From: Kent Gibson <warthog618@gmail.com>
To: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
bgolaszewski@baylibre.com, linus.walleij@linaro.org
Cc: Kent Gibson <warthog618@gmail.com>
Subject: [PATCH v4 10/20] gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
Date: Fri, 14 Aug 2020 11:02:47 +0800 [thread overview]
Message-ID: <20200814030257.135463-11-warthog618@gmail.com> (raw)
In-Reply-To: <20200814030257.135463-1-warthog618@gmail.com>
Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2
line set config ioctl.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
drivers/gpio/gpiolib-cdev.c | 92 +++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 1d42a01f5414..04472c2b6678 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/kfifo.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/pinctrl/consumer.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
@@ -418,6 +419,8 @@ struct edge_detector {
* @seqno: the sequence number for edge events generated on all lines in
* this line request. Note that this is not used when @num_descs is 1, as
* the line_seqno is then the same and is cheaper to calculate.
+ * @config_mutex: mutex for serializing ioctl() calls to ensure consistency
+ * of configuration, particularly multi-step accesses to desc flags.
* @edets: an array of edge detectors, of size @num_descs
* @descs: the GPIO descriptors held by this line request, with @num_descs
* elements.
@@ -429,6 +432,7 @@ struct line {
wait_queue_head_t wait;
DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event);
atomic_t seqno;
+ struct mutex config_mutex;
struct edge_detector *edets;
struct gpio_desc *descs[];
};
@@ -703,6 +707,30 @@ static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc,
return 0;
}
+static int gpio_v2_line_config_change_validate(struct line *line,
+ struct gpio_v2_line_config *lc)
+{
+ int i;
+ u64 flags;
+ struct gpio_desc *desc;
+
+ for (i = 0; i < line->num_descs; i++) {
+ desc = line->descs[i];
+ flags = gpio_v2_line_config_flags(lc, i);
+ /* disallow edge detection changes */
+ if (line->edets[i].flags != (flags & GPIO_V2_LINE_EDGE_FLAGS))
+ return -EINVAL;
+
+ if (line->edets[i].flags) {
+ /* disallow polarity changes */
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags) !=
+ ((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0))
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
static void gpio_v2_line_config_flags_to_desc_flags(u64 flags,
unsigned long *flagsp)
{
@@ -783,6 +811,67 @@ static long line_get_values(struct line *line, void __user *ip)
return 0;
}
+static long line_set_config_locked(struct line *line,
+ struct gpio_v2_line_config *lc)
+{
+ struct gpio_desc *desc;
+ int i, ret;
+ u64 flags;
+
+ ret = gpio_v2_line_config_change_validate(line, lc);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < line->num_descs; i++) {
+ desc = line->descs[i];
+ flags = gpio_v2_line_config_flags(lc, i);
+
+ gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
+ /*
+ * Lines have to be requested explicitly for input
+ * or output, else the line will be treated "as is".
+ */
+ if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
+ int val = gpio_v2_line_config_output_value(lc, i);
+
+ edge_detector_stop(&line->edets[i]);
+ ret = gpiod_direction_output(desc, val);
+ if (ret)
+ return ret;
+ } else if (flags & GPIO_V2_LINE_FLAG_INPUT) {
+ ret = gpiod_direction_input(desc);
+ if (ret)
+ return ret;
+ }
+
+ blocking_notifier_call_chain(&desc->gdev->notifier,
+ GPIO_V2_LINE_CHANGED_CONFIG,
+ desc);
+ }
+ return 0;
+}
+
+static long line_set_config(struct line *line, void __user *ip)
+{
+ struct gpio_v2_line_config lc;
+ int ret;
+
+ if (copy_from_user(&lc, ip, sizeof(lc)))
+ return -EFAULT;
+
+ ret = gpio_v2_line_config_validate(&lc, line->num_descs);
+ if (ret)
+ return ret;
+
+ mutex_lock(&line->config_mutex);
+
+ ret = line_set_config_locked(line, &lc);
+
+ mutex_unlock(&line->config_mutex);
+
+ return ret;
+}
+
static long line_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
@@ -791,6 +880,8 @@ static long line_ioctl(struct file *file, unsigned int cmd,
if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL)
return line_get_values(line, ip);
+ else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL)
+ return line_set_config(line, ip);
return -EINVAL;
}
@@ -964,6 +1055,7 @@ static int line_create(struct gpio_device *gdev, void __user *ip)
}
}
+ mutex_init(&line->config_mutex);
init_waitqueue_head(&line->wait);
if (has_edge_detection) {
size = lr.event_buffer_size;
--
2.28.0
next prev parent reply other threads:[~2020-08-14 3:04 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-14 3:02 [PATCH v4 00/20] gpio: cdev: add uAPI v2 Kent Gibson
2020-08-14 3:02 ` [PATCH v4 01/20] gpiolib: cdev: desc_to_lineinfo should set info offset Kent Gibson
2020-08-14 3:02 ` [PATCH v4 02/20] gpiolib: cdev: replace strncpy with strscpy Kent Gibson
2020-08-14 3:02 ` [PATCH v4 03/20] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Kent Gibson
2020-08-14 3:02 ` [PATCH v4 04/20] gpio: uapi: define uAPI v2 Kent Gibson
2020-08-14 3:02 ` [PATCH v4 05/20] gpiolib: make cdev a build option Kent Gibson
2020-08-14 3:02 ` [PATCH v4 06/20] gpiolib: add build option for CDEV v1 ABI Kent Gibson
2020-08-14 3:02 ` [PATCH v4 07/20] gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL Kent Gibson
2020-08-14 19:31 ` Bartosz Golaszewski
2020-08-15 6:53 ` Kent Gibson
2020-08-15 7:21 ` Bartosz Golaszewski
2020-08-15 13:21 ` Kent Gibson
2020-08-16 12:13 ` Bartosz Golaszewski
2020-08-14 3:02 ` [PATCH v4 08/20] gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL Kent Gibson
2020-08-16 12:03 ` Bartosz Golaszewski
2020-08-14 3:02 ` [PATCH v4 09/20] gpiolib: cdev: support edge detection for uAPI v2 Kent Gibson
2020-08-16 14:32 ` Bartosz Golaszewski
2020-08-18 14:00 ` Kent Gibson
2020-08-14 3:02 ` Kent Gibson [this message]
2020-08-16 14:40 ` [PATCH v4 10/20] gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL Bartosz Golaszewski
2020-08-14 3:02 ` [PATCH v4 11/20] gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL Kent Gibson
2020-08-16 14:57 ` Bartosz Golaszewski
2020-08-14 3:02 ` [PATCH v4 12/20] gpiolib: cdev: support setting debounce Kent Gibson
2020-08-17 18:21 ` Bartosz Golaszewski
2020-08-18 14:37 ` Kent Gibson
2020-08-14 3:02 ` [PATCH v4 13/20] gpio: uapi: document uAPI v1 as deprecated Kent Gibson
2020-08-14 3:02 ` [PATCH v4 14/20] tools: gpio: port lsgpio to v2 uAPI Kent Gibson
2020-08-14 3:02 ` [PATCH v4 15/20] tools: gpio: port gpio-watch " Kent Gibson
2020-08-14 3:02 ` [PATCH v4 16/20] tools: gpio: rename nlines to num_lines Kent Gibson
2020-08-14 3:02 ` [PATCH v4 17/20] tools: gpio: port gpio-hammer to v2 uAPI Kent Gibson
2020-08-14 3:02 ` [PATCH v4 18/20] tools: gpio: port gpio-event-mon " Kent Gibson
2020-08-14 3:02 ` [PATCH v4 19/20] tools: gpio: add multi-line monitoring to gpio-event-mon Kent Gibson
2020-08-14 3:02 ` [PATCH v4 20/20] tools: gpio: add debounce support " Kent Gibson
2020-08-17 18:24 ` [PATCH v4 00/20] gpio: cdev: add uAPI v2 Bartosz Golaszewski
2020-08-17 18:40 ` Andy Shevchenko
2020-08-17 19:25 ` Bartosz Golaszewski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200814030257.135463-11-warthog618@gmail.com \
--to=warthog618@gmail.com \
--cc=bgolaszewski@baylibre.com \
--cc=linus.walleij@linaro.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).