[U-Boot] usb: ehci: Take advantage of the new multi-controller feature for MXC

[Benoît Thébaudeau]

Dear Marek Vasut,

On Monday, November 5, 2012 11:54:12 PM, Marek Vasut wrote:
> Dear Benoît Thébaudeau,
> 
> > Hi Marek,
> > 
> > Thanks to Lucas' series coming with commits c7e3b2b and 676ae06,
> > I'd like
> > to use the multi-controller feature on MXC since most of these SoCs
> > come
> > with a USB IP supporting an OTG controller and multiple host-only
> > controllers.
> > 
> > Currently the MXC code in ehci-mx{c|5|6}.c just ignores the index
> > passed to
> > ehci_hcd_init() and the like, and there are 3 port-specific configs
> > (CONFIG_MXC_USB_PORT, CONFIG_MXC_USB_FLAGS and
> > CONFIG_MXC_USB_PORTSC).
> > 
> > Not all USB ports from the USB IP will be available on each board
> > for a
> > given SoC, so we need a logical to physical USB port mapping.
> > 
> > I would suggest something like the following.
> > 
> > board.h:
> > #define CONFIG_MXC_USB	{ \
> > 	{ \
> > 		0, \
> > 		MXC_EHCI_INTERNAL_PHY, \
> > 		MXC_EHCI_UTMI_16BIT | MXC_EHCI_MODE_UTMI \
> > 	}, { \
> > 		1, \
> > 		MXC_EHCI_POWER_PINS_ENABLED | MXC_EHCI_PWR_PIN_ACTIVE_HIGH | \
> > 		MXC_EHCI_OC_PIN_ACTIVE_LOW, \
> > 		MXC_EHCI_MODE_ULPI \
> > 	}, \
> > }
> > 
> > ehci-fsl.h:
> > struct mxc_ehci_cfg {
> > 	int port;
> > 	u32 flags;
> > 	u32 portsc;
> > };
> > 
> > ehci-mx{c|5|6}.c:
> > static const struct mxc_ehci_cfg
> > cfg[CONFIG_USB_MAX_CONTROLLER_COUNT] =
> > 		CONFIG_MXC_USB;
> > 
> > Then, in ehci_hcd_init(), there would be the following
> > replacements:
> >  - CONFIG_MXC_USB_PORT -> cfg[index].port,
> >  - CONFIG_MXC_USB_FLAGS -> cfg[index].flags,
> >  - CONFIG_MXC_USB_PORTSC -> cfg[index].portsc.
> > 
> > What do you think?
> 
> What about passing port private / platform data instead of ID ?

The ID is already passed to ehci_hcd_init(), so we have to live with it if we
don't want to change the newly introduced multi-controller infrastructure.

Or, perhaps this is what you meant, we could have some:
int ehci_mxc_register(int index, const struct mxc_ehci_cfg *cfg);
This function would simply fill an entry in the cfg array in ehci-mx{c|5|6}.c,
this array becoming an array of pointers to struct mxc_ehci_cfg. This looks
nicer, but it needs more code to do just the same thing as the CONFIG_MXC_USB
would do, without adding any feature. The only benefit would be if index were
actually the same as port here, but ehci_hcd_init() would still be called for
all indexes, so it would have to fail e.g. if port 0 is unused but port 1 is
used, which would probably generate some error noise for the user.

Or did you mean something else?

Best regards,
Benoît