When setting an GPIO to either input or output, we
should ensure that the pin configuration elsewhere
in the chip is set to GPIO in-case the initial
setup has not been done correctly.
Signed-off-by: Ben Dooks <[email protected]>
Index: linux-2.6.26-rc8-quilt3/drivers/mfd/sm501.c
===================================================================
--- linux-2.6.26-rc8-quilt3.orig/drivers/mfd/sm501.c 2008-07-02 15:33:23.000000000 +0100
+++ linux-2.6.26-rc8-quilt3/drivers/mfd/sm501.c 2008-07-02 16:42:59.000000000 +0100
@@ -41,6 +41,7 @@ struct sm501_gpio_chip {
struct gpio_chip gpio;
struct sm501_gpio *ourgpio; /* to get back to parent. */
void __iomem *regbase;
+ void __iomem *control; /* address of control reg. */
};
struct sm501_gpio {
@@ -908,6 +909,25 @@ static int sm501_gpio_get(struct gpio_ch
return result & 1UL;
}
+static void sm501_gpio_ensure_gpio(struct sm501_gpio_chip *smchip,
+ unsigned long bit)
+{
+ unsigned long ctrl;
+
+ /* check and modify if this pin is not set as gpio. */
+
+ if (readl(smchip->control) & bit) {
+ dev_info(sm501_gpio_to_dev(smchip->ourgpio)->dev,
+ "changing mode of gpio, bit %08lx\n", bit);
+
+ ctrl = readl(smchip->control);
+ ctrl &= ~bit;
+ writel(ctrl, smchip->control);
+
+ sm501_sync_regs(sm501_gpio_to_dev(smchip->ourgpio));
+ }
+}
+
static void sm501_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
@@ -929,6 +949,8 @@ static void sm501_gpio_set(struct gpio_c
writel(val, regs);
sm501_sync_regs(sm501_gpio_to_dev(smgpio));
+ sm501_gpio_ensure_gpio(smchip, bit);
+
spin_unlock_irqrestore(&smgpio->lock, save);
}
@@ -941,8 +963,8 @@ static int sm501_gpio_input(struct gpio_
unsigned long save;
unsigned long ddr;
- dev_info(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d)\n",
- __func__, chip, offset);
+ dev_dbg(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d)\n",
+ __func__, chip, offset);
spin_lock_irqsave(&smgpio->lock, save);
@@ -950,6 +972,8 @@ static int sm501_gpio_input(struct gpio_
writel(ddr & ~bit, regs + SM501_GPIO_DDR_LOW);
sm501_sync_regs(sm501_gpio_to_dev(smgpio));
+ sm501_gpio_ensure_gpio(smchip, bit);
+
spin_unlock_irqrestore(&smgpio->lock, save);
return 0;
@@ -1012,9 +1036,11 @@ static int __devinit sm501_gpio_register
if (base > 0)
base += 32;
chip->regbase = gpio->regs + SM501_GPIO_DATA_HIGH;
+ chip->control = sm->regs + SM501_GPIO63_32_CONTROL;
gchip->label = "SM501-HIGH";
} else {
chip->regbase = gpio->regs + SM501_GPIO_DATA_LOW;
+ chip->control = sm->regs + SM501_GPIO31_0_CONTROL;
gchip->label = "SM501-LOW";
}
--
Ben ([email protected], http://www.fluff.org/)
'a smiley only costs 4 bytes'