drivers/extcon/extcon-usb-gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /**
   3  * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
   4  *
   5  * Copyright (C) 2015 Texas Instruments Incorporated - https://www.ti.com
   6  * Author: Roger Quadros <rogerq@ti.com>
   7  */
   8
   9 #include <linux/extcon-provider.h>
  10 #include <linux/gpio.h>
  11 #include <linux/gpio/consumer.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/of_gpio.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/slab.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/pinctrl/consumer.h>
  22
  23 #define USB_GPIO_DEBOUNCE_MS    20      /* ms */
  24
  25 struct usb_extcon_info {
  26         struct device *dev;
  27         struct extcon_dev *edev;
  28
  29         struct gpio_desc *id_gpiod;
  30         struct gpio_desc *vbus_gpiod;
  31         int id_irq;
  32         int vbus_irq;
  33
  34         unsigned long debounce_jiffies;
  35         struct delayed_work wq_detcable;
  36 };
  37
  38 static const unsigned int usb_extcon_cable[] = {
  39         EXTCON_USB,
  40         EXTCON_USB_HOST,
  41         EXTCON_NONE,
  42 };
  43
  44 /*
  45  * "USB" = VBUS and "USB-HOST" = !ID, so we have:
  46  * Both "USB" and "USB-HOST" can't be set as active at the
  47  * same time so if "USB-HOST" is active (i.e. ID is 0)  we keep "USB" inactive
  48  * even if VBUS is on.
  49  *
  50  *  State              |    ID   |   VBUS
  51  * ----------------------------------------
  52  *  [1] USB            |    H    |    H
  53  *  [2] none           |    H    |    L
  54  *  [3] USB-HOST       |    L    |    H
  55  *  [4] USB-HOST       |    L    |    L
  56  *
  57  * In case we have only one of these signals:
  58  * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
  59  * - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
  60 */
  61 static void usb_extcon_detect_cable(struct work_struct *work)
  62 {
  63         int id, vbus;
  64         struct usb_extcon_info *info = container_of(to_delayed_work(work),
  65                                                     struct usb_extcon_info,
  66                                                     wq_detcable);
  67
  68         /* check ID and VBUS and update cable state */
  69         id = info->id_gpiod ?
  70                 gpiod_get_value_cansleep(info->id_gpiod) : 1;
  71         vbus = info->vbus_gpiod ?
  72                 gpiod_get_value_cansleep(info->vbus_gpiod) : id;
  73
  74         /* at first we clean states which are no longer active */
  75         if (id)
  76                 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
  77         if (!vbus)
  78                 extcon_set_state_sync(info->edev, EXTCON_USB, false);
  79
  80         if (!id) {
  81                 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
  82         } else {
  83                 if (vbus)
  84                         extcon_set_state_sync(info->edev, EXTCON_USB, true);
  85         }
  86 }
  87
  88 static irqreturn_t usb_irq_handler(int irq, void *dev_id)
  89 {
  90         struct usb_extcon_info *info = dev_id;
  91
  92         queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
  93                            info->debounce_jiffies);
  94
  95         return IRQ_HANDLED;
  96 }
  97
  98 static int usb_extcon_probe(struct platform_device *pdev)
  99 {
 100         struct device *dev = &pdev->dev;
 101         struct device_node *np = dev->of_node;
 102         struct usb_extcon_info *info;
 103         int ret;
 104
 105         if (!np)
 106                 return -EINVAL;
 107
 108         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 109         if (!info)
 110                 return -ENOMEM;
 111
 112         info->dev = dev;
 113         info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
 114         info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
 115                                                    GPIOD_IN);
 116
 117         if (!info->id_gpiod && !info->vbus_gpiod) {
 118                 dev_err(dev, "failed to get gpios\n");
 119                 return -ENODEV;
 120         }
 121
 122         if (IS_ERR(info->id_gpiod))
 123                 return PTR_ERR(info->id_gpiod);
 124
 125         if (IS_ERR(info->vbus_gpiod))
 126                 return PTR_ERR(info->vbus_gpiod);
 127
 128         info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
 129         if (IS_ERR(info->edev)) {
 130                 dev_err(dev, "failed to allocate extcon device\n");
 131                 return -ENOMEM;
 132         }
 133
 134         ret = devm_extcon_dev_register(dev, info->edev);
 135         if (ret < 0) {
 136                 dev_err(dev, "failed to register extcon device\n");
 137                 return ret;
 138         }
 139
 140         if (info->id_gpiod)
 141                 ret = gpiod_set_debounce(info->id_gpiod,
 142                                          USB_GPIO_DEBOUNCE_MS * 1000);
 143         if (!ret && info->vbus_gpiod)
 144                 ret = gpiod_set_debounce(info->vbus_gpiod,
 145                                          USB_GPIO_DEBOUNCE_MS * 1000);
 146
 147         if (ret < 0)
 148                 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
 149
 150         INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
 151
 152         if (info->id_gpiod) {
 153                 info->id_irq = gpiod_to_irq(info->id_gpiod);
 154                 if (info->id_irq < 0) {
 155                         dev_err(dev, "failed to get ID IRQ\n");
 156                         return info->id_irq;
 157                 }
 158
 159                 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 160                                                 usb_irq_handler,
 161                                                 IRQF_TRIGGER_RISING |
 162                                                 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 163                                                 pdev->name, info);
 164                 if (ret < 0) {
 165                         dev_err(dev, "failed to request handler for ID IRQ\n");
 166                         return ret;
 167                 }
 168         }
 169
 170         if (info->vbus_gpiod) {
 171                 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 172                 if (info->vbus_irq < 0) {
 173                         dev_err(dev, "failed to get VBUS IRQ\n");
 174                         return info->vbus_irq;
 175                 }
 176
 177                 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 178                                                 usb_irq_handler,
 179                                                 IRQF_TRIGGER_RISING |
 180                                                 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 181                                                 pdev->name, info);
 182                 if (ret < 0) {
 183                         dev_err(dev, "failed to request handler for VBUS IRQ\n");
 184                         return ret;
 185                 }
 186         }
 187
 188         platform_set_drvdata(pdev, info);
 189         device_set_wakeup_capable(&pdev->dev, true);
 190
 191         /* Perform initial detection */
 192         usb_extcon_detect_cable(&info->wq_detcable.work);
 193
 194         return 0;
 195 }
 196
 197 static int usb_extcon_remove(struct platform_device *pdev)
 198 {
 199         struct usb_extcon_info *info = platform_get_drvdata(pdev);
 200
 201         cancel_delayed_work_sync(&info->wq_detcable);
 202         device_init_wakeup(&pdev->dev, false);
 203
 204         return 0;
 205 }
 206
 207 #ifdef CONFIG_PM_SLEEP
 208 static int usb_extcon_suspend(struct device *dev)
 209 {
 210         struct usb_extcon_info *info = dev_get_drvdata(dev);
 211         int ret = 0;
 212
 213         if (device_may_wakeup(dev)) {
 214                 if (info->id_gpiod) {
 215                         ret = enable_irq_wake(info->id_irq);
 216                         if (ret)
 217                                 return ret;
 218                 }
 219                 if (info->vbus_gpiod) {
 220                         ret = enable_irq_wake(info->vbus_irq);
 221                         if (ret) {
 222                                 if (info->id_gpiod)
 223                                         disable_irq_wake(info->id_irq);
 224
 225                                 return ret;
 226                         }
 227                 }
 228         }
 229
 230         /*
 231          * We don't want to process any IRQs after this point
 232          * as GPIOs used behind I2C subsystem might not be
 233          * accessible until resume completes. So disable IRQ.
 234          */
 235         if (info->id_gpiod)
 236                 disable_irq(info->id_irq);
 237         if (info->vbus_gpiod)
 238                 disable_irq(info->vbus_irq);
 239
 240         if (!device_may_wakeup(dev))
 241                 pinctrl_pm_select_sleep_state(dev);
 242
 243         return ret;
 244 }
 245
 246 static int usb_extcon_resume(struct device *dev)
 247 {
 248         struct usb_extcon_info *info = dev_get_drvdata(dev);
 249         int ret = 0;
 250
 251         if (!device_may_wakeup(dev))
 252                 pinctrl_pm_select_default_state(dev);
 253
 254         if (device_may_wakeup(dev)) {
 255                 if (info->id_gpiod) {
 256                         ret = disable_irq_wake(info->id_irq);
 257                         if (ret)
 258                                 return ret;
 259                 }
 260                 if (info->vbus_gpiod) {
 261                         ret = disable_irq_wake(info->vbus_irq);
 262                         if (ret) {
 263                                 if (info->id_gpiod)
 264                                         enable_irq_wake(info->id_irq);
 265
 266                                 return ret;
 267                         }
 268                 }
 269         }
 270
 271         if (info->id_gpiod)
 272                 enable_irq(info->id_irq);
 273         if (info->vbus_gpiod)
 274                 enable_irq(info->vbus_irq);
 275
 276         queue_delayed_work(system_power_efficient_wq,
 277                            &info->wq_detcable, 0);
 278
 279         return ret;
 280 }
 281 #endif
 282
 283 static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
 284                          usb_extcon_suspend, usb_extcon_resume);
 285
 286 static const struct of_device_id usb_extcon_dt_match[] = {
 287         { .compatible = "linux,extcon-usb-gpio", },
 288         { /* sentinel */ }
 289 };
 290 MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
 291
 292 static const struct platform_device_id usb_extcon_platform_ids[] = {
 293         { .name = "extcon-usb-gpio", },
 294         { /* sentinel */ }
 295 };
 296 MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);
 297
 298 static struct platform_driver usb_extcon_driver = {
 299         .probe          = usb_extcon_probe,
 300         .remove         = usb_extcon_remove,
 301         .driver         = {
 302                 .name   = "extcon-usb-gpio",
 303                 .pm     = &usb_extcon_pm_ops,
 304                 .of_match_table = usb_extcon_dt_match,
 305         },
 306         .id_table = usb_extcon_platform_ids,
 307 };
 308
 309 module_platform_driver(usb_extcon_driver);
 310
 311 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
 312 MODULE_DESCRIPTION("USB GPIO extcon driver");
 313 MODULE_LICENSE("GPL v2");