ACPI / PM: Fix device power state value after transitions to D3cold
[linux-3.10.git] / drivers / acpi / acpi_i2c.c
1 /*
2  * ACPI I2C enumeration support
3  *
4  * Copyright (C) 2012, Intel Corporation
5  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/acpi.h>
13 #include <linux/device.h>
14 #include <linux/export.h>
15 #include <linux/i2c.h>
16 #include <linux/ioport.h>
17
18 ACPI_MODULE_NAME("i2c");
19
20 static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data)
21 {
22         struct i2c_board_info *info = data;
23
24         if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
25                 struct acpi_resource_i2c_serialbus *sb;
26
27                 sb = &ares->data.i2c_serial_bus;
28                 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
29                         info->addr = sb->slave_address;
30                         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
31                                 info->flags |= I2C_CLIENT_TEN;
32                 }
33         } else if (info->irq < 0) {
34                 struct resource r;
35
36                 if (acpi_dev_resource_interrupt(ares, 0, &r))
37                         info->irq = r.start;
38         }
39
40         /* Tell the ACPI core to skip this resource */
41         return 1;
42 }
43
44 static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
45                                        void *data, void **return_value)
46 {
47         struct i2c_adapter *adapter = data;
48         struct list_head resource_list;
49         struct i2c_board_info info;
50         struct acpi_device *adev;
51         int ret;
52
53         if (acpi_bus_get_device(handle, &adev))
54                 return AE_OK;
55         if (acpi_bus_get_status(adev) || !adev->status.present)
56                 return AE_OK;
57
58         memset(&info, 0, sizeof(info));
59         info.acpi_node.handle = handle;
60         info.irq = -1;
61
62         INIT_LIST_HEAD(&resource_list);
63         ret = acpi_dev_get_resources(adev, &resource_list,
64                                      acpi_i2c_add_resource, &info);
65         acpi_dev_free_resource_list(&resource_list);
66
67         if (ret < 0 || !info.addr)
68                 return AE_OK;
69
70         strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
71         if (!i2c_new_device(adapter, &info)) {
72                 dev_err(&adapter->dev,
73                         "failed to add I2C device %s from ACPI\n",
74                         dev_name(&adev->dev));
75         }
76
77         return AE_OK;
78 }
79
80 /**
81  * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter
82  * @adapter: pointer to adapter
83  *
84  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
85  * namespace. When a device is found it will be added to the Linux device
86  * model and bound to the corresponding ACPI handle.
87  */
88 void acpi_i2c_register_devices(struct i2c_adapter *adapter)
89 {
90         acpi_handle handle;
91         acpi_status status;
92
93         handle = ACPI_HANDLE(&adapter->dev);
94         if (!handle)
95                 return;
96
97         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
98                                      acpi_i2c_add_device, NULL,
99                                      adapter, NULL);
100         if (ACPI_FAILURE(status))
101                 dev_warn(&adapter->dev, "failed to enumerate I2C slaves\n");
102 }
103 EXPORT_SYMBOL_GPL(acpi_i2c_register_devices);