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Message-Id: <200811071332.52608.david-b@pacbell.net>
Date: Fri, 7 Nov 2008 13:32:52 -0800
From: David Brownell <david-b@...bell.net>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: lkml <linux-kernel@...r.kernel.org>
Subject: [patch 2.6.28-rc3-git] twl4030-gpio debounce cleanup
From: David Brownell <dbrownell@...rs.sourceforge.net>
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@...rs.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@...mide.com>
---
drivers/gpio/twl4030-gpio.c | 54 +++++++++++++++++-------------------------
include/linux/i2c/twl4030.h | 9 ++-----
2 files changed, 26 insertions(+), 37 deletions(-)
--- a/drivers/gpio/twl4030-gpio.c
+++ b/drivers/gpio/twl4030-gpio.c
@@ -202,37 +202,6 @@ static int twl4030_get_gpio_datain(int g
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(
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;
--- a/include/linux/i2c/twl4030.h
+++ b/include/linux/i2c/twl4030.h
@@ -234,6 +234,9 @@ struct twl4030_gpio_platform_data {
/* gpio-n should control VMMC(n+1) if BIT(n) in mmc_cd is set */
u8 mmc_cd;
+ /* if BIT(N) is set, or VMMC(n+1) is linked, debounce GPIO-N */
+ u32 debounce;
+
/* For gpio-N, bit (1 << N) in "pullups" is set if that pullup
* should be enabled. Else, if that bit is set in "pulldowns",
* that pulldown is enabled. Don't waste power by letting any
@@ -390,12 +393,6 @@ int twl4030_sih_setup(int module);
#define TWL4030_GPIO_IRQ_NO(n) (TWL4030_GPIO_IRQ_BASE + (n))
-/*
- * Exported TWL4030 GPIO APIs
- *
- * WARNING -- use standard GPIO and IRQ calls instead; these will vanish.
- */
-int twl4030_set_gpio_debounce(int gpio, int enable);
#if defined(CONFIG_TWL4030_BCI_BATTERY) || \
defined(CONFIG_TWL4030_BCI_BATTERY_MODULE)
--
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