +	 * following has to be done:
> +	 * - DM clock framework support for iMX must be implemented
> +	 * - usb_power_config() has to be converted to clock
> framework
> +	 *   -> Thus, the ad-hoc "index" variable goes away.
> +	 * - USB PHY handling has to be factored out into separate
> driver
> +	 *   -> Thus, the ad-hoc "index" variable goes away from the
> PHY
> +	 *      code, the PHY driver must parse it's address from
> DT. This
> +	 *      USB driver must find the PHY driver via DT phandle.
> +	 *   -> usb_power_config() shall be moved to PHY driver
> +	 * With these changes in place, the ad-hoc indexing goes
> away and
> +	 * the driver is fully converted to DT probing.
> +	 */
> +	fdt_size_t size;
> +	fdt_addr_t addr = devfdt_get_addr_size_index(dev, 0, &size);
> +
> +	dev->req_seq = (addr - USB_BASE_ADDR) / size;
> +
> +	return 0;
> +}
> +
>  static int ehci_usb_probe(struct udevice *dev)
>  {
>  	struct usb_platdata *plat = dev_get_platdata(dev);
> @@ -564,6 +600,7 @@ U_BOOT_DRIVER(usb_mx6) = {
>  	.id	= UCLASS_USB,
>  	.of_match = mx6_usb_ids,
>  	.ofdata_to_platdata = ehci_usb_ofdata_to_platdata,
> +	.bind	= ehci_usb_bind,
>  	.probe	= ehci_usb_probe,
>  	.remove = ehci_deregister,
>  	.ops	= &ehci_usb_ops,

Thank you for the patch (and hope that it will not be long int the
tree).

It doesn't break the TPC70 anymore, hence

Tested-by: Lukasz Majewski <lukma at denx.de>


Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
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