linux/drivers/i2c/i2c-acpi.c
Lan Tianyu da3c6647ee I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI config
Clean up ACPI related code in the i2c core and add CONFIG_I2C_ACPI
to enable I2C ACPI code.

Current there is a race between removing I2C ACPI operation region
and ACPI AML code accessing. So make i2c core built-in if CONFIG_I2C_ACPI
is set.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-27 14:50:41 +02:00

363 lines
8.3 KiB
C

/*
* 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);
}