mfd: Ensure sm501 GPIO pin mode is GPIO when configured
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 <ben-linux@fluff.org>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index 170f9d4..0e5761f 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -41,6 +41,7 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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";
}
