Re: [PATCH 1/2] usb: chipidea: usbmisc: Add support for i.MX27/i.MX31 CPUs
Alexander Shiyan
shc_work at mail.ru
Sun Nov 10 23:45:40 EST 2013
> 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.
...
---
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