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