gpio: mxs: Add IRQ_TYPE_EDGE_BOTH support

This patch adds support for IRQ_TYPE_EDGE_BOTH needed for some driver
(gpio-keys).

Inspired from gpio-mxc.c

Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@armadeus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-mxs.c b/drivers/gpio/gpio-mxs.c
index fa2a63c..859b6fa 100644 (file)
--- a/drivers/gpio/gpio-mxs.c
+++ b/drivers/gpio/gpio-mxs.c
@@ -65,6 +65,7 @@ struct mxs_gpio_port {
        struct irq_domain *domain;
        struct bgpio_chip bgc;
        enum mxs_gpio_id devid;
+       u32 both_edges;
 };
 
 static inline int is_imx23_gpio(struct mxs_gpio_port *port)
@@ -81,13 +82,23 @@ static inline int is_imx28_gpio(struct mxs_gpio_port *port)
 
 static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
 {
+       u32 val;
        u32 pin_mask = 1 << d->hwirq;
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct mxs_gpio_port *port = gc->private;
        void __iomem *pin_addr;
        int edge;
 
+       port->both_edges &= ~pin_mask;
        switch (type) {
+       case IRQ_TYPE_EDGE_BOTH:
+               val = gpio_get_value(port->bgc.gc.base + d->hwirq);
+               if (val)
+                       edge = GPIO_INT_FALL_EDGE;
+               else
+                       edge = GPIO_INT_RISE_EDGE;
+               port->both_edges |= pin_mask;
+               break;
        case IRQ_TYPE_EDGE_RISING:
                edge = GPIO_INT_RISE_EDGE;
                break;
@@ -124,6 +135,23 @@ static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
        return 0;
 }
 
+static void mxs_flip_edge(struct mxs_gpio_port *port, u32 gpio)
+{
+       u32 bit, val, edge;
+       void __iomem *pin_addr;
+
+       bit = 1 << gpio;
+
+       pin_addr = port->base + PINCTRL_IRQPOL(port);
+       val = readl(pin_addr);
+       edge = val & bit;
+
+       if (edge)
+               writel(bit, pin_addr + MXS_CLR);
+       else
+               writel(bit, pin_addr + MXS_SET);
+}
+
 /* MXS has one interrupt *per* gpio port */
 static void mxs_gpio_irq_handler(u32 irq, struct irq_desc *desc)
 {
@@ -137,6 +165,9 @@ static void mxs_gpio_irq_handler(u32 irq, struct irq_desc *desc)
 
        while (irq_stat != 0) {
                int irqoffset = fls(irq_stat) - 1;
+               if (port->both_edges & (1 << irqoffset))
+                       mxs_flip_edge(port, irqoffset);
+
                generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
                irq_stat &= ~(1 << irqoffset);
        }