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-rw-r--r--Documentation/gpio.txt5
-rw-r--r--arch/arm/mach-at91/gpio.c3
-rw-r--r--arch/arm/mach-sa1100/generic.c3
-rw-r--r--arch/avr32/mach-at32ap/pio.c4
-rw-r--r--drivers/spi/atmel_spi.c2
-rw-r--r--include/asm-arm/arch-at91/gpio.h2
-rw-r--r--include/asm-arm/arch-omap/gpio.h3
-rw-r--r--include/asm-arm/arch-pxa/gpio.h4
-rw-r--r--include/asm-arm/arch-s3c2410/gpio.h4
-rw-r--r--include/asm-arm/arch-sa1100/gpio.h2
-rw-r--r--include/asm-avr32/arch-at32ap/gpio.h2
11 files changed, 22 insertions, 12 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 576ce463cf44..989f1130f4f3 100644
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -105,12 +105,15 @@ setting up a platform_device using the GPIO, is mark its direction:
/* set as input or output, returning 0 or negative errno */
int gpio_direction_input(unsigned gpio);
- int gpio_direction_output(unsigned gpio);
+ int gpio_direction_output(unsigned gpio, int value);
The return value is zero for success, else a negative errno. It should
be checked, since the get/set calls don't have error returns and since
misconfiguration is possible. (These calls could sleep.)
+For output GPIOs, the value provided becomes the initial output value.
+This helps avoid signal glitching during system startup.
+
Setting the direction can fail if the GPIO number is invalid, or when
that particular GPIO can't be used in that mode. It's generally a bad
idea to rely on boot firmware to have set the direction correctly, since
diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
index 44211a0af19a..ba4a1bb3ee40 100644
--- a/arch/arm/mach-at91/gpio.c
+++ b/arch/arm/mach-at91/gpio.c
@@ -215,13 +215,14 @@ int gpio_direction_input(unsigned pin)
}
EXPORT_SYMBOL(gpio_direction_input);
-int gpio_direction_output(unsigned pin)
+int gpio_direction_output(unsigned pin, int value)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio || !(__raw_readl(pio + PIO_PSR) & mask))
return -EINVAL;
+ __raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
__raw_writel(mask, pio + PIO_OER);
return 0;
}
diff --git a/arch/arm/mach-sa1100/generic.c b/arch/arm/mach-sa1100/generic.c
index 192a5a26cf2b..edc349e5fcf7 100644
--- a/arch/arm/mach-sa1100/generic.c
+++ b/arch/arm/mach-sa1100/generic.c
@@ -153,7 +153,7 @@ int gpio_direction_input(unsigned gpio)
EXPORT_SYMBOL(gpio_direction_input);
-int gpio_direction_output(unsigned gpio)
+int gpio_direction_output(unsigned gpio, int value)
{
unsigned long flags;
@@ -161,6 +161,7 @@ int gpio_direction_output(unsigned gpio)
return -EINVAL;
local_irq_save(flags);
+ gpio_set_value(gpio, value);
GPDR |= GPIO_GPIO(gpio);
local_irq_restore(flags);
return 0;
diff --git a/arch/avr32/mach-at32ap/pio.c b/arch/avr32/mach-at32ap/pio.c
index 9ba5654cde11..1eb99b814f5b 100644
--- a/arch/avr32/mach-at32ap/pio.c
+++ b/arch/avr32/mach-at32ap/pio.c
@@ -214,7 +214,7 @@ int gpio_direction_input(unsigned int gpio)
}
EXPORT_SYMBOL(gpio_direction_input);
-int gpio_direction_output(unsigned int gpio)
+int gpio_direction_output(unsigned int gpio, int value)
{
struct pio_device *pio;
unsigned int pin;
@@ -223,6 +223,8 @@ int gpio_direction_output(unsigned int gpio)
if (!pio)
return -ENODEV;
+ gpio_set_value(gpio, value);
+
pin = gpio & 0x1f;
pio_writel(pio, OER, 1 << pin);
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index 6fa260d1a9be..66e7bc985797 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -425,7 +425,7 @@ static int atmel_spi_setup(struct spi_device *spi)
if (ret)
return ret;
spi->controller_state = (void *)npcs_pin;
- gpio_direction_output(npcs_pin);
+ gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
}
dev_dbg(&spi->dev,
diff --git a/include/asm-arm/arch-at91/gpio.h b/include/asm-arm/arch-at91/gpio.h
index 98ad2114f43a..0a241e2fb672 100644
--- a/include/asm-arm/arch-at91/gpio.h
+++ b/include/asm-arm/arch-at91/gpio.h
@@ -223,7 +223,7 @@ static inline void gpio_free(unsigned gpio)
}
extern int gpio_direction_input(unsigned gpio);
-extern int gpio_direction_output(unsigned gpio);
+extern int gpio_direction_output(unsigned gpio, int value);
static inline int gpio_get_value(unsigned gpio)
{
diff --git a/include/asm-arm/arch-omap/gpio.h b/include/asm-arm/arch-omap/gpio.h
index 3762a6ae6a7f..590917efc94a 100644
--- a/include/asm-arm/arch-omap/gpio.h
+++ b/include/asm-arm/arch-omap/gpio.h
@@ -113,8 +113,9 @@ static inline int gpio_direction_input(unsigned gpio)
return __gpio_set_direction(gpio, 1);
}
-static inline int gpio_direction_output(unsigned gpio)
+static inline int gpio_direction_output(unsigned gpio, int value)
{
+ omap_set_gpio_dataout(gpio, value);
return __gpio_set_direction(gpio, 0);
}
diff --git a/include/asm-arm/arch-pxa/gpio.h b/include/asm-arm/arch-pxa/gpio.h
index 3d348a351157..aeba24347f8e 100644
--- a/include/asm-arm/arch-pxa/gpio.h
+++ b/include/asm-arm/arch-pxa/gpio.h
@@ -43,9 +43,9 @@ static inline int gpio_direction_input(unsigned gpio)
return pxa_gpio_mode(gpio | GPIO_IN);
}
-static inline int gpio_direction_output(unsigned gpio)
+static inline int gpio_direction_output(unsigned gpio, int value)
{
- return pxa_gpio_mode(gpio | GPIO_OUT);
+ return pxa_gpio_mode(gpio | GPIO_OUT | (value ? 0 : GPIO_DFLT_LOW));
}
static inline int __gpio_get_value(unsigned gpio)
diff --git a/include/asm-arm/arch-s3c2410/gpio.h b/include/asm-arm/arch-s3c2410/gpio.h
index d47ae453f8ca..7583895fd336 100644
--- a/include/asm-arm/arch-s3c2410/gpio.h
+++ b/include/asm-arm/arch-s3c2410/gpio.h
@@ -44,9 +44,11 @@ static inline int gpio_direction_input(unsigned gpio)
return 0;
}
-static inline int gpio_direction_output(unsigned gpio)
+static inline int gpio_direction_output(unsigned gpio, int value)
{
s3c2410_gpio_cfgpin(gpio, S3C2410_GPIO_OUTPUT);
+ /* REVISIT can we write the value first, to avoid glitching? */
+ s3c2410_gpio_setpin(gpio, value);
return 0;
}
diff --git a/include/asm-arm/arch-sa1100/gpio.h b/include/asm-arm/arch-sa1100/gpio.h
index da7575b0e5d0..e7a9d26e22a8 100644
--- a/include/asm-arm/arch-sa1100/gpio.h
+++ b/include/asm-arm/arch-sa1100/gpio.h
@@ -38,7 +38,7 @@ static inline void gpio_free(unsigned gpio)
}
extern int gpio_direction_input(unsigned gpio);
-extern int gpio_direction_output(unsigned gpio);
+extern int gpio_direction_output(unsigned gpio, int value);
static inline int gpio_get_value(unsigned gpio)
diff --git a/include/asm-avr32/arch-at32ap/gpio.h b/include/asm-avr32/arch-at32ap/gpio.h
index fcb756bdaa8e..80a21aa9ae77 100644
--- a/include/asm-avr32/arch-at32ap/gpio.h
+++ b/include/asm-avr32/arch-at32ap/gpio.h
@@ -10,7 +10,7 @@ int __must_check gpio_request(unsigned int gpio, const char *label);
void gpio_free(unsigned int gpio);
int gpio_direction_input(unsigned int gpio);
-int gpio_direction_output(unsigned int gpio);
+int gpio_direction_output(unsigned int gpio, int value);
int gpio_get_value(unsigned int gpio);
void gpio_set_value(unsigned int gpio, int value);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.