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 2/6] gpiolib: add support for pull up/down to lineevent_create
Date: Sat, 12 Oct 2019 09:56:24 +0800 [thread overview]
Message-ID: <20191012015628.9604-3-warthog618@gmail.com> (raw)
In-Reply-To: <20191012015628.9604-1-warthog618@gmail.com>
This patch adds support for pull up/down to lineevent_create.
Use cases include receiving asynchronous presses from a
push button without an external pull up/down.
Move all the flags sanitization before any memory allocation in
lineevent_create() in order to remove a couple unneeded gotos.
(from Bartosz Golaszewski <bgolaszewski@baylibre.com>)
Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
drivers/gpio/gpiolib.c | 60 +++++++++++++++++++++++++-----------------
1 file changed, 36 insertions(+), 24 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 9d2a5e2f6e77..053847b6187f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -905,6 +905,38 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
return -EFAULT;
+ offset = eventreq.lineoffset;
+ lflags = eventreq.handleflags;
+ eflags = eventreq.eventflags;
+
+ if (offset >= gdev->ngpio)
+ return -EINVAL;
+
+ /* Return an error if a unknown flag is set */
+ if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
+ (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS))
+ return -EINVAL;
+
+ /* This is just wrong: we don't look for events on output lines */
+ if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
+ (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
+ (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
+ return -EINVAL;
+
+ /* PULL_UP and PULL_DOWN flags only make sense for input mode. */
+ if (!(lflags & GPIOHANDLE_REQUEST_INPUT) &&
+ ((lflags & GPIOHANDLE_REQUEST_PULL_UP) ||
+ (lflags & GPIOHANDLE_REQUEST_PULL_DOWN)))
+ return -EINVAL;
+
+ /*
+ * Do not allow both pull-up and pull-down flags to be set as they
+ * are contradictory.
+ */
+ if ((lflags & GPIOHANDLE_REQUEST_PULL_UP) &&
+ (lflags & GPIOHANDLE_REQUEST_PULL_DOWN))
+ return -EINVAL;
+
le = kzalloc(sizeof(*le), GFP_KERNEL);
if (!le)
return -ENOMEM;
@@ -922,30 +954,6 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
}
}
- offset = eventreq.lineoffset;
- lflags = eventreq.handleflags;
- eflags = eventreq.eventflags;
-
- if (offset >= gdev->ngpio) {
- ret = -EINVAL;
- goto out_free_label;
- }
-
- /* Return an error if a unknown flag is set */
- if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
- (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
- ret = -EINVAL;
- goto out_free_label;
- }
-
- /* This is just wrong: we don't look for events on output lines */
- if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
- (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
- (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
- ret = -EINVAL;
- goto out_free_label;
- }
-
desc = &gdev->descs[offset];
ret = gpiod_request(desc, le->label);
if (ret)
@@ -955,6 +963,10 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &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_direction_input(desc);
if (ret)
--
2.23.0
next 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 ` Kent Gibson [this message]
2019-10-14 12:35 ` [PATCH v2 2/6] gpiolib: add support for pull up/down to lineevent_create 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 ` [PATCH v2 6/6] gpiolib: allow pull up/down on outputs Kent Gibson
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