[ARM] pxa: introduce sysdev for GPIO register saving/restoring

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 57 insertions, 0 deletions

diff --git a/arch/arm/mach-pxa/generic.c b/arch/arm/mach-pxa/generic.c
index 698aeec5296..76970598f55 100644
--- a/arch/arm/mach-pxa/generic.c
+++ b/arch/arm/mach-pxa/generic.c
@@ -23,6 +23,7 @@
 #include <linux/ioport.h>
 #include <linux/pm.h>
 #include <linux/string.h>
+#include <linux/sysdev.h>
 
 #include <asm/hardware.h>
 #include <asm/irq.h>
@@ -226,3 +227,59 @@ void __init pxa_map_io(void)
 	iotable_init(standard_io_desc, ARRAY_SIZE(standard_io_desc));
 	get_clk_frequency_khz(1);
 }
+
+#ifdef CONFIG_PM
+
+static unsigned long saved_gplr[4];
+static unsigned long saved_gpdr[4];
+static unsigned long saved_grer[4];
+static unsigned long saved_gfer[4];
+
+static int pxa_gpio_suspend(struct sys_device *dev, pm_message_t state)
+{
+	int i, gpio;
+
+	for (gpio = 0, i = 0; gpio < pxa_last_gpio; gpio += 32, i++) {
+		saved_gplr[i] = GPLR(gpio);
+		saved_gpdr[i] = GPDR(gpio);
+		saved_grer[i] = GRER(gpio);
+		saved_gfer[i] = GFER(gpio);
+
+		/* Clear GPIO transition detect bits */
+		GEDR(gpio) = GEDR(gpio);
+	}
+	return 0;
+}
+
+static int pxa_gpio_resume(struct sys_device *dev)
+{
+	int i, gpio;
+
+	for (gpio = 0, i = 0; gpio < pxa_last_gpio; gpio += 32, i++) {
+		/* restore level with set/clear */
+		GPSR(gpio) = saved_gplr[i];
+		GPCR(gpio) = ~saved_gplr[i];
+
+		GRER(gpio) = saved_grer[i];
+		GFER(gpio) = saved_gfer[i];
+		GPDR(gpio) = saved_gpdr[i];
+	}
+	return 0;
+}
+#else
+#define pxa_gpio_suspend	NULL
+#define pxa_gpio_resume		NULL
+#endif
+
+struct sysdev_class pxa_gpio_sysclass = {
+	.name		= "gpio",
+	.suspend	= pxa_gpio_suspend,
+	.resume		= pxa_gpio_resume,
+};
+
+static int __init pxa_gpio_init(void)
+{
+	return sysdev_class_register(&pxa_gpio_sysclass);
+}
+
+core_initcall(pxa_gpio_init);