/*
* Device tree integration for the pin control subsystem
*
* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/device.h>
#include <linux/of.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/slab.h>
#include "core.h"
#include "devicetree.h"
/**
* struct pinctrl_dt_map - mapping table chunk parsed from device tree
* @node: list node for struct pinctrl's @dt_maps field
* @pctldev: the pin controller that allocated this struct, and will free it
* @maps: the mapping table entries
*/
struct pinctrl_dt_map {
struct list_head node;
struct pinctrl_dev *pctldev;
struct pinctrl_map *map;
unsigned num_maps;
};
static void dt_free_map(struct pinctrl_dev *pctldev,
struct pinctrl_map *map, unsigned num_maps)
{
if (pctldev) {
struct pinctrl_ops *ops = pctldev->desc->pctlops;
ops->dt_free_map(pctldev, map, num_maps);
} else {
/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
kfree(map);
}
}
void pinctrl_dt_free_maps(struct pinctrl *p)
{
struct pinctrl_dt_map *dt_map, *n1;
list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
pinctrl_unregister_map(dt_map->map);
list_del(&dt_map->node);
dt_free_map(dt_map->pctldev, dt_map->map,
dt_map->num_maps);
kfree(dt_map);
}
of_node_put(p->dev->of_node);
}
static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
struct pinctrl_dev *pctldev,
struct pinctrl_map *map, unsigned num_maps)
{
int i;
struct pinctrl_dt_map *dt_map;
/* Initialize common mapping table entry fields */
for (i = 0; i < num_maps; i++) {
map[i].dev_name = dev_name(p->dev);
map[i].name = statename;
if (pctldev)
map[i].ctrl_dev_name = dev_name(pctldev->dev);
}
/* Remember the converted mapping table entries */
dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
if (!dt_map) {
dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n");
dt_free_map(pctldev, map, num_maps);
return -ENOMEM;
}
dt_map->pctldev = pctldev;
dt_map->map = map;
dt_map->num_maps = num_maps;
list_add_tail(&dt_map->node, &p->dt_maps);
return pinctrl_register_map(map, num_maps, false, true);
}
static struct pinctrl_dev *find_pinctrl_by_of_node(struct device_node *np)
{
struct pinctrl_dev *pctldev;
list_for_each_entry(pctldev, &pinctrldev_list, node)
if (pctldev->dev->of_node == np)
return pctldev;
return NULL;
}
struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
{
struct pinctrl_dev *pctldev;
pctldev = find_pinctrl_by_of_node(np);
if (!pctldev)
return NULL;
return pctldev;
}
static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
struct device_node *np_config)
{
struct device_node *np_pctldev;
struct pinctrl_dev *pctldev;
struct pinctrl_ops *ops;
int ret;
struct pinctrl_map *map;
unsigned num_maps;
/* Find the pin controller containing np_config */
np_pctldev = of_node_get(np_config);
for (;;) {
np_pctldev = of_get_next_parent(np_pctldev);
if (!np_pctldev || of_node_is_root(np_pctldev)) {
dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n",
np_config->full_name);
of_node_put(np_pctldev);
/* OK let's just assume this will appear later then */
return -EPROBE_DEFER;
}
pctldev = find_pinctrl_by_of_node(np_pctldev);
if (pctldev)
break;
/* Do not defer probing of hogs (circular loop) */
if (np_pctldev == p->dev->of_node) {
of_node_put(np_pctldev);
return -ENODEV;
}
}
of_node_put(np_pctldev);
/*
* Call pinctrl driver to parse device tree node, and
* generate mapping table entries
*/
ops = pctldev->desc->pctlops;
if (!ops->dt_node_to_map) {
dev_err(p->dev, "pctldev %s doesn't support DT\n",
dev_name(pctldev->dev));
return -ENODEV;
}
ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
if (ret < 0)
return ret;
/* Stash the mapping table chunk away for later use */
return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
}
static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
{
struct pinctrl_map *map;
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map) {
dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
return -ENOMEM;
}
/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
map->type = PIN_MAP_TYPE_DUMMY_STATE;
return dt_remember_or_free_map(p, statename, NULL, map, 1);
}
int pinctrl_dt_to_map(struct pinctrl *p)
{
struct device_node *np = p->dev->of_node;
int state, ret;
char *propname;
struct property *prop;
const char *statename;
const __be32 *list;
int size, config;
phandle phandle;
struct device_node *np_config;
/* CONFIG_OF enabled, p->dev not instantiated from DT */
if (!np) {
dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
return 0;
}
/* We may store pointers to property names within the node */
of_node_get(np);
/* For each defined state ID */
for (state = 0; ; state++) {
/* Retrieve the pinctrl-* property */
propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
prop = of_find_property(np, propname, &size);
kfree(propname);
if (!prop)
break;
list = prop->value;
size /= sizeof(*list);
/* Determine whether pinctrl-names property names the state */
ret = of_property_read_string_index(np, "pinctrl-names",
state, &statename);
/*
* If not, statename is just the integer state ID. But rather
* than dynamically allocate it and have to free it later,
* just point part way into the property name for the string.
*/
if (ret < 0) {
/* strlen("pinctrl-") == 8 */
statename = prop->name + 8;
}
/* For every referenced pin configuration node in it */
for (config = 0; config < size; config++) {
phandle = be32_to_cpup(list++);
/* Look up the pin configuration node */
np_config = of_find_node_by_phandle(phandle);
if (!np_config) {
dev_err(p->dev,
"prop %s index %i invalid phandle\n",
prop->name, config);
ret = -EINVAL;
goto err;
}
/* Parse the node */
ret = dt_to_map_one_config(p, statename, np_config);
of_node_put(np_config);
if (ret < 0)
goto err;
}
/* No entries in DT? Generate a dummy state table entry */
if (!size) {
ret = dt_remember_dummy_state(p, statename);
if (ret < 0)
goto err;
}
}
return 0;
err:
pinctrl_dt_free_maps(p);
return ret;
}
