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![Thierry Reding](/assets/img/avatar_default.png)
driver_deferred_probe_check_state() may return -ETIMEDOUT instead of
-EPROBE_DEFER after all built-in drivers have been probed. This can
cause issues for built-in drivers that depend on resources provided by
loadable modules.
One such case happens on Tegra where I2C controllers are used during
early boot to set up the system PMIC, so the I2C driver needs to be a
built-in driver. At the same time, some instances of the I2C controller
depend on the DPAUX hardware for pinmuxing. Since the DPAUX is handled
by the display driver, which is usually not built-in, the pin control
states will not become available until after the root filesystem has
been mounted and the display driver loaded from it.
Fixes: bec6c0ecb2
("pinctrl: Remove use of driver_deferred_probe_check_state_continue()")
Suggested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200825143348.1358679-1-thierry.reding@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
425 lines
11 KiB
C
425 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Device tree integration for the pin control subsystem
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*
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* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
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*/
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#include <linux/device.h>
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#include <linux/of.h>
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#include <linux/pinctrl/pinctrl.h>
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#include <linux/slab.h>
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#include "core.h"
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#include "devicetree.h"
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/**
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* struct pinctrl_dt_map - mapping table chunk parsed from device tree
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* @node: list node for struct pinctrl's @dt_maps field
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* @pctldev: the pin controller that allocated this struct, and will free it
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* @map: the mapping table entries
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* @num_maps: number of mapping table entries
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*/
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struct pinctrl_dt_map {
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struct list_head node;
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struct pinctrl_dev *pctldev;
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struct pinctrl_map *map;
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unsigned num_maps;
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};
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static void dt_free_map(struct pinctrl_dev *pctldev,
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struct pinctrl_map *map, unsigned num_maps)
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{
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int i;
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for (i = 0; i < num_maps; ++i) {
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kfree_const(map[i].dev_name);
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map[i].dev_name = NULL;
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}
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if (pctldev) {
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const struct pinctrl_ops *ops = pctldev->desc->pctlops;
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if (ops->dt_free_map)
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ops->dt_free_map(pctldev, map, num_maps);
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} else {
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/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
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kfree(map);
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}
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}
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void pinctrl_dt_free_maps(struct pinctrl *p)
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{
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struct pinctrl_dt_map *dt_map, *n1;
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list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
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pinctrl_unregister_mappings(dt_map->map);
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list_del(&dt_map->node);
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dt_free_map(dt_map->pctldev, dt_map->map,
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dt_map->num_maps);
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kfree(dt_map);
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}
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of_node_put(p->dev->of_node);
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}
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static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
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struct pinctrl_dev *pctldev,
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struct pinctrl_map *map, unsigned num_maps)
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{
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int i;
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struct pinctrl_dt_map *dt_map;
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/* Initialize common mapping table entry fields */
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for (i = 0; i < num_maps; i++) {
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const char *devname;
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devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL);
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if (!devname)
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goto err_free_map;
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map[i].dev_name = devname;
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map[i].name = statename;
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if (pctldev)
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map[i].ctrl_dev_name = dev_name(pctldev->dev);
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}
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/* Remember the converted mapping table entries */
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dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
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if (!dt_map)
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goto err_free_map;
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dt_map->pctldev = pctldev;
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dt_map->map = map;
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dt_map->num_maps = num_maps;
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list_add_tail(&dt_map->node, &p->dt_maps);
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return pinctrl_register_mappings(map, num_maps);
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err_free_map:
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dt_free_map(pctldev, map, num_maps);
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return -ENOMEM;
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}
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struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
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{
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return get_pinctrl_dev_from_of_node(np);
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}
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EXPORT_SYMBOL_GPL(of_pinctrl_get);
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static int dt_to_map_one_config(struct pinctrl *p,
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struct pinctrl_dev *hog_pctldev,
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const char *statename,
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struct device_node *np_config)
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{
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struct pinctrl_dev *pctldev = NULL;
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struct device_node *np_pctldev;
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const struct pinctrl_ops *ops;
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int ret;
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struct pinctrl_map *map;
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unsigned num_maps;
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bool allow_default = false;
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/* Find the pin controller containing np_config */
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np_pctldev = of_node_get(np_config);
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for (;;) {
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if (!allow_default)
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allow_default = of_property_read_bool(np_pctldev,
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"pinctrl-use-default");
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np_pctldev = of_get_next_parent(np_pctldev);
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if (!np_pctldev || of_node_is_root(np_pctldev)) {
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of_node_put(np_pctldev);
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ret = driver_deferred_probe_check_state(p->dev);
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/* keep deferring if modules are enabled */
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if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
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ret = -EPROBE_DEFER;
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return ret;
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}
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/* If we're creating a hog we can use the passed pctldev */
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if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
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pctldev = hog_pctldev;
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break;
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}
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pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
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if (pctldev)
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break;
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/* Do not defer probing of hogs (circular loop) */
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if (np_pctldev == p->dev->of_node) {
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of_node_put(np_pctldev);
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return -ENODEV;
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}
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}
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of_node_put(np_pctldev);
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/*
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* Call pinctrl driver to parse device tree node, and
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* generate mapping table entries
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*/
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ops = pctldev->desc->pctlops;
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if (!ops->dt_node_to_map) {
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dev_err(p->dev, "pctldev %s doesn't support DT\n",
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dev_name(pctldev->dev));
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return -ENODEV;
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}
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ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
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if (ret < 0)
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return ret;
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else if (num_maps == 0) {
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/*
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* If we have no valid maps (maybe caused by empty pinctrl node
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* or typing error) ther is no need remember this, so just
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* return.
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*/
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dev_info(p->dev,
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"there is not valid maps for state %s\n", statename);
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return 0;
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}
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/* Stash the mapping table chunk away for later use */
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return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
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}
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static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
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{
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struct pinctrl_map *map;
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map = kzalloc(sizeof(*map), GFP_KERNEL);
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if (!map)
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return -ENOMEM;
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/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
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map->type = PIN_MAP_TYPE_DUMMY_STATE;
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return dt_remember_or_free_map(p, statename, NULL, map, 1);
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}
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int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
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{
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struct device_node *np = p->dev->of_node;
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int state, ret;
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char *propname;
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struct property *prop;
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const char *statename;
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const __be32 *list;
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int size, config;
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phandle phandle;
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struct device_node *np_config;
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/* CONFIG_OF enabled, p->dev not instantiated from DT */
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if (!np) {
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if (of_have_populated_dt())
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dev_dbg(p->dev,
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"no of_node; not parsing pinctrl DT\n");
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return 0;
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}
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/* We may store pointers to property names within the node */
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of_node_get(np);
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/* For each defined state ID */
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for (state = 0; ; state++) {
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/* Retrieve the pinctrl-* property */
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propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
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prop = of_find_property(np, propname, &size);
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kfree(propname);
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if (!prop) {
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if (state == 0) {
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of_node_put(np);
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return -ENODEV;
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}
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break;
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}
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list = prop->value;
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size /= sizeof(*list);
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/* Determine whether pinctrl-names property names the state */
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ret = of_property_read_string_index(np, "pinctrl-names",
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state, &statename);
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/*
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* If not, statename is just the integer state ID. But rather
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* than dynamically allocate it and have to free it later,
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* just point part way into the property name for the string.
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*/
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if (ret < 0)
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statename = prop->name + strlen("pinctrl-");
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/* For every referenced pin configuration node in it */
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for (config = 0; config < size; config++) {
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phandle = be32_to_cpup(list++);
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/* Look up the pin configuration node */
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np_config = of_find_node_by_phandle(phandle);
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if (!np_config) {
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dev_err(p->dev,
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"prop %s index %i invalid phandle\n",
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prop->name, config);
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ret = -EINVAL;
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goto err;
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}
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/* Parse the node */
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ret = dt_to_map_one_config(p, pctldev, statename,
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np_config);
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of_node_put(np_config);
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if (ret < 0)
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goto err;
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}
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/* No entries in DT? Generate a dummy state table entry */
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if (!size) {
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ret = dt_remember_dummy_state(p, statename);
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if (ret < 0)
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goto err;
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}
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}
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return 0;
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err:
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pinctrl_dt_free_maps(p);
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return ret;
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}
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/*
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* For pinctrl binding, typically #pinctrl-cells is for the pin controller
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* device, so either parent or grandparent. See pinctrl-bindings.txt.
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*/
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static int pinctrl_find_cells_size(const struct device_node *np)
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{
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const char *cells_name = "#pinctrl-cells";
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int cells_size, error;
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error = of_property_read_u32(np->parent, cells_name, &cells_size);
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if (error) {
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error = of_property_read_u32(np->parent->parent,
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cells_name, &cells_size);
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if (error)
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return -ENOENT;
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}
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return cells_size;
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}
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/**
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* pinctrl_get_list_and_count - Gets the list and it's cell size and number
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* @np: pointer to device node with the property
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* @list_name: property that contains the list
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* @list: pointer for the list found
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* @cells_size: pointer for the cell size found
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* @nr_elements: pointer for the number of elements found
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*
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* Typically np is a single pinctrl entry containing the list.
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*/
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static int pinctrl_get_list_and_count(const struct device_node *np,
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const char *list_name,
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const __be32 **list,
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int *cells_size,
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int *nr_elements)
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{
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int size;
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*cells_size = 0;
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*nr_elements = 0;
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*list = of_get_property(np, list_name, &size);
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if (!*list)
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return -ENOENT;
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*cells_size = pinctrl_find_cells_size(np);
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if (*cells_size < 0)
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return -ENOENT;
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/* First element is always the index within the pinctrl device */
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*nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
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return 0;
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}
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/**
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* pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
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* @np: pointer to device node with the property
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* @list_name: property that contains the list
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*
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* Counts the number of elements in a pinctrl array consisting of an index
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* within the controller and a number of u32 entries specified for each
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* entry. Note that device_node is always for the parent pin controller device.
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*/
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int pinctrl_count_index_with_args(const struct device_node *np,
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const char *list_name)
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{
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const __be32 *list;
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int size, nr_cells, error;
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error = pinctrl_get_list_and_count(np, list_name, &list,
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&nr_cells, &size);
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if (error)
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return error;
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return size;
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}
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EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
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/**
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* pinctrl_copy_args - Populates of_phandle_args based on index
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* @np: pointer to device node with the property
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* @list: pointer to a list with the elements
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* @index: entry within the list of elements
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* @nr_cells: number of cells in the list
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* @nr_elem: number of elements for each entry in the list
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* @out_args: returned values
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*
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* Populates the of_phandle_args based on the index in the list.
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*/
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static int pinctrl_copy_args(const struct device_node *np,
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const __be32 *list,
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int index, int nr_cells, int nr_elem,
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struct of_phandle_args *out_args)
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{
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int i;
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memset(out_args, 0, sizeof(*out_args));
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out_args->np = (struct device_node *)np;
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out_args->args_count = nr_cells + 1;
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if (index >= nr_elem)
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return -EINVAL;
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list += index * (nr_cells + 1);
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for (i = 0; i < nr_cells + 1; i++)
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out_args->args[i] = be32_to_cpup(list++);
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return 0;
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}
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/**
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* pinctrl_parse_index_with_args - Find a node pointed by index in a list
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* @np: pointer to device node with the property
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* @list_name: property that contains the list
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* @index: index within the list
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* @out_args: entries in the list pointed by index
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*
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* Finds the selected element in a pinctrl array consisting of an index
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* within the controller and a number of u32 entries specified for each
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* entry. Note that device_node is always for the parent pin controller device.
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*/
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int pinctrl_parse_index_with_args(const struct device_node *np,
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const char *list_name, int index,
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struct of_phandle_args *out_args)
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{
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const __be32 *list;
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int nr_elem, nr_cells, error;
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error = pinctrl_get_list_and_count(np, list_name, &list,
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&nr_cells, &nr_elem);
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if (error || !nr_cells)
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return error;
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error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
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out_args);
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if (error)
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return error;
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return 0;
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}
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EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);
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