[PATCH v3] usb: hcd.h: construct hub class request constants from simpler constants

From: Tal Shorer
Date: Fri Nov 18 2016 - 07:17:55 EST


Currently, each hub class request constant is defined by a line like:
#define ClearHubFeature (0x2000 | USB_REQ_CLEAR_FEATURE)

The "magic" number for the high byte is one of 0x20, 0xa0, 0x23, 0xa3.
The 0x80 bit that changes inditace USB_DIR_IN, and the 0x03 that
pops up is the difference between USB_RECIP_DEVICE (0x00) and
USB_RECIP_OTHER (0x03). The constant 0x20 bit is USB_TYPE_CLASS.

This patch eliminates those magic numbers by defining a macro to help
construct these hub class request from simpler constants.
Note that USB_RT_HUB is defined as (USB_TYPE_CLASS | USB_RECIP_DEVICE)
and that USB_RT_PORT is defined as (USB_TYPE_CLASS | USB_RECIP_OTHER).

Signed-off-by: Tal Shorer <tal.shorer@xxxxxxxxx>
---
include/linux/usb/hcd.h | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 66fc137..40edf6a 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -566,21 +566,22 @@ extern void usb_ep0_reinit(struct usb_device *);
((USB_DIR_OUT|USB_TYPE_STANDARD|USB_RECIP_INTERFACE)<<8)

/* class requests from the USB 2.0 hub spec, table 11-15 */
+#define HUB_CLASS_REQ(dir, type, request) ((((dir) | (type)) << 8) | (request))
/* GetBusState and SetHubDescriptor are optional, omitted */
-#define ClearHubFeature (0x2000 | USB_REQ_CLEAR_FEATURE)
-#define ClearPortFeature (0x2300 | USB_REQ_CLEAR_FEATURE)
-#define GetHubDescriptor (0xa000 | USB_REQ_GET_DESCRIPTOR)
-#define GetHubStatus (0xa000 | USB_REQ_GET_STATUS)
-#define GetPortStatus (0xa300 | USB_REQ_GET_STATUS)
-#define SetHubFeature (0x2000 | USB_REQ_SET_FEATURE)
-#define SetPortFeature (0x2300 | USB_REQ_SET_FEATURE)
+#define ClearHubFeature HUB_CLASS_REQ(USB_DIR_OUT, USB_RT_HUB, USB_REQ_CLEAR_FEATURE)
+#define ClearPortFeature HUB_CLASS_REQ(USB_DIR_OUT, USB_RT_PORT, USB_REQ_CLEAR_FEATURE)
+#define GetHubDescriptor HUB_CLASS_REQ(USB_DIR_IN, USB_RT_HUB, USB_REQ_GET_DESCRIPTOR)
+#define GetHubStatus HUB_CLASS_REQ(USB_DIR_IN, USB_RT_HUB, USB_REQ_GET_STATUS)
+#define GetPortStatus HUB_CLASS_REQ(USB_DIR_IN, USB_RT_PORT, USB_REQ_GET_STATUS)
+#define SetHubFeature HUB_CLASS_REQ(USB_DIR_OUT, USB_RT_HUB, USB_REQ_SET_FEATURE)
+#define SetPortFeature HUB_CLASS_REQ(USB_DIR_OUT, USB_RT_PORT, USB_REQ_SET_FEATURE)


/*-------------------------------------------------------------------------*/

/* class requests from USB 3.1 hub spec, table 10-7 */
-#define SetHubDepth (0x2000 | HUB_SET_DEPTH)
-#define GetPortErrorCount (0xa300 | HUB_GET_PORT_ERR_COUNT)
+#define SetHubDepth HUB_CLASS_REQ(USB_DIR_OUT, USB_RT_HUB, HUB_SET_DEPTH)
+#define GetPortErrorCount HUB_CLASS_REQ(USB_DIR_IN, USB_RT_PORT, HUB_GET_PORT_ERR_COUNT)

/*
* Generic bandwidth allocation constants/support
--
2.5.0