From: Kent Gibson <warthog618@gmail.com>
To: linux-gpio@vger.kernel.org, brgl@bgdev.pl,
linus.walleij@linaro.org, bamv2005@gmail.com
Cc: drew@pdp7.com, Kent Gibson <warthog618@gmail.com>
Subject: [PATCH v2 6/6] gpiolib: allow pull up/down on outputs
Date: Sat, 12 Oct 2019 09:56:28 +0800 [thread overview]
Message-ID: <20191012015628.9604-7-warthog618@gmail.com> (raw)
In-Reply-To: <20191012015628.9604-1-warthog618@gmail.com>
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(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f90b20d548b9..9cc0f9077c7b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -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);
--
2.23.0
prev parent reply other threads:[~2019-10-12 1:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-12 1:56 [PATCH v2 0/6] gpio: expose pull-up/pull-down line flags to userspace Kent Gibson
2019-10-12 1:56 ` [PATCH v2 1/6] " Kent Gibson
2019-10-12 1:56 ` [PATCH v2 2/6] gpiolib: add support for pull up/down to lineevent_create Kent Gibson
2019-10-14 12:35 ` Bartosz Golaszewski
2019-10-14 12:58 ` Kent Gibson
2019-10-14 16:44 ` Bartosz Golaszewski
2019-10-12 1:56 ` [PATCH v2 3/6] gpio: mockup: add set_config to support pull up/down Kent Gibson
2019-10-12 1:56 ` [PATCH v2 4/6] gpiolib: pull requires explicit input mode Kent Gibson
2019-10-14 12:38 ` Bartosz Golaszewski
2019-10-14 12:54 ` Kent Gibson
2019-10-14 17:00 ` Bartosz Golaszewski
2019-10-15 0:52 ` Kent Gibson
2019-10-12 1:56 ` [PATCH v2 5/6] gpiolib: disable bias on inputs when pull up/down are both set Kent Gibson
2019-10-14 12:43 ` Bartosz Golaszewski
2019-10-14 13:04 ` Kent Gibson
2019-10-14 16:50 ` Bartosz Golaszewski
2019-10-15 0:58 ` Kent Gibson
2019-10-15 12:51 ` Bartosz Golaszewski
2019-10-16 1:01 ` Kent Gibson
2019-10-17 5:06 ` Kent Gibson
2019-10-18 8:03 ` Bartosz Golaszewski
2019-10-18 10:13 ` Kent Gibson
2019-10-21 14:57 ` Bartosz Golaszewski
2019-10-21 23:14 ` Kent Gibson
2019-10-22 3:11 ` Kent Gibson
2019-10-18 7:48 ` Bartosz Golaszewski
2019-10-18 9:42 ` Kent Gibson
2019-10-12 1:56 ` Kent Gibson [this message]
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