diff options
author | Felipe Balbi <balbi@ti.com> | 2013-06-30 13:56:45 +0300 |
---|---|---|
committer | Felipe Balbi <balbi@ti.com> | 2013-07-29 13:56:46 +0300 |
commit | 1494a1f62bf7cf57345e9282c8189fe2a21fab64 (patch) | |
tree | 16b5e45329a149af37278811b760422ae5e0d46d /drivers/usb/usb-common.c | |
parent | 410aee70f06da60dd8f78c3ec3346cc74c9bed46 (diff) |
usb: common: introduce of_usb_get_maximum_speed()
this helper will be used for controllers which
want to work at a lower speed even though they
support higher USB transfer rates.
One such case is Texas Instruments' AM437x
SoC where it uses a USB3 controller without
a USB3 PHY, rendering the controller USB2-only.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/usb-common.c')
-rw-r--r-- | drivers/usb/usb-common.c | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/drivers/usb/usb-common.c b/drivers/usb/usb-common.c index 675384dabfe9..d771870a819e 100644 --- a/drivers/usb/usb-common.c +++ b/drivers/usb/usb-common.c @@ -43,20 +43,20 @@ const char *usb_otg_state_string(enum usb_otg_state state) } EXPORT_SYMBOL_GPL(usb_otg_state_string); +static const char *const speed_names[] = { + [USB_SPEED_UNKNOWN] = "UNKNOWN", + [USB_SPEED_LOW] = "low-speed", + [USB_SPEED_FULL] = "full-speed", + [USB_SPEED_HIGH] = "high-speed", + [USB_SPEED_WIRELESS] = "wireless", + [USB_SPEED_SUPER] = "super-speed", +}; + const char *usb_speed_string(enum usb_device_speed speed) { - static const char *const names[] = { - [USB_SPEED_UNKNOWN] = "UNKNOWN", - [USB_SPEED_LOW] = "low-speed", - [USB_SPEED_FULL] = "full-speed", - [USB_SPEED_HIGH] = "high-speed", - [USB_SPEED_WIRELESS] = "wireless", - [USB_SPEED_SUPER] = "super-speed", - }; - - if (speed < 0 || speed >= ARRAY_SIZE(names)) + if (speed < 0 || speed >= ARRAY_SIZE(speed_names)) speed = USB_SPEED_UNKNOWN; - return names[speed]; + return speed_names[speed]; } EXPORT_SYMBOL_GPL(usb_speed_string); @@ -112,6 +112,33 @@ enum usb_dr_mode of_usb_get_dr_mode(struct device_node *np) return USB_DR_MODE_UNKNOWN; } EXPORT_SYMBOL_GPL(of_usb_get_dr_mode); + +/** + * of_usb_get_maximum_speed - Get maximum requested speed for a given USB + * controller. + * @np: Pointer to the given device_node + * + * The function gets the maximum speed string from property "maximum-speed", + * and returns the corresponding enum usb_device_speed. + */ +enum usb_device_speed of_usb_get_maximum_speed(struct device_node *np) +{ + const char *maximum_speed; + int err; + int i; + + err = of_property_read_string(np, "maximum-speed", &maximum_speed); + if (err < 0) + return USB_SPEED_UNKNOWN; + + for (i = 0; i < ARRAY_SIZE(speed_names); i++) + if (strcmp(maximum_speed, speed_names[i]) == 0) + return i; + + return USB_SPEED_UNKNOWN; +} +EXPORT_SYMBOL_GPL(of_usb_get_maximum_speed); + #endif MODULE_LICENSE("GPL"); |