1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
new file mode 100644
index 00000000000..eda13de2e7c
--- /dev/null
+++ b/drivers/pinctrl/devicetree.c
@@ -0,0 +1,256 @@
+/*
+ * 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, true);
+}
+
+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;
+}