[U-Boot] [PATCH v2] usb: add clock support for generic EHCI

[Marek Vasut]

On Monday, January 25, 2016 at 06:17:58 AM, Masahiro Yamada wrote:
> 2016-01-25 14:13 GMT+09:00 Marek Vasut <marex at denx.de>:
> > On Monday, January 25, 2016 at 05:59:30 AM, Masahiro Yamada wrote:
> >> This driver is designed in a generic manner, so clocks should be
> >> handled genericly as well.
> >> 
> >> Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
> >> ---
> >> 
> >> Changes in v2:
> >>   - rephrase git-log
> >>   - rebase on commit 12f229ea
> >>   - do not store clk devices and IDs in the private data
> >>  
> >>  drivers/usb/host/ehci-generic.c | 15 +++++++++++++++
> >>  1 file changed, 15 insertions(+)
> >> 
> >> diff --git a/drivers/usb/host/ehci-generic.c
> >> b/drivers/usb/host/ehci-generic.c index 1292caa..98f9db7 100644
> >> --- a/drivers/usb/host/ehci-generic.c
> >> +++ b/drivers/usb/host/ehci-generic.c
> >> @@ -5,6 +5,7 @@
> >> 
> >>   */
> >>  
> >>  #include <common.h>
> >> 
> >> +#include <clk.h>
> >> 
> >>  #include <dm.h>
> >>  #include "ehci.h"
> >> 
> >> @@ -21,6 +22,20 @@ static int ehci_usb_probe(struct udevice *dev)
> >> 
> >>  {
> >>  
> >>       struct ehci_hccr *hccr = (struct ehci_hccr *)dev_get_addr(dev);
> >>       struct ehci_hcor *hcor;
> >> 
> >> +     int i = 0;
> >> +
> >> +     while (1) {
> > 
> > You can do for (i = 0; ; i++) {} here ;-)

I forgot to mention that if you do the for() thing, you can drop the i++
at the end of this function and you also can drop the explicit int i = 0;
initialization.

> >> +             struct udevice *clk_dev;
> >> +             int clk_id;
> >> +
> >> +             clk_id = clk_get_by_index(dev, i, &clk_dev);
> >> +             if (clk_id < 0)
> >> +                     break;
> >> +             if (clk_enable(clk_dev, clk_id))
> >> +                     printf("failed to enable clock (dev=%s, id=%d)\n",
> >> +                            clk_dev->name, clk_id);
> >> +             i++;
> >> +     }
> >> 
> >>       hcor = (struct ehci_hcor *)((uintptr_t)hccr +
> >>       
> >>                                   HC_LENGTH(ehci_readl(&hccr->cr_capbase
> >>                                   )));
> > 
> > What about disabling the clock? Is it doable with the current clock
> > framework or shall we abandon it for now ?
> 
> clk_disable() is not supported in U-Boot, at least for now.
> (see include/clk.h and you will only find clk_enable.)
> 
> I think this patch is the best I can do now.
> 
> (ccing Simon, again)

In that case, I am fine with it. Thanks!