263 lines
6 KiB
C
263 lines
6 KiB
C
/*
|
|
* 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 const 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;
|
|
u32 reg_io_width;
|
|
int ret;
|
|
struct regmap_config syscon_config = syscon_regmap_config;
|
|
struct resource res;
|
|
|
|
if (!of_device_is_compatible(np, "syscon"))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
|
|
if (!syscon)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (of_address_to_resource(np, 0, &res)) {
|
|
ret = -ENOMEM;
|
|
goto err_map;
|
|
}
|
|
|
|
base = ioremap(res.start, resource_size(&res));
|
|
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;
|
|
else if (of_property_read_bool(np, "native-endian"))
|
|
syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
|
|
|
|
/*
|
|
* search for reg-io-width property in DT. If it is not provided,
|
|
* default to 4 bytes. regmap_init_mmio will return an error if values
|
|
* are invalid so there is no need to check them here.
|
|
*/
|
|
ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
|
|
if (ret)
|
|
reg_io_width = 4;
|
|
|
|
syscon_config.reg_stride = reg_io_width;
|
|
syscon_config.val_bits = reg_io_width * 8;
|
|
syscon_config.max_register = resource_size(&res) - reg_io_width;
|
|
|
|
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 regmap_config syscon_config = syscon_regmap_config;
|
|
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_config.max_register = res->end - res->start - 3;
|
|
if (pdata)
|
|
syscon_config.name = pdata->label;
|
|
syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_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");
|