Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[mirror_ubuntu-hirsute-kernel.git] / drivers / gpio / gpiolib-acpi.c

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index cbbb67a6f1d6064d15481bba121eb4383a73409d..bc34bc51a9487904a7ad4e44917e5d64700fa8a0 100644 (file)
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -943,3 +943,46 @@ int acpi_gpio_count(struct device *dev, const char *con_id)
        }
        return count;
 }
+
+struct acpi_crs_lookup {
+       struct list_head node;
+       struct acpi_device *adev;
+       const char *con_id;
+};
+
+static DEFINE_MUTEX(acpi_crs_lookup_lock);
+static LIST_HEAD(acpi_crs_lookup_list);
+
+bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
+{
+       struct acpi_crs_lookup *l, *lookup = NULL;
+
+       /* Never allow fallback if the device has properties */
+       if (adev->data.properties || adev->driver_gpios)
+               return false;
+
+       mutex_lock(&acpi_crs_lookup_lock);
+
+       list_for_each_entry(l, &acpi_crs_lookup_list, node) {
+               if (l->adev == adev) {
+                       lookup = l;
+                       break;
+               }
+       }
+
+       if (!lookup) {
+               lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
+               if (lookup) {
+                       lookup->adev = adev;
+                       lookup->con_id = con_id;
+                       list_add_tail(&lookup->node, &acpi_crs_lookup_list);
+               }
+       }
+
+       mutex_unlock(&acpi_crs_lookup_lock);
+
+       return lookup &&
+               ((!lookup->con_id && !con_id) ||
+                (lookup->con_id && con_id &&
+                 strcmp(lookup->con_id, con_id) == 0));
+}