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

   1 /*
   2  * HID over I2C Open Firmware Subclass
   3  *
   4  * Copyright (c) 2012 Benjamin Tissoires <[email protected]>
   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 <[email protected]>
  13  *  Copyright (c) 2005 Michael Haboustak <[email protected]> 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/gpio/consumer.h>
  25 #include <linux/hid.h>
  26 #include <linux/i2c.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/of.h>
  30 #include <linux/pm.h>
  31 #include <linux/regulator/consumer.h>
  32
  33 #include "i2c-hid.h"
  34
  35 struct i2c_hid_of {
  36         struct i2chid_ops ops;
  37
  38         struct i2c_client *client;
  39         struct gpio_desc *reset_gpio;
  40         struct regulator_bulk_data supplies[2];
  41         int post_power_delay_ms;
  42         int post_reset_delay_ms;
  43 };
  44
  45 static int i2c_hid_of_power_up(struct i2chid_ops *ops)
  46 {
  47         struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
  48         struct device *dev = &ihid_of->client->dev;
  49         int ret;
  50
  51         ret = regulator_bulk_enable(ARRAY_SIZE(ihid_of->supplies),
  52                                     ihid_of->supplies);
  53         if (ret) {
  54                 dev_warn(dev, "Failed to enable supplies: %d\n", ret);
  55                 return ret;
  56         }
  57
  58         if (ihid_of->post_power_delay_ms)
  59                 msleep(ihid_of->post_power_delay_ms);
  60
  61         gpiod_set_value_cansleep(ihid_of->reset_gpio, 0);
  62         if (ihid_of->post_reset_delay_ms)
  63                 msleep(ihid_of->post_reset_delay_ms);
  64
  65         return 0;
  66 }
  67
  68 static void i2c_hid_of_power_down(struct i2chid_ops *ops)
  69 {
  70         struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
  71
  72         gpiod_set_value_cansleep(ihid_of->reset_gpio, 1);
  73         regulator_bulk_disable(ARRAY_SIZE(ihid_of->supplies),
  74                                ihid_of->supplies);
  75 }
  76
  77 static int i2c_hid_of_probe(struct i2c_client *client)
  78 {
  79         struct device *dev = &client->dev;
  80         struct i2c_hid_of *ihid_of;
  81         u16 hid_descriptor_address;
  82         u32 quirks = 0;
  83         int ret;
  84         u32 val;
  85
  86         ihid_of = devm_kzalloc(dev, sizeof(*ihid_of), GFP_KERNEL);
  87         if (!ihid_of)
  88                 return -ENOMEM;
  89
  90         ihid_of->ops.power_up = i2c_hid_of_power_up;
  91         ihid_of->ops.power_down = i2c_hid_of_power_down;
  92
  93         ret = device_property_read_u32(dev, "hid-descr-addr", &val);
  94         if (ret) {
  95                 dev_err(dev, "HID register address not provided\n");
  96                 return -ENODEV;
  97         }
  98         if (val >> 16) {
  99                 dev_err(dev, "Bad HID register address: 0x%08x\n", val);
 100                 return -EINVAL;
 101         }
 102         hid_descriptor_address = val;
 103
 104         if (!device_property_read_u32(dev, "post-power-on-delay-ms", &val))
 105                 ihid_of->post_power_delay_ms = val;
 106
 107         /*
 108          * Note this is a kernel internal device-property set by x86 platform code,
 109          * this MUST not be used in devicetree files without first adding it to
 110          * the DT bindings.
 111          */
 112         if (!device_property_read_u32(dev, "post-reset-deassert-delay-ms", &val))
 113                 ihid_of->post_reset_delay_ms = val;
 114
 115         /* Start out with reset asserted */
 116         ihid_of->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 117         if (IS_ERR(ihid_of->reset_gpio))
 118                 return PTR_ERR(ihid_of->reset_gpio);
 119
 120         ihid_of->supplies[0].supply = "vdd";
 121         ihid_of->supplies[1].supply = "vddl";
 122         ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ihid_of->supplies),
 123                                       ihid_of->supplies);
 124         if (ret)
 125                 return ret;
 126
 127         if (device_property_read_bool(dev, "touchscreen-inverted-x"))
 128                 quirks |= HID_QUIRK_X_INVERT;
 129
 130         if (device_property_read_bool(dev, "touchscreen-inverted-y"))
 131                 quirks |= HID_QUIRK_Y_INVERT;
 132
 133         return i2c_hid_core_probe(client, &ihid_of->ops,
 134                                   hid_descriptor_address, quirks);
 135 }
 136
 137 #ifdef CONFIG_OF
 138 static const struct of_device_id i2c_hid_of_match[] = {
 139         { .compatible = "hid-over-i2c" },
 140         {},
 141 };
 142 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 143 #endif
 144
 145 static const struct i2c_device_id i2c_hid_of_id_table[] = {
 146         { "hid", 0 },
 147         { "hid-over-i2c", 0 },
 148         { },
 149 };
 150 MODULE_DEVICE_TABLE(i2c, i2c_hid_of_id_table);
 151
 152 static struct i2c_driver i2c_hid_of_driver = {
 153         .driver = {
 154                 .name   = "i2c_hid_of",
 155                 .pm     = &i2c_hid_core_pm,
 156                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 157                 .of_match_table = of_match_ptr(i2c_hid_of_match),
 158         },
 159
 160         .probe          = i2c_hid_of_probe,
 161         .remove         = i2c_hid_core_remove,
 162         .shutdown       = i2c_hid_core_shutdown,
 163         .id_table       = i2c_hid_of_id_table,
 164 };
 165
 166 module_i2c_driver(i2c_hid_of_driver);
 167
 168 MODULE_DESCRIPTION("HID over I2C OF driver");
 169 MODULE_AUTHOR("Benjamin Tissoires <[email protected]>");
 170 MODULE_LICENSE("GPL");