i2c: rename core source file to allow refactorization

The I2C core became quite huge and its monolithic structure makes
maintenance hard. So, prepare to break out some functionality into
separate files by renaming the source file. Note that we keep the
resulting object name constant to avoid regressions.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 3831 insertions, 0 deletions

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
new file mode 100644
index 000000000000..82576aaccc90
--- /dev/null
+++ b/drivers/i2c/i2c-core-base.c
@@ -0,0 +1,3831 @@
+/* i2c-core.c - a device driver for the iic-bus interface		     */
+/* ------------------------------------------------------------------------- */
+/*   Copyright (C) 1995-99 Simon G. Vogl
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    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.			     */
+/* ------------------------------------------------------------------------- */
+
+/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
+   All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
+   SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
+   Jean Delvare <jdelvare@suse.de>
+   Mux support by Rodolfo Giometti <giometti@enneenne.com> and
+   Michael Lawnick <michael.lawnick.ext@nsn.com>
+   OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
+   (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and
+   (c) 2013  Wolfram Sang <wsa@the-dreams.de>
+   I2C ACPI code Copyright (C) 2014 Intel Corp
+   Author: Lan Tianyu <tianyu.lan@intel.com>
+   I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
+ */
+
+#define pr_fmt(fmt) "i2c-core: " fmt
+
+#include <dt-bindings/i2c/i2c.h>
+#include <linux/uaccess.h>
+#include <linux/acpi.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/hardirq.h>
+#include <linux/i2c.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/irqflags.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/property.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+
+#include "i2c-core.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/i2c.h>
+
+#define I2C_ADDR_OFFSET_TEN_BIT	0xa000
+#define I2C_ADDR_OFFSET_SLAVE	0x1000
+
+#define I2C_ADDR_7BITS_MAX	0x77
+#define I2C_ADDR_7BITS_COUNT	(I2C_ADDR_7BITS_MAX + 1)
+
+/* core_lock protects i2c_adapter_idr, and guarantees
+   that device detection, deletion of detected devices, and attach_adapter
+   calls are serialized */
+static DEFINE_MUTEX(core_lock);
+static DEFINE_IDR(i2c_adapter_idr);
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
+
+static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
+static bool is_registered;
+
+int i2c_transfer_trace_reg(void)
+{
+	static_key_slow_inc(&i2c_trace_msg);
+	return 0;
+}
+
+void i2c_transfer_trace_unreg(void)
+{
+	static_key_slow_dec(&i2c_trace_msg);
+}
+
+#if defined(CONFIG_ACPI)
+struct i2c_acpi_handler_data {
+	struct acpi_connection_info info;
+	struct i2c_adapter *adapter;
+};
+
+struct gsb_buffer {
+	u8	status;
+	u8	len;
+	union {
+		u16	wdata;
+		u8	bdata;
+		u8	data[0];
+	};
+} __packed;
+
+struct i2c_acpi_lookup {
+	struct i2c_board_info *info;
+	acpi_handle adapter_handle;
+	acpi_handle device_handle;
+	acpi_handle search_handle;
+	int n;
+	int index;
+	u32 speed;
+	u32 min_speed;
+};
+
+static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
+{
+	struct i2c_acpi_lookup *lookup = data;
+	struct i2c_board_info *info = lookup->info;
+	struct acpi_resource_i2c_serialbus *sb;
+	acpi_status status;
+
+	if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+		return 1;
+
+	sb = &ares->data.i2c_serial_bus;
+	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+		return 1;
+
+	if (lookup->index != -1 && lookup->n++ != lookup->index)
+		return 1;
+
+	status = acpi_get_handle(lookup->device_handle,
+				 sb->resource_source.string_ptr,
+				 &lookup->adapter_handle);
+	if (!ACPI_SUCCESS(status))
+		return 1;
+
+	info->addr = sb->slave_address;
+	lookup->speed = sb->connection_speed;
+	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+		info->flags |= I2C_CLIENT_TEN;
+
+	return 1;
+}
+
+static int i2c_acpi_do_lookup(struct acpi_device *adev,
+			      struct i2c_acpi_lookup *lookup)
+{
+	struct i2c_board_info *info = lookup->info;
+	struct list_head resource_list;
+	int ret;
+
+	if (acpi_bus_get_status(adev) || !adev->status.present ||
+	    acpi_device_enumerated(adev))
+		return -EINVAL;
+
+	memset(info, 0, sizeof(*info));
+	lookup->device_handle = acpi_device_handle(adev);
+
+	/* Look up for I2cSerialBus resource */
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     i2c_acpi_fill_info, lookup);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (ret < 0 || !info->addr)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int i2c_acpi_get_info(struct acpi_device *adev,
+			     struct i2c_board_info *info,
+			     struct i2c_adapter *adapter,
+			     acpi_handle *adapter_handle)
+{
+	struct list_head resource_list;
+	struct resource_entry *entry;
+	struct i2c_acpi_lookup lookup;
+	int ret;
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.info = info;
+	lookup.index = -1;
+
+	ret = i2c_acpi_do_lookup(adev, &lookup);
+	if (ret)
+		return ret;
+
+	if (adapter) {
+		/* The adapter must match the one in I2cSerialBus() connector */
+		if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
+			return -ENODEV;
+	} else {
+		struct acpi_device *adapter_adev;
+
+		/* The adapter must be present */
+		if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
+			return -ENODEV;
+		if (acpi_bus_get_status(adapter_adev) ||
+		    !adapter_adev->status.present)
+			return -ENODEV;
+	}
+
+	info->fwnode = acpi_fwnode_handle(adev);
+	if (adapter_handle)
+		*adapter_handle = lookup.adapter_handle;
+
+	/* Then fill IRQ number if any */
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+	if (ret < 0)
+		return -EINVAL;
+
+	resource_list_for_each_entry(entry, &resource_list) {
+		if (resource_type(entry->res) == IORESOURCE_IRQ) {
+			info->irq = entry->res->start;
+			break;
+		}
+	}
+
+	acpi_dev_free_resource_list(&resource_list);
+
+	acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
+			  sizeof(info->type));
+
+	return 0;
+}
+
+static void i2c_acpi_register_device(struct i2c_adapter *adapter,
+				     struct acpi_device *adev,
+				     struct i2c_board_info *info)
+{
+	adev->power.flags.ignore_parent = true;
+	acpi_device_set_enumerated(adev);
+
+	if (!i2c_new_device(adapter, info)) {
+		adev->power.flags.ignore_parent = false;
+		dev_err(&adapter->dev,
+			"failed to add I2C device %s from ACPI\n",
+			dev_name(&adev->dev));
+	}
+}
+
+static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
+				       void *data, void **return_value)
+{
+	struct i2c_adapter *adapter = data;
+	struct acpi_device *adev;
+	struct i2c_board_info info;
+
+	if (acpi_bus_get_device(handle, &adev))
+		return AE_OK;
+
+	if (i2c_acpi_get_info(adev, &info, adapter, NULL))
+		return AE_OK;
+
+	i2c_acpi_register_device(adapter, adev, &info);
+
+	return AE_OK;
+}
+
+#define I2C_ACPI_MAX_SCAN_DEPTH 32
+
+/**
+ * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
+ * @adap: pointer to adapter
+ *
+ * Enumerate all I2C slave devices behind this adapter by walking the ACPI
+ * namespace. When a device is found it will be added to the Linux device
+ * model and bound to the corresponding ACPI handle.
+ */
+static void i2c_acpi_register_devices(struct i2c_adapter *adap)
+{
+	acpi_status status;
+
+	if (!has_acpi_companion(&adap->dev))
+		return;
+
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+				     I2C_ACPI_MAX_SCAN_DEPTH,
+				     i2c_acpi_add_device, NULL,
+				     adap, NULL);
+	if (ACPI_FAILURE(status))
+		dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
+}
+
+static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
+					   void *data, void **return_value)
+{
+	struct i2c_acpi_lookup *lookup = data;
+	struct acpi_device *adev;
+
+	if (acpi_bus_get_device(handle, &adev))
+		return AE_OK;
+
+	if (i2c_acpi_do_lookup(adev, lookup))
+		return AE_OK;
+
+	if (lookup->search_handle != lookup->adapter_handle)
+		return AE_OK;
+
+	if (lookup->speed <= lookup->min_speed)
+		lookup->min_speed = lookup->speed;
+
+	return AE_OK;
+}
+
+/**
+ * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
+ * @dev: The device owning the bus
+ *
+ * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
+ * devices connected to this bus and use the speed of slowest device.
+ *
+ * Returns the speed in Hz or zero
+ */
+u32 i2c_acpi_find_bus_speed(struct device *dev)
+{
+	struct i2c_acpi_lookup lookup;
+	struct i2c_board_info dummy;
+	acpi_status status;
+
+	if (!has_acpi_companion(dev))
+		return 0;
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.search_handle = ACPI_HANDLE(dev);
+	lookup.min_speed = UINT_MAX;
+	lookup.info = &dummy;
+	lookup.index = -1;
+
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+				     I2C_ACPI_MAX_SCAN_DEPTH,
+				     i2c_acpi_lookup_speed, NULL,
+				     &lookup, NULL);
+
+	if (ACPI_FAILURE(status)) {
+		dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
+		return 0;
+	}
+
+	return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
+
+static int i2c_acpi_match_adapter(struct device *dev, void *data)
+{
+	struct i2c_adapter *adapter = i2c_verify_adapter(dev);
+
+	if (!adapter)
+		return 0;
+
+	return ACPI_HANDLE(dev) == (acpi_handle)data;
+}
+
+static int i2c_acpi_match_device(struct device *dev, void *data)
+{
+	return ACPI_COMPANION(dev) == data;
+}
+
+static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+{
+	struct device *dev;
+
+	dev = bus_find_device(&i2c_bus_type, NULL, handle,
+			      i2c_acpi_match_adapter);
+	return dev ? i2c_verify_adapter(dev) : NULL;
+}
+
+static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
+{
+	struct device *dev;
+
+	dev = bus_find_device(&i2c_bus_type, NULL, adev, i2c_acpi_match_device);
+	return dev ? i2c_verify_client(dev) : NULL;
+}
+
+static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
+			   void *arg)
+{
+	struct acpi_device *adev = arg;
+	struct i2c_board_info info;
+	acpi_handle adapter_handle;
+	struct i2c_adapter *adapter;
+	struct i2c_client *client;
+
+	switch (value) {
+	case ACPI_RECONFIG_DEVICE_ADD:
+		if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
+			break;
+
+		adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
+		if (!adapter)
+			break;
+
+		i2c_acpi_register_device(adapter, adev, &info);
+		break;
+	case ACPI_RECONFIG_DEVICE_REMOVE:
+		if (!acpi_device_enumerated(adev))
+			break;
+
+		client = i2c_acpi_find_client_by_adev(adev);
+		if (!client)
+			break;
+
+		i2c_unregister_device(client);
+		put_device(&client->dev);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block i2c_acpi_notifier = {
+	.notifier_call = i2c_acpi_notify,
+};
+
+/**
+ * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
+ * @dev:     Device owning the ACPI resources to get the client from
+ * @index:   Index of ACPI resource to get
+ * @info:    describes the I2C device; note this is modified (addr gets set)
+ * Context: can sleep
+ *
+ * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
+ * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
+ * resources, in that case this function can be used to create an i2c-client
+ * for other I2cSerialBus resources in the Current Resource Settings table.
+ *
+ * Also see i2c_new_device, which this function calls to create the i2c-client.
+ *
+ * Returns a pointer to the new i2c-client, or NULL if the adapter is not found.
+ */
+struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
+				       struct i2c_board_info *info)
+{
+	struct i2c_acpi_lookup lookup;
+	struct i2c_adapter *adapter;
+	struct acpi_device *adev;
+	LIST_HEAD(resource_list);
+	int ret;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return NULL;
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.info = info;
+	lookup.device_handle = acpi_device_handle(adev);
+	lookup.index = index;
+
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     i2c_acpi_fill_info, &lookup);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (ret < 0 || !info->addr)
+		return NULL;
+
+	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
+	if (!adapter)
+		return NULL;
+
+	return i2c_new_device(adapter, info);
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
+#else /* CONFIG_ACPI */
+static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
+extern struct notifier_block i2c_acpi_notifier;
+#endif /* CONFIG_ACPI */
+
+#ifdef CONFIG_ACPI_I2C_OPREGION
+static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
+		u8 cmd, u8 *data, u8 data_len)
+{
+
+	struct i2c_msg msgs[2];
+	int ret;
+	u8 *buffer;
+
+	buffer = kzalloc(data_len, GFP_KERNEL);
+	if (!buffer)
+		return AE_NO_MEMORY;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = client->flags;
+	msgs[0].len = 1;
+	msgs[0].buf = &cmd;
+
+	msgs[1].addr = client->addr;
+	msgs[1].flags = client->flags | I2C_M_RD;
+	msgs[1].len = data_len;
+	msgs[1].buf = buffer;
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret < 0)
+		dev_err(&client->adapter->dev, "i2c read failed\n");
+	else
+		memcpy(data, buffer, data_len);
+
+	kfree(buffer);
+	return ret;
+}
+
+static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
+		u8 cmd, u8 *data, u8 data_len)
+{
+
+	struct i2c_msg msgs[1];
+	u8 *buffer;
+	int ret = AE_OK;
+
+	buffer = kzalloc(data_len + 1, GFP_KERNEL);
+	if (!buffer)
+		return AE_NO_MEMORY;
+
+	buffer[0] = cmd;
+	memcpy(buffer + 1, data, data_len);
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = client->flags;
+	msgs[0].len = data_len + 1;
+	msgs[0].buf = buffer;
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret < 0)
+		dev_err(&client->adapter->dev, "i2c write failed\n");
+
+	kfree(buffer);
+	return ret;
+}
+
+static acpi_status
+i2c_acpi_space_handler(u32 function, acpi_physical_address command,
+			u32 bits, u64 *value64,
+			void *handler_context, void *region_context)
+{
+	struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
+	struct i2c_acpi_handler_data *data = handler_context;
+	struct acpi_connection_info *info = &data->info;
+	struct acpi_resource_i2c_serialbus *sb;
+	struct i2c_adapter *adapter = data->adapter;
+	struct i2c_client *client;
+	struct acpi_resource *ares;
+	u32 accessor_type = function >> 16;
+	u8 action = function & ACPI_IO_MASK;
+	acpi_status ret;
+	int status;
+
+	ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
+	if (ACPI_FAILURE(ret))
+		return ret;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client) {
+		ret = AE_NO_MEMORY;
+		goto err;
+	}
+
+	if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
+		ret = AE_BAD_PARAMETER;
+		goto err;
+	}
+
+	sb = &ares->data.i2c_serial_bus;
+	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
+		ret = AE_BAD_PARAMETER;
+		goto err;
+	}
+
+	client->adapter = adapter;
+	client->addr = sb->slave_address;
+
+	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+		client->flags |= I2C_CLIENT_TEN;
+
+	switch (accessor_type) {
+	case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
+		if (action == ACPI_READ) {
+			status = i2c_smbus_read_byte(client);
+			if (status >= 0) {
+				gsb->bdata = status;
+				status = 0;
+			}
+		} else {
+			status = i2c_smbus_write_byte(client, gsb->bdata);
+		}
+		break;
+
+	case ACPI_GSB_ACCESS_ATTRIB_BYTE:
+		if (action == ACPI_READ) {
+			status = i2c_smbus_read_byte_data(client, command);
+			if (status >= 0) {
+				gsb->bdata = status;
+				status = 0;
+			}
+		} else {
+			status = i2c_smbus_write_byte_data(client, command,
+					gsb->bdata);
+		}
+		break;
+
+	case ACPI_GSB_ACCESS_ATTRIB_WORD:
+		if (action == ACPI_READ) {
+			status = i2c_smbus_read_word_data(client, command);
+			if (status >= 0) {
+				gsb->wdata = status;
+				status = 0;
+			}
+		} else {
+			status = i2c_smbus_write_word_data(client, command,
+					gsb->wdata);
+		}
+		break;
+
+	case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
+		if (action == ACPI_READ) {
+			status = i2c_smbus_read_block_data(client, command,
+					gsb->data);
+			if (status >= 0) {
+				gsb->len = status;
+				status = 0;
+			}
+		} else {
+			status = i2c_smbus_write_block_data(client, command,
+					gsb->len, gsb->data);
+		}
+		break;
+
+	case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
+		if (action == ACPI_READ) {
+			status = acpi_gsb_i2c_read_bytes(client, command,
+					gsb->data, info->access_length);
+			if (status > 0)
+				status = 0;
+		} else {
+			status = acpi_gsb_i2c_write_bytes(client, command,
+					gsb->data, info->access_length);
+		}
+		break;
+
+	default:
+		dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
+			 accessor_type, client->addr);
+		ret = AE_BAD_PARAMETER;
+		goto err;
+	}
+
+	gsb->status = status;
+
+ err:
+	kfree(client);
+	ACPI_FREE(ares);
+	return ret;
+}
+
+
+static int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
+{
+	acpi_handle handle;
+	struct i2c_acpi_handler_data *data;
+	acpi_status status;
+
+	if (!adapter->dev.parent)
+		return -ENODEV;
+
+	handle = ACPI_HANDLE(adapter->dev.parent);
+
+	if (!handle)
+		return -ENODEV;
+
+	data = kzalloc(sizeof(struct i2c_acpi_handler_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->adapter = adapter;
+	status = acpi_bus_attach_private_data(handle, (void *)data);
+	if (ACPI_FAILURE(status)) {
+		kfree(data);
+		return -ENOMEM;
+	}
+
+	status = acpi_install_address_space_handler(handle,
+				ACPI_ADR_SPACE_GSBUS,
+				&i2c_acpi_space_handler,
+				NULL,
+				data);
+	if (ACPI_FAILURE(status)) {
+		dev_err(&adapter->dev, "Error installing i2c space handler\n");
+		acpi_bus_detach_private_data(handle);
+		kfree(data);
+		return -ENOMEM;
+	}
+
+	acpi_walk_dep_device_list(handle);
+	return 0;
+}
+
+static void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
+{
+	acpi_handle handle;
+	struct i2c_acpi_handler_data *data;
+	acpi_status status;
+
+	if (!adapter->dev.parent)
+		return;
+
+	handle = ACPI_HANDLE(adapter->dev.parent);
+
+	if (!handle)
+		return;
+
+	acpi_remove_address_space_handler(handle,
+				ACPI_ADR_SPACE_GSBUS,
+				&i2c_acpi_space_handler);
+
+	status = acpi_bus_get_private_data(handle, (void **)&data);
+	if (ACPI_SUCCESS(status))
+		kfree(data);
+
+	acpi_bus_detach_private_data(handle);
+}
+#else /* CONFIG_ACPI_I2C_OPREGION */
+static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
+{ }
+
+static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
+{ return 0; }
+#endif /* CONFIG_ACPI_I2C_OPREGION */
+
+/* ------------------------------------------------------------------------- */
+
+const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+						const struct i2c_client *client)
+{
+	if (!(id && client))
+		return NULL;
+
+	while (id->name[0]) {
+		if (strcmp(client->name, id->name) == 0)
+			return id;
+		id++;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(i2c_match_id);
+
+static int i2c_device_match(struct device *dev, struct device_driver *drv)
+{
+	struct i2c_client	*client = i2c_verify_client(dev);
+	struct i2c_driver	*driver;
+
+
+	/* Attempt an OF style match */
+	if (i2c_of_match_device(drv->of_match_table, client))
+		return 1;
+
+	/* Then ACPI style match */
+	if (acpi_driver_match_device(dev, drv))
+		return 1;
+
+	driver = to_i2c_driver(drv);
+
+	/* Finally an I2C match */
+	if (i2c_match_id(driver->id_table, client))
+		return 1;
+
+	return 0;
+}
+
+static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int rc;
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
+
+	return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
+}
+
+/* i2c bus recovery routines */
+static int get_scl_gpio_value(struct i2c_adapter *adap)
+{
+	return gpio_get_value(adap->bus_recovery_info->scl_gpio);
+}
+
+static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
+{
+	gpio_set_value(adap->bus_recovery_info->scl_gpio, val);
+}
+
+static int get_sda_gpio_value(struct i2c_adapter *adap)
+{
+	return gpio_get_value(adap->bus_recovery_info->sda_gpio);
+}
+
+static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+	struct device *dev = &adap->dev;
+	int ret = 0;
+
+	ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN |
+			GPIOF_OUT_INIT_HIGH, "i2c-scl");
+	if (ret) {
+		dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
+		return ret;
+	}
+
+	if (bri->get_sda) {
+		if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
+			/* work without SDA polling */
+			dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
+					bri->sda_gpio);
+			bri->get_sda = NULL;
+		}
+	}
+
+	return ret;
+}
+
+static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+
+	if (bri->get_sda)
+		gpio_free(bri->sda_gpio);
+
+	gpio_free(bri->scl_gpio);
+}
+
+/*
+ * We are generating clock pulses. ndelay() determines durating of clk pulses.
+ * We will generate clock with rate 100 KHz and so duration of both clock levels
+ * is: delay in ns = (10^6 / 100) / 2
+ */
+#define RECOVERY_NDELAY		5000
+#define RECOVERY_CLK_CNT	9
+
+static int i2c_generic_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+	int i = 0, val = 1, ret = 0;
+
+	if (bri->prepare_recovery)
+		bri->prepare_recovery(adap);
+
+	bri->set_scl(adap, val);
+	ndelay(RECOVERY_NDELAY);
+
+	/*
+	 * By this time SCL is high, as we need to give 9 falling-rising edges
+	 */
+	while (i++ < RECOVERY_CLK_CNT * 2) {
+		if (val) {
+			/* Break if SDA is high */
+			if (bri->get_sda && bri->get_sda(adap))
+					break;
+			/* SCL shouldn't be low here */
+			if (!bri->get_scl(adap)) {
+				dev_err(&adap->dev,
+					"SCL is stuck low, exit recovery\n");
+				ret = -EBUSY;
+				break;
+			}
+		}
+
+		val = !val;
+		bri->set_scl(adap, val);
+		ndelay(RECOVERY_NDELAY);
+	}
+
+	if (bri->unprepare_recovery)
+		bri->unprepare_recovery(adap);
+
+	return ret;
+}
+
+int i2c_generic_scl_recovery(struct i2c_adapter *adap)
+{
+	return i2c_generic_recovery(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
+
+int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
+{
+	int ret;
+
+	ret = i2c_get_gpios_for_recovery(adap);
+	if (ret)
+		return ret;
+
+	ret = i2c_generic_recovery(adap);
+	i2c_put_gpios_for_recovery(adap);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);
+
+int i2c_recover_bus(struct i2c_adapter *adap)
+{
+	if (!adap->bus_recovery_info)
+		return -EOPNOTSUPP;
+
+	dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
+	return adap->bus_recovery_info->recover_bus(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_recover_bus);
+
+static void i2c_init_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+	char *err_str;
+
+	if (!bri)
+		return;
+
+	if (!bri->recover_bus) {
+		err_str = "no recover_bus() found";
+		goto err;
+	}
+
+	/* Generic GPIO recovery */
+	if (bri->recover_bus == i2c_generic_gpio_recovery) {
+		if (!gpio_is_valid(bri->scl_gpio)) {
+			err_str = "invalid SCL gpio";
+			goto err;
+		}
+
+		if (gpio_is_valid(bri->sda_gpio))
+			bri->get_sda = get_sda_gpio_value;
+		else
+			bri->get_sda = NULL;
+
+		bri->get_scl = get_scl_gpio_value;
+		bri->set_scl = set_scl_gpio_value;
+	} else if (bri->recover_bus == i2c_generic_scl_recovery) {
+		/* Generic SCL recovery */
+		if (!bri->set_scl || !bri->get_scl) {
+			err_str = "no {get|set}_scl() found";
+			goto err;
+		}
+	}
+
+	return;
+ err:
+	dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
+	adap->bus_recovery_info = NULL;
+}
+
+static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
+{
+	struct i2c_adapter *adap = client->adapter;
+	unsigned int irq;
+
+	if (!adap->host_notify_domain)
+		return -ENXIO;
+
+	if (client->flags & I2C_CLIENT_TEN)
+		return -EINVAL;
+
+	irq = irq_find_mapping(adap->host_notify_domain, client->addr);
+	if (!irq)
+		irq = irq_create_mapping(adap->host_notify_domain,
+					 client->addr);
+
+	return irq > 0 ? irq : -ENXIO;
+}
+
+static int i2c_device_probe(struct device *dev)
+{
+	struct i2c_client	*client = i2c_verify_client(dev);
+	struct i2c_driver	*driver;
+	int status;
+
+	if (!client)
+		return 0;
+
+	driver = to_i2c_driver(dev->driver);
+
+	if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
+		int irq = -ENOENT;
+
+		if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
+			dev_dbg(dev, "Using Host Notify IRQ\n");
+			irq = i2c_smbus_host_notify_to_irq(client);
+		} else if (dev->of_node) {
+			irq = of_irq_get_byname(dev->of_node, "irq");
+			if (irq == -EINVAL || irq == -ENODATA)
+				irq = of_irq_get(dev->of_node, 0);
+		} else if (ACPI_COMPANION(dev)) {
+			irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
+		}
+		if (irq == -EPROBE_DEFER)
+			return irq;
+
+		if (irq < 0)
+			irq = 0;
+
+		client->irq = irq;
+	}
+
+	/*
+	 * An I2C ID table is not mandatory, if and only if, a suitable Device
+	 * Tree match table entry is supplied for the probing device.
+	 */
+	if (!driver->id_table &&
+	    !i2c_of_match_device(dev->driver->of_match_table, client))
+		return -ENODEV;
+
+	if (client->flags & I2C_CLIENT_WAKE) {
+		int wakeirq = -ENOENT;
+
+		if (dev->of_node) {
+			wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
+			if (wakeirq == -EPROBE_DEFER)
+				return wakeirq;
+		}
+
+		device_init_wakeup(&client->dev, true);
+
+		if (wakeirq > 0 && wakeirq != client->irq)
+			status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
+		else if (client->irq > 0)
+			status = dev_pm_set_wake_irq(dev, client->irq);
+		else
+			status = 0;
+
+		if (status)
+			dev_warn(&client->dev, "failed to set up wakeup irq\n");
+	}
+
+	dev_dbg(dev, "probe\n");
+
+	status = of_clk_set_defaults(dev->of_node, false);
+	if (status < 0)
+		goto err_clear_wakeup_irq;
+
+	status = dev_pm_domain_attach(&client->dev, true);
+	if (status == -EPROBE_DEFER)
+		goto err_clear_wakeup_irq;
+
+	/*
+	 * When there are no more users of probe(),
+	 * rename probe_new to probe.
+	 */
+	if (driver->probe_new)
+		status = driver->probe_new(client);
+	else if (driver->probe)
+		status = driver->probe(client,
+				       i2c_match_id(driver->id_table, client));
+	else
+		status = -EINVAL;
+
+	if (status)
+		goto err_detach_pm_domain;
+
+	return 0;
+
+err_detach_pm_domain:
+	dev_pm_domain_detach(&client->dev, true);
+err_clear_wakeup_irq:
+	dev_pm_clear_wake_irq(&client->dev);
+	device_init_wakeup(&client->dev, false);
+	return status;
+}
+
+static int i2c_device_remove(struct device *dev)
+{
+	struct i2c_client	*client = i2c_verify_client(dev);
+	struct i2c_driver	*driver;
+	int status = 0;
+
+	if (!client || !dev->driver)
+		return 0;
+
+	driver = to_i2c_driver(dev->driver);
+	if (driver->remove) {
+		dev_dbg(dev, "remove\n");
+		status = driver->remove(client);
+	}
+
+	dev_pm_domain_detach(&client->dev, true);
+
+	dev_pm_clear_wake_irq(&client->dev);
+	device_init_wakeup(&client->dev, false);
+
+	return status;
+}
+
+static void i2c_device_shutdown(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	struct i2c_driver *driver;
+
+	if (!client || !dev->driver)
+		return;
+	driver = to_i2c_driver(dev->driver);
+	if (driver->shutdown)
+		driver->shutdown(client);
+}
+
+static void i2c_client_dev_release(struct device *dev)
+{
+	kfree(to_i2c_client(dev));
+}
+
+static ssize_t
+show_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
+		       to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
+}
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static ssize_t
+show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
+	if (len != -ENODEV)
+		return len;
+
+	return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
+}
+static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
+
+static struct attribute *i2c_dev_attrs[] = {
+	&dev_attr_name.attr,
+	/* modalias helps coldplug:  modprobe $(cat .../modalias) */
+	&dev_attr_modalias.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(i2c_dev);
+
+struct bus_type i2c_bus_type = {
+	.name		= "i2c",
+	.match		= i2c_device_match,
+	.probe		= i2c_device_probe,
+	.remove		= i2c_device_remove,
+	.shutdown	= i2c_device_shutdown,
+};
+EXPORT_SYMBOL_GPL(i2c_bus_type);
+
+struct device_type i2c_client_type = {
+	.groups		= i2c_dev_groups,
+	.uevent		= i2c_device_uevent,
+	.release	= i2c_client_dev_release,
+};
+EXPORT_SYMBOL_GPL(i2c_client_type);
+
+
+/**
+ * i2c_verify_client - return parameter as i2c_client, or NULL
+ * @dev: device, probably from some driver model iterator
+ *
+ * When traversing the driver model tree, perhaps using driver model
+ * iterators like @device_for_each_child(), you can't assume very much
+ * about the nodes you find.  Use this function to avoid oopses caused
+ * by wrongly treating some non-I2C device as an i2c_client.
+ */
+struct i2c_client *i2c_verify_client(struct device *dev)
+{
+	return (dev->type == &i2c_client_type)
+			? to_i2c_client(dev)
+			: NULL;
+}
+EXPORT_SYMBOL(i2c_verify_client);
+
+
+/* Return a unique address which takes the flags of the client into account */
+static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
+{
+	unsigned short addr = client->addr;
+
+	/* For some client flags, add an arbitrary offset to avoid collisions */
+	if (client->flags & I2C_CLIENT_TEN)
+		addr |= I2C_ADDR_OFFSET_TEN_BIT;
+
+	if (client->flags & I2C_CLIENT_SLAVE)
+		addr |= I2C_ADDR_OFFSET_SLAVE;
+
+	return addr;
+}
+
+/* This is a permissive address validity check, I2C addres