plat-nomadik: implement suspend/resume for GPIO

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 49 insertions, 2 deletions

diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c
index 5b5fd1ee3c04..46f1af869b7f 100644
--- a/arch/arm/plat-nomadik/gpio.c
+++ b/arch/arm/plat-nomadik/gpio.c
@@ -44,6 +44,7 @@ struct nmk_gpio_chip {
         /* Keep track of configured edges */
         u32 edge_rising;
         u32 edge_falling;
+        u32 backup[10];
 };
 
 static void __nmk_gpio_set_mode(struct nmk_gpio_chip *nmk_chip,
@@ -792,14 +793,60 @@ out:
         return ret;
 }
 
+#ifdef CONFIG_PM
+static int nmk_gpio_pm(struct platform_device *dev, bool suspend)
+{
+        struct nmk_gpio_chip *nmk_chip = platform_get_drvdata(dev);
+        int i;
+        static const unsigned int regs[] = {
+                NMK_GPIO_DAT,
+                NMK_GPIO_PDIS,
+                NMK_GPIO_DIR,
+                NMK_GPIO_AFSLA,
+                NMK_GPIO_AFSLB,
+                NMK_GPIO_SLPC,
+                NMK_GPIO_RIMSC,
+                NMK_GPIO_FIMSC,
+                NMK_GPIO_RWIMSC,
+                NMK_GPIO_FWIMSC,
+        };
+
+        BUILD_BUG_ON(ARRAY_SIZE(nmk_chip->backup) != ARRAY_SIZE(regs));
+
+        /* XXX: is this sufficient? what about pull-up/down configuration? */
+
+        for (i = 0; i < ARRAY_SIZE(regs); i++) {
+                if (suspend)
+                        nmk_chip->backup[i] = readl(nmk_chip->addr + regs[i]);
+                else
+                        writel(nmk_chip->backup[i], nmk_chip->addr + regs[i]);
+        }
+
+        return 0;
+}
+
+static int nmk_gpio_suspend(struct platform_device *dev, pm_message_t state)
+{
+        return nmk_gpio_pm(dev, true);
+}
+
+static int nmk_gpio_resume(struct platform_device *dev)
+{
+        return nmk_gpio_pm(dev, false);
+}
+#else
+#define nmk_gpio_suspend        NULL
+#define nmk_gpio_resume         NULL
+#endif
+
 static struct platform_driver nmk_gpio_driver = {
         .driver = {
                 .owner = THIS_MODULE,
                 .name = "gpio",
                 },
         .probe = nmk_gpio_probe,
-        .suspend = NULL, /* to be done */
-        .resume = NULL,
+        .suspend = nmk_gpio_suspend,
+        .resume = nmk_gpio_resume,
 };
 
 static int __init nmk_gpio_init(void)