From: Kent Gibson <warthog618@gmail.com>
To: linux-gpio@vger.kernel.org, bgolaszewski@baylibre.com,
linus.walleij@linaro.org, bamv2005@gmail.com
Cc: drew@pdp7.com, Kent Gibson <warthog618@gmail.com>
Subject: [PATCH v4 1/5] gpio: expose pull-up/pull-down line flags to userspace
Date: Mon, 28 Oct 2019 15:37:09 +0800 [thread overview]
Message-ID: <20191028073713.25664-2-warthog618@gmail.com> (raw)
In-Reply-To: <20191028073713.25664-1-warthog618@gmail.com>
From: Drew Fustini <drew@pdp7.com>
Add pull-up/pull-down flags to the gpio line get and
set ioctl() calls. Use cases include a push button
that does not have an external resistor.
Addition use cases described by Limor Fried (ladyada) of
Adafruit in this PR for Adafruit_Blinka Python lib:
https://github.com/adafruit/Adafruit_Blinka/pull/59
Signed-off-by: Drew Fustini <drew@pdp7.com>
[Kent: added BIAS to GPIO flag names]
Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
drivers/gpio/gpiolib.c | 12 ++++++++++++
include/uapi/linux/gpio.h | 4 ++++
2 files changed, 16 insertions(+)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e8964493c571..e80e689be2cc 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -421,6 +421,8 @@ struct linehandle_state {
(GPIOHANDLE_REQUEST_INPUT | \
GPIOHANDLE_REQUEST_OUTPUT | \
GPIOHANDLE_REQUEST_ACTIVE_LOW | \
+ GPIOHANDLE_REQUEST_BIAS_PULL_UP | \
+ GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
@@ -592,6 +594,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+ if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
+ set_bit(FLAG_PULL_DOWN, &desc->flags);
+ if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
+ set_bit(FLAG_PULL_UP, &desc->flags);
ret = gpiod_set_transitory(desc, false);
if (ret < 0)
@@ -1091,6 +1097,10 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
GPIOLINE_FLAG_IS_OUT);
+ if (test_bit(FLAG_PULL_DOWN, &desc->flags))
+ lineinfo.flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
+ if (test_bit(FLAG_PULL_UP, &desc->flags))
+ lineinfo.flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
@@ -2764,6 +2774,8 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
clear_bit(FLAG_REQUESTED, &desc->flags);
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
+ clear_bit(FLAG_PULL_UP, &desc->flags);
+ clear_bit(FLAG_PULL_DOWN, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
ret = true;
}
diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 4ebfe0ac6c5b..39e6c7854d63 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -33,6 +33,8 @@ struct gpiochip_info {
#define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2)
#define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3)
#define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4)
+#define GPIOLINE_FLAG_BIAS_PULL_UP (1UL << 5)
+#define GPIOLINE_FLAG_BIAS_PULL_DOWN (1UL << 6)
/**
* struct gpioline_info - Information about a certain GPIO line
@@ -62,6 +64,8 @@ struct gpioline_info {
#define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2)
#define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3)
#define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4)
+#define GPIOHANDLE_REQUEST_BIAS_PULL_UP (1UL << 5)
+#define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6)
/**
* struct gpiohandle_request - Information about a GPIO handle request
--
2.23.0
next prev parent reply other threads:[~2019-10-28 7:38 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 7:37 [PATCH v4 0/5] gpio: expose line bias flags to userspace Kent Gibson
2019-10-28 7:37 ` Kent Gibson [this message]
2019-10-28 7:37 ` [PATCH v4 2/5] gpiolib: add support for pull up/down to lineevent_create Kent Gibson
2019-10-31 7:11 ` Bartosz Golaszewski
2019-10-31 7:24 ` Kent Gibson
2019-10-28 7:37 ` [PATCH v4 3/5] gpio: mockup: add set_config to support pull up/down Kent Gibson
2019-10-28 7:37 ` [PATCH v4 4/5] gpiolib: add support for disabling line bias Kent Gibson
2019-10-28 7:37 ` [PATCH v4 5/5] gpiolib: add support for biasing output lines Kent Gibson
2019-10-31 7:10 ` [PATCH v4 0/5] gpio: expose line bias flags to userspace Bartosz Golaszewski
2019-11-04 0:26 ` Linus Walleij
2019-11-04 1:07 ` Kent Gibson
2019-11-04 10:14 ` Bartosz Golaszewski
2019-11-04 11:11 ` Kent Gibson
2019-11-04 11:48 ` Bartosz Golaszewski
2019-11-04 14:22 ` Kent Gibson
2019-11-04 15:20 ` Bartosz Golaszewski
2019-11-04 15:35 ` Kent Gibson
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