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/*
* System Control Driver
*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
* Copyright (C) 2012 Linaro Ltd.
*
* Author: Dong Aisheng <dong.aisheng@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_data/syscon.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>
static struct platform_driver syscon_driver;
static DEFINE_SPINLOCK(syscon_list_slock);
static LIST_HEAD(syscon_list);
struct syscon {
struct device_node *np;
struct regmap *regmap;
struct list_head list;
};
static struct regmap_config syscon_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
static struct syscon *of_syscon_register(struct device_node *np)
{
struct syscon *syscon;
struct regmap *regmap;
void __iomem *base;
int ret;
struct regmap_config syscon_config = syscon_regmap_config;
if (!of_device_is_compatible(np, "syscon"))
return ERR_PTR(-EINVAL);
syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
if (!syscon)
return ERR_PTR(-ENOMEM);
base = of_iomap(np, 0);
if (!base) {
ret = -ENOMEM;
goto err_map;
}
/* Parse the device's DT node for an endianness specification */
if (of_property_read_bool(np, "big-endian"))
syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
else if (of_property_read_bool(np, "little-endian"))
syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
regmap = regmap_init_mmio(NULL, base, &syscon_config);
if (IS_ERR(regmap)) {
pr_err("regmap init failed\n");
ret = PTR_ERR(regmap);
goto err_regmap;
}
syscon->regmap = regmap;
syscon->np = np;
spin_lock(&syscon_list_slock);
list_add_tail(&syscon->list, &syscon_list);
spin_unlock(&syscon_list_slock);
return syscon;
err_regmap:
iounmap(base);
err_map:
kfree(syscon);
return ERR_PTR(ret);
}
struct regmap *syscon_node_to_regmap(struct device_node *np)
{
struct syscon *entry, *syscon = NULL;
spin_lock(&syscon_list_slock);
list_for_each_entry(entry, &syscon_list, list)
if (entry->np == np) {
syscon = entry;
break;
}
spin_unlock(&syscon_list_slock);
if (!syscon)
syscon = of_syscon_register(np);
if (IS_ERR(syscon))
return ERR_CAST(syscon);
return syscon->regmap;
}
EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
{
struct device_node *syscon_np;
struct regmap *regmap;
syscon_np = of_find_compatible_node(NULL, NULL, s);
if (!syscon_np)
return ERR_PTR(-ENODEV);
regmap = syscon_node_to_regmap(syscon_np);
of_node_put(syscon_np);
return regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
static int syscon_match_pdevname(struct device *dev, void *data)
{
return !strcmp(dev_name(dev), (const char *)data);
}
struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
{
struct device *dev;
struct syscon *syscon;
dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
syscon_match_pdevname);
if (!dev)
return ERR_PTR(-EPROBE_DEFER);
syscon = dev_get_drvdata(dev);
return syscon->regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
const char *property)
{
struct device_node *syscon_np;
struct regmap *regmap;
if (property)
syscon_np = of_parse_phandle(np, property, 0);
else
syscon_np = np;
if (!syscon_np)
return ERR_PTR(-ENODEV);
regmap = syscon_node_to_regmap(syscon_np);
of_node_put(syscon_np);
return regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
static int syscon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct syscon_platform_data *pdata = dev_get_platdata(dev);
struct syscon *syscon;
struct resource *res;
void __iomem *base;
syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
if (!syscon)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENOENT;
base = devm_ioremap(dev, res->start, resource_size(res));
if (!base)
return -ENOMEM;
syscon_regmap_config.max_register = res->end - res->start - 3;
if (pdata)
syscon_regmap_config.name = pdata->label;
syscon->regmap = devm_regmap_init_mmio(dev, base,
&syscon_regmap_config);
if (IS_ERR(syscon->regmap)) {
dev_err(dev, "regmap init failed\n");
return PTR_ERR(syscon->regmap);
}
platform_set_drvdata(pdev, syscon);
dev_dbg(dev, "regmap %pR registered\n", res);
return 0;
}
static const struct platform_device_id syscon_ids[] = {
{ "syscon", },
{ }
};
static struct platform_driver syscon_driver = {
.driver = {
.name = "syscon",
},
.probe = syscon_probe,
.id_table = syscon_ids,
};
static int __init syscon_init(void)
{
return platform_driver_register(&syscon_driver);
}
postcore_initcall(syscon_init);
static void __exit syscon_exit(void)
{
platform_driver_unregister(&syscon_driver);
}
module_exit(syscon_exit);
MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
MODULE_DESCRIPTION("System Control driver");
MODULE_LICENSE("GPL v2");
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