u-boot/drivers/core/syscon-uclass.c
Simon Glass 529f57d926 dm: syscon: Don't require a regmap for PCI devices
At present it is not possible to use the syscon devices for PCI devices
since a regmap is required. Since PCI uses a 3-cell address the conversion
of the 'reg' property to an address always fails. In any case, the regmap
is not useful with PCI since devices are accessed through the PCI bus
which regmap does not support.

Add a special case for PCI syscon devices, so that they don't set up a
regmap.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-02-20 15:21:44 +08:00

180 lines
4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#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>
/*
* Caution:
* This API requires the given device has alerady been bound to syscon driver.
* For example,
* compatible = "syscon", "simple-mfd";
* works, but
* compatible = "simple-mfd", "syscon";
* does not. The behavior is different from Linux.
*/
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);
/* Special case for PCI devices, which don't have a regmap */
if (device_get_uclass_id(dev->parent) == UCLASS_PCI)
return 0;
/*
* 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_ofnode(dev), &priv->regmap);
#endif
}
struct regmap *syscon_regmap_lookup_by_phandle(struct udevice *dev,
const char *name)
{
struct udevice *syscon;
struct regmap *r;
int err;
err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
name, &syscon);
if (err) {
dev_dbg(dev, "unable to find syscon device\n");
return ERR_PTR(err);
}
r = syscon_get_regmap(syscon);
if (!r) {
dev_dbg(dev, "unable to find regmap\n");
return ERR_PTR(-ENODEV);
}
return r;
}
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,
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
.bind = dm_scan_fdt_dev,
#endif
.of_match = generic_syscon_ids,
};
/*
* Linux-compatible syscon-to-regmap
* The syscon node can be bound to another driver, but still works
* as a syscon provider.
*/
struct regmap *syscon_node_to_regmap(ofnode node)
{
struct udevice *dev, *parent;
int ret;
if (!uclass_get_device_by_ofnode(UCLASS_SYSCON, node, &dev))
return syscon_get_regmap(dev);
if (!ofnode_device_is_compatible(node, "syscon"))
return ERR_PTR(-EINVAL);
/* bound to driver with same ofnode or to root if not found */
if (device_find_global_by_ofnode(node, &parent))
parent = dm_root();
/* force bound to syscon class */
ret = device_bind_driver_to_node(parent, "syscon",
ofnode_get_name(node),
node, &dev);
if (ret)
return ERR_PTR(ret);
ret = device_probe(dev);
if (ret)
return ERR_PTR(ret);
return syscon_get_regmap(dev);
}