gpio: cdev: prepare gpio_desc_to_lineinfo() for being called from atomic

In order to prepare gpio_desc_to_lineinfo() to being called from atomic
context, add a new argument - bool atomic - which, if set, indicates
that no sleeping functions must be called (currently: only
pinctrl_gpio_can_use_line()).

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-4-c79135e58a1c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index d55d2a246d4187f8e7628d95c4b188469be51937..0cba74381687a9be081f3243f37fe3552e0f3b34 100644 (file)
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2235,7 +2235,7 @@ static void gpio_v2_line_info_changed_to_v1(
 #endif /* CONFIG_GPIO_CDEV_V1 */
 
 static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
-                                 struct gpio_v2_line_info *info)
+                                 struct gpio_v2_line_info *info, bool atomic)
 {
        u32 debounce_period_us;
        unsigned long dflags;
@@ -2277,9 +2277,12 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
            test_bit(FLAG_USED_AS_IRQ, &dflags) ||
            test_bit(FLAG_EXPORT, &dflags) ||
            test_bit(FLAG_SYSFS, &dflags) ||
-           !gpiochip_line_is_valid(guard.gc, info->offset) ||
-           !pinctrl_gpio_can_use_line(guard.gc, info->offset))
+           !gpiochip_line_is_valid(guard.gc, info->offset)) {
                info->flags |= GPIO_V2_LINE_FLAG_USED;
+       } else if (!atomic) {
+               if (!pinctrl_gpio_can_use_line(guard.gc, info->offset))
+                       info->flags |= GPIO_V2_LINE_FLAG_USED;
+       }
 
        if (test_bit(FLAG_IS_OUT, &dflags))
                info->flags |= GPIO_V2_LINE_FLAG_OUTPUT;
@@ -2385,7 +2388,7 @@ static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip,
                        return -EBUSY;
        }
 
-       gpio_desc_to_lineinfo(desc, &lineinfo_v2);
+       gpio_desc_to_lineinfo(desc, &lineinfo_v2, false);
        gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
 
        if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
@@ -2422,7 +2425,7 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
                if (test_and_set_bit(lineinfo.offset, cdev->watched_lines))
                        return -EBUSY;
        }
-       gpio_desc_to_lineinfo(desc, &lineinfo);
+       gpio_desc_to_lineinfo(desc, &lineinfo, false);
 
        if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
                if (watch)
@@ -2514,7 +2517,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
        memset(&chg, 0, sizeof(chg));
        chg.event_type = action;
        chg.timestamp_ns = ktime_get_ns();
-       gpio_desc_to_lineinfo(desc, &chg.info);
+       gpio_desc_to_lineinfo(desc, &chg.info, false);
 
        ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock);
        if (ret)