104 lines
2.7 KiB
C
104 lines
2.7 KiB
C
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/*
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* ACPI I2C enumeration support
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*
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* Copyright (C) 2012, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/acpi.h>
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/i2c.h>
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#include <linux/ioport.h>
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ACPI_MODULE_NAME("i2c");
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static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data)
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{
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struct i2c_board_info *info = data;
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if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
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struct acpi_resource_i2c_serialbus *sb;
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sb = &ares->data.i2c_serial_bus;
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if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
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info->addr = sb->slave_address;
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if (sb->access_mode == ACPI_I2C_10BIT_MODE)
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info->flags |= I2C_CLIENT_TEN;
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}
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} else if (info->irq < 0) {
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struct resource r;
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if (acpi_dev_resource_interrupt(ares, 0, &r))
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info->irq = r.start;
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}
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/* Tell the ACPI core to skip this resource */
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return 1;
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}
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static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
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void *data, void **return_value)
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{
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struct i2c_adapter *adapter = data;
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struct list_head resource_list;
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struct i2c_board_info info;
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struct acpi_device *adev;
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int ret;
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if (acpi_bus_get_device(handle, &adev))
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return AE_OK;
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if (acpi_bus_get_status(adev) || !adev->status.present)
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return AE_OK;
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memset(&info, 0, sizeof(info));
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info.acpi_node.handle = handle;
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info.irq = -1;
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INIT_LIST_HEAD(&resource_list);
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ret = acpi_dev_get_resources(adev, &resource_list,
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acpi_i2c_add_resource, &info);
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acpi_dev_free_resource_list(&resource_list);
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if (ret < 0 || !info.addr)
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return AE_OK;
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strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
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if (!i2c_new_device(adapter, &info)) {
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dev_err(&adapter->dev,
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"failed to add I2C device %s from ACPI\n",
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dev_name(&adev->dev));
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}
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return AE_OK;
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}
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/**
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* acpi_i2c_register_devices - enumerate I2C slave devices behind adapter
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* @adapter: pointer to adapter
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*
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* Enumerate all I2C slave devices behind this adapter by walking the ACPI
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* namespace. When a device is found it will be added to the Linux device
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* model and bound to the corresponding ACPI handle.
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*/
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void acpi_i2c_register_devices(struct i2c_adapter *adapter)
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{
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acpi_handle handle;
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acpi_status status;
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handle = ACPI_HANDLE(&adapter->dev);
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if (!handle)
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return;
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status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
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acpi_i2c_add_device, NULL,
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adapter, NULL);
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if (ACPI_FAILURE(status))
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dev_warn(&adapter->dev, "failed to enumerate I2C slaves\n");
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}
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EXPORT_SYMBOL_GPL(acpi_i2c_register_devices);
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