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/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
 35struct 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
 45static 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
 68static 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
 77static 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->client = client;
 91	ihid_of->ops.power_up = i2c_hid_of_power_up;
 92	ihid_of->ops.power_down = i2c_hid_of_power_down;
 93
 94	ret = device_property_read_u32(dev, "hid-descr-addr", &val);
 95	if (ret) {
 96		dev_err(dev, "HID register address not provided\n");
 97		return -ENODEV;
 98	}
 99	if (val >> 16) {
100		dev_err(dev, "Bad HID register address: 0x%08x\n", val);
101		return -EINVAL;
102	}
103	hid_descriptor_address = val;
104
105	if (!device_property_read_u32(dev, "post-power-on-delay-ms", &val))
106		ihid_of->post_power_delay_ms = val;
107
108	/*
109	 * Note this is a kernel internal device-property set by x86 platform code,
110	 * this MUST not be used in devicetree files without first adding it to
111	 * the DT bindings.
112	 */
113	if (!device_property_read_u32(dev, "post-reset-deassert-delay-ms", &val))
114		ihid_of->post_reset_delay_ms = val;
115
116	/* Start out with reset asserted */
117	ihid_of->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
118	if (IS_ERR(ihid_of->reset_gpio))
119		return PTR_ERR(ihid_of->reset_gpio);
120
121	ihid_of->supplies[0].supply = "vdd";
122	ihid_of->supplies[1].supply = "vddl";
123	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ihid_of->supplies),
124				      ihid_of->supplies);
125	if (ret)
126		return ret;
127
128	if (device_property_read_bool(dev, "touchscreen-inverted-x"))
129		quirks |= HID_QUIRK_X_INVERT;
130
131	if (device_property_read_bool(dev, "touchscreen-inverted-y"))
132		quirks |= HID_QUIRK_Y_INVERT;
133
134	return i2c_hid_core_probe(client, &ihid_of->ops,
135				  hid_descriptor_address, quirks);
136}
137
138#ifdef CONFIG_OF
139static const struct of_device_id i2c_hid_of_match[] = {
140	{ .compatible = "hid-over-i2c" },
141	{},
142};
143MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
144#endif
145
146static const struct i2c_device_id i2c_hid_of_id_table[] = {
147	{ "hid", 0 },
148	{ "hid-over-i2c", 0 },
149	{ },
150};
151MODULE_DEVICE_TABLE(i2c, i2c_hid_of_id_table);
152
153static struct i2c_driver i2c_hid_of_driver = {
154	.driver = {
155		.name	= "i2c_hid_of",
156		.pm	= &i2c_hid_core_pm,
157		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
158		.of_match_table = of_match_ptr(i2c_hid_of_match),
159	},
160
161	.probe		= i2c_hid_of_probe,
162	.remove		= i2c_hid_core_remove,
163	.shutdown	= i2c_hid_core_shutdown,
164	.id_table	= i2c_hid_of_id_table,
165};
166
167module_i2c_driver(i2c_hid_of_driver);
168
169MODULE_DESCRIPTION("HID over I2C OF driver");
170MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
171MODULE_LICENSE("GPL");