twl4030-gpio: cleanup debounce

Provide a static debounce configuration mechanism for twl4030 GPIOs,
replacing the previous dynamic one.  The single user of that mechanism was
for MMC card detect debouncing.

Boards can provide a bitmask saying which GPIOs to debounce (30 msec).
It's always enabled for pins with the MMC card-detect/VMMCx link active,
so most boards won't need to set the debounce mask.

This is a net code shrink, including runtime footprint.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 31 deletions

diff --git a/drivers/gpio/twl4030-gpio.c b/drivers/gpio/twl4030-gpio.c
index 37d3eec8730..afad1479214 100644
--- a/drivers/gpio/twl4030-gpio.c
+++ b/drivers/gpio/twl4030-gpio.c
@@ -202,37 +202,6 @@ static int twl4030_get_gpio_datain(int gpio)
         return ret;
 }
 
-/*
- * Configure debounce timing value for a GPIO pin on TWL4030
- */
-int twl4030_set_gpio_debounce(int gpio, int enable)
-{
-        u8 d_bnk = gpio >> 3;
-        u8 d_msk = BIT(gpio & 0x7);
-        u8 reg = 0;
-        u8 base = 0;
-        int ret = 0;
-
-        if (unlikely((gpio >= TWL4030_GPIO_MAX)
-                || !(gpio_usage_count & BIT(gpio))))
-                return -EPERM;
-
-        base = REG_GPIO_DEBEN1 + d_bnk;
-        mutex_lock(&gpio_lock);
-        ret = gpio_twl4030_read(base);
-        if (ret >= 0) {
-                if (enable)
-                        reg = ret | d_msk;
-                else
-                        reg = ret & ~d_msk;
-
-                ret = gpio_twl4030_write(base, reg);
-        }
-        mutex_unlock(&gpio_lock);
-        return ret;
-}
-EXPORT_SYMBOL(twl4030_set_gpio_debounce);
-
 /*----------------------------------------------------------------------*/
 
 static int twl_request(struct gpio_chip *chip, unsigned offset)
@@ -405,6 +374,23 @@ static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
                                 REG_GPIOPUPDCTR1, 5);
 }
 
+static int __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
+{
+        u8              message[4];
+
+        /* 30 msec of debouncing is always used for MMC card detect,
+         * and is optional for everything else.
+         */
+        message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
+        debounce >>= 8;
+        message[2] = (debounce & 0xff);
+        debounce >>= 8;
+        message[3] = (debounce & 0x03);
+
+        return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
+                                REG_GPIO_DEBEN1, 3);
+}
+
 static int gpio_twl4030_remove(struct platform_device *pdev);
 
 static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
@@ -439,6 +425,12 @@ no_irqs:
                                 pdata->pullups, pdata->pulldowns,
                                 ret);
 
+        ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
+        if (ret)
+                dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
+                                pdata->debounce, pdata->mmc_cd,
+                                ret);
+
         twl_gpiochip.base = pdata->gpio_base;
         twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
         twl_gpiochip.dev = &pdev->dev;