[PATCH 3/5] USB: add clk structure for systems that support clkdev framework

[saeed bishara]

On Sun, May 2, 2010 at 7:05 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Sun, May 02, 2010 at 06:54:15PM +0300, saeed bishara wrote:
>> >> well, I think that those drivers that have more than one clk can be
>> >> redesigned by adding virtual clk for the the usb host, and the clk
>> >> implementation for that soc should manage all the underlying physical
>> >> clocks. I've looked at the omap,at91 and atmel, and it looks to me
>> >> that this is doable. you see can see that the clk stuff in those
>> >> driver has nothing to do with usb itself. what do you think?
>> >
>> > Not happy with this for two reasons:
>> > 1. You're assuming that they can be managed as one entity; that doesn't seem
>> >   true for some of the drivers.
>> can you please give an example?
>
> drivers/usb/host/ohci-da8xx.c has two clocks, and needs to know the
> configuration of the USB block to know whether to manage the USB2.0
> clock:
>
>        cfgchip2 = __raw_readl(CFGCHIP2);
>        if (on) {
>                clk_enable(usb11_clk);
>
>                /*
>                 * If USB 1.1 reference clock is sourced from USB 2.0 PHY, we
>                 * need to enable the USB 2.0 module clocking, start its PHY,
>                 * and not allow it to stop the clock during USB 2.0 suspend.
>                 */
>                if (!(cfgchip2 & CFGCHIP2_USB1PHYCLKMUX)) {
>                        clk_enable(usb20_clk);
>
David, can I've your opinion about this patch? adding the clk struct
to the hcd struct will save the orion-ehci driver from having private
data structure.