path: root/drivers/pinctrl/core.c

/*
 * Core driver for the pin control subsystem
 *
 * Copyright (C) 2011-2012 ST-Ericsson SA
 * Written on behalf of Linaro for ST-Ericsson
 * Based on bits of regulator core, gpio core and clk core
 *
 * Author: Linus Walleij <linus.walleij@linaro.org>
 *
 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
 *
 * License terms: GNU General Public License (GPL) version 2
 */
#define pr_fmt(fmt) "pinctrl core: " fmt

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/sysfs.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/machine.h>
#include "core.h"
#include "pinmux.h"
#include "pinconf.h"

/**
 * struct pinctrl_maps - a list item containing part of the mapping table
 * @node: mapping table list node
 * @maps: array of mapping table entries
 * @num_maps: the number of entries in @maps
 */
struct pinctrl_maps {
	struct list_head node;
	struct pinctrl_map const *maps;
	unsigned num_maps;
};

/* Mutex taken by all entry points */
DEFINE_MUTEX(pinctrl_mutex);

/* Global list of pin control devices (struct pinctrl_dev) */
static LIST_HEAD(pinctrldev_list);

/* List of pin controller handles (struct pinctrl) */
static LIST_HEAD(pinctrl_list);

/* List of pinctrl maps (struct pinctrl_maps) */
static LIST_HEAD(pinctrl_maps);

#define for_each_maps(_maps_node_, _i_, _map_) \
	list_for_each_entry(_maps_node_, &pinctrl_maps, node) \
		for (_i_ = 0, _map_ = &_maps_node_->maps[_i_]; \
			_i_ < _maps_node_->num_maps; \
			i++, _map_ = &_maps_node_->maps[_i_])

const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev)
{
	/* We're not allowed to register devices without name */
	return pctldev->desc->name;
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_name);

void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev)
{
	return pctldev->driver_data;
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_drvdata);

/**
 * get_pinctrl_dev_from_devname() - look up pin controller device
 * @devname: the name of a device instance, as returned by dev_name()
 *
 * Looks up a pin control device matching a certain device name or pure device
 * pointer, the pure device pointer will take precedence.
 */
struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *devname)
{
	struct pinctrl_dev *pctldev = NULL;
	bool found = false;

	if (!devname)
		return NULL;

	list_for_each_entry(pctldev, &pinctrldev_list, node) {
		if (!strcmp(dev_name(pctldev->dev), devname)) {
			/* Matched on device name */
			found = true;
			break;
		}
	}

	return found ? pctldev : NULL;
}

/**
 * pin_get_from_name() - look up a pin number from a name
 * @pctldev: the pin control device to lookup the pin on
 * @name: the name of the pin to look up
 */
int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name)
{
	unsigned i, pin;

	/* The pin number can be retrived from the pin controller descriptor */
	for (i = 0; i < pctldev->desc->npins; i++) {
		struct pin_desc *desc;

		pin = pctldev->desc->pins[i].number;
		desc = pin_desc_get(pctldev, pin);
		/* Pin space may be sparse */
		if (desc == NULL)
			continue;
		if (desc->name && !strcmp(name, desc->name))
			return pin;
	}

	return -EINVAL;
}

/**
 * pin_is_valid() - check if pin exists on controller
 * @pctldev: the pin control device to check the pin on
 * @pin: pin to check, use th