usb: common: Separated decoding functions from dwc3 driver.

Patch moves some decoding functions from driver/usb/dwc3/debug.h driver
to driver/usb/common/debug.c file. These moved functions include:
    dwc3_decode_get_status
    dwc3_decode_set_clear_feature
    dwc3_decode_set_address
    dwc3_decode_get_set_descriptor
    dwc3_decode_get_configuration
    dwc3_decode_set_configuration
    dwc3_decode_get_intf
    dwc3_decode_set_intf
    dwc3_decode_synch_frame
    dwc3_decode_set_sel
    dwc3_decode_set_isoch_delay
    dwc3_decode_ctrl

These functions are used also in inroduced cdns3 driver.

All functions prefixes were changed from dwc3 to usb.
Also, function's parameters has been extended according to the name
of fields in standard SETUP packet.
Additionally, patch adds usb_decode_ctrl function to
include/linux/usb/ch9.h file.

Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index da82606be605..58b83066bea4 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -70,4 +70,31 @@ extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);
  */
 extern const char *usb_state_string(enum usb_device_state state);
 
+#ifdef CONFIG_TRACING
+/**
+ * usb_decode_ctrl - Returns human readable representation of control request.
+ * @str: buffer to return a human-readable representation of control request.
+ *       This buffer should have about 200 bytes.
+ * @size: size of str buffer.
+ * @bRequestType: matches the USB bmRequestType field
+ * @bRequest: matches the USB bRequest field
+ * @wValue: matches the USB wValue field (CPU byte order)
+ * @wIndex: matches the USB wIndex field (CPU byte order)
+ * @wLength: matches the USB wLength field (CPU byte order)
+ *
+ * Function returns decoded, formatted and human-readable description of
+ * control request packet.
+ *
+ * The usage scenario for this is for tracepoints, so function as a return
+ * use the same value as in parameters. This approach allows to use this
+ * function in TP_printk
+ *
+ * Important: wValue, wIndex, wLength parameters before invoking this function
+ * should be processed by le16_to_cpu macro.
+ */
+extern const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,
+				   __u8 bRequest, __u16 wValue, __u16 wIndex,
+				   __u16 wLength);
+#endif
+
 #endif /* __LINUX_USB_CH9_H */