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@xxxxxxxxxxxxx> --- 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 38598b3..4714e31 100644 --- a/drivers/usb/chipidea/ci.h +++ b/drivers/usb/chipidea/ci.h @@ -176,6 +176,8 @@ struct ci_hdrc { bool supports_runtime_pm; bool in_lpm; bool wakeup_int; + /* imx28 needs swp instruction for writing */ + bool imx28_write_fix; }; static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci) @@ -256,6 +258,13 @@ 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 @@ -269,7 +278,14 @@ 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 } /** @@ -284,7 +300,14 @@ 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; } diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c index a9497eb..b89c154 100644 --- a/drivers/usb/chipidea/core.c +++ b/drivers/usb/chipidea/core.c @@ -565,6 +565,8 @@ static int ci_hdrc_probe(struct platform_device *pdev) ci->dev = dev; ci->platdata = dev->platform_data; + ci->imx28_write_fix = !!(ci->platdata->flags & + CI_HDRC_IMX28_WRITE_FIX); ret = hw_device_init(ci, base); if (ret < 0) { diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c index c1d05c4..66866cd 100644 --- a/drivers/usb/chipidea/host.c +++ b/drivers/usb/chipidea/host.c @@ -235,6 +235,7 @@ static int host_start(struct ci_hdrc *ci) ehci->caps = ci->hw_bank.cap; ehci->has_hostpc = ci->hw_bank.lpm; ehci->has_tdi_phy_lpm = ci->hw_bank.lpm; + ehci->imx28_write_fix = ci->imx28_write_fix; if (ci->platdata->reg_vbus) { ret = regulator_enable(ci->platdata->reg_vbus); diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h index 8ce3daf..e66fb19 100644 --- a/include/linux/usb/chipidea.h +++ b/include/linux/usb/chipidea.h @@ -26,6 +26,7 @@ struct ci_hdrc_platform_data { */ #define CI_HDRC_DUAL_ROLE_NOT_OTG BIT(4) #define CI_HDRC_IMX_EHCI_QUIRK BIT(5) +#define CI_HDRC_IMX28_WRITE_FIX BIT(6) enum usb_dr_mode dr_mode; #define CI_HDRC_CONTROLLER_RESET_EVENT 0 #define CI_HDRC_CONTROLLER_STOPPED_EVENT 1 -- 1.7.1 -- 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
