[linux-block.git] / drivers / i2c / i2c-core-acpi.c

/*
 * Linux I2C core ACPI support code
 *
 * Copyright (C) 2014 Intel Corp, Author: Lan Tianyu <tianyu.lan@intel.com>
 *
 * 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.
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "i2c-core.h"

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;
};

/**
 * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
 * @ares:	ACPI resource
 * @i2c:	Pointer to I2cSerialBus resource will be returned here
 *
 * Checks if the given ACPI resource is of type I2cSerialBus.
 * In this case, returns a pointer to it to the caller.
 *
 * Returns true if resource type is of I2cSerialBus, otherwise false.
 */
bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
			       struct acpi_resource_i2c_serialbus **i2c)
{
	struct acpi_resource_i2c_serialbus *sb;

	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
		return false;

	sb = &ares->data.i2c_serial_bus;
	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
		return false;

	*i2c = sb;
	return true;
}
EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);

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 || !i2c_acpi_get_i2c_resource(ares, &sb))
		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_FAILURE(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 const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
	/*
	 * ACPI video acpi_devices, which are handled by the acpi-video driver
	 * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
	 */
	{ ACPI_VIDEO_HID, 0 },
	{}
};

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;

	if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
		return -ENODEV;

	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.
 */
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");
}

const struct acpi_device_id *
i2c_acpi_match_device(const struct acpi_device_id *matches,
		      struct i2c_client *client)
{
	if (!(client && matches))
		return NULL;

	return acpi_match_device(matches, &client->dev);
}

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_find_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_find_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_find_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_find_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;
}

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 error pointer in case of failure.
 * Specifically, -EPROBE_DEFER is returned 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 i2c_client *client;
	struct acpi_device *adev;
	LIST_HEAD(resource_list);
	int ret;

	adev = ACPI_COMPANION(dev);
	if (!adev)
		return ERR_PTR(-EINVAL);

	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);
	if (ret < 0)
		return ERR_PTR(ret);

	acpi_dev_free_resource_list(&resource_list);

	if (!info->addr)
		return ERR_PTR(-EADDRNOTAVAIL);

	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
	if (!adapter)
		return ERR_PTR(-EPROBE_DEFER);

	client = i2c_new_device(adapter, info);
	if (!client)
		return ERR_PTR(-ENODEV);

	return client;
}
EXPORT_SYMBOL_GPL(i2c_acpi_new_device);

#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) {
		/* Getting a NACK is unfortunately normal with some DSTDs */
		if (ret == -EREMOTEIO)
			dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
				data_len, client->addr, cmd, ret);
		else
			dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
				data_len, client->addr, cmd, ret);
	/* 2 transfers must have completed successfully */
	} else if (ret == 2) {
		memcpy(data, buffer, data_len);
		ret = 0;
	} else {
		ret = -EIO;
	}

	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));

	kfree(buffer);

	if (ret < 0) {
		dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
		return ret;
	}

	/* 1 transfer must have completed successfully */
	return (ret == 1) ? 0 : -EIO;
}

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 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
		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);
		} 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;
}


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;
}

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);
}
#endif /* CONFIG_ACPI_I2C_OPREGION */
Commit	Line	Data
53f8f7c5 WS	1	/*
	2	* Linux I2C core ACPI support code
	3	*
	4	* Copyright (C) 2014 Intel Corp, Author: Lan Tianyu <tianyu.lan@intel.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*/
	11
	12	#include <linux/acpi.h>
	13	#include <linux/device.h>
	14	#include <linux/err.h>
	15	#include <linux/i2c.h>
	16	#include <linux/list.h>
	17	#include <linux/module.h>
	18	#include <linux/slab.h>
	19
	20	#include "i2c-core.h"
	21
	22	struct i2c_acpi_handler_data {
	23	struct acpi_connection_info info;
	24	struct i2c_adapter *adapter;
	25	};
	26
	27	struct gsb_buffer {
	28	u8 status;
	29	u8 len;
	30	union {
	31	u16 wdata;
	32	u8 bdata;
	33	u8 data[0];
	34	};
	35	} __packed;
	36
	37	struct i2c_acpi_lookup {
	38	struct i2c_board_info *info;
	39	acpi_handle adapter_handle;
	40	acpi_handle device_handle;
	41	acpi_handle search_handle;
	42	int n;
	43	int index;
	44	u32 speed;
	45	u32 min_speed;
	46	};
	47
0d5102fe AS	48	/**
	49	* i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
	50	* @ares: ACPI resource
	51	* @i2c: Pointer to I2cSerialBus resource will be returned here
	52	*
	53	* Checks if the given ACPI resource is of type I2cSerialBus.
	54	* In this case, returns a pointer to it to the caller.
	55	*
	56	* Returns true if resource type is of I2cSerialBus, otherwise false.
	57	*/
	58	bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
	59	struct acpi_resource_i2c_serialbus **i2c)
	60	{
	61	struct acpi_resource_i2c_serialbus *sb;
	62
	63	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
	64	return false;
	65
	66	sb = &ares->data.i2c_serial_bus;
	67	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
	68	return false;
	69
	70	*i2c = sb;
	71	return true;
	72	}
	73	EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
	74
53f8f7c5 WS	75	static int i2c_acpi_fill_info(struct acpi_resource ares, void data)
	76	{
	77	struct i2c_acpi_lookup *lookup = data;
	78	struct i2c_board_info *info = lookup->info;
	79	struct acpi_resource_i2c_serialbus *sb;
	80	acpi_status status;
	81
0d5102fe	82	if (info->addr \|\| !i2c_acpi_get_i2c_resource(ares, &sb))
53f8f7c5 WS	83	return 1;
	84
	85	if (lookup->index != -1 && lookup->n++ != lookup->index)
	86	return 1;
	87
	88	status = acpi_get_handle(lookup->device_handle,
	89	sb->resource_source.string_ptr,
	90	&lookup->adapter_handle);
5f59d6a1	91	if (ACPI_FAILURE(status))
53f8f7c5 WS	92	return 1;
	93
	94	info->addr = sb->slave_address;
	95	lookup->speed = sb->connection_speed;
	96	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
	97	info->flags \|= I2C_CLIENT_TEN;
	98
	99	return 1;
	100	}
	101
3a4991a9 HG	102	static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
	103	/*
	104	* ACPI video acpi_devices, which are handled by the acpi-video driver
	105	* sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
	106	*/
	107	{ ACPI_VIDEO_HID, 0 },
	108	{}
	109	};
	110
53f8f7c5 WS	111	static int i2c_acpi_do_lookup(struct acpi_device *adev,
	112	struct i2c_acpi_lookup *lookup)
	113	{
	114	struct i2c_board_info *info = lookup->info;
	115	struct list_head resource_list;
	116	int ret;
	117
	118	if (acpi_bus_get_status(adev) \|\| !adev->status.present \|\|
	119	acpi_device_enumerated(adev))
	120	return -EINVAL;
	121
3a4991a9 HG	122	if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
	123	return -ENODEV;
	124
53f8f7c5 WS	125	memset(info, 0, sizeof(*info));
	126	lookup->device_handle = acpi_device_handle(adev);
	127
	128	/* Look up for I2cSerialBus resource */
	129	INIT_LIST_HEAD(&resource_list);
	130	ret = acpi_dev_get_resources(adev, &resource_list,
	131	i2c_acpi_fill_info, lookup);
	132	acpi_dev_free_resource_list(&resource_list);
	133
	134	if (ret < 0 \|\| !info->addr)
	135	return -EINVAL;
	136
	137	return 0;
	138	}
	139
	140	static int i2c_acpi_get_info(struct acpi_device *adev,
	141	struct i2c_board_info *info,
	142	struct i2c_adapter *adapter,
	143	acpi_handle *adapter_handle)
	144	{
	145	struct list_head resource_list;
	146	struct resource_entry *entry;
	147	struct i2c_acpi_lookup lookup;
	148	int ret;
	149
	150	memset(&lookup, 0, sizeof(lookup));
	151	lookup.info = info;
	152	lookup.index = -1;
	153
	154	ret = i2c_acpi_do_lookup(adev, &lookup);
	155	if (ret)
	156	return ret;
	157
	158	if (adapter) {
	159	/* The adapter must match the one in I2cSerialBus() connector */
	160	if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
	161	return -ENODEV;
	162	} else {
	163	struct acpi_device *adapter_adev;
	164
	165	/* The adapter must be present */
	166	if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
	167	return -ENODEV;
	168	if (acpi_bus_get_status(adapter_adev) \|\|
	169	!adapter_adev->status.present)
	170	return -ENODEV;
	171	}
	172
	173	info->fwnode = acpi_fwnode_handle(adev);
	174	if (adapter_handle)
	175	*adapter_handle = lookup.adapter_handle;
	176
	177	/* Then fill IRQ number if any */
	178	INIT_LIST_HEAD(&resource_list);
	179	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
	180	if (ret < 0)
	181	return -EINVAL;
	182
	183	resource_list_for_each_entry(entry, &resource_list) {
	184	if (resource_type(entry->res) == IORESOURCE_IRQ) {
	185	info->irq = entry->res->start;
	186	break;
	187	}
	188	}
189
190	acpi_dev_free_resource_list(&resource_list);
191
192	acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
193	sizeof(info->type));
194
195	return 0;
196	}
197
198	static void i2c_acpi_register_device(struct i2c_adapter *adapter,
199	struct acpi_device *adev,
200	struct i2c_board_info *info)
201	{
202	adev->power.flags.ignore_parent = true;
203	acpi_device_set_enumerated(adev);
204
205	if (!i2c_new_device(adapter, info)) {
206	adev->power.flags.ignore_parent = false;
207	dev_err(&adapter->dev,
208	"failed to add I2C device %s from ACPI\n",
209	dev_name(&adev->dev));
210	}
211	}
212
213	static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
214	void data, void *return_value)
215	{
216	struct i2c_adapter *adapter = data;
217	struct acpi_device *adev;
218	struct i2c_board_info info;
219
220	if (acpi_bus_get_device(handle, &adev))
221	return AE_OK;
222
223	if (i2c_acpi_get_info(adev, &info, adapter, NULL))
224	return AE_OK;
225
226	i2c_acpi_register_device(adapter, adev, &info);
227
228	return AE_OK;
229	}
230
231	#define I2C_ACPI_MAX_SCAN_DEPTH 32
232
233	/**
234	* i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
235	* @adap: pointer to adapter
236	*
237	* Enumerate all I2C slave devices behind this adapter by walking the ACPI
238	* namespace. When a device is found it will be added to the Linux device
239	* model and bound to the corresponding ACPI handle.
240	*/
241	void i2c_acpi_register_devices(struct i2c_adapter *adap)
242	{
243	acpi_status status;
244
245	if (!has_acpi_companion(&adap->dev))
246	return;
247
248	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
249	I2C_ACPI_MAX_SCAN_DEPTH,
250	i2c_acpi_add_device, NULL,
251	adap, NULL);
252	if (ACPI_FAILURE(status))
253	dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
254	}
255
c64ffff7 AS	256	const struct acpi_device_id *
	257	i2c_acpi_match_device(const struct acpi_device_id *matches,
	258	struct i2c_client *client)
	259	{
	260	if (!(client && matches))
	261	return NULL;
	262
	263	return acpi_match_device(matches, &client->dev);
	264	}
	265
53f8f7c5 WS	266	static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
	267	void data, void *return_value)
	268	{
	269	struct i2c_acpi_lookup *lookup = data;
	270	struct acpi_device *adev;
	271
	272	if (acpi_bus_get_device(handle, &adev))
	273	return AE_OK;
	274
	275	if (i2c_acpi_do_lookup(adev, lookup))
	276	return AE_OK;
	277
	278	if (lookup->search_handle != lookup->adapter_handle)
	279	return AE_OK;
	280
	281	if (lookup->speed <= lookup->min_speed)
	282	lookup->min_speed = lookup->speed;
	283
	284	return AE_OK;
	285	}
	286
	287	/**
	288	* i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
	289	* @dev: The device owning the bus
	290	*
	291	* Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
	292	* devices connected to this bus and use the speed of slowest device.
	293	*
	294	* Returns the speed in Hz or zero
	295	*/
	296	u32 i2c_acpi_find_bus_speed(struct device *dev)
	297	{
	298	struct i2c_acpi_lookup lookup;
	299	struct i2c_board_info dummy;
	300	acpi_status status;
	301
	302	if (!has_acpi_companion(dev))
	303	return 0;
	304
	305	memset(&lookup, 0, sizeof(lookup));
	306	lookup.search_handle = ACPI_HANDLE(dev);
	307	lookup.min_speed = UINT_MAX;
	308	lookup.info = &dummy;
	309	lookup.index = -1;
	310
	311	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
	312	I2C_ACPI_MAX_SCAN_DEPTH,
	313	i2c_acpi_lookup_speed, NULL,
	314	&lookup, NULL);
	315
	316	if (ACPI_FAILURE(status)) {
	317	dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
	318	return 0;
	319	}
	320
	321	return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
	322	}
	323	EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
	324
c64ffff7	325	static int i2c_acpi_find_match_adapter(struct device dev, void data)
53f8f7c5 WS	326	{
	327	struct i2c_adapter *adapter = i2c_verify_adapter(dev);
	328
	329	if (!adapter)
	330	return 0;
	331
	332	return ACPI_HANDLE(dev) == (acpi_handle)data;
	333	}
	334
c64ffff7	335	static int i2c_acpi_find_match_device(struct device dev, void data)
53f8f7c5 WS	336	{
	337	return ACPI_COMPANION(dev) == data;
	338	}
	339
	340	static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
	341	{
	342	struct device *dev;
	343
	344	dev = bus_find_device(&i2c_bus_type, NULL, handle,
c64ffff7	345	i2c_acpi_find_match_adapter);
53f8f7c5 WS	346	return dev ? i2c_verify_adapter(dev) : NULL;
	347	}
	348
	349	static struct i2c_client i2c_acpi_find_client_by_adev(struct acpi_device adev)
	350	{
	351	struct device *dev;
	352
c64ffff7 AS	353	dev = bus_find_device(&i2c_bus_type, NULL, adev,
c64ffff7 AS	354	i2c_acpi_find_match_device);
53f8f7c5 WS	355	return dev ? i2c_verify_client(dev) : NULL;
	356	}
	357
	358	static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
	359	void *arg)
	360	{
	361	struct acpi_device *adev = arg;
	362	struct i2c_board_info info;
	363	acpi_handle adapter_handle;
	364	struct i2c_adapter *adapter;
	365	struct i2c_client *client;
	366
	367	switch (value) {
	368	case ACPI_RECONFIG_DEVICE_ADD:
	369	if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
	370	break;
	371
	372	adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
	373	if (!adapter)
	374	break;
	375
	376	i2c_acpi_register_device(adapter, adev, &info);
	377	break;
	378	case ACPI_RECONFIG_DEVICE_REMOVE:
	379	if (!acpi_device_enumerated(adev))
	380	break;
	381
	382	client = i2c_acpi_find_client_by_adev(adev);
	383	if (!client)
	384	break;
	385
	386	i2c_unregister_device(client);
	387	put_device(&client->dev);
	388	break;
	389	}
	390
	391	return NOTIFY_OK;
	392	}
	393
	394	struct notifier_block i2c_acpi_notifier = {
	395	.notifier_call = i2c_acpi_notify,
	396	};
	397
	398	/**
	399	* i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
	400	* @dev: Device owning the ACPI resources to get the client from
	401	* @index: Index of ACPI resource to get
	402	* @info: describes the I2C device; note this is modified (addr gets set)
	403	* Context: can sleep
	404	*
	405	* By default the i2c subsys creates an i2c-client for the first I2cSerialBus
	406	* resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
	407	* resources, in that case this function can be used to create an i2c-client
	408	* for other I2cSerialBus resources in the Current Resource Settings table.
	409	*
	410	* Also see i2c_new_device, which this function calls to create the i2c-client.
	411	*
2dea645f AS	412	* Returns a pointer to the new i2c-client, or error pointer in case of failure.
2dea645f AS	413	* Specifically, -EPROBE_DEFER is returned if the adapter is not found.
53f8f7c5 WS	414	*/
	415	struct i2c_client i2c_acpi_new_device(struct device dev, int index,
	416	struct i2c_board_info *info)
	417	{
	418	struct i2c_acpi_lookup lookup;
	419	struct i2c_adapter *adapter;
2dea645f	420	struct i2c_client *client;
53f8f7c5 WS	421	struct acpi_device *adev;
	422	LIST_HEAD(resource_list);
	423	int ret;
	424
	425	adev = ACPI_COMPANION(dev);
	426	if (!adev)
2dea645f	427	return ERR_PTR(-EINVAL);
53f8f7c5 WS	428
	429	memset(&lookup, 0, sizeof(lookup));
	430	lookup.info = info;
	431	lookup.device_handle = acpi_device_handle(adev);
	432	lookup.index = index;
	433
	434	ret = acpi_dev_get_resources(adev, &resource_list,
	435	i2c_acpi_fill_info, &lookup);
2dea645f AS	436	if (ret < 0)
	437	return ERR_PTR(ret);
	438
53f8f7c5 WS	439	acpi_dev_free_resource_list(&resource_list);
53f8f7c5 WS	440
2dea645f AS	441	if (!info->addr)
2dea645f AS	442	return ERR_PTR(-EADDRNOTAVAIL);
53f8f7c5 WS	443
	444	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
	445	if (!adapter)
2dea645f AS	446	return ERR_PTR(-EPROBE_DEFER);
	447
	448	client = i2c_new_device(adapter, info);
	449	if (!client)
	450	return ERR_PTR(-ENODEV);
53f8f7c5	451
2dea645f	452	return client;
53f8f7c5 WS	453	}
	454	EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
	455
	456	#ifdef CONFIG_ACPI_I2C_OPREGION
	457	static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
	458	u8 cmd, u8 *data, u8 data_len)
	459	{
	460
	461	struct i2c_msg msgs[2];
	462	int ret;
	463	u8 *buffer;
	464
	465	buffer = kzalloc(data_len, GFP_KERNEL);
	466	if (!buffer)
	467	return AE_NO_MEMORY;
	468
	469	msgs[0].addr = client->addr;
	470	msgs[0].flags = client->flags;
	471	msgs[0].len = 1;
	472	msgs[0].buf = &cmd;
	473
	474	msgs[1].addr = client->addr;
	475	msgs[1].flags = client->flags \| I2C_M_RD;
	476	msgs[1].len = data_len;
	477	msgs[1].buf = buffer;
	478
	479	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
7781edae HG	480	if (ret < 0) {
	481	/* Getting a NACK is unfortunately normal with some DSTDs */
	482	if (ret == -EREMOTEIO)
	483	dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
	484	data_len, client->addr, cmd, ret);
	485	else
	486	dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
	487	data_len, client->addr, cmd, ret);
0a30446c HG	488	/* 2 transfers must have completed successfully */
0a30446c HG	489	} else if (ret == 2) {
53f8f7c5	490	memcpy(data, buffer, data_len);
0a30446c HG	491	ret = 0;
	492	} else {
	493	ret = -EIO;
7781edae	494	}
53f8f7c5 WS	495
	496	kfree(buffer);
	497	return ret;
	498	}
	499
	500	static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
	501	u8 cmd, u8 *data, u8 data_len)
	502	{
	503
	504	struct i2c_msg msgs[1];
	505	u8 *buffer;
	506	int ret = AE_OK;
	507
	508	buffer = kzalloc(data_len + 1, GFP_KERNEL);
	509	if (!buffer)
	510	return AE_NO_MEMORY;
	511
	512	buffer[0] = cmd;
	513	memcpy(buffer + 1, data, data_len);
	514
	515	msgs[0].addr = client->addr;
	516	msgs[0].flags = client->flags;
	517	msgs[0].len = data_len + 1;
	518	msgs[0].buf = buffer;
	519
	520	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
53f8f7c5 WS	521
53f8f7c5 WS	522	kfree(buffer);
c463a158 HG	523
	524	if (ret < 0) {
	525	dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
	526	return ret;
	527	}
	528
	529	/* 1 transfer must have completed successfully */
	530	return (ret == 1) ? 0 : -EIO;
53f8f7c5 WS	531	}
	532
	533	static acpi_status
	534	i2c_acpi_space_handler(u32 function, acpi_physical_address command,
	535	u32 bits, u64 *value64,
	536	void handler_context, void region_context)
	537	{
	538	struct gsb_buffer gsb = (struct gsb_buffer )value64;
	539	struct i2c_acpi_handler_data *data = handler_context;
	540	struct acpi_connection_info *info = &data->info;
	541	struct acpi_resource_i2c_serialbus *sb;
	542	struct i2c_adapter *adapter = data->adapter;
	543	struct i2c_client *client;
	544	struct acpi_resource *ares;
	545	u32 accessor_type = function >> 16;
	546	u8 action = function & ACPI_IO_MASK;
	547	acpi_status ret;
	548	int status;
	549
	550	ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
	551	if (ACPI_FAILURE(ret))
	552	return ret;
	553
	554	client = kzalloc(sizeof(*client), GFP_KERNEL);
	555	if (!client) {
	556	ret = AE_NO_MEMORY;
	557	goto err;
	558	}
	559
0d5102fe	560	if (!value64 \|\| !i2c_acpi_get_i2c_resource(ares, &sb)) {
53f8f7c5 WS	561	ret = AE_BAD_PARAMETER;
	562	goto err;
	563	}
	564
	565	client->adapter = adapter;
	566	client->addr = sb->slave_address;
	567
	568	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
	569	client->flags \|= I2C_CLIENT_TEN;
	570
	571	switch (accessor_type) {
	572	case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
	573	if (action == ACPI_READ) {
	574	status = i2c_smbus_read_byte(client);
	575	if (status >= 0) {
	576	gsb->bdata = status;
	577	status = 0;
	578	}
	579	} else {
	580	status = i2c_smbus_write_byte(client, gsb->bdata);
	581	}
	582	break;
	583
	584	case ACPI_GSB_ACCESS_ATTRIB_BYTE:
	585	if (action == ACPI_READ) {
	586	status = i2c_smbus_read_byte_data(client, command);
	587	if (status >= 0) {
	588	gsb->bdata = status;
	589	status = 0;
	590	}
	591	} else {
	592	status = i2c_smbus_write_byte_data(client, command,
	593	gsb->bdata);
	594	}
	595	break;
	596
	597	case ACPI_GSB_ACCESS_ATTRIB_WORD:
	598	if (action == ACPI_READ) {
	599	status = i2c_smbus_read_word_data(client, command);
	600	if (status >= 0) {
	601	gsb->wdata = status;
	602	status = 0;
	603	}
	604	} else {
	605	status = i2c_smbus_write_word_data(client, command,
	606	gsb->wdata);
	607	}
	608	break;
	609
	610	case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
	611	if (action == ACPI_READ) {
	612	status = i2c_smbus_read_block_data(client, command,
	613	gsb->data);
	614	if (status >= 0) {
	615	gsb->len = status;
	616	status = 0;
	617	}
	618	} else {
	619	status = i2c_smbus_write_block_data(client, command,
	620	gsb->len, gsb->data);
	621	}
	622	break;
	623
	624	case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
625	if (action == ACPI_READ) {
626	status = acpi_gsb_i2c_read_bytes(client, command,
627	gsb->data, info->access_length);
53f8f7c5 WS	628	} else {
	629	status = acpi_gsb_i2c_write_bytes(client, command,
	630	gsb->data, info->access_length);
	631	}
	632	break;
	633
	634	default:
	635	dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
	636	accessor_type, client->addr);
	637	ret = AE_BAD_PARAMETER;
	638	goto err;
	639	}
	640
	641	gsb->status = status;
	642
	643	err:
	644	kfree(client);
	645	ACPI_FREE(ares);
	646	return ret;
	647	}
	648
	649
	650	int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
	651	{
	652	acpi_handle handle;
	653	struct i2c_acpi_handler_data *data;
	654	acpi_status status;
	655
	656	if (!adapter->dev.parent)
	657	return -ENODEV;
	658
	659	handle = ACPI_HANDLE(adapter->dev.parent);
	660
	661	if (!handle)
	662	return -ENODEV;
	663
	664	data = kzalloc(sizeof(struct i2c_acpi_handler_data),
	665	GFP_KERNEL);
	666	if (!data)
	667	return -ENOMEM;
	668
	669	data->adapter = adapter;
	670	status = acpi_bus_attach_private_data(handle, (void *)data);
	671	if (ACPI_FAILURE(status)) {
	672	kfree(data);
	673	return -ENOMEM;
	674	}
	675
	676	status = acpi_install_address_space_handler(handle,
	677	ACPI_ADR_SPACE_GSBUS,
	678	&i2c_acpi_space_handler,
	679	NULL,
	680	data);
	681	if (ACPI_FAILURE(status)) {
	682	dev_err(&adapter->dev, "Error installing i2c space handler\n");
	683	acpi_bus_detach_private_data(handle);
	684	kfree(data);
	685	return -ENOMEM;
	686	}
	687
	688	acpi_walk_dep_device_list(handle);
	689	return 0;
	690	}
	691
692	void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
693	{
694	acpi_handle handle;
695	struct i2c_acpi_handler_data *data;
696	acpi_status status;
697
698	if (!adapter->dev.parent)
699	return;
700
701	handle = ACPI_HANDLE(adapter->dev.parent);
702
703	if (!handle)
704	return;
705
706	acpi_remove_address_space_handler(handle,
707	ACPI_ADR_SPACE_GSBUS,
708	&i2c_acpi_space_handler);
709
710	status = acpi_bus_get_private_data(handle, (void **)&data);
711	if (ACPI_SUCCESS(status))
712	kfree(data);
713
714	acpi_bus_detach_private_data(handle);
715	}
716	#endif /* CONFIG_ACPI_I2C_OPREGION */