/* * 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; }