[PATCH 1/2] usb: chipidea: usbmisc: Add support for i.MX27/i.MX31 CPUs

[Peter Chen]

On Mon, Nov 11, 2013 at 12:45 PM, Alexander Shiyan <shc_work at mail.ru> wrote:
>> Hi Alexander,
>>
>> On Sunday, November 10, 2013 03:18 PM, Alexander Shiyan wrote:
>> > This adds i.MX27 and i.MX31 as the next user of the usbmisc driver.
>> >
>> > Signed-off-by: Alexander Shiyan<shc_work at mail.ru>
>> > ---
>> >   drivers/usb/chipidea/usbmisc_imx.c | 42 ++++++++++++++++++++++++++++++++++++++
>> >   1 file changed, 42 insertions(+)
>> >
>> > diff --git a/drivers/usb/chipidea/usbmisc_imx.c b/drivers/usb/chipidea/usbmisc_imx.c
> ...
>> > +static int usbmisc_imx27_init(struct imx_usbmisc_data *data)
>> > +{
>> > +   unsigned long flags;
>> > +   u32 val;
>> > +
>> > +   switch (data->index) {
>> > +   case 0:
>> > +           val = MX27_OTG_PM_BIT;
>> > +           break;
>> > +   case 1:
>> > +           val = MX27_H1_PM_BIT;
>> > +           break;
>> > +   case 2:
>> > +           val = MX27_H2_PM_BIT;
>> > +           break;
>> > +   default:
>> > +           return -EINVAL;
>> > +   };
>> > +
>>
>>  From my understanding this can not work, the usbmisc->base not point into the
>> usb control register (USB_CTRL). Reference manual 30.5.1.1 says
>> BASE + 0x600
>> you must add the offset to the readl instruction.
>
> Why not work?
> usbotg: usb at 10024000
> usbh1: usb at 10024200
> usbh2: usb at 10024400
> usbmisc: usbmisc at 10024600
> So, offset to USB_CTRL should already be defined by DTS.
>
>
>> > +   spin_lock_irqsave(&usbmisc->lock, flags);
>> > +   if (data->disable_oc)
>> > +           val = readl(usbmisc->base) | val;
>>
>> else part not needed, the registers bits are set to 0 (reset)
>> the function is called on start-up once only, right?!
>>
>> > +   else
>> > +           val = readl(usbmisc->base)&  ~val;
>> > +   writel(val, usbmisc->base);
>> > +   spin_unlock_irqrestore(&usbmisc->lock, flags);
>> > +
>> > +   return 0;
>> > +}
>
> Bit can be set/cleared wrongly by the bootloader, it is not a big
> overhead to set it in proper state.
>

I think the "else" is needed, unless the over-current is not connected
or the user wants to disable it, we need to enable over-current by
default.

Acked-by: Peter Chen <peter.chen at freescale.com>

> ...
>
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-- 
BR,
Peter Chen