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path: root/drivers/gpio/devres.c
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-rw-r--r--drivers/gpio/devres.c392
1 files changed, 392 insertions, 0 deletions
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
new file mode 100644
index 000000000..07ba82317
--- /dev/null
+++ b/drivers/gpio/devres.c
@@ -0,0 +1,392 @@
+/*
+ * drivers/gpio/devres.c - managed gpio resources
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * This file is based on kernel/irq/devres.c
+ *
+ * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/device.h>
+#include <linux/gfp.h>
+
+static void devm_gpiod_release(struct device *dev, void *res)
+{
+ struct gpio_desc **desc = res;
+
+ gpiod_put(*desc);
+}
+
+static int devm_gpiod_match(struct device *dev, void *res, void *data)
+{
+ struct gpio_desc **this = res, **gpio = data;
+
+ return *this == *gpio;
+}
+
+static void devm_gpiod_release_array(struct device *dev, void *res)
+{
+ struct gpio_descs **descs = res;
+
+ gpiod_put_array(*descs);
+}
+
+static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
+{
+ struct gpio_descs **this = res, **gpios = data;
+
+ return *this == *gpios;
+}
+
+/**
+ * devm_gpiod_get - Resource-managed gpiod_get()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get(). GPIO descriptors returned from this function are
+ * automatically disposed on driver detach. See gpiod_get() for detailed
+ * information about behavior and return values.
+ */
+struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+{
+ return devm_gpiod_get_index(dev, con_id, 0, flags);
+}
+EXPORT_SYMBOL(__devm_gpiod_get);
+
+/**
+ * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_optional(). GPIO descriptors returned from this function
+ * are automatically disposed on driver detach. See gpiod_get_optional() for
+ * detailed information about behavior and return values.
+ */
+struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+{
+ return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
+}
+EXPORT_SYMBOL(__devm_gpiod_get_optional);
+
+/**
+ * devm_gpiod_get_index - Resource-managed gpiod_get_index()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @idx: index of the GPIO to obtain in the consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_index(). GPIO descriptors returned from this function are
+ * automatically disposed on driver detach. See gpiod_get_index() for detailed
+ * information about behavior and return values.
+ */
+struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
+ const char *con_id,
+ unsigned int idx,
+ enum gpiod_flags flags)
+{
+ struct gpio_desc **dr;
+ struct gpio_desc *desc;
+
+ dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
+ GFP_KERNEL);
+ if (!dr)
+ return ERR_PTR(-ENOMEM);
+
+ desc = gpiod_get_index(dev, con_id, idx, flags);
+ if (IS_ERR(desc)) {
+ devres_free(dr);
+ return desc;
+ }
+
+ *dr = desc;
+ devres_add(dev, dr);
+
+ return desc;
+}
+EXPORT_SYMBOL(__devm_gpiod_get_index);
+
+/**
+ * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @child: firmware node (child of @dev)
+ *
+ * GPIO descriptors returned from this function are automatically disposed on
+ * driver detach.
+ */
+struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
+ const char *con_id,
+ struct fwnode_handle *child)
+{
+ static const char * const suffixes[] = { "gpios", "gpio" };
+ char prop_name[32]; /* 32 is max size of property name */
+ struct gpio_desc **dr;
+ struct gpio_desc *desc;
+ unsigned int i;
+
+ dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
+ GFP_KERNEL);
+ if (!dr)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
+ if (con_id)
+ snprintf(prop_name, sizeof(prop_name), "%s-%s",
+ con_id, suffixes[i]);
+ else
+ snprintf(prop_name, sizeof(prop_name), "%s",
+ suffixes[i]);
+
+ desc = fwnode_get_named_gpiod(child, prop_name);
+ if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
+ break;
+ }
+ if (IS_ERR(desc)) {
+ devres_free(dr);
+ return desc;
+ }
+
+ *dr = desc;
+ devres_add(dev, dr);
+
+ return desc;
+}
+EXPORT_SYMBOL(devm_get_gpiod_from_child);
+
+/**
+ * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @index: index of the GPIO to obtain in the consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
+ * function are automatically disposed on driver detach. See
+ * gpiod_get_index_optional() for detailed information about behavior and
+ * return values.
+ */
+struct gpio_desc *__must_check __devm_gpiod_get_index_optional(struct device *dev,
+ const char *con_id,
+ unsigned int index,
+ enum gpiod_flags flags)
+{
+ struct gpio_desc *desc;
+
+ desc = devm_gpiod_get_index(dev, con_id, index, flags);
+ if (IS_ERR(desc)) {
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ }
+
+ return desc;
+}
+EXPORT_SYMBOL(__devm_gpiod_get_index_optional);
+
+/**
+ * devm_gpiod_get_array - Resource-managed gpiod_get_array()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_array(). GPIO descriptors returned from this function are
+ * automatically disposed on driver detach. See gpiod_get_array() for detailed
+ * information about behavior and return values.
+ */
+struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+{
+ struct gpio_descs **dr;
+ struct gpio_descs *descs;
+
+ dr = devres_alloc(devm_gpiod_release_array,
+ sizeof(struct gpio_descs *), GFP_KERNEL);
+ if (!dr)
+ return ERR_PTR(-ENOMEM);
+
+ descs = gpiod_get_array(dev, con_id, flags);
+ if (IS_ERR(descs)) {
+ devres_free(dr);
+ return descs;
+ }
+
+ *dr = descs;
+ devres_add(dev, dr);
+
+ return descs;
+}
+EXPORT_SYMBOL(devm_gpiod_get_array);
+
+/**
+ * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
+ * function are automatically disposed on driver detach.
+ * See gpiod_get_array_optional() for detailed information about behavior and
+ * return values.
+ */
+struct gpio_descs *__must_check
+devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
+{
+ struct gpio_descs *descs;
+
+ descs = devm_gpiod_get_array(dev, con_id, flags);
+ if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
+ return NULL;
+
+ return descs;
+}
+EXPORT_SYMBOL(devm_gpiod_get_array_optional);
+
+/**
+ * devm_gpiod_put - Resource-managed gpiod_put()
+ * @desc: GPIO descriptor to dispose of
+ *
+ * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
+ * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
+ * will be disposed of by the resource management code.
+ */
+void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
+{
+ WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
+ &desc));
+}
+EXPORT_SYMBOL(devm_gpiod_put);
+
+/**
+ * devm_gpiod_put_array - Resource-managed gpiod_put_array()
+ * @descs: GPIO descriptor array to dispose of
+ *
+ * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
+ * Normally this function will not be called as the GPIOs will be disposed of
+ * by the resource management code.
+ */
+void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
+{
+ WARN_ON(devres_release(dev, devm_gpiod_release_array,
+ devm_gpiod_match_array, &descs));
+}
+EXPORT_SYMBOL(devm_gpiod_put_array);
+
+
+
+
+static void devm_gpio_release(struct device *dev, void *res)
+{
+ unsigned *gpio = res;
+
+ gpio_free(*gpio);
+}
+
+static int devm_gpio_match(struct device *dev, void *res, void *data)
+{
+ unsigned *this = res, *gpio = data;
+
+ return *this == *gpio;
+}
+
+/**
+ * devm_gpio_request - request a GPIO for a managed device
+ * @dev: device to request the GPIO for
+ * @gpio: GPIO to allocate
+ * @label: the name of the requested GPIO
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as
+ * gpio_request(). GPIOs requested with this function will be
+ * automatically freed on driver detach.
+ *
+ * If an GPIO allocated with this function needs to be freed
+ * separately, devm_gpio_free() must be used.
+ */
+
+int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
+{
+ unsigned *dr;
+ int rc;
+
+ dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ rc = gpio_request(gpio, label);
+ if (rc) {
+ devres_free(dr);
+ return rc;
+ }
+
+ *dr = gpio;
+ devres_add(dev, dr);
+
+ return 0;
+}
+EXPORT_SYMBOL(devm_gpio_request);
+
+/**
+ * devm_gpio_request_one - request a single GPIO with initial setup
+ * @dev: device to request for
+ * @gpio: the GPIO number
+ * @flags: GPIO configuration as specified by GPIOF_*
+ * @label: a literal description string of this GPIO
+ */
+int devm_gpio_request_one(struct device *dev, unsigned gpio,
+ unsigned long flags, const char *label)
+{
+ unsigned *dr;
+ int rc;
+
+ dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ rc = gpio_request_one(gpio, flags, label);
+ if (rc) {
+ devres_free(dr);
+ return rc;
+ }
+
+ *dr = gpio;
+ devres_add(dev, dr);
+
+ return 0;
+}
+EXPORT_SYMBOL(devm_gpio_request_one);
+
+/**
+ * devm_gpio_free - free a GPIO
+ * @dev: device to free GPIO for
+ * @gpio: GPIO to free
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as gpio_free().
+ * This function instead of gpio_free() should be used to manually
+ * free GPIOs allocated with devm_gpio_request().
+ */
+void devm_gpio_free(struct device *dev, unsigned int gpio)
+{
+
+ WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
+ &gpio));
+}
+EXPORT_SYMBOL(devm_gpio_free);