[U-Boot] [PATCH] mxc: Make gpio_get_value() use PSR
gpio_get_value() should use PSR like Linux, not DR, because DR does not always reflect the pin state, while PSR does. This is especially useful to detect a short circuit on a GPIO pin configured as output, or to read the level of a pin controlled by a non-GPIO IOMUX function.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Stefano Babic sbabic@denx.de --- This patch depends on http://patchwork.ozlabs.org/patch/178694/ .
.../drivers/gpio/mxc_gpio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c index 6615535..e9bf278 100644 --- u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c +++ u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c @@ -116,7 +116,7 @@ int gpio_get_value(unsigned gpio)
regs = (struct gpio_regs *)gpio_ports[port];
- val = (readl(®s->gpio_dr) >> gpio) & 0x01; + val = (readl(®s->gpio_psr) >> gpio) & 0x01;
return val; }
On 20/08/2012 22:55, Benoît Thébaudeau wrote:
gpio_get_value() should use PSR like Linux, not DR, because DR does not always reflect the pin state, while PSR does. This is especially useful to detect a short circuit on a GPIO pin configured as output, or to read the level of a pin controlled by a non-GPIO IOMUX function.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Stefano Babic sbabic@denx.de
This patch depends on http://patchwork.ozlabs.org/patch/178694/ .
.../drivers/gpio/mxc_gpio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c index 6615535..e9bf278 100644 --- u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c +++ u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c @@ -116,7 +116,7 @@ int gpio_get_value(unsigned gpio)
regs = (struct gpio_regs *)gpio_ports[port];
- val = (readl(®s->gpio_dr) >> gpio) & 0x01;
val = (readl(®s->gpio_psr) >> gpio) & 0x01;
return val;
}
Kernel does the same.
Acked-by: Stefano Babic sbabic@denx.de
Best regards, Stefano Babic
On 20/08/2012 22:55, Benoît Thébaudeau wrote:
gpio_get_value() should use PSR like Linux, not DR, because DR does not always reflect the pin state, while PSR does. This is especially useful to detect a short circuit on a GPIO pin configured as output, or to read the level of a pin controlled by a non-GPIO IOMUX function.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Stefano Babic sbabic@denx.de
This patch depends on http://patchwork.ozlabs.org/patch/178694/ .
.../drivers/gpio/mxc_gpio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c index 6615535..e9bf278 100644 --- u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c +++ u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c @@ -116,7 +116,7 @@ int gpio_get_value(unsigned gpio)
regs = (struct gpio_regs *)gpio_ports[port];
- val = (readl(®s->gpio_dr) >> gpio) & 0x01;
val = (readl(®s->gpio_psr) >> gpio) & 0x01;
return val;
}
Applied to u-boot-imx, thanks.
Best regards, Stefano Babic
participants (2)
-
Benoît Thébaudeau -
Stefano Babic