1 /* 2 * HID over I2C ACPI Subclass 3 * 4 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com> 5 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France 6 * Copyright (c) 2012 Red Hat, Inc 7 * 8 * This code was forked out of the core code, which was partly based on 9 * "USB HID support for Linux": 10 * 11 * Copyright (c) 1999 Andreas Gal 12 * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz> 13 * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc 14 * Copyright (c) 2007-2008 Oliver Neukum 15 * Copyright (c) 2006-2010 Jiri Kosina 16 * 17 * This file is subject to the terms and conditions of the GNU General Public 18 * License. See the file COPYING in the main directory of this archive for 19 * more details. 20 */ 21 22 #include <linux/acpi.h> 23 #include <linux/device.h> 24 #include <linux/i2c.h> 25 #include <linux/kernel.h> 26 #include <linux/module.h> 27 #include <linux/pm.h> 28 #include <linux/uuid.h> 29 30 #include "i2c-hid.h" 31 32 struct i2c_hid_acpi { 33 struct i2chid_ops ops; 34 struct acpi_device *adev; 35 }; 36 37 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { 38 /* 39 * The CHPN0001 ACPI device, which is used to describe the Chipone 40 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. 41 */ 42 { "CHPN0001" }, 43 { } 44 }; 45 46 /* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */ 47 static guid_t i2c_hid_guid = 48 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 49 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); 50 51 static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi) 52 { 53 struct acpi_device *adev = ihid_acpi->adev; 54 acpi_handle handle = acpi_device_handle(adev); 55 union acpi_object *obj; 56 u16 hid_descriptor_address; 57 58 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 59 return -ENODEV; 60 61 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 62 ACPI_TYPE_INTEGER); 63 if (!obj) { 64 acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n"); 65 return -ENODEV; 66 } 67 68 hid_descriptor_address = obj->integer.value; 69 ACPI_FREE(obj); 70 71 return hid_descriptor_address; 72 } 73 74 static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops) 75 { 76 struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops); 77 78 acpi_device_set_power(ihid_acpi->adev, ACPI_STATE_D3_COLD); 79 } 80 81 static int i2c_hid_acpi_probe(struct i2c_client *client) 82 { 83 struct device *dev = &client->dev; 84 struct i2c_hid_acpi *ihid_acpi; 85 u16 hid_descriptor_address; 86 int ret; 87 88 ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL); 89 if (!ihid_acpi) 90 return -ENOMEM; 91 92 ihid_acpi->adev = ACPI_COMPANION(dev); 93 ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail; 94 95 ret = i2c_hid_acpi_get_descriptor(ihid_acpi); 96 if (ret < 0) 97 return ret; 98 hid_descriptor_address = ret; 99 100 acpi_device_fix_up_power(ihid_acpi->adev); 101 102 return i2c_hid_core_probe(client, &ihid_acpi->ops, 103 hid_descriptor_address, 0); 104 } 105 106 static const struct acpi_device_id i2c_hid_acpi_match[] = { 107 { "ACPI0C50" }, 108 { "PNP0C50" }, 109 { } 110 }; 111 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 112 113 static struct i2c_driver i2c_hid_acpi_driver = { 114 .driver = { 115 .name = "i2c_hid_acpi", 116 .pm = &i2c_hid_core_pm, 117 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 118 .acpi_match_table = i2c_hid_acpi_match, 119 }, 120 121 .probe = i2c_hid_acpi_probe, 122 .remove = i2c_hid_core_remove, 123 .shutdown = i2c_hid_core_shutdown, 124 }; 125 126 module_i2c_driver(i2c_hid_acpi_driver); 127 128 MODULE_DESCRIPTION("HID over I2C ACPI driver"); 129 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 130 MODULE_LICENSE("GPL"); 131