linux/drivers/bus/vexpress-config.c

204 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (C) 2014 ARM Limited
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/vexpress.h>
struct vexpress_config_bridge {
struct vexpress_config_bridge_ops *ops;
void *context;
};
static DEFINE_MUTEX(vexpress_config_mutex);
static struct class *vexpress_config_class;
static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
void vexpress_config_set_master(u32 site)
{
vexpress_config_site_master = site;
}
u32 vexpress_config_get_master(void)
{
return vexpress_config_site_master;
}
void vexpress_config_lock(void *arg)
{
mutex_lock(&vexpress_config_mutex);
}
void vexpress_config_unlock(void *arg)
{
mutex_unlock(&vexpress_config_mutex);
}
static void vexpress_config_find_prop(struct device_node *node,
const char *name, u32 *val)
{
/* Default value */
*val = 0;
of_node_get(node);
while (node) {
if (of_property_read_u32(node, name, val) == 0) {
of_node_put(node);
return;
}
node = of_get_next_parent(node);
}
}
int vexpress_config_get_topo(struct device_node *node, u32 *site,
u32 *position, u32 *dcc)
{
vexpress_config_find_prop(node, "arm,vexpress,site", site);
if (*site == VEXPRESS_SITE_MASTER)
*site = vexpress_config_site_master;
if (WARN_ON(vexpress_config_site_master == VEXPRESS_SITE_MASTER))
return -EINVAL;
vexpress_config_find_prop(node, "arm,vexpress,position", position);
vexpress_config_find_prop(node, "arm,vexpress,dcc", dcc);
return 0;
}
static void vexpress_config_devres_release(struct device *dev, void *res)
{
struct vexpress_config_bridge *bridge = dev_get_drvdata(dev->parent);
struct regmap *regmap = res;
bridge->ops->regmap_exit(regmap, bridge->context);
}
struct regmap *devm_regmap_init_vexpress_config(struct device *dev)
{
struct vexpress_config_bridge *bridge;
struct regmap *regmap;
struct regmap **res;
if (WARN_ON(dev->parent->class != vexpress_config_class))
return ERR_PTR(-ENODEV);
bridge = dev_get_drvdata(dev->parent);
if (WARN_ON(!bridge))
return ERR_PTR(-EINVAL);
res = devres_alloc(vexpress_config_devres_release, sizeof(*res),
GFP_KERNEL);
if (!res)
return ERR_PTR(-ENOMEM);
regmap = (bridge->ops->regmap_init)(dev, bridge->context);
if (IS_ERR(regmap)) {
devres_free(res);
return regmap;
}
*res = regmap;
devres_add(dev, res);
return regmap;
}
EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
struct device *vexpress_config_bridge_register(struct device *parent,
struct vexpress_config_bridge_ops *ops, void *context)
{
struct device *dev;
struct vexpress_config_bridge *bridge;
if (!vexpress_config_class) {
vexpress_config_class = class_create(THIS_MODULE,
"vexpress-config");
if (IS_ERR(vexpress_config_class))
return (void *)vexpress_config_class;
}
dev = device_create(vexpress_config_class, parent, 0,
NULL, "%s.bridge", dev_name(parent));
if (IS_ERR(dev))
return dev;
bridge = devm_kmalloc(dev, sizeof(*bridge), GFP_KERNEL);
if (!bridge) {
put_device(dev);
device_unregister(dev);
return ERR_PTR(-ENOMEM);
}
bridge->ops = ops;
bridge->context = context;
dev_set_drvdata(dev, bridge);
dev_dbg(parent, "Registered bridge '%s', parent node %p\n",
dev_name(dev), parent->of_node);
return dev;
}
static int vexpress_config_node_match(struct device *dev, const void *data)
{
const struct device_node *node = data;
dev_dbg(dev, "Parent node %p, looking for %p\n",
dev->parent->of_node, node);
return dev->parent->of_node == node;
}
static int vexpress_config_populate(struct device_node *node)
{
struct device_node *bridge;
struct device *parent;
int ret;
bridge = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);
if (!bridge)
return -EINVAL;
parent = class_find_device(vexpress_config_class, NULL, bridge,
vexpress_config_node_match);
of_node_put(bridge);
if (WARN_ON(!parent))
return -ENODEV;
ret = of_platform_populate(node, NULL, NULL, parent);
put_device(parent);
return ret;
}
static int __init vexpress_config_init(void)
{
int err = 0;
struct device_node *node;
/* Need the config devices early, before the "normal" devices... */
for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
err = vexpress_config_populate(node);
if (err) {
of_node_put(node);
break;
}
}
return err;
}
postcore_initcall(vexpress_config_init);