diff options
| author | Rabin Vincent <rabin.vincent@stericsson.com> | 2011-09-28 12:19:11 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2012-04-23 11:06:08 +0200 |
| commit | ebc6178dab43b38042f0e089526bad49081870e5 (patch) | |
| tree | 394a03b4d884ec7805424a7d12be0672b07ebe30 | |
| parent | gpio/nomadik: fix spurious interrupts with SKE (diff) | |
| download | linux-ebc6178dab43b38042f0e089526bad49081870e5.tar.xz linux-ebc6178dab43b38042f0e089526bad49081870e5.zip | |
gpio/nomadik: support low EMI mode
Low EMI (Electro-Magnetic Interference) mode means lower slew
rate on the signals. The Nomadik GPIO controller supports
this so create an interface to enable it.
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| -rw-r--r-- | arch/arm/plat-nomadik/include/plat/gpio-nomadik.h | 1 | ||||
| -rw-r--r-- | arch/arm/plat-nomadik/include/plat/pincfg.h | 6 | ||||
| -rw-r--r-- | drivers/gpio/gpio-nomadik.c | 25 |
3 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/plat-nomadik/include/plat/gpio-nomadik.h b/arch/arm/plat-nomadik/include/plat/gpio-nomadik.h index 9605bf227df9..3e8b7f16fb78 100644 --- a/arch/arm/plat-nomadik/include/plat/gpio-nomadik.h +++ b/arch/arm/plat-nomadik/include/plat/gpio-nomadik.h @@ -29,6 +29,7 @@ #define NMK_GPIO_SLPC 0x1c #define NMK_GPIO_AFSLA 0x20 #define NMK_GPIO_AFSLB 0x24 +#define NMK_GPIO_LOWEMI 0x28 #define NMK_GPIO_RIMSC 0x40 #define NMK_GPIO_FIMSC 0x44 diff --git a/arch/arm/plat-nomadik/include/plat/pincfg.h b/arch/arm/plat-nomadik/include/plat/pincfg.h index 22cb97d2d8ad..da6b1e35e171 100644 --- a/arch/arm/plat-nomadik/include/plat/pincfg.h +++ b/arch/arm/plat-nomadik/include/plat/pincfg.h @@ -105,6 +105,12 @@ typedef unsigned long pin_cfg_t; #define PIN_SLPM_VAL_LOW ((1 + 0) << PIN_SLPM_VAL_SHIFT) #define PIN_SLPM_VAL_HIGH ((1 + 1) << PIN_SLPM_VAL_SHIFT) +#define PIN_LOWEMI_SHIFT 25 +#define PIN_LOWEMI_MASK (0x1 << PIN_LOWEMI_SHIFT) +#define PIN_LOWEMI(x) (((x) & PIN_LOWEMI_MASK) >> PIN_LOWEMI_SHIFT) +#define PIN_LOWEMI_DISABLED (0 << PIN_LOWEMI_SHIFT) +#define PIN_LOWEMI_ENABLED (1 << PIN_LOWEMI_SHIFT) + /* Shortcuts. Use these instead of separate DIR, PULL, and VAL. */ #define PIN_INPUT_PULLDOWN (PIN_DIR_INPUT | PIN_PULL_DOWN) #define PIN_INPUT_PULLUP (PIN_DIR_INPUT | PIN_PULL_UP) diff --git a/drivers/gpio/gpio-nomadik.c b/drivers/gpio/gpio-nomadik.c index 681daee80291..7b45d88b4f44 100644 --- a/drivers/gpio/gpio-nomadik.c +++ b/drivers/gpio/gpio-nomadik.c @@ -61,6 +61,7 @@ struct nmk_gpio_chip { u32 rimsc; u32 fimsc; u32 pull_up; + u32 lowemi; }; static struct nmk_gpio_chip * @@ -125,6 +126,24 @@ static void __nmk_gpio_set_pull(struct nmk_gpio_chip *nmk_chip, } } +static void __nmk_gpio_set_lowemi(struct nmk_gpio_chip *nmk_chip, + unsigned offset, bool lowemi) +{ + u32 bit = BIT(offset); + bool enabled = nmk_chip->lowemi & bit; + + if (lowemi == enabled) + return; + + if (lowemi) + nmk_chip->lowemi |= bit; + else + nmk_chip->lowemi &= ~bit; + + writel_relaxed(nmk_chip->lowemi, + nmk_chip->addr + NMK_GPIO_LOWEMI); +} + static void __nmk_gpio_make_input(struct nmk_gpio_chip *nmk_chip, unsigned offset) { @@ -269,6 +288,8 @@ static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset, __nmk_gpio_set_pull(nmk_chip, offset, pull); } + __nmk_gpio_set_lowemi(nmk_chip, offset, PIN_LOWEMI(cfg)); + /* * If the pin is switching to altfunc, and there was an interrupt * installed on it which has been lazy disabled, actually mask the @@ -1181,6 +1202,10 @@ static int __devinit nmk_gpio_probe(struct platform_device *dev) chip->dev = &dev->dev; chip->owner = THIS_MODULE; + clk_enable(nmk_chip->clk); + nmk_chip->lowemi = readl_relaxed(nmk_chip->addr + NMK_GPIO_LOWEMI); + clk_disable(nmk_chip->clk); + ret = gpiochip_add(&nmk_chip->chip); if (ret) goto out_free; |