diff options
| author | Peter Chen <peter.chen@freescale.com> | 2013-10-23 15:41:08 +0800 |
|---|---|---|
| committer | Peter Chen <peter.chen@freescale.com> | 2013-11-06 11:05:01 +0800 |
| commit | 7229aca4df2217f5ecdc17a0f8bef0ec2402f062 (patch) | |
| tree | aae1743842a90c9ba1ae5f7181e6b213a42c289b | |
| parent | 390bda1711c1d80b3b7f0cc2fffc4c3542f26f6c (diff) | |
usb: ehci: 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 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 <peter.chen@freescale.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
| -rw-r--r-- | 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 7c978b23520d..9b6732a7ace1 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -200,6 +200,7 @@ 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) @@ -675,6 +676,13 @@ 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) +{ + __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) { @@ -682,6 +690,11 @@ 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 |