gpio: aggregator: add gpio_aggregator_{alloc,free}()

Prepare for the upcoming configfs interface. These functions will be
used by both the existing sysfs interface and the new configfs
interface, reducing code duplication.

No functional change.

Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250407043019.4105613-4-koichiro.den@canonical.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index ff5cd5eaa550b95f86878f4316f3d75290e2a08a..6f933a76b2b9a72172507bc1264f5e3cd01cc654 100644 (file)
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -36,12 +36,41 @@
 struct gpio_aggregator {
        struct gpiod_lookup_table *lookups;
        struct platform_device *pdev;
+       int id;
        char args[];
 };
 
 static DEFINE_MUTEX(gpio_aggregator_lock);     /* protects idr */
 static DEFINE_IDR(gpio_aggregator_idr);
 
+static int gpio_aggregator_alloc(struct gpio_aggregator **aggr, size_t arg_size)
+{
+       int ret;
+
+       struct gpio_aggregator *new __free(kfree) = kzalloc(
+                                       sizeof(*new) + arg_size, GFP_KERNEL);
+       if (!new)
+               return -ENOMEM;
+
+       scoped_guard(mutex, &gpio_aggregator_lock)
+               ret = idr_alloc(&gpio_aggregator_idr, new, 0, 0, GFP_KERNEL);
+
+       if (ret < 0)
+               return ret;
+
+       new->id = ret;
+       *aggr = no_free_ptr(new);
+       return 0;
+}
+
+static void gpio_aggregator_free(struct gpio_aggregator *aggr)
+{
+       scoped_guard(mutex, &gpio_aggregator_lock)
+               idr_remove(&gpio_aggregator_idr, aggr->id);
+
+       kfree(aggr);
+}
+
 static int gpio_aggregator_add_gpio(struct gpio_aggregator *aggr,
                                    const char *key, int hwnum, unsigned int *n)
 {
@@ -454,17 +483,15 @@ static ssize_t gpio_aggregator_new_device_store(struct device_driver *driver,
 {
        struct gpio_aggregator *aggr;
        struct platform_device *pdev;
-       int res, id;
+       int res;
 
        if (!try_module_get(THIS_MODULE))
                return -ENOENT;
 
        /* kernfs guarantees string termination, so count + 1 is safe */
-       aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL);
-       if (!aggr) {
-               res = -ENOMEM;
+       res = gpio_aggregator_alloc(&aggr, count + 1);
+       if (res)
                goto put_module;
-       }
 
        memcpy(aggr->args, buf, count + 1);
 
@@ -475,19 +502,10 @@ static ssize_t gpio_aggregator_new_device_store(struct device_driver *driver,
                goto free_ga;
        }
 
-       mutex_lock(&gpio_aggregator_lock);
-       id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
-       mutex_unlock(&gpio_aggregator_lock);
-
-       if (id < 0) {
-               res = id;
-               goto free_table;
-       }
-
-       aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id);
+       aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, aggr->id);
        if (!aggr->lookups->dev_id) {
                res = -ENOMEM;
-               goto remove_idr;
+               goto free_table;
        }
 
        res = gpio_aggregator_parse(aggr);
@@ -496,7 +514,7 @@ static ssize_t gpio_aggregator_new_device_store(struct device_driver *driver,
 
        gpiod_add_lookup_table(aggr->lookups);
 
-       pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0);
+       pdev = platform_device_register_simple(DRV_NAME, aggr->id, NULL, 0);
        if (IS_ERR(pdev)) {
                res = PTR_ERR(pdev);
                goto remove_table;
@@ -510,14 +528,10 @@ remove_table:
        gpiod_remove_lookup_table(aggr->lookups);
 free_dev_id:
        kfree(aggr->lookups->dev_id);
-remove_idr:
-       mutex_lock(&gpio_aggregator_lock);
-       idr_remove(&gpio_aggregator_idr, id);
-       mutex_unlock(&gpio_aggregator_lock);
 free_table:
        kfree(aggr->lookups);
 free_ga:
-       kfree(aggr);
+       gpio_aggregator_free(aggr);
 put_module:
        module_put(THIS_MODULE);
        return res;