On Mon, Oct 28, 2013 at 11:47:53AM +0100, Marek Vasut wrote: > Dear Hector Palacios, > > > Dear Peter, > > > > On 10/25/2013 08:02 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 special hw_write > > > and hw_test_and_clear for imx28. > > > > > > Discussion for it at below: > > > http://marc.info/?l=linux-usb&m=137996395529294&w=2 > > > > > > Signed-off-by: Peter Chen > > > <peter.chen-KZfg59tc24xl57MIdRCFDg@xxxxxxxxxxxxxxxx> --- > > > Changes for v2: > > > - Rebase to latest usb-next tree > > > > > > drivers/usb/chipidea/ci.h | 23 +++++++++++++++++++++++ > > > drivers/usb/chipidea/core.c | 2 ++ > > > drivers/usb/chipidea/host.c | 1 + > > > include/linux/usb/chipidea.h | 1 + > > > 4 files changed, 27 insertions(+), 0 deletions(-) > > > > > > diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h > > > index 1c94fc5..4eb61d0 100644 > > > --- a/drivers/usb/chipidea/ci.h > > > +++ b/drivers/usb/chipidea/ci.h > > > @@ -173,6 +173,8 @@ struct ci_hdrc { > > > > > > struct dentry *debugfs; > > > bool id_event; > > > bool b_sess_valid_event; > > > > > > + /* imx28 needs swp instruction for writing */ > > > + bool imx28_write_fix; > > > > > > }; > > > > > > static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci) > > > > > > @@ -253,6 +255,13 @@ static inline u32 hw_read(struct ci_hdrc *ci, enum > > > ci_hw_regs reg, u32 mask) > > > > > > return ioread32(ci->hw_bank.regmap[reg]) & mask; > > > > > > } > > > > > > +#ifdef CONFIG_SOC_IMX28 > > > +static inline void imx28_ci_writel(u32 val32, volatile u32 *addr) > > > +{ > > > + __asm__ ("swp %0, %0, [%1]" : : "r"(val32), "r"(addr)); > > > +} > > > +#endif > > > + > > > > > > /** > > > > > > * hw_write: writes to a hw register > > > * @reg: register index > > > > > > @@ -266,7 +275,14 @@ static inline void hw_write(struct ci_hdrc *ci, enum > > > ci_hw_regs reg, > > > > > > data = (ioread32(ci->hw_bank.regmap[reg]) & ~mask) > > > > > > | (data & mask); > > > > > > +#ifdef CONFIG_SOC_IMX28 > > > + if (ci->imx28_write_fix) > > > + imx28_ci_writel(data, ci->hw_bank.regmap[reg]); > > > + else > > > + iowrite32(data, ci->hw_bank.regmap[reg]); > > > +#else > > > > > > iowrite32(data, ci->hw_bank.regmap[reg]); > > > > > > +#endif > > > > > > } > > > > > > /** > > > > > > @@ -281,7 +297,14 @@ static inline u32 hw_test_and_clear(struct ci_hdrc > > > *ci, enum ci_hw_regs reg, > > > > > > { > > > > > > u32 val = ioread32(ci->hw_bank.regmap[reg]) & mask; > > > > > > +#ifdef CONFIG_SOC_IMX28 > > > + if (ci->imx28_write_fix) > > > + imx28_ci_writel(val, ci->hw_bank.regmap[reg]); > > > + else > > > + iowrite32(val, ci->hw_bank.regmap[reg]); > > > +#else > > > > > > iowrite32(val, ci->hw_bank.regmap[reg]); > > > > > > +#endif > > > > > > return val; > > > > > > } > > > > Can't we remove the #ifdefs CONFIG_SOC_IMX28 all around? > > The check is done on the new flag ci->imx28_write_fix which exists for all > > platforms, isn't it?. > > The SWP instruction is specific to ARM, so you'd need to stub-out the > imx28_ci_writel() with ifdef then. That's better than the mess of #ifdefs this patch adds, which isn't ok at all :( -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
