| Message ID | 1400113986-339-6-git-send-email-abrestic@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/14/2014 06:33 PM, Andrew Bresticker wrote: > Board-specific USB configuration data is stored in FUSE_SKU_CALIB_0. > Export a function to read it so the PHY can be properly configured. This patch seems conceptually fine to me. Presumably once Peter's fuse driver is fleshed out, it can expose the exact same semantic interface to drivers. I suppose one could argue that we should create/use an explicit fuse subsystem with a standard API that drivers can call into, rather than a custom API. We can get the appropriate handle to use for that API from a phandle (plus fuse IDs?) in a DT property (in the XHCI device node, pointing at the fuse device node) much like any other cross-device resource reference. I'm not too bothered whether the code actually does that in the first instance, although we should make sure we add that DT property (containing all required fuse ID information) so that the code /can/ work that way if we want it to in the future.
diff --git a/arch/arm/mach-tegra/fuse.c b/arch/arm/mach-tegra/fuse.c index c9ac23b..e457ef7 100644 --- a/arch/arm/mach-tegra/fuse.c +++ b/arch/arm/mach-tegra/fuse.c @@ -34,6 +34,7 @@ #define FUSE_UID_HIGH 0x10c /* Tegra30 and later */ +#define FUSE_USB_CALIB 0x1f0 #define FUSE_VENDOR_CODE 0x200 #define FUSE_FAB_CODE 0x204 #define FUSE_LOT_CODE_0 0x208 @@ -154,6 +155,18 @@ u32 tegra_read_chipid(void) return readl_relaxed(IO_ADDRESS(TEGRA_APB_MISC_BASE) + 0x804); } +u32 tegra_read_usb_calibration_data(void) +{ + u32 reg; + + tegra_fuse_enable_clk(); + reg = tegra_fuse_readl(FUSE_USB_CALIB); + tegra_fuse_disable_clk(); + + return reg; +} +EXPORT_SYMBOL(tegra_read_usb_calibration_data); + static void __init tegra20_fuse_init_randomness(void) { u32 randomness[2]; diff --git a/include/linux/tegra-soc.h b/include/linux/tegra-soc.h index 95f611d..492dc95 100644 --- a/include/linux/tegra-soc.h +++ b/include/linux/tegra-soc.h @@ -18,5 +18,6 @@ #define __LINUX_TEGRA_SOC_H_ u32 tegra_read_chipid(void); +u32 tegra_read_usb_calibration_data(void); #endif /* __LINUX_TEGRA_SOC_H_ */
Board-specific USB configuration data is stored in FUSE_SKU_CALIB_0. Export a function to read it so the PHY can be properly configured. Signed-off-by: Andrew Bresticker <abrestic@chromium.org> --- arch/arm/mach-tegra/fuse.c | 13 +++++++++++++ include/linux/tegra-soc.h | 1 + 2 files changed, 14 insertions(+)