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 v2 08/18] gpiolib: cdev: support GPIOLINE_SET_CONFIG_IOCTL
Date: Sat, 25 Jul 2020 12:19:45 +0800 [thread overview]
Message-ID: <20200725041955.9985-9-warthog618@gmail.com> (raw)
In-Reply-To: <20200725041955.9985-1-warthog618@gmail.com>
Add support for GPIOLINE_SET_CONFIG_IOCTL, the uAPI v2
line set config ioctl.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
drivers/gpio/gpiolib-cdev.c | 91 +++++++++++++++++++++++++++++++++++++
1 file changed, 91 insertions(+)
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 8caebb460557..9d944ca0ff59 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>
@@ -417,6 +418,8 @@ 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, partiuclarly 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.
@@ -428,6 +431,7 @@ struct line {
wait_queue_head_t wait;
DECLARE_KFIFO_PTR(events, struct gpioline_event);
atomic_t seqno;
+ struct mutex config_mutex;
struct edge_detector *edets;
/* descs must be last so it can be dynamically sized */
struct gpio_desc *descs[];
@@ -709,6 +713,30 @@ static int gpioline_config_validate(struct gpioline_config *lc, int num_lines)
return 0;
}
+static int gpioline_config_change_validate(struct line *line,
+ struct gpioline_config *lc)
+{
+ int i;
+ u64 flags;
+ struct gpio_desc *desc;
+
+ for (i = 0; i < line->num_descs; i++) {
+ desc = line->descs[i];
+ flags = gpioline_config_flags(lc, i);
+ /* disallow edge detection changes */
+ if (line->edets[i].flags != (flags & GPIOLINE_EDGE_FLAGS))
+ return -EINVAL;
+
+ if (line->edets[i].flags) {
+ /* disallow polarity changes */
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags) !=
+ ((flags & GPIOLINE_FLAG_V2_ACTIVE_LOW) != 0))
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
static void gpioline_config_flags_to_desc_flags(u64 flags,
unsigned long *flagsp)
{
@@ -757,6 +785,66 @@ static long line_get_values(struct line *line, void __user *ip)
return 0;
}
+static long line_set_config_locked(struct line *line,
+ struct gpioline_config *lc)
+{
+ struct gpio_desc *desc;
+ int i, ret;
+ u64 flags;
+
+ ret = gpioline_config_change_validate(line, lc);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < line->num_descs; i++) {
+ desc = line->descs[i];
+ flags = gpioline_config_flags(lc, i);
+
+ gpioline_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 & GPIOLINE_FLAG_V2_OUTPUT) {
+ int val = gpioline_config_output_value(lc, i);
+
+ edge_detector_stop(&line->edets[i]);
+ ret = gpiod_direction_output(desc, val);
+ if (ret)
+ return ret;
+ } else if (flags & GPIOLINE_FLAG_V2_INPUT) {
+ ret = gpiod_direction_input(desc);
+ if (ret)
+ return ret;
+ }
+
+ blocking_notifier_call_chain(&desc->gdev->notifier,
+ GPIOLINE_CHANGED_CONFIG, desc);
+ }
+ return 0;
+}
+
+static long line_set_config(struct line *line, void __user *ip)
+{
+ struct gpioline_config lc;
+ int ret;
+
+ if (copy_from_user(&lc, ip, sizeof(lc)))
+ return -EFAULT;
+
+ ret = gpioline_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)
{
@@ -765,6 +853,8 @@ static long line_ioctl(struct file *file, unsigned int cmd,
if (cmd == GPIOLINE_GET_VALUES_IOCTL)
return line_get_values(line, ip);
+ else if (cmd == GPIOLINE_SET_CONFIG_IOCTL)
+ return line_set_config(line, ip);
return -EINVAL;
}
@@ -937,6 +1027,7 @@ 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 = linereq.event_buffer_size;
--
2.27.0
next prev parent reply other threads:[~2020-07-25 4:21 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-25 4:19 [PATCH v2 00/18] gpio: cdev: add uAPI V2 Kent Gibson
2020-07-25 4:19 ` [PATCH v2 01/18] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Kent Gibson
2020-07-25 4:19 ` [PATCH v2 02/18] gpio: uapi: define uAPI v2 Kent Gibson
2020-08-04 17:42 ` Bartosz Golaszewski
2020-08-05 5:18 ` Kent Gibson
2020-08-05 17:47 ` Bartosz Golaszewski
2020-08-06 1:03 ` Kent Gibson
2020-08-06 1:15 ` Kent Gibson
2020-08-06 15:53 ` Bartosz Golaszewski
2020-07-25 4:19 ` [PATCH v2 03/18] gpiolib: make cdev a build option Kent Gibson
2020-07-25 20:29 ` Andy Shevchenko
2020-07-26 22:25 ` Linus Walleij
2020-07-27 1:46 ` Kent Gibson
2020-07-27 5:57 ` Kent Gibson
2020-07-27 8:15 ` Linus Walleij
2020-07-25 4:19 ` [PATCH v2 04/18] gpiolib: add build option for CDEV v1 ABI Kent Gibson
2020-07-25 4:19 ` [PATCH v2 05/18] gpiolib: cdev: support GPIO_GET_LINE_IOCTL and GPIOLINE_GET_VALUES_IOCTL Kent Gibson
2020-07-25 20:51 ` Andy Shevchenko
2020-07-26 1:12 ` Kent Gibson
2020-07-26 3:24 ` Kent Gibson
2020-07-29 2:28 ` Kent Gibson
2020-07-29 8:05 ` Andy Shevchenko
2020-07-29 10:01 ` Kent Gibson
2020-07-31 16:05 ` Bartosz Golaszewski
2020-08-02 3:31 ` Kent Gibson
2020-08-02 9:32 ` Kent Gibson
2020-08-03 19:59 ` Bartosz Golaszewski
2020-08-03 20:02 ` Bartosz Golaszewski
2020-08-03 23:01 ` Kent Gibson
2020-08-04 17:47 ` Bartosz Golaszewski
2020-08-05 3:06 ` Kent Gibson
2020-07-25 4:19 ` [PATCH v2 06/18] gpiolib: cdev: support GPIO_GET_LINEINFO_V2_IOCTL and GPIO_GET_LINEINFO_WATCH_V2_IOCTL Kent Gibson
2020-07-25 4:19 ` [PATCH v2 07/18] gpiolib: cdev: support edge detection for uAPI v2 Kent Gibson
2020-08-04 19:28 ` Bartosz Golaszewski
2020-07-25 4:19 ` Kent Gibson [this message]
2020-07-25 4:19 ` [PATCH v2 09/18] gpiolib: cdev: support GPIOLINE_SET_VALUES_IOCTL Kent Gibson
2020-07-25 4:19 ` [PATCH v2 10/18] gpiolib: cdev: support setting debounce Kent Gibson
2020-07-25 4:19 ` [PATCH v2 11/18] gpio: uapi: document uAPI v1 as deprecated Kent Gibson
2020-08-04 19:43 ` Bartosz Golaszewski
2020-07-25 4:19 ` [PATCH v2 12/18] tools: gpio: port lsgpio to v2 uAPI Kent Gibson
2020-07-25 4:19 ` [PATCH v2 13/18] tools: gpio: port gpio-watch " Kent Gibson
2020-07-25 4:19 ` [PATCH v2 14/18] tools: gpio: rename nlines to num_lines Kent Gibson
2020-07-25 4:19 ` [PATCH v2 15/18] tools: gpio: port gpio-hammer to v2 uAPI Kent Gibson
2020-07-25 4:19 ` [PATCH v2 16/18] tools: gpio: port gpio-event-mon " Kent Gibson
2020-07-25 4:19 ` [PATCH v2 17/18] tools: gpio: add debounce support to gpio-event-mon Kent Gibson
2020-07-25 4:19 ` [PATCH v2 18/18] tools: gpio: add multi-line monitoring " Kent Gibson
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