| Mika Westerberg | 907ddf8 | 2012-11-23 12:23:40 +0100 | [diff] [blame] | 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); |