[PATCH 3/7] usb: xhci: improve xhci_decode_portsc()

[Niklas Neronin <niklas.neronin@linux.intel.com>]

This patch improves xhci_decode_portsc(), which is used in PORTCS tracing.
The upcoming patch will add tracing to all PORTCS writes.

Read-Write 1 to Clear (RW1C) bits are now grouped together and prefixed
with "RW1C: " if needed. This is because the meaning of a set RW1C bit
differs between reading and writing. For instance, when reading 'PORT_PE',
a value of '1' indicates the port is enabled, while '0' means it is
disabled. Conversely, writing a '1' to 'PORT_PE' signifies that the port
is being disabled.

Add Port Link State Write Strobe (LWS) to the decoder.

Simplify and reduce the length of the message.

==== Examples ====

Before:
0x00201203 Powered Connected Enabled Link:U0 PortSpeed:4 Change: PRC Wake:
0x0a0002a0 Powered Not-connected Disabled Link:RxDetect PortSpeed:0 \
 Change: Wake: WCE WOE

After:
0x00201203 Power:1 Connect:1 Link:U0 Speed:4 RW1C: PED PRC
0x0a0002a0 Power:1 Connect:0 Link:RxDetect Speed:0 WCE WOE

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
---
I am aware that the 'XHCI_PORT_RW1CS' macro could replace
'(PORT_PE | PORT_CHANGE_MASK)'. However, it is not located in xhci-port.h,
does not utilize established port macros, and is inaccessible in xhci.h.
To avoid complicating this patch set further, I've decided to defer this
change to part 2. Otherwise, this patch set will grow forever :D
Part 2 will tackle xhci-port.h and all associated macros.

 drivers/usb/host/xhci.h | 52 +++++++++++++++++++++++------------------
 1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index a20f4e7cd43a..f37965e64fd5 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2395,37 +2395,22 @@ static inline const char *xhci_decode_portsc(char *str, u32 portsc)
 	if (portsc == ~(u32)0)
 		return str;
 
-	ret += sprintf(str + ret, "%s %s %s Link:%s PortSpeed:%d ",
-		      portsc & PORT_POWER	? "Powered" : "Powered-off",
-		      portsc & PORT_CONNECT	? "Connected" : "Not-connected",
-		      portsc & PORT_PE		? "Enabled" : "Disabled",
+	ret += sprintf(str + ret, "Power:%d Connect:%d Link:%s Speed:%d ",
+		      !!(portsc & PORT_POWER),
+		      !!(portsc & PORT_CONNECT),
 		      xhci_portsc_link_state_string(portsc),
 		      DEV_PORT_SPEED(portsc));
 
-	if (portsc & PORT_OC)
-		ret += sprintf(str + ret, "OverCurrent ");
+	/* Read-Write 1 to Set */
 	if (portsc & PORT_RESET)
 		ret += sprintf(str + ret, "In-Reset ");
 
-	ret += sprintf(str + ret, "Change: ");
-	if (portsc & PORT_CSC)
-		ret += sprintf(str + ret, "CSC ");
-	if (portsc & PORT_PEC)
-		ret += sprintf(str + ret, "PEC ");
-	if (portsc & PORT_WRC)
-		ret += sprintf(str + ret, "WRC ");
-	if (portsc & PORT_OCC)
-		ret += sprintf(str + ret, "OCC ");
-	if (portsc & PORT_RC)
-		ret += sprintf(str + ret, "PRC ");
-	if (portsc & PORT_PLC)
-		ret += sprintf(str + ret, "PLC ");
-	if (portsc & PORT_CEC)
-		ret += sprintf(str + ret, "CEC ");
+	if (portsc & PORT_OC)
+		ret += sprintf(str + ret, "OCA ");
+	if (portsc & PORT_LINK_STROBE)
+		ret += sprintf(str + ret, "LWS ");
 	if (portsc & PORT_CAS)
 		ret += sprintf(str + ret, "CAS ");
-
-	ret += sprintf(str + ret, "Wake: ");
 	if (portsc & PORT_WKCONN_E)
 		ret += sprintf(str + ret, "WCE ");
 	if (portsc & PORT_WKDISC_E)
@@ -2433,6 +2418,27 @@ static inline const char *xhci_decode_portsc(char *str, u32 portsc)
 	if (portsc & PORT_WKOC_E)
 		ret += sprintf(str + ret, "WOE ");
 
+	/* Read-Write 1 to Clear */
+	if (portsc & (PORT_PE | PORT_CHANGE_MASK)) {
+		ret += sprintf(str + ret, "RW1C: ");
+		if (portsc & PORT_PE)
+			ret += sprintf(str + ret, "PED ");
+		if (portsc & PORT_CSC)
+			ret += sprintf(str + ret, "CSC ");
+		if (portsc & PORT_PEC)
+			ret += sprintf(str + ret, "PEC ");
+		if (portsc & PORT_WRC)
+			ret += sprintf(str + ret, "WRC ");
+		if (portsc & PORT_OCC)
+			ret += sprintf(str + ret, "OCC ");
+		if (portsc & PORT_RC)
+			ret += sprintf(str + ret, "PRC ");
+		if (portsc & PORT_PLC)
+			ret += sprintf(str + ret, "PLC ");
+		if (portsc & PORT_CEC)
+			ret += sprintf(str + ret, "CEC ");
+	}
+
 	return str;
 }
 
-- 
2.50.1