commit b27b6d03f245e5eaf6473da58a2612077fb7cfe7
author Cyril Chemparathy <cyril@ti.com> Sat May 01 18:37:55 2010 -0400
committer Kevin Hilman <khilman@deeprootsystems.com> Thu May 06 15:02:09 2010 -0700
tree b6ed359c8b604edcaed5025aa83c57d77daec1a9
parent 686b634a07451fc4fe3b712fe211bfa861a53241

Davinci: gpio - fine grained locking

This patch eliminates the global gpio_lock, and implements a per-controller
lock instead.  This also switches to irqsave/irqrestore locks in case gpios
are manipulated in isr.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Tested-by: Sandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/gpio.c

diff --git a/arch/arm/mach-davinci/gpio.c b/arch/arm/mach-davinci/gpio.c
index e422cd3..b62d5e2 100644
--- a/arch/arm/mach-davinci/gpio.c
+++ b/arch/arm/mach-davinci/gpio.c
@@ -33,8 +33,6 @@
 	u32	intstat;
 };
 
-static DEFINE_SPINLOCK(gpio_lock);
-
 #define chip2controller(chip)	\
 	container_of(chip, struct davinci_gpio_controller, chip)
 
@@ -83,10 +81,11 @@
 {
 	struct davinci_gpio_controller *d = chip2controller(chip);
 	struct davinci_gpio_regs __iomem *g = d->regs;
+	unsigned long flags;
 	u32 temp;
 	u32 mask = 1 << offset;
 
-	spin_lock(&gpio_lock);
+	spin_lock_irqsave(&d->lock, flags);
 	temp = __raw_readl(&g->dir);
 	if (out) {
 		temp &= ~mask;
@@ -95,7 +94,7 @@
 		temp |= mask;
 	}
 	__raw_writel(temp, &g->dir);
-	spin_unlock(&gpio_lock);
+	spin_unlock_irqrestore(&d->lock, flags);
 
 	return 0;
 }
@@ -175,6 +174,8 @@
 		if (chips[i].chip.ngpio > 32)
 			chips[i].chip.ngpio = 32;
 
+		spin_lock_init(&chips[i].lock);
+
 		regs = gpio2regs(base);
 		chips[i].regs = regs;
 		chips[i].set_data = &regs->set_data;