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

[linux@arm.linux.org.uk (Russell King - ARM Linux)]

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);