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 <[email protected]> Signed-off-by: Linus Walleij <[email protected]> --- drivers/gpio/gpio-altera.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpio-altera.c b/drivers/gpio/gpio-altera.c index 9b7e0b3db387..9087647e765a 100644 --- a/drivers/gpio/gpio-altera.c +++ b/drivers/gpio/gpio-altera.c @@ -42,6 +42,11 @@ struct altera_gpio_chip { 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 @@ static void altera_gpio_irq_unmask(struct irq_data *d) 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 @@ static void altera_gpio_irq_mask(struct irq_data *d) 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 @@ static int altera_gpio_irq_set_type(struct irq_data *d, { 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; @@ -211,7 +216,7 @@ static void altera_gpio_irq_edge_handler(unsigned int irq, 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; @@ -241,7 +246,7 @@ static void altera_gpio_irq_leveL_high_handler(unsigned int irq, 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; -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
