gpio/mxs: convert gpio-mxs to use generic irq chip

The patch converts gpio-mxs driver to use generic irq chip.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

2 files changed, 35 insertions, 61 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 531bfb6c874..b84666a69af 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -102,6 +102,7 @@ config GPIO_MXS
         def_bool y
         depends on ARCH_MXS
         select GPIO_GENERIC
+        select GENERIC_IRQ_CHIP
 
 config GPIO_PLAT_SAMSUNG
         def_bool y
diff --git a/drivers/gpio/gpio-mxs.c b/drivers/gpio/gpio-mxs.c
index ddde0f44ba7..d8cafba8c82 100644
--- a/drivers/gpio/gpio-mxs.c
+++ b/drivers/gpio/gpio-mxs.c
@@ -59,51 +59,12 @@ struct mxs_gpio_port {
 
 /* Note: This driver assumes 32 GPIOs are handled in one register */
 
-static void clear_gpio_irqstatus(struct mxs_gpio_port *port, u32 index)
-{
-        writel(1 << index, port->base + PINCTRL_IRQSTAT(port->id) + MXS_CLR);
-}
-
-static void set_gpio_irqenable(struct mxs_gpio_port *port, u32 index,
-                                int enable)
-{
-        if (enable) {
-                writel(1 << index,
-                        port->base + PINCTRL_IRQEN(port->id) + MXS_SET);
-                writel(1 << index,
-                        port->base + PINCTRL_PIN2IRQ(port->id) + MXS_SET);
-        } else {
-                writel(1 << index,
-                        port->base + PINCTRL_IRQEN(port->id) + MXS_CLR);
-        }
-}
-
-static void mxs_gpio_ack_irq(struct irq_data *d)
-{
-        struct mxs_gpio_port *port = irq_data_get_irq_chip_data(d);
-        u32 gpio = irq_to_gpio(d->irq);
-        clear_gpio_irqstatus(port, gpio & 0x1f);
-}
-
-static void mxs_gpio_mask_irq(struct irq_data *d)
-{
-        struct mxs_gpio_port *port = irq_data_get_irq_chip_data(d);
-        u32 gpio = irq_to_gpio(d->irq);
-        set_gpio_irqenable(port, gpio & 0x1f, 0);
-}
-
-static void mxs_gpio_unmask_irq(struct irq_data *d)
-{
-        struct mxs_gpio_port *port = irq_data_get_irq_chip_data(d);
-        u32 gpio = irq_to_gpio(d->irq);
-        set_gpio_irqenable(port, gpio & 0x1f, 1);
-}
-
 static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
 {
         u32 gpio = irq_to_gpio(d->irq);
         u32 pin_mask = 1 << (gpio & 31);
-        struct mxs_gpio_port *port = irq_data_get_irq_chip_data(d);
+        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;
 
@@ -138,7 +99,8 @@ static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
         else
                 writel(pin_mask, pin_addr + MXS_CLR);
 
-        clear_gpio_irqstatus(port, gpio & 0x1f);
+        writel(1 << (gpio & 0x1f),
+               port->base + PINCTRL_IRQSTAT(port->id) + MXS_CLR);
 
         return 0;
 }
@@ -173,7 +135,8 @@ static void mxs_gpio_irq_handler(u32 irq, struct irq_desc *desc)
  */
 static int mxs_gpio_set_wake_irq(struct irq_data *d, unsigned int enable)
 {
-        struct mxs_gpio_port *port = irq_data_get_irq_chip_data(d);
+        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+        struct mxs_gpio_port *port = gc->private;
 
         if (enable)
                 enable_irq_wake(port->irq);
@@ -183,14 +146,26 @@ static int mxs_gpio_set_wake_irq(struct irq_data *d, unsigned int enable)
         return 0;
 }
 
-static struct irq_chip gpio_irq_chip = {
-        .name = "mxs gpio",
-        .irq_ack = mxs_gpio_ack_irq,
-        .irq_mask = mxs_gpio_mask_irq,
-        .irq_unmask = mxs_gpio_unmask_irq,
-        .irq_set_type = mxs_gpio_set_irq_type,
-        .irq_set_wake = mxs_gpio_set_wake_irq,
-};
+static void __init mxs_gpio_init_gc(struct mxs_gpio_port *port)
+{
+        struct irq_chip_generic *gc;
+        struct irq_chip_type *ct;
+
+        gc = irq_alloc_generic_chip("gpio-mxs", 1, port->virtual_irq_start,
+                                    port->base, handle_level_irq);
+        gc->private = port;
+
+        ct = gc->chip_types;
+        ct->chip.irq_ack = irq_gc_ack,
+        ct->chip.irq_mask = irq_gc_mask_clr_bit;
+        ct->chip.irq_unmask = irq_gc_mask_set_bit;
+        ct->chip.irq_set_type = mxs_gpio_set_irq_type;
+        ct->chip.irq_set_wake = mxs_gpio_set_wake_irq,
+        ct->regs.ack = PINCTRL_IRQSTAT(port->id) + MXS_CLR;
+        ct->regs.mask = PINCTRL_IRQEN(port->id);
+
+        irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
+}
 
 static int mxs_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 {
@@ -206,7 +181,7 @@ static int __devinit mxs_gpio_probe(struct platform_device *pdev)
         static void __iomem *base;
         struct mxs_gpio_port *port;
         struct resource *iores = NULL;
-        int err, i;
+        int err;
 
         port = kzalloc(sizeof(struct mxs_gpio_port), GFP_KERNEL);
         if (!port)
@@ -246,20 +221,18 @@ static int __devinit mxs_gpio_probe(struct platform_device *pdev)
                 goto out_iounmap;
         }
 
-        /* disable the interrupt and clear the status */
-        writel(0, port->base + PINCTRL_PIN2IRQ(port->id));
+        /*
+         * select the pin interrupt functionality but initially
+         * disable the interrupts
+         */
+        writel(~0U, port->base + PINCTRL_PIN2IRQ(port->id));
         writel(0, port->base + PINCTRL_IRQEN(port->id));
 
         /* clear address has to be used to clear IRQSTAT bits */
         writel(~0U, port->base + PINCTRL_IRQSTAT(port->id) + MXS_CLR);
 
-        for (i = port->virtual_irq_start;
-                i < port->virtual_irq_start + 32; i++) {
-                irq_set_chip_and_handler(i, &gpio_irq_chip,
-                                         handle_level_irq);
-                set_irq_flags(i, IRQF_VALID);
-                irq_set_chip_data(i, port);
-        }
+        /* gpio-mxs can be a generic irq chip */
+        mxs_gpio_init_gc(port);
 
         /* setup one handler for each entry */
         irq_set_chained_handler(port->irq, mxs_gpio_irq_handler);