@@ -554,8 +554,9 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
return -EINVAL;
- /* PULL_UP and PULL_DOWN flags only make sense for input mode. */
- if (!(lflags & GPIOHANDLE_REQUEST_INPUT) &&
+ /* PULL_UP and PULL_DOWN flags only allowed for input or output mode. */
+ if (!((lflags & GPIOHANDLE_REQUEST_INPUT) ||
+ (lflags & GPIOHANDLE_REQUEST_OUTPUT)) &&
((lflags & GPIOHANDLE_REQUEST_PULL_UP) ||
(lflags & GPIOHANDLE_REQUEST_PULL_DOWN)))
return -EINVAL;
@@ -2932,6 +2933,24 @@ static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
}
+static int gpio_set_bias(struct gpio_chip *chip, struct gpio_desc *desc)
+{
+ int bias = 0;
+
+ if (test_bit(FLAG_PULL_UP, &desc->flags) &&
+ test_bit(FLAG_PULL_DOWN, &desc->flags))
+ bias = PIN_CONFIG_BIAS_DISABLE;
+ else if (test_bit(FLAG_PULL_UP, &desc->flags))
+ bias = PIN_CONFIG_BIAS_PULL_UP;
+ else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
+ bias = PIN_CONFIG_BIAS_PULL_DOWN;
+
+ if (bias)
+ return gpio_set_config(chip, gpio_chip_hwgpio(desc), bias);
+
+ return 0;
+}
+
/**
* gpiod_direction_input - set the GPIO direction to input
* @desc: GPIO to set to input
@@ -2979,16 +2998,7 @@ int gpiod_direction_input(struct gpio_desc *desc)
if (ret == 0)
clear_bit(FLAG_IS_OUT, &desc->flags);
- if (test_bit(FLAG_PULL_UP, &desc->flags) &&
- test_bit(FLAG_PULL_DOWN, &desc->flags))
- gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_DISABLE);
- else if (test_bit(FLAG_PULL_UP, &desc->flags))
- gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_PULL_UP);
- else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
- gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_PULL_DOWN);
+ gpio_set_bias(chip, desc);
trace_gpio_direction(desc_to_gpio(desc), 1, ret);
@@ -3114,6 +3124,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
}
set_output_value:
+ gpio_set_bias(gc, desc);
return gpiod_direction_output_raw_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
This patch allows pull up/down bias to be set on outputs. Use case is for open source or open drain applications where internal pull up/down may conflict with external biasing. Signed-off-by: Kent Gibson <warthog618@gmail.com> --- drivers/gpio/gpiolib.c | 35 +++++++++++++++++++++++------------ 1 file changed, 23 insertions(+), 12 deletions(-)