tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Intel INT3496 ACPI device extcon driver
3 *
4 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
5 *
6 * Based on android x86 kernel code which is:
7 *
8 * Copyright (c) 2014, Intel Corporation.
9 * Author: David Cohen <david.a.cohen@linux.intel.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 */
20
21#include <linux/acpi.h>
22#include <linux/extcon-provider.h>
23#include <linux/gpio.h>
24#include <linux/interrupt.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27
28#define INT3496_GPIO_USB_ID 0
29#define INT3496_GPIO_VBUS_EN 1
30#define INT3496_GPIO_USB_MUX 2
31#define DEBOUNCE_TIME msecs_to_jiffies(50)
32
33struct int3496_data {
34 struct device *dev;
35 struct extcon_dev *edev;
36 struct delayed_work work;
37 struct gpio_desc *gpio_usb_id;
38 struct gpio_desc *gpio_vbus_en;
39 struct gpio_desc *gpio_usb_mux;
40 int usb_id_irq;
41};
42
43static const unsigned int int3496_cable[] = {
44 EXTCON_USB_HOST,
45 EXTCON_NONE,
46};
47
48static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
49static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
50static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
51
52static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
53 { "id-gpios", &id_gpios, 1 },
54 { "vbus-gpios", &vbus_gpios, 1 },
55 { "mux-gpios", &mux_gpios, 1 },
56 { },
57};
58
59static void int3496_do_usb_id(struct work_struct *work)
60{
61 struct int3496_data *data =
62 container_of(work, struct int3496_data, work.work);
63 int id = gpiod_get_value_cansleep(data->gpio_usb_id);
64
65 /* id == 1: PERIPHERAL, id == 0: HOST */
66 dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
67
68 /*
69 * Peripheral: set USB mux to peripheral and disable VBUS
70 * Host: set USB mux to host and enable VBUS
71 */
72 if (!IS_ERR(data->gpio_usb_mux))
73 gpiod_direction_output(data->gpio_usb_mux, id);
74
75 if (!IS_ERR(data->gpio_vbus_en))
76 gpiod_direction_output(data->gpio_vbus_en, !id);
77
78 extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
79}
80
81static irqreturn_t int3496_thread_isr(int irq, void *priv)
82{
83 struct int3496_data *data = priv;
84
85 /* Let the pin settle before processing it */
86 mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
87
88 return IRQ_HANDLED;
89}
90
91static int int3496_probe(struct platform_device *pdev)
92{
93 struct device *dev = &pdev->dev;
94 struct int3496_data *data;
95 int ret;
96
97 ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
98 if (ret) {
99 dev_err(dev, "can't add GPIO ACPI mapping\n");
100 return ret;
101 }
102
103 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
104 if (!data)
105 return -ENOMEM;
106
107 data->dev = dev;
108 INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
109
110 data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
111 if (IS_ERR(data->gpio_usb_id)) {
112 ret = PTR_ERR(data->gpio_usb_id);
113 dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
114 return ret;
115 } else if (gpiod_get_direction(data->gpio_usb_id) != GPIOF_DIR_IN) {
116 dev_warn(dev, FW_BUG "USB ID GPIO not in input mode, fixing\n");
117 gpiod_direction_input(data->gpio_usb_id);
118 }
119
120 data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
121 if (data->usb_id_irq < 0) {
122 dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
123 return data->usb_id_irq;
124 }
125
126 data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
127 if (IS_ERR(data->gpio_vbus_en))
128 dev_info(dev, "can't request VBUS EN GPIO\n");
129
130 data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
131 if (IS_ERR(data->gpio_usb_mux))
132 dev_info(dev, "can't request USB MUX GPIO\n");
133
134 /* register extcon device */
135 data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
136 if (IS_ERR(data->edev))
137 return -ENOMEM;
138
139 ret = devm_extcon_dev_register(dev, data->edev);
140 if (ret < 0) {
141 dev_err(dev, "can't register extcon device: %d\n", ret);
142 return ret;
143 }
144
145 ret = devm_request_threaded_irq(dev, data->usb_id_irq,
146 NULL, int3496_thread_isr,
147 IRQF_SHARED | IRQF_ONESHOT |
148 IRQF_TRIGGER_RISING |
149 IRQF_TRIGGER_FALLING,
150 dev_name(dev), data);
151 if (ret < 0) {
152 dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
153 return ret;
154 }
155
156 /* queue initial processing of id-pin */
157 queue_delayed_work(system_wq, &data->work, 0);
158
159 platform_set_drvdata(pdev, data);
160
161 return 0;
162}
163
164static int int3496_remove(struct platform_device *pdev)
165{
166 struct int3496_data *data = platform_get_drvdata(pdev);
167
168 devm_free_irq(&pdev->dev, data->usb_id_irq, data);
169 cancel_delayed_work_sync(&data->work);
170
171 return 0;
172}
173
174static const struct acpi_device_id int3496_acpi_match[] = {
175 { "INT3496" },
176 { }
177};
178MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
179
180static struct platform_driver int3496_driver = {
181 .driver = {
182 .name = "intel-int3496",
183 .acpi_match_table = int3496_acpi_match,
184 },
185 .probe = int3496_probe,
186 .remove = int3496_remove,
187};
188
189module_platform_driver(int3496_driver);
190
191MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
192MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
193MODULE_LICENSE("GPL");