Roger Quadros | e52817f | 2015-02-02 12:21:59 +0200 | [diff] [blame] | 1 | /** |
| 2 | * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver |
| 3 | * |
| 4 | * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com |
| 5 | * Author: Roger Quadros <rogerq@ti.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/extcon.h> |
| 18 | #include <linux/init.h> |
| 19 | #include <linux/interrupt.h> |
| 20 | #include <linux/irq.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/of_gpio.h> |
| 24 | #include <linux/platform_device.h> |
| 25 | #include <linux/slab.h> |
| 26 | #include <linux/workqueue.h> |
| 27 | |
| 28 | #define USB_GPIO_DEBOUNCE_MS 20 /* ms */ |
| 29 | |
| 30 | struct usb_extcon_info { |
| 31 | struct device *dev; |
| 32 | struct extcon_dev *edev; |
| 33 | |
| 34 | struct gpio_desc *id_gpiod; |
| 35 | int id_irq; |
| 36 | |
| 37 | unsigned long debounce_jiffies; |
| 38 | struct delayed_work wq_detcable; |
| 39 | }; |
| 40 | |
| 41 | /* List of detectable cables */ |
| 42 | enum { |
| 43 | EXTCON_CABLE_USB = 0, |
| 44 | EXTCON_CABLE_USB_HOST, |
| 45 | |
| 46 | EXTCON_CABLE_END, |
| 47 | }; |
| 48 | |
| 49 | static const char *usb_extcon_cable[] = { |
| 50 | [EXTCON_CABLE_USB] = "USB", |
| 51 | [EXTCON_CABLE_USB_HOST] = "USB-HOST", |
| 52 | NULL, |
| 53 | }; |
| 54 | |
| 55 | static void usb_extcon_detect_cable(struct work_struct *work) |
| 56 | { |
| 57 | int id; |
| 58 | struct usb_extcon_info *info = container_of(to_delayed_work(work), |
| 59 | struct usb_extcon_info, |
| 60 | wq_detcable); |
| 61 | |
| 62 | /* check ID and update cable state */ |
| 63 | id = gpiod_get_value_cansleep(info->id_gpiod); |
| 64 | if (id) { |
| 65 | /* |
| 66 | * ID = 1 means USB HOST cable detached. |
| 67 | * As we don't have event for USB peripheral cable attached, |
| 68 | * we simulate USB peripheral attach here. |
| 69 | */ |
| 70 | extcon_set_cable_state(info->edev, |
| 71 | usb_extcon_cable[EXTCON_CABLE_USB_HOST], |
| 72 | false); |
| 73 | extcon_set_cable_state(info->edev, |
| 74 | usb_extcon_cable[EXTCON_CABLE_USB], |
| 75 | true); |
| 76 | } else { |
| 77 | /* |
| 78 | * ID = 0 means USB HOST cable attached. |
| 79 | * As we don't have event for USB peripheral cable detached, |
| 80 | * we simulate USB peripheral detach here. |
| 81 | */ |
| 82 | extcon_set_cable_state(info->edev, |
| 83 | usb_extcon_cable[EXTCON_CABLE_USB], |
| 84 | false); |
| 85 | extcon_set_cable_state(info->edev, |
| 86 | usb_extcon_cable[EXTCON_CABLE_USB_HOST], |
| 87 | true); |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | static irqreturn_t usb_irq_handler(int irq, void *dev_id) |
| 92 | { |
| 93 | struct usb_extcon_info *info = dev_id; |
| 94 | |
| 95 | queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, |
| 96 | info->debounce_jiffies); |
| 97 | |
| 98 | return IRQ_HANDLED; |
| 99 | } |
| 100 | |
| 101 | static int usb_extcon_probe(struct platform_device *pdev) |
| 102 | { |
| 103 | struct device *dev = &pdev->dev; |
| 104 | struct device_node *np = dev->of_node; |
| 105 | struct usb_extcon_info *info; |
| 106 | int ret; |
| 107 | |
| 108 | if (!np) |
| 109 | return -EINVAL; |
| 110 | |
| 111 | info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); |
| 112 | if (!info) |
| 113 | return -ENOMEM; |
| 114 | |
| 115 | info->dev = dev; |
| 116 | info->id_gpiod = devm_gpiod_get(&pdev->dev, "id"); |
| 117 | if (IS_ERR(info->id_gpiod)) { |
| 118 | dev_err(dev, "failed to get ID GPIO\n"); |
| 119 | return PTR_ERR(info->id_gpiod); |
| 120 | } |
| 121 | |
| 122 | ret = gpiod_set_debounce(info->id_gpiod, |
| 123 | USB_GPIO_DEBOUNCE_MS * 1000); |
| 124 | if (ret < 0) |
| 125 | info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS); |
| 126 | |
| 127 | INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable); |
| 128 | |
| 129 | info->id_irq = gpiod_to_irq(info->id_gpiod); |
| 130 | if (info->id_irq < 0) { |
| 131 | dev_err(dev, "failed to get ID IRQ\n"); |
| 132 | return info->id_irq; |
| 133 | } |
| 134 | |
| 135 | ret = devm_request_threaded_irq(dev, info->id_irq, NULL, |
| 136 | usb_irq_handler, |
| 137 | IRQF_TRIGGER_RISING | |
| 138 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| 139 | pdev->name, info); |
| 140 | if (ret < 0) { |
| 141 | dev_err(dev, "failed to request handler for ID IRQ\n"); |
| 142 | return ret; |
| 143 | } |
| 144 | |
| 145 | info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable); |
| 146 | if (IS_ERR(info->edev)) { |
| 147 | dev_err(dev, "failed to allocate extcon device\n"); |
| 148 | return -ENOMEM; |
| 149 | } |
| 150 | |
| 151 | ret = devm_extcon_dev_register(dev, info->edev); |
| 152 | if (ret < 0) { |
| 153 | dev_err(dev, "failed to register extcon device\n"); |
| 154 | return ret; |
| 155 | } |
| 156 | |
| 157 | platform_set_drvdata(pdev, info); |
| 158 | device_init_wakeup(dev, 1); |
| 159 | |
| 160 | /* Perform initial detection */ |
| 161 | usb_extcon_detect_cable(&info->wq_detcable.work); |
| 162 | |
| 163 | return 0; |
| 164 | } |
| 165 | |
| 166 | static int usb_extcon_remove(struct platform_device *pdev) |
| 167 | { |
| 168 | struct usb_extcon_info *info = platform_get_drvdata(pdev); |
| 169 | |
| 170 | cancel_delayed_work_sync(&info->wq_detcable); |
| 171 | |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | #ifdef CONFIG_PM_SLEEP |
| 176 | static int usb_extcon_suspend(struct device *dev) |
| 177 | { |
| 178 | struct usb_extcon_info *info = dev_get_drvdata(dev); |
| 179 | int ret = 0; |
| 180 | |
| 181 | if (device_may_wakeup(dev)) { |
| 182 | ret = enable_irq_wake(info->id_irq); |
| 183 | if (ret) |
| 184 | return ret; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * We don't want to process any IRQs after this point |
| 189 | * as GPIOs used behind I2C subsystem might not be |
| 190 | * accessible until resume completes. So disable IRQ. |
| 191 | */ |
| 192 | disable_irq(info->id_irq); |
| 193 | |
| 194 | return ret; |
| 195 | } |
| 196 | |
| 197 | static int usb_extcon_resume(struct device *dev) |
| 198 | { |
| 199 | struct usb_extcon_info *info = dev_get_drvdata(dev); |
| 200 | int ret = 0; |
| 201 | |
| 202 | if (device_may_wakeup(dev)) { |
| 203 | ret = disable_irq_wake(info->id_irq); |
| 204 | if (ret) |
| 205 | return ret; |
| 206 | } |
| 207 | |
| 208 | enable_irq(info->id_irq); |
| 209 | |
| 210 | return ret; |
| 211 | } |
| 212 | #endif |
| 213 | |
| 214 | static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops, |
| 215 | usb_extcon_suspend, usb_extcon_resume); |
| 216 | |
Chanwoo Choi | 34825e5 | 2015-03-07 01:41:36 +0900 | [diff] [blame] | 217 | static const struct of_device_id usb_extcon_dt_match[] = { |
Roger Quadros | e52817f | 2015-02-02 12:21:59 +0200 | [diff] [blame] | 218 | { .compatible = "linux,extcon-usb-gpio", }, |
| 219 | { /* sentinel */ } |
| 220 | }; |
| 221 | MODULE_DEVICE_TABLE(of, usb_extcon_dt_match); |
| 222 | |
| 223 | static struct platform_driver usb_extcon_driver = { |
| 224 | .probe = usb_extcon_probe, |
| 225 | .remove = usb_extcon_remove, |
| 226 | .driver = { |
| 227 | .name = "extcon-usb-gpio", |
| 228 | .pm = &usb_extcon_pm_ops, |
| 229 | .of_match_table = usb_extcon_dt_match, |
| 230 | }, |
| 231 | }; |
| 232 | |
| 233 | module_platform_driver(usb_extcon_driver); |
| 234 | |
| 235 | MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>"); |
| 236 | MODULE_DESCRIPTION("USB GPIO extcon driver"); |
| 237 | MODULE_LICENSE("GPL v2"); |