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", 0 }, 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 acpi_device *adev) 52 { 53 acpi_handle handle = acpi_device_handle(adev); 54 union acpi_object *obj; 55 u16 hid_descriptor_address; 56 57 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 58 return -ENODEV; 59 60 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 61 ACPI_TYPE_INTEGER); 62 if (!obj) { 63 acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n"); 64 return -ENODEV; 65 } 66 67 hid_descriptor_address = obj->integer.value; 68 ACPI_FREE(obj); 69 70 return hid_descriptor_address; 71 } 72 73 static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops) 74 { 75 struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops); 76 77 acpi_device_set_power(ihid_acpi->adev, ACPI_STATE_D3_COLD); 78 } 79 80 static int i2c_hid_acpi_probe(struct i2c_client *client) 81 { 82 struct device *dev = &client->dev; 83 struct i2c_hid_acpi *ihid_acpi; 84 struct acpi_device *adev; 85 u16 hid_descriptor_address; 86 int ret; 87 88 adev = ACPI_COMPANION(dev); 89 if (!adev) { 90 dev_err(&client->dev, "Error could not get ACPI device\n"); 91 return -ENODEV; 92 } 93 94 ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL); 95 if (!ihid_acpi) 96 return -ENOMEM; 97 98 ihid_acpi->adev = adev; 99 ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail; 100 101 ret = i2c_hid_acpi_get_descriptor(adev); 102 if (ret < 0) 103 return ret; 104 hid_descriptor_address = ret; 105 106 acpi_device_fix_up_power(adev); 107 108 if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) { 109 device_set_wakeup_capable(dev, true); 110 device_set_wakeup_enable(dev, false); 111 } 112 113 return i2c_hid_core_probe(client, &ihid_acpi->ops, 114 hid_descriptor_address, 0); 115 } 116 117 static const struct acpi_device_id i2c_hid_acpi_match[] = { 118 {"ACPI0C50", 0 }, 119 {"PNP0C50", 0 }, 120 { }, 121 }; 122 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 123 124 static struct i2c_driver i2c_hid_acpi_driver = { 125 .driver = { 126 .name = "i2c_hid_acpi", 127 .pm = &i2c_hid_core_pm, 128 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 129 .acpi_match_table = i2c_hid_acpi_match, 130 }, 131 132 .probe_new = i2c_hid_acpi_probe, 133 .remove = i2c_hid_core_remove, 134 .shutdown = i2c_hid_core_shutdown, 135 }; 136 137 module_i2c_driver(i2c_hid_acpi_driver); 138 139 MODULE_DESCRIPTION("HID over I2C ACPI driver"); 140 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 141 MODULE_LICENSE("GPL"); 142