--- /dev/null
+/*
+ * 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) {
+ const 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);
+}
+
+struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
+{
+ struct pinctrl_dev *pctldev;
+
+ pctldev = get_pinctrl_dev_from_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;
+ const 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 = 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) {
+ 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) {
+ 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)
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff