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>

diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c
index 5b5fd1e..46f1af8 100644 (file)
--- 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)