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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/pinctrl/devicetree.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/pinctrl/devicetree.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c new file mode 100644 index 000000000..6e0a40962 --- /dev/null +++ b/drivers/pinctrl/devicetree.c @@ -0,0 +1,427 @@ +// 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 + * @map: the mapping table entries + * @num_maps: number of 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) +{ + int i; + + for (i = 0; i < num_maps; ++i) { + kfree_const(map[i].dev_name); + map[i].dev_name = NULL; + } + + 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_mappings(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++) { + const char *devname; + + devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL); + if (!devname) + goto err_free_map; + + map[i].dev_name = devname; + 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) + goto err_free_map; + + 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_mappings(map, num_maps); + +err_free_map: + dt_free_map(pctldev, map, num_maps); + return -ENOMEM; +} + +struct pinctrl_dev *of_pinctrl_get(struct device_node *np) +{ + return get_pinctrl_dev_from_of_node(np); +} +EXPORT_SYMBOL_GPL(of_pinctrl_get); + +static int dt_to_map_one_config(struct pinctrl *p, + struct pinctrl_dev *hog_pctldev, + const char *statename, + struct device_node *np_config) +{ + 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 = -ENODEV; + /* keep deferring if modules are enabled */ + if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0) + ret = -EPROBE_DEFER; + return ret; + } + /* If we're creating a hog we can use the passed pctldev */ + if (hog_pctldev && (np_pctldev == p->dev->of_node)) { + pctldev = hog_pctldev; + break; + } + 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; + else if (num_maps == 0) { + /* + * If we have no valid maps (maybe caused by empty pinctrl node + * or typing error) ther is no need remember this, so just + * return. + */ + dev_info(p->dev, + "there is not valid maps for state %s\n", statename); + return 0; + } + + /* 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); +} + +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); + if (!propname) + return -ENOMEM; + 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) + statename = prop->name + strlen("pinctrl-"); + + /* 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_args: 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); |