linux/drivers/pinctrl/devicetree.c

417 lines
11 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-only
/*
* Device tree integration for the pin control subsystem
*
* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
*/
#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) {
const struct pinctrl_ops *ops = pctldev->desc->pctlops;
if (ops->dt_free_map)
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) {
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);
pinctrl: Don't just pretend to protect pinctrl_maps, do it for real Way back, when the world was a simpler place and there was no war, no evil, and no kernel bugs, there was just a single pinctrl lock. That was how the world was when (57291ce pinctrl: core device tree mapping table parsing support) was written. In that case, there were instances where the pinctrl mutex was already held when pinctrl_register_map() was called, hence a "locked" parameter was passed to the function to indicate that the mutex was already locked (so we shouldn't lock it again). A few years ago in (42fed7b pinctrl: move subsystem mutex to pinctrl_dev struct), we switched to a separate pinctrl_maps_mutex. ...but (oops) we forgot to re-think about the whole "locked" parameter for pinctrl_register_map(). Basically the "locked" parameter appears to still refer to whether the bigger pinctrl_dev mutex is locked, but we're using it to skip locks of our (now separate) pinctrl_maps_mutex. That's kind of a bad thing(TM). Probably nobody noticed because most of the calls to pinctrl_register_map happen at boot time and we've got synchronous device probing. ...and even cases where we're asynchronous don't end up actually hitting the race too often. ...but after banging my head against the wall for a bug that reproduced 1 out of 1000 reboots and lots of looking through kgdb, I finally noticed this. Anyway, we can now safely remove the "locked" parameter and go back to a war-free, evil-free, and kernel-bug-free world. Fixes: 42fed7ba44e4 ("pinctrl: move subsystem mutex to pinctrl_dev struct") Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-02 00:01:27 +08:00
return pinctrl_register_map(map, num_maps, false);
}
struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
{
return get_pinctrl_dev_from_of_node(np);
}
static int dt_to_map_one_config(struct pinctrl *p,
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-08 00:51:33 +08:00
struct pinctrl_dev *hog_pctldev,
const char *statename,
struct device_node *np_config)
{
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-08 00:51:33 +08:00
struct pinctrl_dev *pctldev = NULL;
struct device_node *np_pctldev;
const struct pinctrl_ops *ops;
int ret;
struct pinctrl_map *map;
unsigned num_maps;
bool allow_default = false;
/* Find the pin controller containing np_config */
np_pctldev = of_node_get(np_config);
for (;;) {
if (!allow_default)
allow_default = of_property_read_bool(np_pctldev,
"pinctrl-use-default");
np_pctldev = of_get_next_parent(np_pctldev);
if (!np_pctldev || of_node_is_root(np_pctldev)) {
of_node_put(np_pctldev);
ret = driver_deferred_probe_check_state(p->dev);
/* keep deferring if modules are enabled unless we've timed out */
if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret == -ENODEV)
ret = -EPROBE_DEFER;
return ret;
}
/* If we're creating a hog we can use the passed pctldev */
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-08 00:51:33 +08:00
if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
pctldev = hog_pctldev;
break;
pinctrl: devicetree: Fix pctldev pointer overwrite Commit b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") causes the pinctrl hog pins to not get initialized on i.MX platforms leaving them with the IOMUX settings untouched. This causes several regressions on i.MX such as: - OV5640 camera driver can not be probed anymore on imx6qdl-sabresd because the camera clock pin is in a pinctrl_hog group and since its pinctrl initialization is skipped, the camera clock is kept in GPIO functionality instead of CLK_CKO function. - Audio stopped working on imx6qdl-wandboard and imx53-qsb for the same reason. Richard Fitzgerald explains the problem: "I see the bug. If the hog node isn't a 1st level child of the pinctrl parent node it will go around the for(;;) loop again but on the first pass I overwrite pctldev with the result of get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver any more." Fix the issue by stashing the original pctldev so it doesn't get overwritten. Fixes: b89405b6102f ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs") Cc: <stable@vger.kernel.org> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Reported-by: Steve Longerbeam <slongerbeam@gmail.com> Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-08 00:51:33 +08:00
}
pctldev = get_pinctrl_dev_from_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)
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);
}
bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
{
struct device_node *np;
struct property *prop;
int size;
np = pctldev->dev->of_node;
if (!np)
return false;
prop = of_find_property(np, "pinctrl-0", &size);
return prop ? true : false;
}
int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
{
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) {
if (of_have_populated_dt())
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) {
if (state == 0) {
of_node_put(np);
return -ENODEV;
}
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, pctldev, 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;
}
/*
* For pinctrl binding, typically #pinctrl-cells is for the pin controller
* device, so either parent or grandparent. See pinctrl-bindings.txt.
*/
static int pinctrl_find_cells_size(const struct device_node *np)
{
const char *cells_name = "#pinctrl-cells";
int cells_size, error;
error = of_property_read_u32(np->parent, cells_name, &cells_size);
if (error) {
error = of_property_read_u32(np->parent->parent,
cells_name, &cells_size);
if (error)
return -ENOENT;
}
return cells_size;
}
/**
* pinctrl_get_list_and_count - Gets the list and it's cell size and number
* @np: pointer to device node with the property
* @list_name: property that contains the list
* @list: pointer for the list found
* @cells_size: pointer for the cell size found
* @nr_elements: pointer for the number of elements found
*
* Typically np is a single pinctrl entry containing the list.
*/
static int pinctrl_get_list_and_count(const struct device_node *np,
const char *list_name,
const __be32 **list,
int *cells_size,
int *nr_elements)
{
int size;
*cells_size = 0;
*nr_elements = 0;
*list = of_get_property(np, list_name, &size);
if (!*list)
return -ENOENT;
*cells_size = pinctrl_find_cells_size(np);
if (*cells_size < 0)
return -ENOENT;
/* First element is always the index within the pinctrl device */
*nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
return 0;
}
/**
* pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
* @np: pointer to device node with the property
* @list_name: property that contains the list
*
* Counts the number of elements in a pinctrl array consisting of an index
* within the controller and a number of u32 entries specified for each
* entry. Note that device_node is always for the parent pin controller device.
*/
int pinctrl_count_index_with_args(const struct device_node *np,
const char *list_name)
{
const __be32 *list;
int size, nr_cells, error;
error = pinctrl_get_list_and_count(np, list_name, &list,
&nr_cells, &size);
if (error)
return error;
return size;
}
EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
/**
* pinctrl_copy_args - Populates of_phandle_args based on index
* @np: pointer to device node with the property
* @list: pointer to a list with the elements
* @index: entry within the list of elements
* @nr_cells: number of cells in the list
* @nr_elem: number of elements for each entry in the list
* @out_args: returned values
*
* Populates the of_phandle_args based on the index in the list.
*/
static int pinctrl_copy_args(const struct device_node *np,
const __be32 *list,
int index, int nr_cells, int nr_elem,
struct of_phandle_args *out_args)
{
int i;
memset(out_args, 0, sizeof(*out_args));
out_args->np = (struct device_node *)np;
out_args->args_count = nr_cells + 1;
if (index >= nr_elem)
return -EINVAL;
list += index * (nr_cells + 1);
for (i = 0; i < nr_cells + 1; i++)
out_args->args[i] = be32_to_cpup(list++);
return 0;
}
/**
* pinctrl_parse_index_with_args - Find a node pointed by index in a list
* @np: pointer to device node with the property
* @list_name: property that contains the list
* @index: index within the list
* @out_arts: entries in the list pointed by index
*
* Finds the selected element in a pinctrl array consisting of an index
* within the controller and a number of u32 entries specified for each
* entry. Note that device_node is always for the parent pin controller device.
*/
int pinctrl_parse_index_with_args(const struct device_node *np,
const char *list_name, int index,
struct of_phandle_args *out_args)
{
const __be32 *list;
int nr_elem, nr_cells, error;
error = pinctrl_get_list_and_count(np, list_name, &list,
&nr_cells, &nr_elem);
if (error || !nr_cells)
return error;
error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
out_args);
if (error)
return error;
return 0;
}
EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);