[PATCH] gpio/mxc: use the edge_sel feature if available

[Benoît Thébaudeau]

Some mxc processors have an edge_sel feature, which allows the IRQ to be
triggered by any edge.

This patch makes use of this feature if available, which skips mxc_flip_edge().

Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Linus Walleij <linus.walleij at stericsson.com>
Cc: Sascha Hauer <kernel at pengutronix.de>
Cc: <linux-arm-kernel at lists.infradead.org>
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
---
 .../drivers/gpio/gpio-mxc.c                        |   44 ++++++++++++++------
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git linux-next-HEAD-6c86b58.orig/drivers/gpio/gpio-mxc.c linux-next-HEAD-6c86b58/drivers/gpio/gpio-mxc.c
index c337143..4c74482 100644
--- linux-next-HEAD-6c86b58.orig/drivers/gpio/gpio-mxc.c
+++ linux-next-HEAD-6c86b58/drivers/gpio/gpio-mxc.c
@@ -30,6 +30,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/module.h>
+#include <mach/hardware.h>
 #include <asm-generic/bug.h>
 #include <asm/mach/irq.h>
 
@@ -104,12 +105,13 @@ static struct mxc_gpio_hwdata *mxc_gpio_hwdata;
 #define GPIO_ICR2		(mxc_gpio_hwdata->icr2_reg)
 #define GPIO_IMR		(mxc_gpio_hwdata->imr_reg)
 #define GPIO_ISR		(mxc_gpio_hwdata->isr_reg)
+#define GPIO_EDGE_SEL		0x1c
 
 #define GPIO_INT_LOW_LEV	(mxc_gpio_hwdata->low_level)
 #define GPIO_INT_HIGH_LEV	(mxc_gpio_hwdata->high_level)
 #define GPIO_INT_RISE_EDGE	(mxc_gpio_hwdata->rise_edge)
 #define GPIO_INT_FALL_EDGE	(mxc_gpio_hwdata->fall_edge)
-#define GPIO_INT_NONE		0x4
+#define GPIO_INT_BOTH_EDGES	0x4
 
 static struct platform_device_id mxc_gpio_devtype[] = {
 	{
@@ -150,6 +152,7 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type)
 	u32 bit, val;
 	int edge;
 	void __iomem *reg = port->base;
+	bool edge_sel = cpu_is_mx25() || cpu_is_mx35() || cpu_is_mx51() || cpu_is_mx53();
 
 	port->both_edges &= ~(1 << (gpio & 31));
 	switch (type) {
@@ -160,15 +163,19 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type)
 		edge = GPIO_INT_FALL_EDGE;
 		break;
 	case IRQ_TYPE_EDGE_BOTH:
-		val = gpio_get_value(gpio);
-		if (val) {
-			edge = GPIO_INT_LOW_LEV;
-			pr_debug("mxc: set GPIO %d to low trigger\n", gpio);
+		if (edge_sel) {
+			edge = GPIO_INT_BOTH_EDGES;
 		} else {
-			edge = GPIO_INT_HIGH_LEV;
-			pr_debug("mxc: set GPIO %d to high trigger\n", gpio);
+			val = gpio_get_value(gpio);
+			if (val) {
+				edge = GPIO_INT_LOW_LEV;
+				pr_debug("mxc: set GPIO %d to low trigger\n", gpio);
+			} else {
+				edge = GPIO_INT_HIGH_LEV;
+				pr_debug("mxc: set GPIO %d to high trigger\n", gpio);
+			}
+			port->both_edges |= 1 << (gpio & 31);
 		}
-		port->both_edges |= 1 << (gpio & 31);
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		edge = GPIO_INT_LOW_LEV;
@@ -180,10 +187,23 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type)
 		return -EINVAL;
 	}
 
-	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
-	bit = gpio & 0xf;
-	val = readl(reg) & ~(0x3 << (bit << 1));
-	writel(val | (edge << (bit << 1)), reg);
+	if (edge_sel) {
+		val = readl(port->base + GPIO_EDGE_SEL);
+		if (edge == GPIO_INT_BOTH_EDGES)
+			writel(val | (1 << (gpio & 0x1f)),
+				port->base + GPIO_EDGE_SEL);
+		else
+			writel(val & ~(1 << (gpio & 0x1f)),
+				port->base + GPIO_EDGE_SEL);
+	}
+
+	if (edge != GPIO_INT_BOTH_EDGES) {
+		reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
+		bit = gpio & 0xf;
+		val = readl(reg) & ~(0x3 << (bit << 1));
+		writel(val | (edge << (bit << 1)), reg);
+	}
+
 	writel(1 << (gpio & 0x1f), port->base + GPIO_ISR);
 
 	return 0;