On Fri, Mar 23, 2012 at 02:27:19AM +0800, Stephen Warren wrote:

During pinctrl_get(), if the client device has a device tree node, look
for the common pinctrl properties there. If found, parse the referenced
device tree nodes, with the help of the pinctrl drivers, and generate
mapping table entries from them.

During pinctrl_put(), free any results of device tree parsing.

Signed-off-by: Stephen Warren <redacted>
---
v3: Add explit check for devies without dev->of_node. Add comments re:
    lack of pctldev for PIN_MAP_TYPE_DUMMY_STATE.
v2: Place most code into new file devicetree.c

pinctrl core dt fixup
---

.......

+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;
+	struct pinctrl_dt_map *dt_map;
+
+	/* CONFIG_OF enabled, p->dev not instantiated from DT */
+	if (!np)
+		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 */
+			if (strlen(prop->name) < 8) {

You thought this checking is still needed?
prop->name should be exactly what you search above ("pinctrl-%d"), right?

+				dev_err(p->dev, "prop %s inconsistent length\n",
+					prop->name);
+				ret = -EINVAL;
+				goto err;
+			}
+			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);

It seems we're still keeping the intermediate pinctrl_dt_map, although
not know the result you found,
but i'm ok we just do it currently.

Regards
Dong Aisheng