[PATCH v4 4/4] gpio: pl061: enable interrupts with DT style binding

From: Rob Herring
Date: Fri Feb 03 2012 - 17:35:51 EST


From: Rob Herring <rob.herring@xxxxxxxxxxx>

Enable DT interrupt binding support for pl061 gpio lines. If the gpio
node has an interrupt-controller property, then it will be setup to
handle interrupts on gpio lines.

Signed-off-by: Rob Herring <rob.herring@xxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
Cc: Linus Walleij <linus.ml.walleij@xxxxxxxxx>
---
.../devicetree/bindings/gpio/pl061-gpio.txt | 15 ++++++
drivers/gpio/gpio-pl061.c | 48 ++++++++++---------
2 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
index a2c416b..9671d4e 100644
--- a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
@@ -8,3 +8,18 @@ Required properties:
- gpio-controller : Marks the device node as a GPIO controller.
- interrupts : Interrupt mapping for GPIO IRQ.

+Optional properties:
+- interrupt-controller : Identifies the node as an interrupt controller. Must
+ be present if using gpios lines for interrupts.
+- #interrupt-cells : Specifies the number of cells needed to encode an
+ interrupt source. The type shall be a <u32> and the value shall be 2.
+
+ The 1st cell contains the interrupt number 0-7 corresponding to the gpio
+ line.
+
+ The 2nd cell is the flags, encoding trigger type and level flags.
+ 1 = low-to-high edge triggered
+ 2 = high-to-low edge triggered
+ 4 = active high level-sensitive
+ 8 = active low level-sensitive
+
diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
index 77c9cc7..b271a17 100644
--- a/drivers/gpio/gpio-pl061.c
+++ b/drivers/gpio/gpio-pl061.c
@@ -15,6 +15,8 @@
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
#include <linux/bitops.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
@@ -56,7 +58,6 @@ struct pl061_gpio {
spinlock_t lock; /* GPIO registers */

void __iomem *base;
- int irq_base;
struct irq_chip_generic *irq_gc;
struct gpio_chip gc;

@@ -126,18 +127,16 @@ static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
-
- if (chip->irq_base <= 0)
- return -EINVAL;
-
- return chip->irq_base + offset;
+ if (!chip->irq_gc)
+ return -ENXIO;
+ return irq_find_mapping(chip->irq_gc->domain, offset);
}

static int pl061_irq_type(struct irq_data *d, unsigned trigger)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct pl061_gpio *chip = gc->private;
- int offset = d->irq - chip->irq_base;
+ int offset = d->hwirq;
unsigned long flags;
u8 gpiois, gpioibe, gpioiev;

@@ -197,30 +196,25 @@ static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
chained_irq_exit(irqchip, desc);
}

-static void __init pl061_init_gc(struct pl061_gpio *chip, int irq_base)
+static void __init pl061_init_gc(struct irq_chip_generic *gc)
{
- struct irq_chip_type *ct;
+ struct irq_chip_type *ct = gc->chip_types;
+ struct pl061_gpio *chip = gc->private;

- chip->irq_gc = irq_alloc_generic_chip("gpio-pl061", 1, irq_base,
- chip->base, handle_simple_irq);
- chip->irq_gc->private = chip;
+ chip->irq_gc = gc;

- ct = chip->irq_gc->chip_types;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->chip.irq_set_type = pl061_irq_type;
ct->chip.irq_set_wake = irq_gc_set_wake;
ct->regs.mask = GPIOIE;
-
- irq_setup_generic_chip(chip->irq_gc, IRQ_MSK(PL061_GPIO_NR),
- IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0);
}

static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
{
struct pl061_platform_data *pdata;
struct pl061_gpio *chip;
- int ret, irq, i;
+ int ret, irq, i, irq_base;

chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
@@ -229,10 +223,13 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
pdata = dev->dev.platform_data;
if (pdata) {
chip->gc.base = pdata->gpio_base;
- chip->irq_base = pdata->irq_base;
+ irq_base = pdata->irq_base;
} else if (dev->dev.of_node) {
chip->gc.base = -1;
- chip->irq_base = 0;
+ if (of_get_property(dev->dev.of_node, "interrupt-controller", NULL))
+ irq_base = -1;
+ else
+ irq_base = 0;
} else {
ret = -ENODEV;
goto free_mem;
@@ -267,13 +264,18 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
goto iounmap;

/*
- * irq_chip support
+ * irq_chip support. If irq_base is 0, then we don't support interrupts
+ * on gpio lines and just return now. Otherwise setup the interrupts.
*/
-
- if (chip->irq_base <= 0)
+ if (!irq_base)
return 0;

- pl061_init_gc(chip, chip->irq_base);
+ irq_setup_generic_chip_domain("gpio-pl061",
+ of_node_get(dev->dev.of_node),
+ 1, irq_base, chip->base,
+ handle_simple_irq,
+ PL061_GPIO_NR, IRQ_GC_INIT_NESTED_LOCK,
+ IRQ_NOREQUEST, 0, pl061_init_gc, chip);

writeb(0, chip->base + GPIOIE); /* disable irqs */
irq = dev->irq[0];
--
1.7.5.4

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