From: Drew Fustini <drew@pdp7.com>
To: linux-gpio@vger.kernel.org, brgl@bgdev.pl,
linus.walleij@linaro.org, thomas.petazzoni@bootlin.com
Cc: Drew Fustini <drew@pdp7.com>
Subject: [RFC] gpio: expose pull-up/pull-down line flags to userspace
Date: Sat, 21 Sep 2019 12:25:23 +0200 [thread overview]
Message-ID: <20190921102522.8970-1-drew@pdp7.com> (raw)
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>
---
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 d9074191edef..9da1093cc7f5 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -427,6 +427,8 @@ struct linehandle_state {
(GPIOHANDLE_REQUEST_INPUT | \
GPIOHANDLE_REQUEST_OUTPUT | \
GPIOHANDLE_REQUEST_ACTIVE_LOW | \
+ GPIOHANDLE_REQUEST_PULL_UP | \
+ GPIOHANDLE_REQUEST_PULL_DOWN | \
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
@@ -598,6 +600,10 @@ 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_PULL_DOWN)
+ set_bit(FLAG_PULL_DOWN, &desc->flags);
+ if (lflags & GPIOHANDLE_REQUEST_PULL_UP)
+ set_bit(FLAG_PULL_UP, &desc->flags);
ret = gpiod_set_transitory(desc, false);
if (ret < 0)
@@ -1102,6 +1108,10 @@ 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_PULL_DOWN;
+ if (test_bit(FLAG_PULL_UP, &desc->flags))
+ lineinfo.flags |= GPIOLINE_FLAG_PULL_UP;
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
@@ -2475,6 +2485,8 @@ 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..c2d1f7d908d6 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_PULL_UP (1UL << 5)
+#define GPIOLINE_FLAG_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_PULL_UP (1UL << 5)
+#define GPIOHANDLE_REQUEST_PULL_DOWN (1UL << 6)
/**
* struct gpiohandle_request - Information about a GPIO handle request
--
2.20.1
next reply other threads:[~2019-09-21 10:27 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-21 10:25 Drew Fustini [this message]
2019-09-23 8:38 ` [RFC] gpio: expose pull-up/pull-down line flags to userspace Bartosz Golaszewski
2019-10-02 11:10 ` Drew Fustini
2019-10-03 12:47 ` Linus Walleij
2019-10-04 7:22 ` Bartosz Golaszewski
2019-10-04 12:46 ` Bartosz Golaszewski
2019-10-05 17:02 ` Linus Walleij
2019-10-06 3:12 ` Kent Gibson
2019-10-06 21:06 ` Linus Walleij
2019-10-07 4:37 ` Kent Gibson
2019-10-08 6:15 ` Kent Gibson
2019-10-08 20:56 ` Bartosz Golaszewski
2019-10-08 23:21 ` Kent Gibson
2019-10-08 23:30 ` Bartosz Golaszewski
2019-10-08 23:56 ` Kent Gibson
2019-10-09 0:03 ` Bartosz Golaszewski
2019-10-09 0:22 ` Kent Gibson
2019-10-09 6:55 ` Kent Gibson
2019-10-09 12:57 ` Drew Fustini
2019-10-09 13:23 ` Kent Gibson
2019-10-09 13:30 ` Drew Fustini
2019-10-09 14:11 ` Kent Gibson
2019-10-09 15:50 ` Bartosz Golaszewski
2019-10-09 16:19 ` Kent Gibson
2019-10-09 23:59 ` Kent Gibson
2019-10-10 7:47 ` Drew Fustini
2019-10-10 10:14 ` Kent Gibson
2019-10-10 11:17 ` Kent Gibson
2019-10-11 13:04 ` Drew Fustini
2019-10-11 13:06 ` Drew Fustini
2019-10-11 13:49 ` Kent Gibson
2019-10-09 11:32 ` Drew Fustini
2019-10-09 13:57 ` Drew Fustini
2019-10-09 14:01 ` Kent Gibson
2019-10-09 11:46 ` Drew Fustini
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