[PATCH] ehci, registers to driverfs (for debug)

When debugging, it's useful to see what the registers are
saying is up without needing to poke around in the kernel.
This patch exposes them.

drivers/usb/host/ehci-dbg.c

@@ -26,8 +26,10 @@
 
 #ifdef	DEBUG
 
-/* check the values in the HCSPARAMS register - host controller structural parameters */
-/* see EHCI 0.95 Spec, Table 2-4 for each value */
+/* check the values in the HCSPARAMS register
+ * (host controller _Structural_ parameters)
+ * see EHCI spec, Table 2-4 for each value
+ */
 static void dbg_hcs_params (struct ehci_hcd *ehci, char *label)
 {
 	u32	params = readl (&ehci->caps->hcs_params);
@@ -67,8 +69,10 @@ static inline void dbg_hcs_params (struct ehci_hcd *ehci, char *label) {}
 
 #ifdef	DEBUG
 
-/* check the values in the HCCPARAMS register - host controller capability parameters */
-/* see EHCI 0.95 Spec, Table 2-5 for each value */
+/* check the values in the HCCPARAMS register
+ * (host controller _Capability_ parameters)
+ * see EHCI Spec, Table 2-5 for each value
+ * */
 static void dbg_hcc_params (struct ehci_hcd *ehci, char *label)
 {
 	u32	params = readl (&ehci->caps->hcc_params);
@@ -79,13 +83,13 @@ static void dbg_hcc_params (struct ehci_hcd *ehci, char *label)
 			label, HCC_EXT_CAPS (params));
 	}
 	if (HCC_ISOC_CACHE (params)) {
-		dbg ("%s hcc_params 0x%04x caching frame %s%s%s",
+		dbg ("%s hcc_params %04x caching frame %s%s%s",
 		     label, params,
 		     HCC_PGM_FRAMELISTLEN (params) ? "256/512/1024" : "1024",
 		     HCC_CANPARK (params) ? " park" : "",
 		     HCC_64BIT_ADDR (params) ? " 64 bit addr" : "");
 	} else {
-		dbg ("%s hcc_params 0x%04x caching %d uframes %s%s%s",
+		dbg ("%s hcc_params %04x caching %d uframes %s%s%s",
 		     label,
 		     params,
 		     HCC_ISOC_THRES (params),
@@ -118,62 +122,131 @@ dbg_qh (char *label, struct ehci_hcd *ehci, struct ehci_qh *qh)
 	}
 }
 
+static int dbg_status_buf (char *buf, unsigned len, char *label, u32 status)
+{
+	return snprintf (buf, len,
+		"%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
+		label, label [0] ? " " : "", status,
+		(status & STS_ASS) ? " Async" : "",
+		(status & STS_PSS) ? " Periodic" : "",
+		(status & STS_RECL) ? " Recl" : "",
+		(status & STS_HALT) ? " Halt" : "",
+		(status & STS_IAA) ? " IAA" : "",
+		(status & STS_FATAL) ? " FATAL" : "",
+		(status & STS_FLR) ? " FLR" : "",
+		(status & STS_PCD) ? " PCD" : "",
+		(status & STS_ERR) ? " ERR" : "",
+		(status & STS_INT) ? " INT" : ""
+		);
+}
+
+static int dbg_intr_buf (char *buf, unsigned len, char *label, u32 enable)
+{
+	return snprintf (buf, len,
+		"%s%sintrenable %02x%s%s%s%s%s%s",
+		label, label [0] ? " " : "", enable,
+		(enable & STS_IAA) ? " IAA" : "",
+		(enable & STS_FATAL) ? " FATAL" : "",
+		(enable & STS_FLR) ? " FLR" : "",
+		(enable & STS_PCD) ? " PCD" : "",
+		(enable & STS_ERR) ? " ERR" : "",
+		(enable & STS_INT) ? " INT" : ""
+		);
+}
+
 static const char *const fls_strings [] =
     { "1024", "512", "256", "??" };
 
+static int dbg_command_buf (char *buf, unsigned len, char *label, u32 command)
+{
+	return snprintf (buf, len,
+		"%s%scommand %06x %s=%d ithresh=%d%s%s%s%s period=%s%s %s",
+		label, label [0] ? " " : "", command,
+		(command & CMD_PARK) ? "park" : "(park)",
+		CMD_PARK_CNT (command),
+		(command >> 16) & 0x3f,
+		(command & CMD_LRESET) ? " LReset" : "",
+		(command & CMD_IAAD) ? " IAAD" : "",
+		(command & CMD_ASE) ? " Async" : "",
+		(command & CMD_PSE) ? " Periodic" : "",
+		fls_strings [(command >> 2) & 0x3],
+		(command & CMD_RESET) ? " Reset" : "",
+		(command & CMD_RUN) ? "RUN" : "HALT"
+		);
+}
+
+static int
+dbg_port_buf (char *buf, unsigned len, char *label, int port, u32 status)
+{
+	char	*sig;
+
+	/* signaling state */
+	switch (status & (3 << 10)) {
+	case 0 << 10: sig = "se0"; break;
+	case 1 << 10: sig = "k"; break;		/* low speed */
+	case 2 << 10: sig = "j"; break;
+	default: sig = "?"; break;
+	}
+
+	return snprintf (buf, len,
+		"%s%sport %d status %06x%s%s sig=%s %s%s%s%s%s%s%s%s%s",
+		label, label [0] ? " " : "", port, status,
+		(status & PORT_POWER) ? " POWER" : "",
+		(status & PORT_OWNER) ? " OWNER" : "",
+		sig,
+		(status & PORT_RESET) ? " RESET" : "",
+		(status & PORT_SUSPEND) ? " SUSPEND" : "",
+		(status & PORT_RESUME) ? " RESUME" : "",
+		(status & PORT_OCC) ? " OCC" : "",
+		(status & PORT_OC) ? " OC" : "",
+		(status & PORT_PEC) ? " PEC" : "",
+		(status & PORT_PE) ? " PE" : "",
+		(status & PORT_CSC) ? " CSC" : "",
+		(status & PORT_CONNECT) ? " CONNECT" : ""
+	    );
+}
+
 #else
 static inline void __attribute__((__unused__))
-dbg_qh (char *label, struct ehci_hcd *ehci, struct ehci_qh *qh) {}
+dbg_qh (char *label, struct ehci_hcd *ehci, struct ehci_qh *qh)
+{}
+
+static inline int __attribute__((__unused__))
+dbg_status_buf (char *buf, unsigned len, char *label, u32 status)
+{}
+
+static inline int __attribute__((__unused__))
+dbg_command_buf (char *buf, unsigned len, char *label, u32 command)
+{}
+
+static inline int __attribute__((__unused__))
+dbg_intr_buf (char *buf, unsigned len, char *label, u32 enable)
+{}
+
+static inline int __attribute__((__unused__))
+dbg_port_buf (char *buf, unsigned len, char *label, int port, u32 status)
+{}
+
 #endif	/* DEBUG */
 
 /* functions have the "wrong" filename when they're output... */
+#define dbg_status(ehci, label, status) { \
+	char _buf [80]; \
+	dbg_status_buf (_buf, sizeof _buf, label, status); \
+	dbg ("%s", _buf); \
+}
 
-#define dbg_status(ehci, label, status) \
-	dbg ("%s status 0x%x%s%s%s%s%s%s%s%s%s%s", \
-		label, status, \
-		(status & STS_ASS) ? " Async" : "", \
-		(status & STS_PSS) ? " Periodic" : "", \
-		(status & STS_RECL) ? " Recl" : "", \
-		(status & STS_HALT) ? " Halt" : "", \
-		(status & STS_IAA) ? " IAA" : "", \
-		(status & STS_FATAL) ? " FATAL" : "", \
-		(status & STS_FLR) ? " FLR" : "", \
-		(status & STS_PCD) ? " PCD" : "", \
-		(status & STS_ERR) ? " ERR" : "", \
-		(status & STS_INT) ? " INT" : "" \
-		)
-
-#define dbg_cmd(ehci, label, command) \
-	dbg ("%s %x cmd %s=%d ithresh=%d%s%s%s%s period=%s%s %s", \
-		label, command, \
-		(command & CMD_PARK) ? "park" : "(park)", \
-		CMD_PARK_CNT (command), \
-		(command >> 16) & 0x3f, \
-		(command & CMD_LRESET) ? " LReset" : "", \
-		(command & CMD_IAAD) ? " IAAD" : "", \
-		(command & CMD_ASE) ? " Async" : "", \
-		(command & CMD_PSE) ? " Periodic" : "", \
-		fls_strings [(command >> 2) & 0x3], \
-		(command & CMD_RESET) ? " Reset" : "", \
-		(command & CMD_RUN) ? "RUN" : "HALT" \
-		)
-
-#define dbg_port(hcd, label, port, status) \
-	dbg ("%s port %d status 0x%x%s%s speed=%d%s%s%s%s%s%s%s%s%s", \
-		label, port, status, \
-		(status & PORT_OWNER) ? " OWNER" : "", \
-		(status & PORT_POWER) ? " POWER" : "", \
-		(status >> 10) & 3, \
-		(status & PORT_RESET) ? " RESET" : "", \
-		(status & PORT_SUSPEND) ? " SUSPEND" : "", \
-		(status & PORT_RESUME) ? " RESUME" : "", \
-		(status & PORT_OCC) ? " OCC" : "", \
-		(status & PORT_OC) ? " OC" : "", \
-		(status & PORT_PEC) ? " PEC" : "", \
-		(status & PORT_PE) ? " PE" : "", \
-		(status & PORT_CSC) ? " CSC" : "", \
-		(status & PORT_CONNECT) ? " CONNECT" : "" \
-	    )
+#define dbg_cmd(ehci, label, command) { \
+	char _buf [80]; \
+	dbg_command_buf (_buf, sizeof _buf, label, command); \
+	dbg ("%s", _buf); \
+}
+
+#define dbg_port(hcd, label, port, status) { \
+	char _buf [80]; \
+	dbg_port_buf (_buf, sizeof _buf, label, port, status); \
+	dbg ("%s", _buf); \
+}
 
 #ifdef DEBUG
 
@@ -228,8 +301,9 @@ show_async (struct device *dev, char *buf, size_t count, loff_t off)
 						qtd_list);
 				scratch = cpu_to_le32p (&td->hw_token);
 				temp = snprintf (next, size,
-						", td %p len=%d %s",
+						", td %p len=%d tok %04x %s",
 						td, scratch >> 16,
+						scratch & 0xffff,
 						({ char *tmp;
 						 switch ((scratch>>8)&0x03) {
 						 case 0: tmp = "out"; break;
@@ -364,16 +438,104 @@ static DEVICE_ATTR (periodic, S_IRUSR, show_periodic, NULL);
 
 #undef DBG_SCHED_LIMIT
 
+static ssize_t
+show_registers (struct device *dev, char *buf, size_t count, loff_t off)
+{
+	struct pci_dev		*pdev;
+	struct ehci_hcd		*ehci;
+	unsigned long		flags;
+	unsigned		temp, size, i;
+	char			*next, scratch [80];
+	static char		fmt [] = "%*s\n";
+	static char		label [] = "";
+
+	if (off != 0)
+		return 0;
+
+	pdev = container_of (dev, struct pci_dev, dev);
+	ehci = container_of (pci_get_drvdata (pdev), struct ehci_hcd, hcd);
+
+	next = buf;
+	size = count;
+
+	spin_lock_irqsave (&ehci->lock, flags);
+
+	/* Capability Registers */
+	i = readw (&ehci->caps->hci_version);
+	temp = snprintf (next, size, "EHCI %x.%02x, hcd state %d\n",
+		i >> 8, i & 0x0ff, ehci->hcd.state);
+	size -= temp;
+	next += temp;
+
+	// FIXME interpret both types of params
+	i = readl (&ehci->caps->hcs_params);
+	temp = snprintf (next, size, "structural params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	i = readl (&ehci->caps->hcc_params);
+	temp = snprintf (next, size, "capability params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	/* Operational Registers */
+	temp = dbg_status_buf (scratch, sizeof scratch, label,
+			readl (&ehci->regs->status));
+	temp = snprintf (next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_command_buf (scratch, sizeof scratch, label,
+			readl (&ehci->regs->command));
+	temp = snprintf (next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_intr_buf (scratch, sizeof scratch, label,
+			readl (&ehci->regs->intr_enable));
+	temp = snprintf (next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = snprintf (next, size, "uframe %04x\n",
+			readl (&ehci->regs->frame_index));
+	size -= temp;
+	next += temp;
+
+	for (i = 0; i < HCS_N_PORTS (ehci->hcs_params); i++) {
+		temp = dbg_port_buf (scratch, sizeof scratch, label, i,
+				readl (&ehci->regs->port_status [i]));
+		temp = snprintf (next, size, fmt, temp, scratch);
+		size -= temp;
+		next += temp;
+	}
+
+	if (ehci->reclaim) {
+		temp = snprintf (next, size, "reclaim qh %p%s\n",
+				ehci->reclaim,
+				ehci->reclaim_ready ? " ready" : "");
+		size -= temp;
+		next += temp;
+	}
+
+	spin_unlock_irqrestore (&ehci->lock, flags);
+
+	return count - size;
+}
+static DEVICE_ATTR (registers, S_IRUSR, show_registers, NULL);
+
 static inline void create_debug_files (struct ehci_hcd *bus)
 {
 	device_create_file (&bus->hcd.pdev->dev, &dev_attr_async);
 	device_create_file (&bus->hcd.pdev->dev, &dev_attr_periodic);
+	device_create_file (&bus->hcd.pdev->dev, &dev_attr_registers);
 }
 
 static inline void remove_debug_files (struct ehci_hcd *bus)
 {
 	device_remove_file (&bus->hcd.pdev->dev, &dev_attr_async);
 	device_remove_file (&bus->hcd.pdev->dev, &dev_attr_periodic);
+	device_remove_file (&bus->hcd.pdev->dev, &dev_attr_registers);
 }
 
 #else /* DEBUG */