drivers/extcon/extcon-usb-gpio.c

   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/gpio.h>
  19 #include <linux/gpio/consumer.h>
  20 #include <linux/init.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/irq.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/of_gpio.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/pm_wakeirq.h>
  28 #include <linux/slab.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/acpi.h>
  31
  32 #define USB_GPIO_DEBOUNCE_MS    20      /* ms */
  33
  34 struct usb_extcon_info {
  35         struct device *dev;
  36         struct extcon_dev *edev;
  37
  38         struct gpio_desc *id_gpiod;
  39         int id_irq;
  40
  41         unsigned long debounce_jiffies;
  42         struct delayed_work wq_detcable;
  43 };
  44
  45 static const unsigned int usb_extcon_cable[] = {
  46         EXTCON_USB,
  47         EXTCON_USB_HOST,
  48         EXTCON_NONE,
  49 };
  50
  51 static void usb_extcon_detect_cable(struct work_struct *work)
  52 {
  53         int id;
  54         struct usb_extcon_info *info = container_of(to_delayed_work(work),
  55                                                     struct usb_extcon_info,
  56                                                     wq_detcable);
  57
  58         /* check ID and update cable state */
  59         id = gpiod_get_value_cansleep(info->id_gpiod);
  60         if (id) {
  61                 /*
  62                  * ID = 1 means USB HOST cable detached.
  63                  * As we don't have event for USB peripheral cable attached,
  64                  * we simulate USB peripheral attach here.
  65                  */
  66                 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
  67                 extcon_set_state_sync(info->edev, EXTCON_USB, true);
  68         } else {
  69                 /*
  70                  * ID = 0 means USB HOST cable attached.
  71                  * As we don't have event for USB peripheral cable detached,
  72                  * we simulate USB peripheral detach here.
  73                  */
  74                 extcon_set_state_sync(info->edev, EXTCON_USB, false);
  75                 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
  76         }
  77 }
  78
  79 static irqreturn_t usb_irq_handler(int irq, void *dev_id)
  80 {
  81         struct usb_extcon_info *info = dev_id;
  82
  83         queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
  84                            info->debounce_jiffies);
  85
  86         return IRQ_HANDLED;
  87 }
  88
  89 static int usb_extcon_probe(struct platform_device *pdev)
  90 {
  91         struct device *dev = &pdev->dev;
  92         struct device_node *np = dev->of_node;
  93         struct usb_extcon_info *info;
  94         int ret;
  95
  96         if (!np && !ACPI_HANDLE(dev))
  97                 return -EINVAL;
  98
  99         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 100         if (!info)
 101                 return -ENOMEM;
 102
 103         info->dev = dev;
 104         info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
 105         if (IS_ERR(info->id_gpiod)) {
 106                 dev_err(dev, "failed to get ID GPIO\n");
 107                 return PTR_ERR(info->id_gpiod);
 108         }
 109
 110         info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
 111         if (IS_ERR(info->edev)) {
 112                 dev_err(dev, "failed to allocate extcon device\n");
 113                 return -ENOMEM;
 114         }
 115
 116         ret = devm_extcon_dev_register(dev, info->edev);
 117         if (ret < 0) {
 118                 dev_err(dev, "failed to register extcon device\n");
 119                 return ret;
 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         platform_set_drvdata(pdev, info);
 146         device_init_wakeup(dev, true);
 147         dev_pm_set_wake_irq(dev, info->id_irq);
 148
 149         /* Perform initial detection */
 150         usb_extcon_detect_cable(&info->wq_detcable.work);
 151
 152         return 0;
 153 }
 154
 155 static int usb_extcon_remove(struct platform_device *pdev)
 156 {
 157         struct usb_extcon_info *info = platform_get_drvdata(pdev);
 158
 159         cancel_delayed_work_sync(&info->wq_detcable);
 160
 161         dev_pm_clear_wake_irq(&pdev->dev);
 162         device_init_wakeup(&pdev->dev, false);
 163
 164         return 0;
 165 }
 166
 167 #ifdef CONFIG_PM_SLEEP
 168 static int usb_extcon_suspend(struct device *dev)
 169 {
 170         struct usb_extcon_info *info = dev_get_drvdata(dev);
 171         int ret = 0;
 172
 173         /*
 174          * We don't want to process any IRQs after this point
 175          * as GPIOs used behind I2C subsystem might not be
 176          * accessible until resume completes. So disable IRQ.
 177          */
 178         disable_irq(info->id_irq);
 179
 180         return ret;
 181 }
 182
 183 static int usb_extcon_resume(struct device *dev)
 184 {
 185         struct usb_extcon_info *info = dev_get_drvdata(dev);
 186         int ret = 0;
 187
 188         enable_irq(info->id_irq);
 189         if (!device_may_wakeup(dev))
 190                 queue_delayed_work(system_power_efficient_wq,
 191                                    &info->wq_detcable, 0);
 192
 193         return ret;
 194 }
 195 #endif
 196
 197 static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
 198                          usb_extcon_suspend, usb_extcon_resume);
 199
 200 static const struct of_device_id usb_extcon_dt_match[] = {
 201         { .compatible = "linux,extcon-usb-gpio", },
 202         { /* sentinel */ }
 203 };
 204 MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
 205
 206 static const struct platform_device_id usb_extcon_platform_ids[] = {
 207         { .name = "extcon-usb-gpio", },
 208         { /* sentinel */ }
 209 };
 210 MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);
 211
 212 static struct platform_driver usb_extcon_driver = {
 213         .probe          = usb_extcon_probe,
 214         .remove         = usb_extcon_remove,
 215         .driver         = {
 216                 .name   = "extcon-usb-gpio",
 217                 .pm     = &usb_extcon_pm_ops,
 218                 .of_match_table = usb_extcon_dt_match,
 219         },
 220         .id_table = usb_extcon_platform_ids,
 221 };
 222
 223 module_platform_driver(usb_extcon_driver);
 224
 225 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
 226 MODULE_DESCRIPTION("USB GPIO extcon driver");
 227 MODULE_LICENSE("GPL v2");