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);