mfd: vexpress: Convert custom func API to regmap

Components of the Versatile Express platform (configuration
microcontrollers on motherboard and daughterboards in particular)
talk to each other over a custom configuration bus. They
provide miscellaneous functions (from clock generator control
to energy sensors) which are represented as platform devices
(and Device Tree nodes). The transactions on the bus can
be generated by different "bridges" in the system, some
of which are universal for the whole platform (for the price
of high transfer latencies), others restricted to a subsystem
(but much faster).

Until now drivers for such functions were using custom "func"
API, which is being replaced in this patch by regmap calls.
This required:

* a rework (and move to drivers/bus directory, as suggested
  by Samuel and Arnd) of the config bus core, which is much
  simpler now and uses device model infrastructure (class)
  to keep track of the bridges; non-DT case (soon to be
  retired anyway) is simply covered by a special device
  registration function

* the new config-bus driver also takes over device population,
  so there is no need for special matching table for
  of_platform_populate nor "simple-bus" hack in the arm64
  model dtsi file (relevant bindings documentation has
  been updated); this allows all the vexpress devices
  fit into normal device model, making it possible
  to remove plenty of early inits and other hacks in
  the near future

* adaptation of the syscfg bridge implementation in the
  sysreg driver, again making it much simpler; there is
  a special case of the "energy" function spanning two
  registers, where they should be both defined in the tree
  now, but backward compatibility is maintained in the code

* modification of the relevant drivers:

  * hwmon - just a straight-forward API change
  * power/reset driver - API change
  * regulator - API change plus error handling
    simplification
  * osc clock driver - this one required larger rework
    in order to turn in into a standard platform driver

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mike Turquette <mturquette@linaro.org>

10 files changed, 491 insertions, 585 deletions

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 552373c..f24e79d 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -41,4 +41,13 @@ config ARM_CCI
 	help
 	  Driver supporting the CCI cache coherent interconnect for ARM
 	  platforms.
+
+config VEXPRESS_CONFIG
+	bool "Versatile Express configuration bus"
+	default y if ARCH_VEXPRESS
+	depends on ARM || ARM64
+	select REGMAP
+	help
+	  Platform configuration infrastructure for the ARM Ltd.
+	  Versatile Express.
 endmenu
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 8947bdd..f095aa7 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -10,3 +10,5 @@ obj-$(CONFIG_OMAP_OCP2SCP)	+= omap-ocp2scp.o
 obj-$(CONFIG_OMAP_INTERCONNECT)	+= omap_l3_smx.o omap_l3_noc.o
 # CCI cache coherent interconnect for ARM platforms
 obj-$(CONFIG_ARM_CCI)		+= arm-cci.o
+
+obj-$(CONFIG_VEXPRESS_CONFIG)	+= vexpress-config.o
diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
new file mode 100644
index 0000000..27a07df
--- /dev/null
+++ b/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;
+}
+
+
+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);
+
diff --git a/drivers/clk/versatile/clk-vexpress-osc.c b/drivers/clk/versatile/clk-vexpress-osc.c
index 4223912..529a59c 100644
--- a/drivers/clk/versatile/clk-vexpress-osc.c
+++ b/drivers/clk/versatile/clk-vexpress-osc.c
@@ -11,8 +11,6 @@
  * Copyright (C) 2012 ARM Limited
  */
 
-#define pr_fmt(fmt) "vexpress-osc: " fmt
-
 #include <linux/clkdev.h>
 #include <linux/clk-provider.h>
 #include <linux/err.h>
@@ -22,7 +20,7 @@
 #include <linux/vexpress.h>
 
 struct vexpress_osc {
-	struct vexpress_config_func *func;
+	struct regmap *reg;
 	struct clk_hw hw;
 	unsigned long rate_min;
 	unsigned long rate_max;
@@ -36,7 +34,7 @@ static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
 	struct vexpress_osc *osc = to_vexpress_osc(hw);
 	u32 rate;
 
-	vexpress_config_read(osc->func, 0, &rate);
+	regmap_read(osc->reg, 0, &rate);
 
 	return rate;
 }
@@ -60,7 +58,7 @@ static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
 {
 	struct vexpress_osc *osc = to_vexpress_osc(hw);
 
-	return vexpress_config_write(osc->func, 0, rate);
+	return regmap_write(osc->reg, 0, rate);
 }
 
 static struct clk_ops vexpress_osc_ops = {
@@ -70,58 +68,31 @@ static struct clk_ops vexpress_osc_ops = {
 };
 
 
-struct clk * __init vexpress_osc_setup(struct device *dev)
-{
-	struct clk_init_data init;
-	struct vexpress_osc *osc = kzalloc(sizeof(*osc), GFP_KERNEL);
-
-	if (!osc)
-		return NULL;
-
-	osc->func = vexpress_config_func_get_by_dev(dev);
-	if (!osc->func) {
-		kfree(osc);
-		return NULL;
-	}
-
-	init.name = dev_name(dev);
-	init.ops = &vexpress_osc_ops;
-	init.flags = CLK_IS_ROOT;
-	init.num_parents = 0;
-	osc->hw.init = &init;
-
-	return clk_register(NULL, &osc->hw);
-}
-
-void __init vexpress_osc_of_setup(struct device_node *node)
+static int vexpress_osc_probe(struct platform_device *pdev)
 {
+	struct clk_lookup *cl = pdev->dev.platform_data; /* Non-DT lookup */
 	struct clk_init_data init;
 	struct vexpress_osc *osc;
 	struct clk *clk;
 	u32 range[2];
 
-	vexpress_sysreg_of_early_init();
-
-	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
+	osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
 	if (!osc)
-		return;
+		return -ENOMEM;
 
-	osc->func = vexpress_config_func_get_by_node(node);
-	if (!osc->func) {
-		pr_err("Failed to obtain config func for node '%s'!\n",
-				node->full_name);
-		goto error;
-	}
+	osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
+	if (IS_ERR(osc->reg))
+		return PTR_ERR(osc->reg);
 
-	if (of_property_read_u32_array(node, "freq-range", range,
+	if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
 			ARRAY_SIZE(range)) == 0) {
 		osc->rate_min = range[0];
 		osc->rate_max = range[1];
 	}
 
-	of_property_read_string(node, "clock-output-names", &init.name);
-	if (!init.name)
-		init.name = node->full_name;
+	if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
+			&init.name) != 0)
+		init.name = dev_name(&pdev->dev);
 
 	init.ops = &vexpress_osc_ops;
 	init.flags = CLK_IS_ROOT;
@@ -130,20 +101,37 @@ void __init vexpress_osc_of_setup(struct device_node *node)
 	osc->hw.init = &init;
 
 	clk = clk_register(NULL, &osc->hw);
-	if (IS_ERR(clk)) {
-		pr_err("Failed to register clock '%s'!\n", init.name);
-		goto error;
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk);
+
+	/* Only happens for non-DT cases */
+	if (cl) {
+		cl->clk = clk;
+		clkdev_add(cl);
 	}
 
-	of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
+
+	return 0;
+}
 
-	pr_debug("Registered clock '%s'\n", init.name);
+static struct of_device_id vexpress_osc_of_match[] = {
+	{ .compatible = "arm,vexpress-osc", },
+	{}
+};
 
-	return;
+static struct platform_driver vexpress_osc_driver = {
+	.driver	= {
+		.name = "vexpress-osc",
+		.of_match_table = vexpress_osc_of_match,
+	},
+	.probe = vexpress_osc_probe,
+};
 
-error:
-	if (osc->func)
-		vexpress_config_func_put(osc->func);
-	kfree(osc);
+static int __init vexpress_osc_init(void)
+{
+	return platform_driver_register(&vexpress_osc_driver);
 }
-CLK_OF_DECLARE(vexpress_soc, "arm,vexpress-osc", vexpress_osc_of_setup);
+core_initcall(vexpress_osc_init);
diff --git a/drivers/hwmon/vexpress.c b/drivers/hwmon/vexpress.c
index 8242b75..611f34c 100644
--- a/drivers/hwmon/vexpress.c
+++ b/drivers/hwmon/vexpress.c
@@ -26,7 +26,7 @@
 
 struct vexpress_hwmon_data {
 	struct device *hwmon_dev;
-	struct vexpress_config_func *func;
+	struct regmap *reg;
 	const char *name;
 };
 
@@ -53,7 +53,7 @@ static ssize_t vexpress_hwmon_u32_show(struct device *dev,
 	int err;
 	u32 value;
 
-	err = vexpress_config_read(data->func, 0, &value);
+	err = regmap_read(data->reg, 0, &value);
 	if (err)
 		return err;
 
@@ -68,11 +68,11 @@ static ssize_t vexpress_hwmon_u64_show(struct device *dev,
 	int err;
 	u32 value_hi, value_lo;
 
-	err = vexpress_config_read(data->func, 0, &value_lo);
+	err = regmap_read(data->reg, 0, &value_lo);
 	if (err)
 		return err;
 
-	err = vexpress_config_read(data->func, 1, &value_hi);
+	err = regmap_read(data->reg, 1, &value_hi);
 	if (err)
 		return err;
 
@@ -234,9 +234,9 @@ static int vexpress_hwmon_probe(struct platform_device *pdev)
 	type = match->data;
 	data->name = type->name;
 
-	data->func = vexpress_config_func_get_by_dev(&pdev->dev);
-	if (!data->func)
-		return -ENODEV;
+	data->reg = devm_regmap_init_vexpress_config(&pdev->dev);
+	if (IS_ERR(data->reg))
+		return PTR_ERR(data->reg);
 
 	err = sysfs_create_groups(&pdev->dev.kobj, type->attr_groups);
 	if (err)
@@ -252,7 +252,6 @@ static int vexpress_hwmon_probe(struct platform_device *pdev)
 
 error:
 	sysfs_remove_group(&pdev->dev.kobj, match->data);
-	vexpress_config_func_put(data->func);
 	return err;
 }
 
@@ -266,8 +265,6 @@ static int vexpress_hwmon_remove(struct platform_device *pdev)
 	match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
 	sysfs_remove_group(&pdev->dev.kobj, match->data);
 
-	vexpress_config_func_put(data->func);
-
 	return 0;
 }
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 2851275..9ba838e 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -161,7 +161,7 @@ obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
 obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
 obj-$(CONFIG_MFD_SYSCON)	+= syscon.o
 obj-$(CONFIG_MFD_LM3533)	+= lm3533-core.o lm3533-ctrlbank.o
-obj-$(CONFIG_VEXPRESS_CONFIG)	+= vexpress-config.o vexpress-sysreg.o
+obj-$(CONFIG_VEXPRESS_CONFIG)	+= vexpress-sysreg.o
 obj-$(CONFIG_MFD_RETU)		+= retu-mfd.o
 obj-$(CONFIG_MFD_AS3711)	+= as3711.o
 obj-$(CONFIG_MFD_AS3722)	+= as3722.o
diff --git a/drivers/mfd/vexpress-config.c b/drivers/mfd/vexpress-config.c
deleted file mode 100644
index d0db89d..0000000
--- a/drivers/mfd/vexpress-config.c
+++ /dev/null
@@ -1,287 +0,0 @@
-/*
- * 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) 2012 ARM Limited
- */
-
-#define pr_fmt(fmt) "vexpress-config: " fmt
-
-#include <linux/bitops.h>
-#include <linux/completion.h>
-#include <linux/export.h>
-#include <linux/list.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/vexpress.h>
-
-
-#define VEXPRESS_CONFIG_MAX_BRIDGES 2
-
-static struct vexpress_config_bridge {
-	struct device_node *node;
-	struct vexpress_config_bridge_info *info;
-	struct list_head transactions;
-	spinlock_t transactions_lock;
-} vexpress_config_bridges[VEXPRESS_CONFIG_MAX_BRIDGES];
-
-static DECLARE_BITMAP(vexpress_config_bridges_map,
-		ARRAY_SIZE(vexpress_config_bridges));
-static DEFINE_MUTEX(vexpress_config_bridges_mutex);
-
-struct vexpress_config_bridge *vexpress_config_bridge_register(
-		struct device_node *node,
-		struct vexpress_config_bridge_info *info)
-{
-	struct vexpress_config_bridge *bridge;
-	int i;
-
-	pr_debug("Registering bridge '%s'\n", info->name);
-
-	mutex_lock(&vexpress_config_bridges_mutex);
-	i = find_first_zero_bit(vexpress_config_bridges_map,
-			ARRAY_SIZE(vexpress_config_bridges));
-	if (i >= ARRAY_SIZE(vexpress_config_bridges)) {
-		pr_err("Can't register more bridges!\n");
-		mutex_unlock(&vexpress_config_bridges_mutex);
-		return NULL;
-	}
-	__set_bit(i, vexpress_config_bridges_map);
-	bridge = &vexpress_config_bridges[i];
-
-	bridge->node = node;
-	bridge->info = info;
-	INIT_LIST_HEAD(&bridge->transactions);
-	spin_lock_init(&bridge->transactions_lock);
-
-	mutex_unlock(&vexpress_config_bridges_mutex);
-
-	return bridge;
-}
-EXPORT_SYMBOL(vexpress_config_bridge_register);
-
-void vexpress_config_bridge_unregister(struct vexpress_config_bridge *bridge)
-{
-	struct vexpress_config_bridge __bridge = *bridge;
-	int i;
-
-	mutex_lock(&vexpress_config_bridges_mutex);
-	for (i = 0; i < ARRAY_SIZE(vexpress_config_bridges); i++)
-		if (&vexpress_config_bridges[i] == bridge)
-			__clear_bit(i, vexpress_config_bridges_map);
-	mutex_unlock(&vexpress_config_bridges_mutex);
-
-	WARN_ON(!list_empty(&__bridge.transactions));
-	while (!list_empty(&__bridge.transactions))
-		cpu_relax();
-}
-EXPORT_SYMBOL(vexpress_config_bridge_unregister);
-
-
-struct vexpress_config_func {
-	struct vexpress_config_bridge *bridge;
-	void *func;
-};
-
-struct vexpress_config_func *__vexpress_config_func_get(struct device *dev,
-		struct device_node *node)
-{
-	struct device_node *bridge_node;
-	struct vexpress_config_func *func;
-	int i;
-
-	if (WARN_ON(dev && node && dev->of_node != node))
-		return NULL;
-	if (dev && !node)
-		node = dev->of_node;
-
-	func = kzalloc(sizeof(*func), GFP_KERNEL);
-	if (!func)
-		return NULL;
-
-	bridge_node = of_node_get(node);
-	while (bridge_node) {
-		const __be32 *prop = of_get_property(bridge_node,
-				"arm,vexpress,config-bridge", NULL);
-
-		if (prop) {
-			bridge_node = of_find_node_by_phandle(
-					be32_to_cpup(prop));
-			break;
-		}
-
-		bridge_node = of_get_next_parent(bridge_node);
-	}
-
-	mutex_lock(&vexpress_config_bridges_mutex);
-	for (i = 0; i < ARRAY_SIZE(vexpress_config_bridges); i++) {
-		struct vexpress_config_bridge *bridge =
-				&vexpress_config_bridges[i];
-
-		if (test_bit(i, vexpress_config_bridges_map) &&
-				bridge->node == bridge_node) {
-			func->bridge = bridge;
-			func->func = bridge->info->func_get(dev, node);
-			break;
-		}
-	}
-	mutex_unlock(&vexpress_config_bridges_mutex);
-
-	if (!func->func) {
-		of_node_put(node);
-		kfree(func);
-		return NULL;
-	}
-
-	return func;
-}
-EXPORT_SYMBOL(__vexpress_config_func_get);
-
-void vexpress_config_func_put(struct vexpress_config_func *func)
-{
-	func->bridge->info->func_put(func->func);
-	of_node_put(func->bridge->node);
-	kfree(func);
-}
-EXPORT_SYMBOL(vexpress_config_func_put);
-
-struct vexpress_config_trans {
-	struct vexpress_config_func *func;
-	int offset;
-	bool write;
-	u32 *data;
-	int status;
-	struct completion completion;
-	struct list_head list;
-};
-
-static void vexpress_config_dump_trans(const char *what,
-		struct vexpress_config_trans *trans)
-{
-	pr_debug("%s %s trans %p func 0x%p offset %d data 0x%x status %d\n",
-			what, trans->write ? "write" : "read", trans,
-			trans->func->func, trans->offset,
-			trans->data ? *trans->data : 0, trans->status);
-}
-
-static int vexpress_config_schedule(struct vexpress_config_trans *trans)
-{
-	int status;
-	struct vexpress_config_bridge *bridge = trans->func->bridge;
-	unsigned long flags;
-
-	init_completion(&trans->completion);
-	trans->status = -EFAULT;
-
-	spin_lock_irqsave(&bridge->transactions_lock, flags);
-
-	if (list_empty(&bridge->transactions)) {
-		vexpress_config_dump_trans("Executing", trans);
-		status = bridge->info->func_exec(trans->func->func,
-				trans->offset, trans->write, trans->data);
-	} else {
-		vexpress_config_dump_trans("Queuing", trans);
-		status = VEXPRESS_CONFIG_STATUS_WAIT;
-	}
-
-	switch (status) {
-	case VEXPRESS_CONFIG_STATUS_DONE:
-		vexpress_config_dump_trans("Finished", trans);
-		trans->status = status;
-		break;
-	case VEXPRESS_CONFIG_STATUS_WAIT:
-		list_add_tail(&trans->list, &bridge->transactions);
-		break;
-	}
-
-	spin_unlock_irqrestore(&bridge->transactions_lock, flags);
-
-	return status;
-}
-
-void vexpress_config_complete(struct vexpress_config_bridge *bridge,
-		int status)
-{
-	struct vexpress_config_trans *trans;
-	unsigned long flags;
-	const char *message = "Completed";
-
-	spin_lock_irqsave(&bridge->transactions_lock, flags);
-
-	trans = list_first_entry(&bridge->transactions,
-			struct vexpress_config_trans, list);
-	trans->status = status;
-
-	do {
-		vexpress_config_dump_trans(message, trans);
-		list_del(&trans->list);
-		complete(&trans->completion);
-
-		if (list_empty(&bridge->transactions))
-			break;
-
-		trans = list_first_entry(&bridge->transactions,
-				struct vexpress_config_trans, list);
-		vexpress_config_dump_trans("Executing pending", trans);
-		trans->status = bridge->info->func_exec(trans->func->func,
-				trans->offset, trans->write, trans->data);
-		message = "Finished pending";
-	} while (trans->status == VEXPRESS_CONFIG_STATUS_DONE);
-
-	spin_unlock_irqrestore(&bridge->transactions_lock, flags);
-}
-EXPORT_SYMBOL(vexpress_config_complete);
-
-int vexpress_config_wait(struct vexpress_config_trans *trans)
-{
-	wait_for_completion(&trans->completion);
-
-	return trans->status;
-}
-EXPORT_SYMBOL(vexpress_config_wait);
-
-int vexpress_config_read(struct vexpress_config_func *func, int offset,
-		u32 *data)
-{
-	struct vexpress_config_trans trans = {
-		.func = func,
-		.offset = offset,
-		.write = false,
-		.data = data,
-		.status = 0,
-	};
-	int status = vexpress_config_schedule(&trans);
-
-	if (status == VEXPRESS_CONFIG_STATUS_WAIT)
-		status = vexpress_config_wait(&trans);
-
-	return status;
-}
-EXPORT_SYMBOL(vexpress_config_read);
-
-int vexpress_config_write(struct vexpress_config_func *func, int offset,
-		u32 data)
-{
-	struct vexpress_config_trans trans = {
-		.func = func,
-		.offset = offset,
-		.write = true,
-		.data = &data,
-		.status = 0,
-	};
-	int status = vexpress_config_schedule(&trans);
-
-	if (status == VEXPRESS_CONFIG_STATUS_WAIT)
-		status = vexpress_config_wait(&trans);
-
-	return status;
-}
-EXPORT_SYMBOL(vexpress_config_write);
diff --git a/drivers/mfd/vexpress-sysreg.c b/drivers/mfd/vexpress-sysreg.c
index 35281e8..b4138a7 100644
--- a/drivers/mfd/vexpress-sysreg.c
+++ b/drivers/mfd/vexpress-sysreg.c
@@ -16,8 +16,10 @@
 #include <linux/io.h>
 #include <linux/leds.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/timer.h>
@@ -72,9 +74,18 @@
 
 static void __iomem *vexpress_sysreg_base;
 static struct device *vexpress_sysreg_dev;
-static int vexpress_master_site;
+static LIST_HEAD(vexpress_sysreg_config_funcs);
+static struct device *vexpress_sysreg_config_bridge;
 
 
+static int vexpress_sysreg_get_master(void)
+{
+	if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
+		return VEXPRESS_SITE_DB2;
+
+	return VEXPRESS_SITE_DB1;
+}
+
 void vexpress_flags_set(u32 data)
 {
 	writel(~0, vexpress_sysreg_base + SYS_FLAGSCLR);
@@ -84,7 +95,7 @@ void vexpress_flags_set(u32 data)
 u32 vexpress_get_procid(int site)
 {
 	if (site == VEXPRESS_SITE_MASTER)
-		site = vexpress_master_site;
+		site = vexpress_sysreg_get_master();
 
 	return readl(vexpress_sysreg_base + (site == VEXPRESS_SITE_DB1 ?
 			SYS_PROCID0 : SYS_PROCID1));
@@ -114,130 +125,33 @@ void __iomem *vexpress_get_24mhz_clock_base(void)
 }
 
 
-static void vexpress_sysreg_find_prop(struct device_node *node,
-		const char *name, u32 *val)
-{
-	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);
-	}
-}
-
-unsigned __vexpress_get_site(struct device *dev, struct device_node *node)
-{
-	u32 site = 0;
-
-	WARN_ON(dev && node && dev->of_node != node);
-	if (dev && !node)
-		node = dev->of_node;
-
-	if (node) {
-		vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
-	} else if (dev && dev->bus == &platform_bus_type) {
-		struct platform_device *pdev = to_platform_device(dev);
-
-		if (pdev->num_resources == 1 &&
-				pdev->resource[0].flags == IORESOURCE_BUS)
-			site = pdev->resource[0].start;
-	} else if (dev && strncmp(dev_name(dev), "ct:", 3) == 0) {
-		site = VEXPRESS_SITE_MASTER;
-	}
-
-	if (site == VEXPRESS_SITE_MASTER)
-		site = vexpress_master_site;
-
-	return site;
-}
-
-
 struct vexpress_sysreg_config_func {
-	u32 template;
-	u32 device;
+	struct list_head list;
+	struct regmap *regmap;
+	int num_templates;
+	u32 template[0]; /* Keep this last */
 };
 
-static struct vexpress_config_bridge *vexpress_sysreg_config_bridge;
-static struct timer_list vexpress_sysreg_config_timer;
-static u32 *vexpress_sysreg_config_data;
-static int vexpress_sysreg_config_tries;
-
-static void *vexpress_sysreg_config_func_get(struct device *dev,
-		struct device_node *node)
+static int vexpress_sysreg_config_exec(struct vexpress_sysreg_config_func *func,
+		int index, bool write, u32 *data)
 {
-	struct vexpress_sysreg_config_func *config_func;
-	u32 site = 0;
-	u32 position = 0;
-	u32 dcc = 0;
-	u32 func_device[2];
-	int err = -EFAULT;
-
-	if (node) {
-		of_node_get(node);
-		vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
-		vexpress_sysreg_find_prop(node, "arm,vexpress,position",
-				&position);
-		vexpress_sysreg_find_prop(node, "arm,vexpress,dcc", &dcc);
-		err = of_property_read_u32_array(node,
-				"arm,vexpress-sysreg,func", func_device,
-				ARRAY_SIZE(func_device));
-		of_node_put(node);
-	} else if (dev && dev->bus == &platform_bus_type) {
-		struct platform_device *pdev = to_platform_device(dev);
-
-		if (pdev->num_resources == 1 &&
-				pdev->resource[0].flags == IORESOURCE_BUS) {
-			site = pdev->resource[0].start;
-			func_device[0] = pdev->resource[0].end;
-			func_device[1] = pdev->id;
-			err = 0;
-		}
-	}
-	if (err)
-		return NULL;
-
-	config_func = kzalloc(sizeof(*config_func), GFP_KERNEL);
-	if (!config_func)
-		return NULL;
-
-	config_func->template = SYS_CFGCTRL_DCC(dcc);
-	config_func->template |= SYS_CFGCTRL_FUNC(func_device[0]);
-	config_func->template |= SYS_CFGCTRL_SITE(site == VEXPRESS_SITE_MASTER ?
-			vexpress_master_site : site);
-	config_func->template |= SYS_CFGCTRL_POSITION(position);
-	config_func->device |= func_device[1];
-
-	dev_dbg(vexpress_sysreg_dev, "func 0x%p = 0x%x, %d\n", config_func,
-			config_func->template, config_func->device);
-
-	return config_func;
-}
-
-static void vexpress_sysreg_config_func_put(void *func)
-{
-	kfree(func);
-}
-
-static int vexpress_sysreg_config_func_exec(void *func, int offset,
-		bool write, u32 *data)
-{
-	int status;
-	struct vexpress_sysreg_config_func *config_func = func;
-	u32 command;
+	u32 command, status;
+	int tries;
+	long timeout;
 
 	if (WARN_ON(!vexpress_sysreg_base))
 		return -ENOENT;
 
+	if (WARN_ON(index > func->num_templates))
+		return -EINVAL;
+
 	command = readl(vexpress_sysreg_base + SYS_CFGCTRL);
 	if (WARN_ON(command & SYS_CFGCTRL_START))
 		return -EBUSY;
 
-	command = SYS_CFGCTRL_START;
+	command = func->template[index];
+	command |= SYS_CFGCTRL_START;
 	command |= write ? SYS_CFGCTRL_WRITE : 0;
-	command |= config_func->template;
-	command |= SYS_CFGCTRL_DEVICE(config_func->device + offset);
 
 	/* Use a canary for reads */
 	if (!write)
@@ -250,90 +164,190 @@ static int vexpress_sysreg_config_func_exec(void *func, int offset,
 	writel(command, vexpress_sysreg_base + SYS_CFGCTRL);
 	mb();
 
-	if (vexpress_sysreg_dev) {
-		/* Schedule completion check */
-		if (!write)
-			vexpress_sysreg_config_data = data;
-		vexpress_sysreg_config_tries = 100;
-		mod_timer(&vexpress_sysreg_config_timer,
-				jiffies + usecs_to_jiffies(100));
-		status = VEXPRESS_CONFIG_STATUS_WAIT;
-	} else {
-		/* Early execution, no timer available, have to spin */
-		u32 cfgstat;
+	/* The operation can take ages... Go to sleep, 100us initially */
+	tries = 100;
+	timeout = 100;
+	do {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(usecs_to_jiffies(timeout));
+		if (signal_pending(current))
+			return -EINTR;
+
+		status = readl(vexpress_sysreg_base + SYS_CFGSTAT);
+		if (status & SYS_CFGSTAT_ERR)
+			return -EFAULT;
+
+		if (timeout > 20)
+			timeout -= 20;
+	} while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
+	if (WARN_ON_ONCE(!tries))
+		return -ETIMEDOUT;
+
+	if (!write) {
+		*data = readl(vexpress_sysreg_base + SYS_CFGDATA);
+		dev_dbg(vexpress_sysreg_dev, "func %p, read data %x\n",
+				func, *data);
+	}
 
-		do {
-			cpu_relax();
-			cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
-		} while (!cfgstat);
+	return 0;
+}
 
-		if (!write && (cfgstat & SYS_CFGSTAT_COMPLETE))
-			*data = readl(vexpress_sysreg_base + SYS_CFGDATA);
-		status = VEXPRESS_CONFIG_STATUS_DONE;
+static int vexpress_sysreg_config_read(void *context, unsigned int index,
+		unsigned int *val)
+{
+	struct vexpress_sysreg_config_func *func = context;
 
-		if (cfgstat & SYS_CFGSTAT_ERR)
-			status = -EINVAL;
-	}
+	return vexpress_sysreg_config_exec(func, index, false, val);
+}
 
-	return status;
+static int vexpress_sysreg_config_write(void *context, unsigned int index,
+		unsigned int val)
+{
+	struct vexpress_sysreg_config_func *func = context;
+
+	return vexpress_sysreg_config_exec(func, index, true, &val);
 }
 
-struct vexpress_config_bridge_info vexpress_sysreg_config_bridge_info = {
-	.name = "vexpress-sysreg",
-	.func_get = vexpress_sysreg_config_func_get,
-	.func_put = vexpress_sysreg_config_func_put,
-	.func_exec = vexpress_sysreg_config_func_exec,
+struct regmap_config vexpress_sysreg_regmap_config = {
+	.lock = vexpress_config_lock,
+	.unlock = vexpress_config_unlock,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_read = vexpress_sysreg_config_read,
+	.reg_write = vexpress_sysreg_config_write,
+	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
 };
 
-static void vexpress_sysreg_config_complete(unsigned long data)
+static struct regmap *vexpress_sysreg_config_regmap_init(struct device *dev,
+		void *context)
 {
-	int status = VEXPRESS_CONFIG_STATUS_DONE;
-	u32 cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
-
-	if (cfgstat & SYS_CFGSTAT_ERR)
-		status = -EINVAL;
-	if (!vexpress_sysreg_config_tries--)
-		status = -ETIMEDOUT;
-
-	if (status < 0) {
-		dev_err(vexpress_sysreg_dev, "error %d\n", status);
-	} else if (!(cfgstat & SYS_CFGSTAT_COMPLETE)) {
-		mod_timer(&vexpress_sysreg_config_timer,
-				jiffies + usecs_to_jiffies(50));
-		return;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct vexpress_sysreg_config_func *func;
+	struct property *prop;
+	const __be32 *val = NULL;
+	__be32 energy_quirk[4];
+	int num;
+	u32 site, position, dcc;
+	int err;
+	int i;
+
+	if (dev->of_node) {
+		err = vexpress_config_get_topo(dev->of_node, &site, &position,
+				&dcc);
+		if (err)
+			return ERR_PTR(err);
+
+		prop = of_find_property(dev->of_node,
+				"arm,vexpress-sysreg,func", NULL);
+		if (!prop)
+			return ERR_PTR(-EINVAL);
+
+		num = prop->length / sizeof(u32) / 2;
+		val = prop->value;
+	} else {
+		if (pdev->num_resources != 1 ||
+				pdev->resource[0].flags != IORESOURCE_BUS)
+			return ERR_PTR(-EFAULT);
+
+		site = pdev->resource[0].start;
+		if (site == VEXPRESS_SITE_MASTER)
+			site = vexpress_sysreg_get_master();
+		position = 0;
+		dcc = 0;
+		num = 1;
 	}
 
-	if (vexpress_sysreg_config_data) {
-		*vexpress_sysreg_config_data = readl(vexpress_sysreg_base +
-				SYS_CFGDATA);
-		dev_dbg(vexpress_sysreg_dev, "read data %x\n",
-				*vexpress_sysreg_config_data);
-		vexpress_sysreg_config_data = NULL;
+	/*
+	 * "arm,vexpress-energy" function used to be described
+	 * by its first device only, now it requires both
+	 */
+	if (num == 1 && of_device_is_compatible(dev->of_node,
+			"arm,vexpress-energy")) {
+		num = 2;
+		energy_quirk[0] = *val;
+		energy_quirk[2] = *val++;
+		energy_quirk[1] = *val;
+		energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
+		val = energy_quirk;
 	}
 
-	vexpress_config_complete(vexpress_sysreg_config_bridge, status);
-}
+	func = kzalloc(sizeof(*func) + sizeof(*func->template) * num,
+			GFP_KERNEL);
+	if (!func)
+		return NULL;
 
+	func->num_templates = num;
 
-void vexpress_sysreg_setup(struct device_node *node)
-{
-	if (WARN_ON(!vexpress_sysreg_base))
-		return;
+	for (i = 0; i < num; i++) {
+		u32 function, device;
 
-	if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
-		vexpress_master_site = VEXPRESS_SITE_DB2;
+		if (dev->of_node) {
+			function = be32_to_cpup(val++);
+			device = be32_to_cpup(val++);
+		} else {
+			function = pdev->resource[0].end;
+			device = pdev->id;
+		}
+
+		dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
+				func, site, position, dcc,
+				function, device);
+
+		func->template[i] = SYS_CFGCTRL_DCC(dcc);
+		func->template[i] |= SYS_CFGCTRL_SITE(site);
+		func->template[i] |= SYS_CFGCTRL_POSITION(position);
+		func->template[i] |= SYS_CFGCTRL_FUNC(function);
+		func->template[i] |= SYS_CFGCTRL_DEVICE(device);
+	}
+
+	vexpress_sysreg_regmap_config.max_register = num - 1;
+
+	func->regmap = regmap_init(dev, NULL, func,
+			&vexpress_sysreg_regmap_config);
+
+	if (IS_ERR(func->regmap))
+		kfree(func);
 	else
-		vexpress_master_site = VEXPRESS_SITE_DB1;
+		list_add(&func->list, &vexpress_sysreg_config_funcs);
 
-	vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
-			node, &vexpress_sysreg_config_bridge_info);
-	WARN_ON(!vexpress_sysreg_config_bridge);
+	return func->regmap;
+}
+
+static void vexpress_sysreg_config_regmap_exit(struct regmap *regmap,
+		void *context)
+{
+	struct vexpress_sysreg_config_func *func, *tmp;
+
+	regmap_exit(regmap);
+
+	list_for_each_entry_safe(func, tmp, &vexpress_sysreg_config_funcs,
+			list) {
+		if (func->regmap == regmap) {
+			list_del(&vexpress_sysreg_config_funcs);
+			kfree(func);
+			break;
+		}
+	}
+}
+
+static struct vexpress_config_bridge_ops vexpress_sysreg_config_bridge_ops = {
+	.regmap_init = vexpress_sysreg_config_regmap_init,
+	.regmap_exit = vexpress_sysreg_config_regmap_exit,
+};
+
+int vexpress_sysreg_config_device_register(struct platform_device *pdev)
+{
+	pdev->dev.parent = vexpress_sysreg_config_bridge;
+
+	return platform_device_register(pdev);
 }
 
+
 void __init vexpress_sysreg_early_init(void __iomem *base)
 {
 	vexpress_sysreg_base = base;
-	vexpress_sysreg_setup(NULL);
+	vexpress_config_set_master(vexpress_sysreg_get_master());
 }
 
 void __init vexpress_sysreg_of_early_init(void)
@@ -344,10 +358,14 @@ void __init vexpress_sysreg_of_early_init(void)
 		return;
 
 	node = of_find_compatible_node(NULL, NULL, "arm,vexpress-sysreg");
-	if (node) {
-		vexpress_sysreg_base = of_iomap(node, 0);
-		vexpress_sysreg_setup(node);
-	}
+	if (WARN_ON(!node))
+		return;
+
+	vexpress_sysreg_base = of_iomap(node, 0);
+	if (WARN_ON(!vexpress_sysreg_base))
+		return;
+
+	vexpress_config_set_master(vexpress_sysreg_get_master());
 }
 
 
@@ -470,28 +488,22 @@ static int vexpress_sysreg_probe(struct platform_device *pdev)
 		return -EBUSY;
 	}
 
-	if (!vexpress_sysreg_base) {
+	if (!vexpress_sysreg_base)
 		vexpress_sysreg_base = devm_ioremap(&pdev->dev, res->start,
 				resource_size(res));
-		vexpress_sysreg_setup(pdev->dev.of_node);
-	}
 
 	if (!vexpress_sysreg_base) {
 		dev_err(&pdev->dev, "Failed to obtain base address!\n");
 		return -EFAULT;
 	}
 
-	setup_timer(&vexpress_sysreg_config_timer,
-			vexpress_sysreg_config_complete, 0);
-
+	vexpress_config_set_master(vexpress_sysreg_get_master());
 	vexpress_sysreg_dev = &pdev->dev;
 
 #ifdef CONFIG_GPIOLIB
 	vexpress_sysreg_gpio_chip.dev = &pdev->dev;
 	err = gpiochip_add(&vexpress_sysreg_gpio_chip);
 	if (err) {
-		vexpress_config_bridge_unregister(
-				vexpress_sysreg_config_bridge);
 		dev_err(&pdev->dev, "Failed to register GPIO chip! (%d)\n",
 				err);
 		return err;
@@ -502,6 +514,10 @@ static int vexpress_sysreg_probe(struct platform_device *pdev)
 			sizeof(vexpress_sysreg_leds_pdata));
 #endif
 
+	vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
+			&pdev->dev, &vexpress_sysreg_config_bridge_ops, NULL);
+	WARN_ON(!vexpress_sysreg_config_bridge);
+
 	device_create_file(vexpress_sysreg_dev, &dev_attr_sys_id);
 
 	return 0;
@@ -522,7 +538,12 @@ static struct platform_driver vexpress_sysreg_driver = {
 
 static int __init vexpress_sysreg_init(void)
 {
-	vexpress_sysreg_of_early_init();
+	struct device_node *node;
+
+	/* Need the sysreg early, before any other device... */
+	for_each_matching_node(node, vexpress_sysreg_match)
+		of_platform_device_create(node, NULL, NULL);
+
 	return platform_driver_register(&vexpress_sysreg_driver);
 }
 core_initcall(vexpress_sysreg_init);
diff --git a/drivers/power/reset/vexpress-poweroff.c b/drivers/power/reset/vexpress-poweroff.c
index b95cf71..4dc102e2 100644
--- a/drivers/power/reset/vexpress-poweroff.c
+++ b/drivers/power/reset/vexpress-poweroff.c
@@ -23,10 +23,10 @@
 static void vexpress_reset_do(struct device *dev, const char *what)
 {
 	int err = -ENOENT;
-	struct vexpress_config_func *func = dev_get_drvdata(dev);
+	struct regmap *reg = dev_get_drvdata(dev);
 
-	if (func) {
-		err = vexpress_config_write(func, 0, 0);
+	if (reg) {
+		err = regmap_write(reg, 0, 0);
 		if (!err)
 			mdelay(1000);
 	}
@@ -91,17 +91,17 @@ static int vexpress_reset_probe(struct platform_device *pdev)
 	enum vexpress_reset_func func;
 	const struct of_device_id *match =
 			of_match_device(vexpress_reset_of_match, &pdev->dev);
-	struct vexpress_config_func *config_func;
+	struct regmap *regmap;
 
 	if (match)
 		func = (enum vexpress_reset_func)match->data;
 	else
 		func = pdev->id_entry->driver_data;
 
-	config_func = vexpress_config_func_get_by_dev(&pdev->dev);
-	if (!config_func)
-		return -EINVAL;
-	dev_set_drvdata(&pdev->dev, config_func);
+	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+	dev_set_drvdata(&pdev->dev, regmap);
 
 	switch (func) {
 	case FUNC_SHUTDOWN:
diff --git a/drivers/regulator/vexpress.c b/drivers/regulator/vexpress.c
index f3ae28a..2863428 100644
--- a/drivers/regulator/vexpress.c
+++ b/drivers/regulator/vexpress.c
@@ -26,14 +26,14 @@
 struct vexpress_regulator {
 	struct regulator_desc desc;
 	struct regulator_dev *regdev;
-	struct vexpress_config_func *func;
+	struct regmap *regmap;
 };
 
 static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
 {
 	struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
 	u32 uV;
-	int err = vexpress_config_read(reg->func, 0, &uV);
+	int err = regmap_read(reg->regmap, 0, &uV);
 
 	return err ? err : uV;
 }
@@ -43,7 +43,7 @@ static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
 {
 	struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
 
-	return vexpress_config_write(reg->func, 0, min_uV);
+	return regmap_write(reg->regmap, 0, min_uV);
 }
 
 static struct regulator_ops vexpress_regulator_ops_ro = {
@@ -57,22 +57,17 @@ static struct regulator_ops vexpress_regulator_ops = {
 
 static int vexpress_regulator_probe(struct platform_device *pdev)
 {
-	int err;
 	struct vexpress_regulator *reg;
 	struct regulator_init_data *init_data;
 	struct regulator_config config = { };
 
 	reg = devm_kzalloc(&pdev->dev, sizeof(*reg), GFP_KERNEL);
-	if (!reg) {
-		err = -ENOMEM;
-		goto error_kzalloc;
-	}
+	if (!reg)
+		return -ENOMEM;
 
-	reg->func = vexpress_config_func_get_by_dev(&pdev->dev);
-	if (!reg->func) {
-		err = -ENXIO;
-		goto error_get_func;
-	}
+	reg->regmap = devm_regmap_init_vexpress_config(&pdev->dev);
+	if (IS_ERR(reg->regmap))
+		return PTR_ERR(reg->regmap);
 
 	reg->desc.name = dev_name(&pdev->dev);
 	reg->desc.type = REGULATOR_VOLTAGE;
@@ -80,10 +75,8 @@ static int vexpress_regulator_probe(struct platform_device *pdev)
 	reg->desc.continuous_voltage_range = true;
 
 	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node);
-	if (!init_data) {
-		err = -EINVAL;
-		goto error_get_regulator_init_data;
-	}
+	if (!init_data)
+		return -EINVAL;
 
 	init_data->constraints.apply_uV = 0;
 	if (init_data->constraints.min_uV && init_data->constraints.max_uV)
@@ -97,30 +90,12 @@ static int vexpress_regulator_probe(struct platform_device *pdev)
 	config.of_node = pdev->dev.of_node;
 
 	reg->regdev = devm_regulator_register(&pdev->dev, &reg->desc, &config);
-	if (IS_ERR(reg->regdev)) {
-		err = PTR_ERR(reg->regdev);
-		goto error_regulator_register;
-	}
+	if (IS_ERR(reg->regdev))
+		return PTR_ERR(reg->regdev);
 
 	platform_set_drvdata(pdev, reg);
 
 	return 0;
-
-error_regulator_register:
-error_get_regulator_init_data:
-	vexpress_config_func_put(reg->func);
-error_get_func:
-error_kzalloc:
-	return err;
-}
-
-static int vexpress_regulator_remove(struct platform_device *pdev)
-{
-	struct vexpress_regulator *reg = platform_get_drvdata(pdev);
-
-	vexpress_config_func_put(reg->func);
-
-	return 0;
 }
 
 static struct of_device_id vexpress_regulator_of_match[] = {
@@ -130,7 +105,6 @@ static struct of_device_id vexpress_regulator_of_match[] = {
 
 static struct platform_driver vexpress_regulator_driver = {
 	.probe = vexpress_regulator_probe,
-	.remove = vexpress_regulator_remove,
 	.driver	= {
 		.name = DRVNAME,
 		.owner = THIS_MODULE,