PCI: add power-state name strings

This patch (as1235) adds an array of PCI power-state names, together
with a simple inline accessor routine.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/pci.c

@@ -24,6 +24,11 @@
 #include <asm/setup.h>
 #include "pci.h"
 
+const char *pci_power_names[] = {
+	"error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
+};
+EXPORT_SYMBOL_GPL(pci_power_names);
+
 unsigned int pci_pm_d3_delay = PCI_PM_D3_WAIT;
 
 #ifdef CONFIG_PCI_DOMAINS

include/linux/pci.h

@@ -124,6 +124,14 @@ typedef int __bitwise pci_power_t;
 #define PCI_UNKNOWN	((pci_power_t __force) 5)
 #define PCI_POWER_ERROR	((pci_power_t __force) -1)
 
+/* Remember to update this when the list above changes! */
+extern const char *pci_power_names[];
+
+static inline const char *pci_power_name(pci_power_t state)
+{
+	return pci_power_names[1 + (int) state];
+}
+
 #define PCI_PM_D2_DELAY	200
 #define PCI_PM_D3_WAIT	10
 #define PCI_PM_BUS_WAIT	50