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/consumer.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
33 struct 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
43 static const unsigned int int3496_cable[] = {
44 EXTCON_USB_HOST,
45 EXTCON_NONE,
46 };
47
48 static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
49 static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
50 static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
51
52 static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
53 /*
54 * Some platforms have a bug in ACPI GPIO description making IRQ
55 * GPIO to be output only. Ask the GPIO core to ignore this limit.
56 */
57 { "id-gpios", &id_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
58 { "vbus-gpios", &vbus_gpios, 1 },
59 { "mux-gpios", &mux_gpios, 1 },
60 { },
61 };
62
int3496_do_usb_id(struct work_struct * work)63 static void int3496_do_usb_id(struct work_struct *work)
64 {
65 struct int3496_data *data =
66 container_of(work, struct int3496_data, work.work);
67 int id = gpiod_get_value_cansleep(data->gpio_usb_id);
68
69 /* id == 1: PERIPHERAL, id == 0: HOST */
70 dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
71
72 /*
73 * Peripheral: set USB mux to peripheral and disable VBUS
74 * Host: set USB mux to host and enable VBUS
75 */
76 if (!IS_ERR(data->gpio_usb_mux))
77 gpiod_direction_output(data->gpio_usb_mux, id);
78
79 if (!IS_ERR(data->gpio_vbus_en))
80 gpiod_direction_output(data->gpio_vbus_en, !id);
81
82 extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
83 }
84
int3496_thread_isr(int irq,void * priv)85 static irqreturn_t int3496_thread_isr(int irq, void *priv)
86 {
87 struct int3496_data *data = priv;
88
89 /* Let the pin settle before processing it */
90 mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
91
92 return IRQ_HANDLED;
93 }
94
int3496_probe(struct platform_device * pdev)95 static int int3496_probe(struct platform_device *pdev)
96 {
97 struct device *dev = &pdev->dev;
98 struct int3496_data *data;
99 int ret;
100
101 ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
102 if (ret) {
103 dev_err(dev, "can't add GPIO ACPI mapping\n");
104 return ret;
105 }
106
107 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
108 if (!data)
109 return -ENOMEM;
110
111 data->dev = dev;
112 INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
113
114 data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
115 if (IS_ERR(data->gpio_usb_id)) {
116 ret = PTR_ERR(data->gpio_usb_id);
117 dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
118 return ret;
119 }
120
121 data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
122 if (data->usb_id_irq < 0) {
123 dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
124 return data->usb_id_irq;
125 }
126
127 data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
128 if (IS_ERR(data->gpio_vbus_en))
129 dev_info(dev, "can't request VBUS EN GPIO\n");
130
131 data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
132 if (IS_ERR(data->gpio_usb_mux))
133 dev_info(dev, "can't request USB MUX GPIO\n");
134
135 /* register extcon device */
136 data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
137 if (IS_ERR(data->edev))
138 return -ENOMEM;
139
140 ret = devm_extcon_dev_register(dev, data->edev);
141 if (ret < 0) {
142 dev_err(dev, "can't register extcon device: %d\n", ret);
143 return ret;
144 }
145
146 ret = devm_request_threaded_irq(dev, data->usb_id_irq,
147 NULL, int3496_thread_isr,
148 IRQF_SHARED | IRQF_ONESHOT |
149 IRQF_TRIGGER_RISING |
150 IRQF_TRIGGER_FALLING,
151 dev_name(dev), data);
152 if (ret < 0) {
153 dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
154 return ret;
155 }
156
157 /* process id-pin so that we start with the right status */
158 queue_delayed_work(system_wq, &data->work, 0);
159 flush_delayed_work(&data->work);
160
161 platform_set_drvdata(pdev, data);
162
163 return 0;
164 }
165
int3496_remove(struct platform_device * pdev)166 static int int3496_remove(struct platform_device *pdev)
167 {
168 struct int3496_data *data = platform_get_drvdata(pdev);
169
170 devm_free_irq(&pdev->dev, data->usb_id_irq, data);
171 cancel_delayed_work_sync(&data->work);
172
173 return 0;
174 }
175
176 static const struct acpi_device_id int3496_acpi_match[] = {
177 { "INT3496" },
178 { }
179 };
180 MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
181
182 static struct platform_driver int3496_driver = {
183 .driver = {
184 .name = "intel-int3496",
185 .acpi_match_table = int3496_acpi_match,
186 },
187 .probe = int3496_probe,
188 .remove = int3496_remove,
189 };
190
191 module_platform_driver(int3496_driver);
192
193 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
194 MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
195 MODULE_LICENSE("GPL");
196
