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![Krzysztof Kozlowski](/assets/img/avatar_default.png)
Several gpiolib functions receive pointer to struct device_node which is later passed to OF functions. These OF functions accept already pointer to const, so gpiolib can follow similar approach to indicate they are not modifying the struct device_node. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
516 lines
14 KiB
C
516 lines
14 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* devres.c - managed gpio resources
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* This file is based on kernel/irq/devres.c
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*
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* Copyright (c) 2011 John Crispin <john@phrozen.org>
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*/
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/gpio/consumer.h>
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#include <linux/device.h>
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#include <linux/gfp.h>
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#include "gpiolib.h"
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static void devm_gpiod_release(struct device *dev, void *res)
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{
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struct gpio_desc **desc = res;
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gpiod_put(*desc);
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}
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static int devm_gpiod_match(struct device *dev, void *res, void *data)
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{
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struct gpio_desc **this = res, **gpio = data;
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return *this == *gpio;
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}
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static void devm_gpiod_release_array(struct device *dev, void *res)
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{
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struct gpio_descs **descs = res;
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gpiod_put_array(*descs);
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}
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static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
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{
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struct gpio_descs **this = res, **gpios = data;
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return *this == *gpios;
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}
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/**
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* devm_gpiod_get - Resource-managed gpiod_get()
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* @dev: GPIO consumer
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* @con_id: function within the GPIO consumer
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* @flags: optional GPIO initialization flags
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*
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* Managed gpiod_get(). GPIO descriptors returned from this function are
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* automatically disposed on driver detach. See gpiod_get() for detailed
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* information about behavior and return values.
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*/
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struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
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const char *con_id,
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enum gpiod_flags flags)
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{
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return devm_gpiod_get_index(dev, con_id, 0, flags);
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get);
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/**
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* devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
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* @dev: GPIO consumer
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* @con_id: function within the GPIO consumer
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* @flags: optional GPIO initialization flags
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*
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* Managed gpiod_get_optional(). GPIO descriptors returned from this function
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* are automatically disposed on driver detach. See gpiod_get_optional() for
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* detailed information about behavior and return values.
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*/
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struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
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const char *con_id,
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enum gpiod_flags flags)
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{
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return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get_optional);
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/**
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* devm_gpiod_get_index - Resource-managed gpiod_get_index()
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* @dev: GPIO consumer
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* @con_id: function within the GPIO consumer
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* @idx: index of the GPIO to obtain in the consumer
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* @flags: optional GPIO initialization flags
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*
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* Managed gpiod_get_index(). GPIO descriptors returned from this function are
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* automatically disposed on driver detach. See gpiod_get_index() for detailed
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* information about behavior and return values.
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*/
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struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
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const char *con_id,
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unsigned int idx,
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enum gpiod_flags flags)
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{
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struct gpio_desc **dr;
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struct gpio_desc *desc;
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desc = gpiod_get_index(dev, con_id, idx, flags);
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if (IS_ERR(desc))
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return desc;
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/*
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* For non-exclusive GPIO descriptors, check if this descriptor is
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* already under resource management by this device.
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*/
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if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
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struct devres *dres;
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dres = devres_find(dev, devm_gpiod_release,
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devm_gpiod_match, &desc);
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if (dres)
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return desc;
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}
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dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
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GFP_KERNEL);
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if (!dr) {
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gpiod_put(desc);
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return ERR_PTR(-ENOMEM);
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}
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*dr = desc;
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devres_add(dev, dr);
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return desc;
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get_index);
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/**
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* devm_gpiod_get_from_of_node() - obtain a GPIO from an OF node
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* @dev: device for lifecycle management
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* @node: handle of the OF node
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* @propname: name of the DT property representing the GPIO
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* @index: index of the GPIO to obtain for the consumer
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* @dflags: GPIO initialization flags
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* @label: label to attach to the requested GPIO
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*
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* Returns:
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* On successful request the GPIO pin is configured in accordance with
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* provided @dflags.
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*
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* In case of error an ERR_PTR() is returned.
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*/
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struct gpio_desc *devm_gpiod_get_from_of_node(struct device *dev,
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const struct device_node *node,
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const char *propname, int index,
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enum gpiod_flags dflags,
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const char *label)
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{
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struct gpio_desc **dr;
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struct gpio_desc *desc;
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desc = gpiod_get_from_of_node(node, propname, index, dflags, label);
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if (IS_ERR(desc))
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return desc;
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/*
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* For non-exclusive GPIO descriptors, check if this descriptor is
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* already under resource management by this device.
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*/
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if (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
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struct devres *dres;
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dres = devres_find(dev, devm_gpiod_release,
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devm_gpiod_match, &desc);
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if (dres)
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return desc;
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}
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dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
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GFP_KERNEL);
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if (!dr) {
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gpiod_put(desc);
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return ERR_PTR(-ENOMEM);
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}
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*dr = desc;
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devres_add(dev, dr);
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return desc;
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get_from_of_node);
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/**
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* devm_fwnode_gpiod_get_index - get a GPIO descriptor from a given node
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* @dev: GPIO consumer
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* @fwnode: firmware node containing GPIO reference
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* @con_id: function within the GPIO consumer
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* @index: index of the GPIO to obtain in the consumer
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* @flags: GPIO initialization flags
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* @label: label to attach to the requested GPIO
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*
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* GPIO descriptors returned from this function are automatically disposed on
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* driver detach.
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*
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* On successful request the GPIO pin is configured in accordance with
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* provided @flags.
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*/
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struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
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struct fwnode_handle *fwnode,
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const char *con_id, int index,
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enum gpiod_flags flags,
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const char *label)
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{
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struct gpio_desc **dr;
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struct gpio_desc *desc;
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dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
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GFP_KERNEL);
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if (!dr)
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return ERR_PTR(-ENOMEM);
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desc = fwnode_gpiod_get_index(fwnode, con_id, index, flags, label);
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if (IS_ERR(desc)) {
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devres_free(dr);
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return desc;
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}
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*dr = desc;
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devres_add(dev, dr);
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return desc;
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}
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EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_index);
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/**
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* devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
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* @dev: GPIO consumer
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* @con_id: function within the GPIO consumer
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* @index: index of the GPIO to obtain in the consumer
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* @flags: optional GPIO initialization flags
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*
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* Managed gpiod_get_index_optional(). GPIO descriptors returned from this
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* function are automatically disposed on driver detach. See
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* gpiod_get_index_optional() for detailed information about behavior and
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* return values.
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*/
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struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
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const char *con_id,
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unsigned int index,
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enum gpiod_flags flags)
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{
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struct gpio_desc *desc;
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desc = devm_gpiod_get_index(dev, con_id, index, flags);
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if (gpiod_not_found(desc))
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return NULL;
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return desc;
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
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/**
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* devm_gpiod_get_array - Resource-managed gpiod_get_array()
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* @dev: GPIO consumer
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* @con_id: function within the GPIO consumer
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* @flags: optional GPIO initialization flags
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*
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* Managed gpiod_get_array(). GPIO descriptors returned from this function are
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* automatically disposed on driver detach. See gpiod_get_array() for detailed
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* information about behavior and return values.
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*/
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struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
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const char *con_id,
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enum gpiod_flags flags)
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{
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struct gpio_descs **dr;
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struct gpio_descs *descs;
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dr = devres_alloc(devm_gpiod_release_array,
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sizeof(struct gpio_descs *), GFP_KERNEL);
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if (!dr)
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return ERR_PTR(-ENOMEM);
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descs = gpiod_get_array(dev, con_id, flags);
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if (IS_ERR(descs)) {
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devres_free(dr);
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return descs;
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}
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*dr = descs;
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devres_add(dev, dr);
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return descs;
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
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/**
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* devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
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* @dev: GPIO consumer
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* @con_id: function within the GPIO consumer
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* @flags: optional GPIO initialization flags
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*
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* Managed gpiod_get_array_optional(). GPIO descriptors returned from this
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* function are automatically disposed on driver detach.
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* See gpiod_get_array_optional() for detailed information about behavior and
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* return values.
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*/
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struct gpio_descs *__must_check
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devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
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enum gpiod_flags flags)
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{
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struct gpio_descs *descs;
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descs = devm_gpiod_get_array(dev, con_id, flags);
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if (gpiod_not_found(descs))
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return NULL;
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return descs;
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_get_array_optional);
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/**
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* devm_gpiod_put - Resource-managed gpiod_put()
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* @dev: GPIO consumer
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* @desc: GPIO descriptor to dispose of
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*
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* Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
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* devm_gpiod_get_index(). Normally this function will not be called as the GPIO
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* will be disposed of by the resource management code.
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*/
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void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
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{
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WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
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&desc));
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_put);
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/**
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* devm_gpiod_unhinge - Remove resource management from a gpio descriptor
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* @dev: GPIO consumer
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* @desc: GPIO descriptor to remove resource management from
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*
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* Remove resource management from a GPIO descriptor. This is needed when
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* you want to hand over lifecycle management of a descriptor to another
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* mechanism.
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*/
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void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)
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{
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int ret;
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if (IS_ERR_OR_NULL(desc))
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return;
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ret = devres_destroy(dev, devm_gpiod_release,
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devm_gpiod_match, &desc);
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/*
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* If the GPIO descriptor is requested as nonexclusive, we
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* may call this function several times on the same descriptor
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* so it is OK if devres_destroy() returns -ENOENT.
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*/
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if (ret == -ENOENT)
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return;
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/* Anything else we should warn about */
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WARN_ON(ret);
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_unhinge);
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/**
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* devm_gpiod_put_array - Resource-managed gpiod_put_array()
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* @dev: GPIO consumer
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* @descs: GPIO descriptor array to dispose of
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*
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* Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
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* Normally this function will not be called as the GPIOs will be disposed of
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* by the resource management code.
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*/
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void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
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{
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WARN_ON(devres_release(dev, devm_gpiod_release_array,
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devm_gpiod_match_array, &descs));
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}
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EXPORT_SYMBOL_GPL(devm_gpiod_put_array);
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static void devm_gpio_release(struct device *dev, void *res)
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{
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unsigned *gpio = res;
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gpio_free(*gpio);
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}
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static int devm_gpio_match(struct device *dev, void *res, void *data)
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{
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unsigned *this = res, *gpio = data;
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return *this == *gpio;
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}
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/**
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* devm_gpio_request - request a GPIO for a managed device
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* @dev: device to request the GPIO for
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* @gpio: GPIO to allocate
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* @label: the name of the requested GPIO
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*
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* Except for the extra @dev argument, this function takes the
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* same arguments and performs the same function as
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* gpio_request(). GPIOs requested with this function will be
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* automatically freed on driver detach.
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*
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* If an GPIO allocated with this function needs to be freed
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* separately, devm_gpio_free() must be used.
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*/
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int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
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{
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unsigned *dr;
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int rc;
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dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
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if (!dr)
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return -ENOMEM;
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rc = gpio_request(gpio, label);
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if (rc) {
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devres_free(dr);
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return rc;
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}
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*dr = gpio;
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devres_add(dev, dr);
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return 0;
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}
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EXPORT_SYMBOL_GPL(devm_gpio_request);
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/**
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* devm_gpio_request_one - request a single GPIO with initial setup
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* @dev: device to request for
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* @gpio: the GPIO number
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* @flags: GPIO configuration as specified by GPIOF_*
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* @label: a literal description string of this GPIO
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*/
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int devm_gpio_request_one(struct device *dev, unsigned gpio,
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unsigned long flags, const char *label)
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{
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unsigned *dr;
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int rc;
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dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
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if (!dr)
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return -ENOMEM;
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rc = gpio_request_one(gpio, flags, label);
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if (rc) {
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devres_free(dr);
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return rc;
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}
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*dr = gpio;
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devres_add(dev, dr);
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return 0;
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}
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EXPORT_SYMBOL_GPL(devm_gpio_request_one);
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/**
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* devm_gpio_free - free a GPIO
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* @dev: device to free GPIO for
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* @gpio: GPIO to free
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*
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* Except for the extra @dev argument, this function takes the
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* same arguments and performs the same function as gpio_free().
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* This function instead of gpio_free() should be used to manually
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* free GPIOs allocated with devm_gpio_request().
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*/
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void devm_gpio_free(struct device *dev, unsigned int gpio)
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{
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WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
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&gpio));
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}
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EXPORT_SYMBOL_GPL(devm_gpio_free);
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static void devm_gpio_chip_release(void *data)
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{
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struct gpio_chip *gc = data;
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gpiochip_remove(gc);
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}
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/**
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* devm_gpiochip_add_data_with_key() - Resource managed gpiochip_add_data_with_key()
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* @dev: pointer to the device that gpio_chip belongs to.
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* @gc: the GPIO chip to register
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* @data: driver-private data associated with this chip
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* @lock_key: lockdep class for IRQ lock
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* @request_key: lockdep class for IRQ request
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*
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* Context: potentially before irqs will work
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*
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* The gpio chip automatically be released when the device is unbound.
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*
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* Returns:
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* A negative errno if the chip can't be registered, such as because the
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* gc->base is invalid or already associated with a different chip.
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* Otherwise it returns zero as a success code.
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*/
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int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc, void *data,
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struct lock_class_key *lock_key,
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struct lock_class_key *request_key)
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{
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int ret;
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ret = gpiochip_add_data_with_key(gc, data, lock_key, request_key);
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if (ret < 0)
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return ret;
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return devm_add_action_or_reset(dev, devm_gpio_chip_release, gc);
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}
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EXPORT_SYMBOL_GPL(devm_gpiochip_add_data_with_key);
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