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authorLennert Buytenhek <buytenh@wantstofly.org>2008-10-20 01:51:03 +0200
committerNicolas Pitre <nico@cam.org>2008-12-20 18:24:05 +0100
commit07332318f33da6acd88abb762a8b6febdfc560a3 (patch)
tree911c34bb215427f1f8771a52e7c3d4433397ab83 /arch/arm/plat-orion
parent[ARM] Orion: share GPIO handling code (diff)
downloadlinux-07332318f33da6acd88abb762a8b6febdfc560a3.tar.xz
linux-07332318f33da6acd88abb762a8b6febdfc560a3.zip
[ARM] Orion: share GPIO IRQ handling code
Split off Orion GPIO IRQ handling code into plat-orion/. Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Signed-off-by: Nicolas Pitre <nico@marvell.com>
Diffstat (limited to 'arch/arm/plat-orion')
-rw-r--r--arch/arm/plat-orion/gpio.c176
-rw-r--r--arch/arm/plat-orion/include/plat/gpio.h7
2 files changed, 183 insertions, 0 deletions
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
index d86fc085e489..967186425ca1 100644
--- a/arch/arm/plat-orion/gpio.c
+++ b/arch/arm/plat-orion/gpio.c
@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/irq.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
@@ -237,3 +238,178 @@ void orion_gpio_set_blink(unsigned pin, int blink)
spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(orion_gpio_set_blink);
+
+
+/*****************************************************************************
+ * Orion GPIO IRQ
+ *
+ * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
+ * value of the line or the opposite value.
+ *
+ * Level IRQ handlers: DATA_IN is used directly as cause register.
+ * Interrupt are masked by LEVEL_MASK registers.
+ * Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE.
+ * Interrupt are masked by EDGE_MASK registers.
+ * Both-edge handlers: Similar to regular Edge handlers, but also swaps
+ * the polarity to catch the next line transaction.
+ * This is a race condition that might not perfectly
+ * work on some use cases.
+ *
+ * Every eight GPIO lines are grouped (OR'ed) before going up to main
+ * cause register.
+ *
+ * EDGE cause mask
+ * data-in /--------| |-----| |----\
+ * -----| |----- ---- to main cause reg
+ * X \----------------| |----/
+ * polarity LEVEL mask
+ *
+ ****************************************************************************/
+static void gpio_irq_edge_ack(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+
+ writel(~(1 << (pin & 31)), GPIO_EDGE_CAUSE(pin));
+}
+
+static void gpio_irq_edge_mask(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ u32 u;
+
+ u = readl(GPIO_EDGE_MASK(pin));
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_EDGE_MASK(pin));
+}
+
+static void gpio_irq_edge_unmask(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ u32 u;
+
+ u = readl(GPIO_EDGE_MASK(pin));
+ u |= 1 << (pin & 31);
+ writel(u, GPIO_EDGE_MASK(pin));
+}
+
+static void gpio_irq_level_mask(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ u32 u;
+
+ u = readl(GPIO_LEVEL_MASK(pin));
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_LEVEL_MASK(pin));
+}
+
+static void gpio_irq_level_unmask(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ u32 u;
+
+ u = readl(GPIO_LEVEL_MASK(pin));
+ u |= 1 << (pin & 31);
+ writel(u, GPIO_LEVEL_MASK(pin));
+}
+
+static int gpio_irq_set_type(u32 irq, u32 type)
+{
+ int pin = irq_to_gpio(irq);
+ struct irq_desc *desc;
+ u32 u;
+
+ u = readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31));
+ if (!u) {
+ printk(KERN_ERR "orion gpio_irq_set_type failed "
+ "(irq %d, pin %d).\n", irq, pin);
+ return -EINVAL;
+ }
+
+ desc = irq_desc + irq;
+
+ /*
+ * Set edge/level type.
+ */
+ if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) {
+ desc->chip = &orion_gpio_irq_edge_chip;
+ } else if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
+ desc->chip = &orion_gpio_irq_level_chip;
+ } else {
+ printk(KERN_ERR "failed to set irq=%d (type=%d)\n", irq, type);
+ return -EINVAL;
+ }
+
+ /*
+ * Configure interrupt polarity.
+ */
+ if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
+ u = readl(GPIO_IN_POL(pin));
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_IN_POL(pin));
+ } else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
+ u = readl(GPIO_IN_POL(pin));
+ u |= 1 << (pin & 31);
+ writel(u, GPIO_IN_POL(pin));
+ } else if (type == IRQ_TYPE_EDGE_BOTH) {
+ u32 v;
+
+ v = readl(GPIO_IN_POL(pin)) ^ readl(GPIO_DATA_IN(pin));
+
+ /*
+ * set initial polarity based on current input level
+ */
+ u = readl(GPIO_IN_POL(pin));
+ if (v & (1 << (pin & 31)))
+ u |= 1 << (pin & 31); /* falling */
+ else
+ u &= ~(1 << (pin & 31)); /* rising */
+ writel(u, GPIO_IN_POL(pin));
+ }
+
+ desc->status = (desc->status & ~IRQ_TYPE_SENSE_MASK) | type;
+
+ return 0;
+}
+
+struct irq_chip orion_gpio_irq_edge_chip = {
+ .name = "orion_gpio_irq_edge",
+ .ack = gpio_irq_edge_ack,
+ .mask = gpio_irq_edge_mask,
+ .unmask = gpio_irq_edge_unmask,
+ .set_type = gpio_irq_set_type,
+};
+
+struct irq_chip orion_gpio_irq_level_chip = {
+ .name = "orion_gpio_irq_level",
+ .mask = gpio_irq_level_mask,
+ .mask_ack = gpio_irq_level_mask,
+ .unmask = gpio_irq_level_unmask,
+ .set_type = gpio_irq_set_type,
+};
+
+void orion_gpio_irq_handler(int pinoff)
+{
+ u32 cause;
+ int pin;
+
+ cause = readl(GPIO_DATA_IN(pinoff)) & readl(GPIO_LEVEL_MASK(pinoff));
+ cause |= readl(GPIO_EDGE_CAUSE(pinoff)) & readl(GPIO_EDGE_MASK(pinoff));
+
+ for (pin = pinoff; pin < pinoff + 8; pin++) {
+ int irq = gpio_to_irq(pin);
+ struct irq_desc *desc = irq_desc + irq;
+
+ if (!(cause & (1 << (pin & 31))))
+ continue;
+
+ if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
+ /* Swap polarity (race with GPIO line) */
+ u32 polarity;
+
+ polarity = readl(GPIO_IN_POL(pin));
+ polarity ^= 1 << (pin & 31);
+ writel(polarity, GPIO_IN_POL(pin));
+ }
+ desc_handle_irq(irq, desc);
+ }
+}
diff --git a/arch/arm/plat-orion/include/plat/gpio.h b/arch/arm/plat-orion/include/plat/gpio.h
index 956658df269f..54deaf274b52 100644
--- a/arch/arm/plat-orion/include/plat/gpio.h
+++ b/arch/arm/plat-orion/include/plat/gpio.h
@@ -28,5 +28,12 @@ void orion_gpio_set_unused(unsigned pin);
void orion_gpio_set_valid(unsigned pin, int valid);
void orion_gpio_set_blink(unsigned pin, int blink);
+/*
+ * GPIO interrupt handling.
+ */
+extern struct irq_chip orion_gpio_irq_edge_chip;
+extern struct irq_chip orion_gpio_irq_level_chip;
+void orion_gpio_irq_handler(int irqoff);
+
#endif