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> --- Changes for v4: - introducing __hw_write to encapsulate low level write, it can reduce the duplicated code. drivers/usb/chipidea/ci.h | 26 ++++++++++++++++++++++++-- drivers/usb/chipidea/core.c | 2 ++ drivers/usb/chipidea/host.c | 1 + include/linux/usb/chipidea.h | 1 + 4 files changed, 28 insertions(+), 2 deletions(-) diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h index 1c94fc5..f9b1914 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 +255,26 @@ 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 + +static inline void __hw_write(struct ci_hdrc *ci, u32 val, + void __iomem *addr) +{ +#ifdef CONFIG_SOC_IMX28 + if (ci->imx28_write_fix) + imx28_ci_writel(val, addr); + else + iowrite32(val, addr); +#else + iowrite32(val, addr); +#endif +} + /** * hw_write: writes to a hw register * @reg: register index @@ -266,7 +288,7 @@ static inline void hw_write(struct ci_hdrc *ci, enum ci_hw_regs reg, data = (ioread32(ci->hw_bank.regmap[reg]) & ~mask) | (data & mask); - iowrite32(data, ci->hw_bank.regmap[reg]); + __hw_write(ci, data, ci->hw_bank.regmap[reg]); } /** @@ -281,7 +303,7 @@ 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; - iowrite32(val, ci->hw_bank.regmap[reg]); + __hw_write(ci, val, ci->hw_bank.regmap[reg]); return val; } diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c index 06204b7..357a059 100644 --- a/drivers/usb/chipidea/core.c +++ b/drivers/usb/chipidea/core.c @@ -551,6 +551,8 @@ 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 59e6020..06fd042 100644 --- a/drivers/usb/chipidea/host.c +++ b/drivers/usb/chipidea/host.c @@ -65,6 +65,7 @@ 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 7d39967..708bd11 100644 --- a/include/linux/usb/chipidea.h +++ b/include/linux/usb/chipidea.h @@ -24,6 +24,7 @@ struct ci_hdrc_platform_data { * but otg is not supported (no register otgsc). */ #define CI_HDRC_DUAL_ROLE_NOT_OTG BIT(4) +#define CI_HDRC_IMX28_WRITE_FIX BIT(5) 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
