gpio/mxc: use the edge_sel feature if available

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@secretlab.ca>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Sascha Hauer <kernel@pengutronix.de>
Cc: <linux-arm-kernel@lists.infradead.org>
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index c337143..bb985e8 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -38,7 +38,8 @@
 enum mxc_gpio_hwtype {
 	IMX1_GPIO,	/* runs on i.mx1 */
 	IMX21_GPIO,	/* runs on i.mx21 and i.mx27 */
-	IMX31_GPIO,	/* runs on all other i.mx */
+	IMX31_GPIO,	/* runs on i.mx31 */
+	IMX35_GPIO,	/* runs on all other i.mx */
 };
 
 /* device type dependent stuff */
@@ -50,6 +51,7 @@
 	unsigned icr2_reg;
 	unsigned imr_reg;
 	unsigned isr_reg;
+	int edge_sel_reg;
 	unsigned low_level;
 	unsigned high_level;
 	unsigned rise_edge;
@@ -74,6 +76,7 @@
 	.icr2_reg	= 0x2c,
 	.imr_reg	= 0x30,
 	.isr_reg	= 0x34,
+	.edge_sel_reg	= -EINVAL,
 	.low_level	= 0x03,
 	.high_level	= 0x02,
 	.rise_edge	= 0x00,
@@ -88,6 +91,22 @@
 	.icr2_reg	= 0x10,
 	.imr_reg	= 0x14,
 	.isr_reg	= 0x18,
+	.edge_sel_reg	= -EINVAL,
+	.low_level	= 0x00,
+	.high_level	= 0x01,
+	.rise_edge	= 0x02,
+	.fall_edge	= 0x03,
+};
+
+static struct mxc_gpio_hwdata imx35_gpio_hwdata = {
+	.dr_reg		= 0x00,
+	.gdir_reg	= 0x04,
+	.psr_reg	= 0x08,
+	.icr1_reg	= 0x0c,
+	.icr2_reg	= 0x10,
+	.imr_reg	= 0x14,
+	.isr_reg	= 0x18,
+	.edge_sel_reg	= 0x1c,
 	.low_level	= 0x00,
 	.high_level	= 0x01,
 	.rise_edge	= 0x02,
@@ -104,12 +123,13 @@
 #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		(mxc_gpio_hwdata->edge_sel_reg)
 
 #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[] = {
 	{
@@ -122,6 +142,9 @@
 		.name = "imx31-gpio",
 		.driver_data = IMX31_GPIO,
 	}, {
+		.name = "imx35-gpio",
+		.driver_data = IMX35_GPIO,
+	}, {
 		/* sentinel */
 	}
 };
@@ -130,6 +153,7 @@
 	{ .compatible = "fsl,imx1-gpio", .data = &mxc_gpio_devtype[IMX1_GPIO], },
 	{ .compatible = "fsl,imx21-gpio", .data = &mxc_gpio_devtype[IMX21_GPIO], },
 	{ .compatible = "fsl,imx31-gpio", .data = &mxc_gpio_devtype[IMX31_GPIO], },
+	{ .compatible = "fsl,imx35-gpio", .data = &mxc_gpio_devtype[IMX35_GPIO], },
 	{ /* sentinel */ }
 };
 
@@ -160,15 +184,19 @@
 		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 (GPIO_EDGE_SEL >= 0) {
+			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 +208,23 @@
 		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 (GPIO_EDGE_SEL >= 0) {
+		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;
@@ -338,7 +379,9 @@
 		return;
 	}
 
-	if (hwtype == IMX31_GPIO)
+	if (hwtype == IMX35_GPIO)
+		mxc_gpio_hwdata = &imx35_gpio_hwdata;
+	else if (hwtype == IMX31_GPIO)
 		mxc_gpio_hwdata = &imx31_gpio_hwdata;
 	else
 		mxc_gpio_hwdata = &imx1_imx21_gpio_hwdata;