drivers/i2c/i2c-acpi.c - kernel/msm-4.9 - Gitiles

 /*
  * I2C ACPI 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 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.
  */
 #define pr_fmt(fmt) "I2C/ACPI : " fmt

 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/acpi.h>

 struct acpi_i2c_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;

 static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data)
 {
 	struct i2c_board_info *info = data;

 	if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
 		struct acpi_resource_i2c_serialbus *sb;

 		sb = &ares->data.i2c_serial_bus;
 		if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
 			info->addr = sb->slave_address;
 			if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 				info->flags |= I2C_CLIENT_TEN;
 		}
 	} else if (info->irq < 0) {
 		struct resource r;

 		if (acpi_dev_resource_interrupt(ares, 0, &r))
 			info->irq = r.start;
 	}

 	/* Tell the ACPI core to skip this resource */
 	return 1;
 }

 static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
 				       void *data, void **return_value)
 {
 	struct i2c_adapter *adapter = data;
 	struct list_head resource_list;
 	struct i2c_board_info info;
 	struct acpi_device *adev;
 	int ret;

 	if (acpi_bus_get_device(handle, &adev))
 		return AE_OK;
 	if (acpi_bus_get_status(adev) || !adev->status.present)
 		return AE_OK;

 	memset(&info, 0, sizeof(info));
 	info.acpi_node.companion = adev;
 	info.irq = -1;

 	INIT_LIST_HEAD(&resource_list);
 	ret = acpi_dev_get_resources(adev, &resource_list,
 				     acpi_i2c_add_resource, &info);
 	acpi_dev_free_resource_list(&resource_list);

 	if (ret < 0 || !info.addr)
 		return AE_OK;

 	adev->power.flags.ignore_parent = true;
 	strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
 	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));
 	}

 	return AE_OK;
 }

 /**
  * acpi_i2c_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 acpi_i2c_register_devices(struct i2c_adapter *adap)
 {
 	acpi_handle handle;
 	acpi_status status;

 	if (!adap->dev.parent)
 		return;

 	handle = ACPI_HANDLE(adap->dev.parent);
 	if (!handle)
 		return;

 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 				     acpi_i2c_add_device, NULL,
 				     adap, NULL);
 	if (ACPI_FAILURE(status))
 		dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 }

 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
 acpi_i2c_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 acpi_i2c_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 = AE_OK;
 	int status;

 	ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 	if (ACPI_FAILURE(ret))
 		return ret;

 	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;
 	}

 	memset(&client, 0, sizeof(client));
 	client.adapter = adapter;
 	client.addr = sb->slave_address;
 	client.flags = 0;

 	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:
 		pr_info("protocol(0x%02x) is not supported.\n", accessor_type);
 		ret = AE_BAD_PARAMETER;
 		goto err;
 	}

 	gsb->status = status;

  err:
 	ACPI_FREE(ares);
 	return ret;
 }


 int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
 {
 	acpi_handle handle = ACPI_HANDLE(adapter->dev.parent);
 	struct acpi_i2c_handler_data *data;
 	acpi_status status;

 	if (!handle)
 		return -ENODEV;

 	data = kzalloc(sizeof(struct acpi_i2c_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,
 				&acpi_i2c_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;
 	}

 	return 0;
 }

 void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
 {
 	acpi_handle handle = ACPI_HANDLE(adapter->dev.parent);
 	struct acpi_i2c_handler_data *data;
 	acpi_status status;

 	if (!handle)
 		return;

 	acpi_remove_address_space_handler(handle,
 				ACPI_ADR_SPACE_GSBUS,
 				&acpi_i2c_space_handler);

 	status = acpi_bus_get_private_data(handle, (void **)&data);
 	if (ACPI_SUCCESS(status))
 		kfree(data);

 	acpi_bus_detach_private_data(handle);
 }
	/*
	* I2C ACPI 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 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.
	*/
	#define pr_fmt(fmt) "I2C/ACPI : " fmt

	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/err.h>
	#include <linux/i2c.h>
	#include <linux/acpi.h>

	struct acpi_i2c_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;

	static int acpi_i2c_add_resource(struct acpi_resource ares, void data)
	{
	struct i2c_board_info *info = data;

	if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
	struct acpi_resource_i2c_serialbus *sb;

	sb = &ares->data.i2c_serial_bus;
	if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
	info->addr = sb->slave_address;
	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
	info->flags \|= I2C_CLIENT_TEN;
	}
	} else if (info->irq < 0) {
	struct resource r;

	if (acpi_dev_resource_interrupt(ares, 0, &r))
	info->irq = r.start;
	}

	/* Tell the ACPI core to skip this resource */
	return 1;
	}

	static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
	void data, void *return_value)
	{
	struct i2c_adapter *adapter = data;
	struct list_head resource_list;
	struct i2c_board_info info;
	struct acpi_device *adev;
	int ret;

	if (acpi_bus_get_device(handle, &adev))
	return AE_OK;
	if (acpi_bus_get_status(adev) \|\| !adev->status.present)
	return AE_OK;

	memset(&info, 0, sizeof(info));
	info.acpi_node.companion = adev;
	info.irq = -1;

	INIT_LIST_HEAD(&resource_list);
	ret = acpi_dev_get_resources(adev, &resource_list,
	acpi_i2c_add_resource, &info);
	acpi_dev_free_resource_list(&resource_list);

	if (ret < 0 \|\| !info.addr)
	return AE_OK;

	adev->power.flags.ignore_parent = true;
	strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
	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));
	}

	return AE_OK;
	}

	/**
	* acpi_i2c_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 acpi_i2c_register_devices(struct i2c_adapter *adap)
	{
	acpi_handle handle;
	acpi_status status;

	if (!adap->dev.parent)
	return;

	handle = ACPI_HANDLE(adap->dev.parent);
	if (!handle)
	return;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
	acpi_i2c_add_device, NULL,
	adap, NULL);
	if (ACPI_FAILURE(status))
	dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
	}

	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
	acpi_i2c_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 acpi_i2c_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 = AE_OK;
	int status;

	ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
	if (ACPI_FAILURE(ret))
	return ret;

	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;
	}

	memset(&client, 0, sizeof(client));
	client.adapter = adapter;
	client.addr = sb->slave_address;
	client.flags = 0;

	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:
	pr_info("protocol(0x%02x) is not supported.\n", accessor_type);
	ret = AE_BAD_PARAMETER;
	goto err;
	}

	gsb->status = status;

	err:
	ACPI_FREE(ares);
	return ret;
	}


	int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
	{
	acpi_handle handle = ACPI_HANDLE(adapter->dev.parent);
	struct acpi_i2c_handler_data *data;
	acpi_status status;

	if (!handle)
	return -ENODEV;

	data = kzalloc(sizeof(struct acpi_i2c_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,
	&acpi_i2c_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;
	}

	return 0;
	}

	void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
	{
	acpi_handle handle = ACPI_HANDLE(adapter->dev.parent);
	struct acpi_i2c_handler_data *data;
	acpi_status status;

	if (!handle)
	return;

	acpi_remove_address_space_handler(handle,
	ACPI_ADR_SPACE_GSBUS,
	&acpi_i2c_space_handler);

	status = acpi_bus_get_private_data(handle, (void **)&data);
	if (ACPI_SUCCESS(status))
	kfree(data);

	acpi_bus_detach_private_data(handle);
	}