On 10/30/2013 04:06 AM, Peter Chen wrote: > According to Freescale imx28 Errata, "ENGR119653 USB: ARM to USB > register error issue", All USB register write operations must > use the ARM SWP instruction. So, we implement a special ehci_write > for imx28. > > Discussion for it at below: > http://marc.info/?l=linux-usb&m=137996395529294&w=2 > > Signed-off-by: Peter Chen <[email protected]> > Acked-by: Alan Stern <[email protected]> > --- > drivers/usb/host/ehci.h | 13 +++++++++++++ > 1 files changed, 13 insertions(+), 0 deletions(-) > > diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h > index e8f41c5..535aa8b 100644 > --- a/drivers/usb/host/ehci.h > +++ b/drivers/usb/host/ehci.h > @@ -225,6 +225,7 @@ struct ehci_hcd { /* one per controller */ > unsigned has_synopsys_hc_bug:1; /* Synopsys HC */ > unsigned frame_index_bug:1; /* MosChip (AKA NetMos) */ > unsigned need_oc_pp_cycle:1; /* MPC834X port power */ > + unsigned imx28_write_fix:1; /* For Freescale i.MX28 */ > > /* required for usb32 quirk */ > #define OHCI_CTRL_HCFS (3 << 6) > @@ -728,6 +729,13 @@ static inline unsigned int ehci_readl(const struct > ehci_hcd *ehci, > #endif > } > > +#ifdef CONFIG_SOC_IMX28 > +static inline void imx28_ehci_writel(u32 val32, volatile u32 *addr)
You should annotate the addr pointer with __iomem, or better use the
signature of ehci_writel():
static inline void imx28_ehci_writel(const unsinged int val32, __u32
__iomem *addr)
Marc
> +{
> + __asm__ ("swp %0, %0, [%1]" : : "r"(val32), "r"(addr));
> +}
> +#endif
> +
> static inline void ehci_writel(const struct ehci_hcd *ehci,
> const unsigned int val, __u32 __iomem *regs)
> {
> @@ -735,6 +743,11 @@ static inline void ehci_writel(const struct ehci_hcd
> *ehci,
> ehci_big_endian_mmio(ehci) ?
> writel_be(val, regs) :
> writel(val, regs);
> +#elif defined(CONFIG_SOC_IMX28)
> + if (ehci->imx28_write_fix)
> + imx28_ehci_writel(val, regs);
> + else
> + writel(val, regs);
> #else
> writel(val, regs);
> #endif
>
--
Pengutronix e.K. | Marc Kleine-Budde |
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