drivers/hid/i2c-hid/i2c-hid-of.c

   1 /*
   2  * HID over I2C Open Firmware 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/delay.h>
  23 #include <linux/device.h>
  24 #include <linux/i2c.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/of.h>
  28 #include <linux/pm.h>
  29 #include <linux/regulator/consumer.h>
  30
  31 #include "i2c-hid.h"
  32
  33 struct i2c_hid_of {
  34         struct i2chid_ops ops;
  35
  36         struct i2c_client *client;
  37         struct regulator_bulk_data supplies[2];
  38         int post_power_delay_ms;
  39 };
  40
  41 static int i2c_hid_of_power_up(struct i2chid_ops *ops)
  42 {
  43         struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
  44         struct device *dev = &ihid_of->client->dev;
  45         int ret;
  46
  47         ret = regulator_bulk_enable(ARRAY_SIZE(ihid_of->supplies),
  48                                     ihid_of->supplies);
  49         if (ret) {
  50                 dev_warn(dev, "Failed to enable supplies: %d\n", ret);
  51                 return ret;
  52         }
  53
  54         if (ihid_of->post_power_delay_ms)
  55                 msleep(ihid_of->post_power_delay_ms);
  56
  57         return 0;
  58 }
  59
  60 static void i2c_hid_of_power_down(struct i2chid_ops *ops)
  61 {
  62         struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
  63
  64         regulator_bulk_disable(ARRAY_SIZE(ihid_of->supplies),
  65                                ihid_of->supplies);
  66 }
  67
  68 static int i2c_hid_of_probe(struct i2c_client *client,
  69                             const struct i2c_device_id *dev_id)
  70 {
  71         struct device *dev = &client->dev;
  72         struct i2c_hid_of *ihid_of;
  73         u16 hid_descriptor_address;
  74         int ret;
  75         u32 val;
  76
  77         ihid_of = devm_kzalloc(&client->dev, sizeof(*ihid_of), GFP_KERNEL);
  78         if (!ihid_of)
  79                 return -ENOMEM;
  80
  81         ihid_of->ops.power_up = i2c_hid_of_power_up;
  82         ihid_of->ops.power_down = i2c_hid_of_power_down;
  83
  84         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
  85         if (ret) {
  86                 dev_err(&client->dev, "HID register address not provided\n");
  87                 return -ENODEV;
  88         }
  89         if (val >> 16) {
  90                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
  91                         val);
  92                 return -EINVAL;
  93         }
  94         hid_descriptor_address = val;
  95
  96         if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms",
  97                                       &val))
  98                 ihid_of->post_power_delay_ms = val;
  99
 100         ihid_of->supplies[0].supply = "vdd";
 101         ihid_of->supplies[1].supply = "vddl";
 102         ret = devm_regulator_bulk_get(&client->dev,
 103                                       ARRAY_SIZE(ihid_of->supplies),
 104                                       ihid_of->supplies);
 105         if (ret)
 106                 return ret;
 107
 108         return i2c_hid_core_probe(client, &ihid_of->ops,
 109                                   hid_descriptor_address);
 110 }
 111
 112 static const struct of_device_id i2c_hid_of_match[] = {
 113         { .compatible = "hid-over-i2c" },
 114         {},
 115 };
 116 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 117
 118 static const struct i2c_device_id i2c_hid_of_id_table[] = {
 119         { "hid", 0 },
 120         { "hid-over-i2c", 0 },
 121         { },
 122 };
 123 MODULE_DEVICE_TABLE(i2c, i2c_hid_of_id_table);
 124
 125 static struct i2c_driver i2c_hid_of_driver = {
 126         .driver = {
 127                 .name   = "i2c_hid_of",
 128                 .pm     = &i2c_hid_core_pm,
 129                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 130                 .of_match_table = of_match_ptr(i2c_hid_of_match),
 131         },
 132
 133         .probe          = i2c_hid_of_probe,
 134         .remove         = i2c_hid_core_remove,
 135         .shutdown       = i2c_hid_core_shutdown,
 136         .id_table       = i2c_hid_of_id_table,
 137 };
 138
 139 module_i2c_driver(i2c_hid_of_driver);
 140
 141 MODULE_DESCRIPTION("HID over I2C OF driver");
 142 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
 143 MODULE_LICENSE("GPL");