gpiolib: add gpiod_get_array and gpiod_put_array functions

[karo-tx-linux.git] / drivers / gpio / gpiolib-acpi.c

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index c0929d938ced866e343e0230e00fc5c9cda77c0b..c4919966453dc18bd4a4651ec32a44ebfa8584c2 100644 (file)
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -712,3 +712,87 @@ void acpi_gpiochip_remove(struct gpio_chip *chip)
        acpi_detach_data(handle, acpi_gpio_chip_dh);
        kfree(acpi_gpio);
 }
+
+static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
+{
+       const union acpi_object *element = obj->package.elements;
+       const union acpi_object *end = element + obj->package.count;
+       unsigned int count = 0;
+
+       while (element < end) {
+               if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
+                       count++;
+
+               element++;
+       }
+       return count;
+}
+
+static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
+{
+       unsigned int *count = data;
+
+       if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
+               *count += ares->data.gpio.pin_table_length;
+
+       return 1;
+}
+
+/**
+ * acpi_gpio_count - return the number of GPIOs associated with a
+ *             device / function or -ENOENT if no GPIO has been
+ *             assigned to the requested function.
+ * @dev:       GPIO consumer, can be NULL for system-global GPIOs
+ * @con_id:    function within the GPIO consumer
+ */
+int acpi_gpio_count(struct device *dev, const char *con_id)
+{
+       struct acpi_device *adev = ACPI_COMPANION(dev);
+       const union acpi_object *obj;
+       const struct acpi_gpio_mapping *gm;
+       int count = -ENOENT;
+       int ret;
+       char propname[32];
+       unsigned int i;
+
+       /* Try first from _DSD */
+       for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+               if (con_id && strcmp(con_id, "gpios"))
+                       snprintf(propname, sizeof(propname), "%s-%s",
+                                con_id, gpio_suffixes[i]);
+               else
+                       snprintf(propname, sizeof(propname), "%s",
+                                gpio_suffixes[i]);
+
+               ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
+                                           &obj);
+               if (ret == 0) {
+                       if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
+                               count = 1;
+                       else if (obj->type == ACPI_TYPE_PACKAGE)
+                               count = acpi_gpio_package_count(obj);
+               } else if (adev->driver_gpios) {
+                       for (gm = adev->driver_gpios; gm->name; gm++)
+                               if (strcmp(propname, gm->name) == 0) {
+                                       count = gm->size;
+                                       break;
+                               }
+               }
+               if (count >= 0)
+                       break;
+       }
+
+       /* Then from plain _CRS GPIOs */
+       if (count < 0) {
+               struct list_head resource_list;
+               unsigned int crs_count = 0;
+
+               INIT_LIST_HEAD(&resource_list);
+               acpi_dev_get_resources(adev, &resource_list,
+                                      acpi_find_gpio_count, &crs_count);
+               acpi_dev_free_resource_list(&resource_list);
+               if (crs_count > 0)
+                       count = crs_count;
+       }
+       return count;
+}