1 files changed, 249 insertions, 0 deletions

diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
new file mode 100644
index 000000000000..fcb1de45473c
--- /dev/null
+++ b/drivers/pinctrl/devicetree.c
@@ -0,0 +1,249 @@
+/*
+ * 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) {
+                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);
+}
+
+static struct pinctrl_dev *find_pinctrl_by_of_node(struct device_node *np)
+{
+        struct pinctrl_dev *pctldev;
+
+        list_for_each_entry(pctldev, &pinctrldev_list, node)
+                if (pctldev->dev->of_node == np)
+                        return pctldev;
+
+        return NULL;
+}
+
+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;
+        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 = find_pinctrl_by_of_node(np_pctldev);
+                if (pctldev)
+                        break;
+        }
+        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) {
+                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;
+}