Fixed MTP to work with TWRP

drivers/bus/vexpress-config.c

@@ -0,0 +1,202 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * Copyright (C) 2014 ARM Limited
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/vexpress.h>
+
+
+struct vexpress_config_bridge {
+	struct vexpress_config_bridge_ops *ops;
+	void *context;
+};
+
+
+static DEFINE_MUTEX(vexpress_config_mutex);
+static struct class *vexpress_config_class;
+static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
+
+
+void vexpress_config_set_master(u32 site)
+{
+	vexpress_config_site_master = site;
+}
+
+u32 vexpress_config_get_master(void)
+{
+	return vexpress_config_site_master;
+}
+
+void vexpress_config_lock(void *arg)
+{
+	mutex_lock(&vexpress_config_mutex);
+}
+
+void vexpress_config_unlock(void *arg)
+{
+	mutex_unlock(&vexpress_config_mutex);
+}
+
+
+static void vexpress_config_find_prop(struct device_node *node,
+		const char *name, u32 *val)
+{
+	/* Default value */
+	*val = 0;
+
+	of_node_get(node);
+	while (node) {
+		if (of_property_read_u32(node, name, val) == 0) {
+			of_node_put(node);
+			return;
+		}
+		node = of_get_next_parent(node);
+	}
+}
+
+int vexpress_config_get_topo(struct device_node *node, u32 *site,
+		u32 *position, u32 *dcc)
+{
+	vexpress_config_find_prop(node, "arm,vexpress,site", site);
+	if (*site == VEXPRESS_SITE_MASTER)
+		*site = vexpress_config_site_master;
+	if (WARN_ON(vexpress_config_site_master == VEXPRESS_SITE_MASTER))
+		return -EINVAL;
+	vexpress_config_find_prop(node, "arm,vexpress,position", position);
+	vexpress_config_find_prop(node, "arm,vexpress,dcc", dcc);
+
+	return 0;
+}
+
+
+static void vexpress_config_devres_release(struct device *dev, void *res)
+{
+	struct vexpress_config_bridge *bridge = dev_get_drvdata(dev->parent);
+	struct regmap *regmap = res;
+
+	bridge->ops->regmap_exit(regmap, bridge->context);
+}
+
+struct regmap *devm_regmap_init_vexpress_config(struct device *dev)
+{
+	struct vexpress_config_bridge *bridge;
+	struct regmap *regmap;
+	struct regmap **res;
+
+	if (WARN_ON(dev->parent->class != vexpress_config_class))
+		return ERR_PTR(-ENODEV);
+
+	bridge = dev_get_drvdata(dev->parent);
+	if (WARN_ON(!bridge))
+		return ERR_PTR(-EINVAL);
+
+	res = devres_alloc(vexpress_config_devres_release, sizeof(*res),
+			GFP_KERNEL);
+	if (!res)
+		return ERR_PTR(-ENOMEM);
+
+	regmap = bridge->ops->regmap_init(dev, bridge->context);
+	if (IS_ERR(regmap)) {
+		devres_free(res);
+		return regmap;
+	}
+
+	*res = regmap;
+	devres_add(dev, res);
+
+	return regmap;
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
+
+struct device *vexpress_config_bridge_register(struct device *parent,
+		struct vexpress_config_bridge_ops *ops, void *context)
+{
+	struct device *dev;
+	struct vexpress_config_bridge *bridge;
+
+	if (!vexpress_config_class) {
+		vexpress_config_class = class_create(THIS_MODULE,
+				"vexpress-config");
+		if (IS_ERR(vexpress_config_class))
+			return (void *)vexpress_config_class;
+	}
+
+	dev = device_create(vexpress_config_class, parent, 0,
+			NULL, "%s.bridge", dev_name(parent));
+
+	if (IS_ERR(dev))
+		return dev;
+
+	bridge = devm_kmalloc(dev, sizeof(*bridge), GFP_KERNEL);
+	if (!bridge) {
+		put_device(dev);
+		device_unregister(dev);
+		return ERR_PTR(-ENOMEM);
+	}
+	bridge->ops = ops;
+	bridge->context = context;
+
+	dev_set_drvdata(dev, bridge);
+
+	dev_dbg(parent, "Registered bridge '%s', parent node %p\n",
+			dev_name(dev), parent->of_node);
+
+	return dev;
+}
+
+
+static int vexpress_config_node_match(struct device *dev, const void *data)
+{
+	const struct device_node *node = data;
+
+	dev_dbg(dev, "Parent node %p, looking for %p\n",
+			dev->parent->of_node, node);
+
+	return dev->parent->of_node == node;
+}
+
+static int vexpress_config_populate(struct device_node *node)
+{
+	struct device_node *bridge;
+	struct device *parent;
+
+	bridge = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);
+	if (!bridge)
+		return -EINVAL;
+
+	parent = class_find_device(vexpress_config_class, NULL, bridge,
+			vexpress_config_node_match);
+	if (WARN_ON(!parent))
+		return -ENODEV;
+
+	return of_platform_populate(node, NULL, NULL, parent);
+}
+
+static int __init vexpress_config_init(void)
+{
+	int err = 0;
+	struct device_node *node;
+
+	/* Need the config devices early, before the "normal" devices... */
+	for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
+		err = vexpress_config_populate(node);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+postcore_initcall(vexpress_config_init);
+