gpio: vf610: add system PM suspend/resume

Store the state of the GPIO module (which contains the GPIO output
state) in memory during suspend. The driver already maintains an
interrupt configuration in memory, hence we can use this
configuration to restore the port control register (PCR).

diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
index 87b950cec6ec929689a3d52b428f9224acebc623..03b5dfa59a12ca3e8399e70d253e66016ab9b094 100644 (file)
--- a/drivers/gpio/gpio-vf610.c
+++ b/drivers/gpio/gpio-vf610.c
@@ -37,6 +37,7 @@ struct vf610_gpio_port {
        void __iomem *gpio_base;
        u8 irqc[VF610_GPIO_PER_PORT];
        int irq;
+       u32 state;
 };
 
 #define GPIO_PDOR              0x00
@@ -220,6 +221,40 @@ static struct irq_chip vf610_gpio_irq_chip = {
        .irq_set_wake   = vf610_gpio_irq_set_wake,
 };
 
+static int __maybe_unused vf610_gpio_suspend(struct device *dev)
+{
+       struct vf610_gpio_port *port = dev_get_drvdata(dev);
+
+       port->state = vf610_gpio_readl(port->gpio_base + GPIO_PDOR);
+
+       /*
+        * There is no need to store Port state since we maintain the state
+        * alread in the irqc array
+        */
+
+       return 0;
+}
+
+static int __maybe_unused vf610_gpio_resume(struct device *dev)
+{
+       struct vf610_gpio_port *port = dev_get_drvdata(dev);
+       int i;
+
+       vf610_gpio_writel(port->state, port->gpio_base + GPIO_PDOR);
+
+       for (i = 0; i < port->gc.ngpio; i++) {
+               u32 irqc = port->irqc[i] << PORT_PCR_IRQC_OFFSET;
+
+               vf610_gpio_writel(irqc, port->base + PORT_PCR(i));
+       }
+
+       return 0;
+}
+
+static const struct dev_pm_ops vf610_gpio_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(vf610_gpio_suspend, vf610_gpio_resume)
+};
+
 static int vf610_gpio_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
@@ -277,6 +312,7 @@ static int vf610_gpio_probe(struct platform_device *pdev)
        }
        gpiochip_set_chained_irqchip(gc, &vf610_gpio_irq_chip, port->irq,
                                     vf610_gpio_irq_handler);
+       platform_set_drvdata(pdev, port);
 
        return 0;
 }
@@ -284,6 +320,7 @@ static int vf610_gpio_probe(struct platform_device *pdev)
 static struct platform_driver vf610_gpio_driver = {
        .driver         = {
                .name   = "gpio-vf610",
+               .pm = &vf610_gpio_pm_ops,
                .of_match_table = vf610_gpio_dt_ids,
        },
        .probe          = vf610_gpio_probe,