[PATCHv3 2/2] ARM: imx: Add wake functionality to GPIO

From: Dinh.Nguyen
Date: Tue Oct 19 2010 - 14:38:27 EST


From: Dinh Nguyen <Dinh.Nguyen@xxxxxxxxxxxxx>

Add function definition for irq_chip.set_wake to enable GPIO to
wake-up the system.

This patch is based on Sascha Hauer's imx/linux-2.6 for-rmk tree.

Signed-off-by: Dinh Nguyen <Dinh.Nguyen@xxxxxxxxxxxxx>
---
arch/arm/plat-mxc/gpio.c | 34 +++++++++++++++++++++++++++++++++
arch/arm/plat-mxc/include/mach/gpio.h | 1 +
2 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-mxc/gpio.c b/arch/arm/plat-mxc/gpio.c
index 9d38da0..e52c658 100644
--- a/arch/arm/plat-mxc/gpio.c
+++ b/arch/arm/plat-mxc/gpio.c
@@ -20,6 +20,7 @@
*/

#include <linux/init.h>
+#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/gpio.h>
@@ -201,11 +202,44 @@ static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc)
}
}

+/*
+ * Set interrupt number "irq" in the GPIO as a wake-up source.
+ * While system is running, all registered GPIO interrupts need to have
+ * wake-up enabled. When system is suspended, only selected GPIO interrupts
+ * need to have wake-up enabled.
+ * @param irq interrupt source number
+ * @param enable enable as wake-up if equal to non-zero
+ * @return This function returns 0 on success.
+ */
+static int gpio_set_wake_irq(u32 irq, u32 enable)
+{
+ u32 gpio = irq_to_gpio(irq);
+ u32 gpio_idx = gpio & 0x1F;
+ struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
+
+ if (enable) {
+ port->suspend_wakeup |= (1 << gpio_idx);
+ if (port->irq_high && (gpio_idx >= 16))
+ enable_irq_wake(port->irq_high);
+ else
+ enable_irq_wake(port->irq);
+ } else {
+ port->suspend_wakeup &= ~(1 << gpio_idx);
+ if (port->irq_high && (gpio_idx >= 16))
+ disable_irq_wake(port->irq_high);
+ else
+ disable_irq_wake(port->irq);
+ }
+
+ return 0;
+}
+
static struct irq_chip gpio_irq_chip = {
.ack = gpio_ack_irq,
.mask = gpio_mask_irq,
.unmask = gpio_unmask_irq,
.set_type = gpio_set_irq_type,
+ .set_wake = gpio_set_wake_irq,
};

static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
diff --git a/arch/arm/plat-mxc/include/mach/gpio.h b/arch/arm/plat-mxc/include/mach/gpio.h
index af33b74..133150e 100644
--- a/arch/arm/plat-mxc/include/mach/gpio.h
+++ b/arch/arm/plat-mxc/include/mach/gpio.h
@@ -39,6 +39,7 @@ struct mxc_gpio_port {
struct gpio_chip chip;
u32 both_edges;
spinlock_t lock;
+ u32 suspend_wakeup;
};

int mxc_gpio_init(struct mxc_gpio_port*, int);
--
1.6.0.4


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