[PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups

From: Alek Du
Date: Sat Nov 21 2009 - 21:58:21 EST


1. Use >= N to check invalid gpio number (unsigned type)
2. Remove wrong and unnecessary unmask operation
3. Remove extra GEDR reading

The 2) and 3) will fix interrupts losing when two or more pins are triggered at close time.

Signed-off-by: Alek Du <alek.du@xxxxxxxxx>
---
drivers/gpio/langwell_gpio.c | 13 ++-----------
1 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/gpio/langwell_gpio.c b/drivers/gpio/langwell_gpio.c
index 5711ce5..6c0ebbd 100644
--- a/drivers/gpio/langwell_gpio.c
+++ b/drivers/gpio/langwell_gpio.c
@@ -123,7 +123,7 @@ static int lnw_irq_type(unsigned irq, unsigned type)
void __iomem *grer = (void __iomem *)(&lnw->reg_base->GRER[reg]);
void __iomem *gfer = (void __iomem *)(&lnw->reg_base->GFER[reg]);

- if (gpio < 0 || gpio > lnw->chip.ngpio)
+ if (gpio >= lnw->chip.ngpio)
return -EINVAL;
spin_lock_irqsave(&lnw->lock, flags);
if (type & IRQ_TYPE_EDGE_RISING)
@@ -144,13 +144,6 @@ static int lnw_irq_type(unsigned irq, unsigned type)

static void lnw_irq_unmask(unsigned irq)
{
- struct lnw_gpio *lnw = get_irq_chip_data(irq);
- u32 gpio = irq - lnw->irq_base;
- u8 reg = gpio / 32;
- void __iomem *gedr;
-
- gedr = (void __iomem *)(&lnw->reg_base->GEDR[reg]);
- writel(BIT(gpio % 32), gedr);
};

static void lnw_irq_mask(unsigned irq)
@@ -183,13 +176,11 @@ static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
gedr_v = readl(gedr);
if (!gedr_v)
continue;
- for (gpio = reg*32; gpio < reg*32+32; gpio++) {
- gedr_v = readl(gedr);
+ for (gpio = reg*32; gpio < reg*32+32; gpio++)
if (gedr_v & BIT(gpio % 32)) {
pr_debug("pin %d triggered\n", gpio);
generic_handle_irq(lnw->irq_base + gpio);
}
- }
/* clear the edge detect status bit */
writel(gedr_v, gedr);
}
--
1.6.3.3

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