From ed8f8318d2ef3e5f9e4ddf79349508c116b68d7f Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Fri, 10 Jan 2014 13:51:27 +0800 Subject: usb: chipidea: add freescale imx28 special write register method 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 This patch is needed for stable tree 3.11+. Cc: stable@vger.kernel.org Cc: robert.hodaszi@digi.com Signed-off-by: Peter Chen Signed-off-by: Marc Kleine-Budde Tested-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/usb/chipidea/ci.h | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'drivers/usb/chipidea/ci.h') diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h index a71dc1c89aa2..88b80f7728e4 100644 --- a/drivers/usb/chipidea/ci.h +++ b/drivers/usb/chipidea/ci.h @@ -164,6 +164,7 @@ struct hw_bank { * @id_event: indicates there is an id event, and handled at ci_otg_work * @b_sess_valid_event: indicates there is a vbus event, and handled * at ci_otg_work + * @imx28_write_fix: Freescale imx28 needs swp instruction for writing */ struct ci_hdrc { struct device *dev; @@ -202,6 +203,7 @@ struct ci_hdrc { struct dentry *debugfs; bool id_event; bool b_sess_valid_event; + bool imx28_write_fix; }; static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci) @@ -250,6 +252,26 @@ 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 val, volatile void __iomem *addr) +{ + __asm__ ("swp %0, %0, [%1]" : : "r"(val), "r"(addr)); +} +#else +static inline void imx28_ci_writel(u32 val, volatile void __iomem *addr) +{ +} +#endif + +static inline void __hw_write(struct ci_hdrc *ci, u32 val, + void __iomem *addr) +{ + if (ci->imx28_write_fix) + imx28_ci_writel(val, addr); + else + iowrite32(val, addr); +} + /** * hw_write: writes to a hw register * @reg: register index @@ -263,7 +285,7 @@ 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]); } /** @@ -278,7 +300,7 @@ 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; } -- cgit v1.2.3