gpio: altera: use container_of() to get state container
The state container of the Altera GPIO driver is extracted from
the gpio_chip exploiting the fact that offsetof() the
struct gpio_chip inside the struct of_mm_gpio_chip are both 0, so
the container_of() is in practice a noop. However if a member
is added to struct altera_gpio_chip in front of
struct of_mm_gpio_chip, things will break. Using proper
container_of() avoids this problem.
Semantically this is a noop, the compiler will optimize it away,
but syntactically it makes me happier.
Cc: Tien Hock Loh <thloh@altera.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-altera.c b/drivers/gpio/gpio-altera.c
index 1b44941..3e6661b 100644
--- a/drivers/gpio/gpio-altera.c
+++ b/drivers/gpio/gpio-altera.c
@@ -42,6 +42,11 @@
int mapped_irq;
};
+static struct altera_gpio_chip *to_altera(struct gpio_chip *gc)
+{
+ return container_of(gc, struct altera_gpio_chip, mmchip.gc);
+}
+
static void altera_gpio_irq_unmask(struct irq_data *d)
{
struct altera_gpio_chip *altera_gc;
@@ -49,7 +54,7 @@
unsigned long flags;
u32 intmask;
- altera_gc = irq_data_get_irq_chip_data(d);
+ altera_gc = to_altera(irq_data_get_irq_chip_data(d));
mm_gc = &altera_gc->mmchip;
spin_lock_irqsave(&altera_gc->gpio_lock, flags);
@@ -67,7 +72,7 @@
unsigned long flags;
u32 intmask;
- altera_gc = irq_data_get_irq_chip_data(d);
+ altera_gc = to_altera(irq_data_get_irq_chip_data(d));
mm_gc = &altera_gc->mmchip;
spin_lock_irqsave(&altera_gc->gpio_lock, flags);
@@ -87,7 +92,7 @@
{
struct altera_gpio_chip *altera_gc;
- altera_gc = irq_data_get_irq_chip_data(d);
+ altera_gc = to_altera(irq_data_get_irq_chip_data(d));
if (type == IRQ_TYPE_NONE)
return 0;
@@ -210,7 +215,7 @@
unsigned long status;
int i;
- altera_gc = irq_desc_get_handler_data(desc);
+ altera_gc = to_altera(irq_desc_get_handler_data(desc));
chip = irq_desc_get_chip(desc);
mm_gc = &altera_gc->mmchip;
irqdomain = altera_gc->mmchip.gc.irqdomain;
@@ -239,7 +244,7 @@
unsigned long status;
int i;
- altera_gc = irq_desc_get_handler_data(desc);
+ altera_gc = to_altera(irq_desc_get_handler_data(desc));
chip = irq_desc_get_chip(desc);
mm_gc = &altera_gc->mmchip;
irqdomain = altera_gc->mmchip.gc.irqdomain;