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i2c: break out ACPI support into separate file

Browse Source 
Removes some ifdeffery. Also add the new file to the relevant
MAINTAINERS section.

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>
This commit is contained in:
Wolfram Sang 2017-05-23 16:22:23 +02:00
parent 5bf4fa7dae
commit 53f8f7c5cf
5 changed files with 670 additions and 648 deletions
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1
MAINTAINERS
View File

@ -6273,6 +6273,7 @@ M: Mika Westerberg <mika.westerberg@linux.intel.com>
L: linux-i2c@vger.kernel.org
L: linux-acpi@vger.kernel.org
S: Maintained
F: drivers/i2c/i2c-core-acpi.c
I2C-TAOS-EVM DRIVER
M: Jean Delvare <jdelvare@suse.com>

1
drivers/i2c/Makefile
View File

@ -5,6 +5,7 @@
obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o
obj-$(CONFIG_I2C) += i2c-core.o
i2c-core-objs := i2c-core-base.o i2c-core-smbus.o
i2c-core-$(CONFIG_ACPI) += i2c-core-acpi.o
i2c-core-$(CONFIG_I2C_SLAVE) += i2c-core-slave.o
i2c-core-$(CONFIG_OF) += i2c-core-of.o

653
drivers/i2c/i2c-core-acpi.c Normal file
View File

@ -0,0 +1,653 @@
/*
* 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;
};
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.
*/
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;
}
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);
#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;
}
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 */

648
drivers/i2c/i2c-core-base.c
View File

@ -16,8 +16,6 @@
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
Mux support by Rodolfo Giometti <giometti@enneenne.com> and
Michael Lawnick <michael.lawnick.ext@nsn.com>
I2C ACPI code Copyright (C) 2014 Intel Corp
Author: Lan Tianyu <tianyu.lan@intel.com>
*/
#define pr_fmt(fmt) "i2c-core: " fmt
@ -83,652 +81,6 @@ 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)
{

15
drivers/i2c/i2c-core.h
View File

@ -30,6 +30,21 @@ extern int __i2c_first_dynamic_bus_num;
int i2c_check_addr_validity(unsigned addr, unsigned short flags);
int i2c_check_7bit_addr_validity_strict(unsigned short addr);
#ifdef CONFIG_ACPI
void i2c_acpi_register_devices(struct i2c_adapter *adap);
#else /* CONFIG_ACPI */
static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
#endif /* CONFIG_ACPI */
extern struct notifier_block i2c_acpi_notifier;
#ifdef CONFIG_ACPI_I2C_OPREGION
int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
#else /* CONFIG_ACPI_I2C_OPREGION */
static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
#endif /* CONFIG_ACPI_I2C_OPREGION */
#ifdef CONFIG_OF
void of_i2c_register_devices(struct i2c_adapter *adap);
#else