u-boot/drivers/core/syscon-uclass.c
Paul Burton 8291bc8747 dm: syscon: Provide a generic syscon driver
Provide a trivial syscon driver matching the generic "syscon" compatible
string, allowing for simple system controllers to be used without a
custom driver just as in Linux.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2016-09-21 15:04:32 +02:00

109 lines
2.3 KiB
C

/*
* Copyright (C) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <syscon.h>
#include <dm.h>
#include <errno.h>
#include <regmap.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/root.h>
#include <linux/err.h>
struct regmap *syscon_get_regmap(struct udevice *dev)
{
struct syscon_uc_info *priv;
if (device_get_uclass_id(dev) != UCLASS_SYSCON)
return ERR_PTR(-ENOEXEC);
priv = dev_get_uclass_priv(dev);
return priv->regmap;
}
static int syscon_pre_probe(struct udevice *dev)
{
struct syscon_uc_info *priv = dev_get_uclass_priv(dev);
/*
* With OF_PLATDATA we really have no way of knowing the format of
* the device-specific platform data. So we assume that it starts with
* a 'reg' member, and this holds a single address and size. Drivers
* using OF_PLATDATA will need to ensure that this is true.
*/
#if CONFIG_IS_ENABLED(OF_PLATDATA)
struct syscon_base_platdata *plat = dev_get_platdata(dev);
return regmap_init_mem_platdata(dev, plat->reg, ARRAY_SIZE(plat->reg),
&priv->regmap);
#else
return regmap_init_mem(dev, &priv->regmap);
#endif
}
int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp)
{
struct udevice *dev;
struct uclass *uc;
int ret;
*devp = NULL;
ret = uclass_get(UCLASS_SYSCON, &uc);
if (ret)
return ret;
uclass_foreach_dev(dev, uc) {
if (dev->driver_data == driver_data) {
*devp = dev;
return device_probe(dev);
}
}
return -ENODEV;
}
struct regmap *syscon_get_regmap_by_driver_data(ulong driver_data)
{
struct syscon_uc_info *priv;
struct udevice *dev;
int ret;
ret = syscon_get_by_driver_data(driver_data, &dev);
if (ret)
return ERR_PTR(ret);
priv = dev_get_uclass_priv(dev);
return priv->regmap;
}
void *syscon_get_first_range(ulong driver_data)
{
struct regmap *map;
map = syscon_get_regmap_by_driver_data(driver_data);
if (IS_ERR(map))
return map;
return regmap_get_range(map, 0);
}
UCLASS_DRIVER(syscon) = {
.id = UCLASS_SYSCON,
.name = "syscon",
.per_device_auto_alloc_size = sizeof(struct syscon_uc_info),
.pre_probe = syscon_pre_probe,
};
static const struct udevice_id generic_syscon_ids[] = {
{ .compatible = "syscon" },
{ }
};
U_BOOT_DRIVER(generic_syscon) = {
.name = "syscon",
.id = UCLASS_SYSCON,
.of_match = generic_syscon_ids,
};