drivers/usb/common/usb-conn-gpio.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB GPIO Based Connection Detection Driver
   4  *
   5  * Copyright (C) 2019 MediaTek Inc.
   6  *
   7  * Author: Chunfeng Yun <[email protected]>
   8  *
   9  * Some code borrowed from drivers/extcon/extcon-usb-gpio.c
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/gpio/consumer.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/irq.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18 #include <linux/pinctrl/consumer.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/power_supply.h>
  21 #include <linux/regulator/consumer.h>
  22 #include <linux/usb/role.h>
  23
  24 #define USB_GPIO_DEB_MS         20      /* ms */
  25 #define USB_GPIO_DEB_US         ((USB_GPIO_DEB_MS) * 1000)      /* us */
  26
  27 #define USB_CONN_IRQF   \
  28         (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)
  29
  30 struct usb_conn_info {
  31         struct device *dev;
  32         struct usb_role_switch *role_sw;
  33         enum usb_role last_role;
  34         struct regulator *vbus;
  35         struct delayed_work dw_det;
  36         unsigned long debounce_jiffies;
  37
  38         struct gpio_desc *id_gpiod;
  39         struct gpio_desc *vbus_gpiod;
  40         int id_irq;
  41         int vbus_irq;
  42
  43         struct power_supply_desc desc;
  44         struct power_supply *charger;
  45 };
  46
  47 /*
  48  * "DEVICE" = VBUS and "HOST" = !ID, so we have:
  49  * Both "DEVICE" and "HOST" can't be set as active at the same time
  50  * so if "HOST" is active (i.e. ID is 0)  we keep "DEVICE" inactive
  51  * even if VBUS is on.
  52  *
  53  *  Role          |   ID  |  VBUS
  54  * ------------------------------------
  55  *  [1] DEVICE    |   H   |   H
  56  *  [2] NONE      |   H   |   L
  57  *  [3] HOST      |   L   |   H
  58  *  [4] HOST      |   L   |   L
  59  *
  60  * In case we have only one of these signals:
  61  * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1
  62  * - ID only - we want to distinguish between [1] and [4], so VBUS = ID
  63  */
  64 static void usb_conn_detect_cable(struct work_struct *work)
  65 {
  66         struct usb_conn_info *info;
  67         enum usb_role role;
  68         int id, vbus, ret;
  69
  70         info = container_of(to_delayed_work(work),
  71                             struct usb_conn_info, dw_det);
  72
  73         /* check ID and VBUS */
  74         id = info->id_gpiod ?
  75                 gpiod_get_value_cansleep(info->id_gpiod) : 1;
  76         vbus = info->vbus_gpiod ?
  77                 gpiod_get_value_cansleep(info->vbus_gpiod) : id;
  78
  79         if (!id)
  80                 role = USB_ROLE_HOST;
  81         else if (vbus)
  82                 role = USB_ROLE_DEVICE;
  83         else
  84                 role = USB_ROLE_NONE;
  85
  86         dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n",
  87                 usb_role_string(info->last_role), usb_role_string(role), id, vbus);
  88
  89         if (info->last_role == role) {
  90                 dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role));
  91                 return;
  92         }
  93
  94         if (info->last_role == USB_ROLE_HOST && info->vbus)
  95                 regulator_disable(info->vbus);
  96
  97         ret = usb_role_switch_set_role(info->role_sw, role);
  98         if (ret)
  99                 dev_err(info->dev, "failed to set role: %d\n", ret);
 100
 101         if (role == USB_ROLE_HOST && info->vbus) {
 102                 ret = regulator_enable(info->vbus);
 103                 if (ret)
 104                         dev_err(info->dev, "enable vbus regulator failed\n");
 105         }
 106
 107         info->last_role = role;
 108
 109         if (info->vbus)
 110                 dev_dbg(info->dev, "vbus regulator is %s\n",
 111                         regulator_is_enabled(info->vbus) ? "enabled" : "disabled");
 112
 113         power_supply_changed(info->charger);
 114 }
 115
 116 static void usb_conn_queue_dwork(struct usb_conn_info *info,
 117                                  unsigned long delay)
 118 {
 119         queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
 120 }
 121
 122 static irqreturn_t usb_conn_isr(int irq, void *dev_id)
 123 {
 124         struct usb_conn_info *info = dev_id;
 125
 126         usb_conn_queue_dwork(info, info->debounce_jiffies);
 127
 128         return IRQ_HANDLED;
 129 }
 130
 131 static enum power_supply_property usb_charger_properties[] = {
 132         POWER_SUPPLY_PROP_ONLINE,
 133 };
 134
 135 static int usb_charger_get_property(struct power_supply *psy,
 136                                     enum power_supply_property psp,
 137                                     union power_supply_propval *val)
 138 {
 139         struct usb_conn_info *info = power_supply_get_drvdata(psy);
 140
 141         switch (psp) {
 142         case POWER_SUPPLY_PROP_ONLINE:
 143                 val->intval = info->last_role == USB_ROLE_DEVICE;
 144                 break;
 145         default:
 146                 return -EINVAL;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int usb_conn_psy_register(struct usb_conn_info *info)
 153 {
 154         struct device *dev = info->dev;
 155         struct power_supply_desc *desc = &info->desc;
 156         struct power_supply_config cfg = {
 157                 .of_node = dev->of_node,
 158         };
 159
 160         desc->name = "usb-charger";
 161         desc->properties = usb_charger_properties;
 162         desc->num_properties = ARRAY_SIZE(usb_charger_properties);
 163         desc->get_property = usb_charger_get_property;
 164         desc->type = POWER_SUPPLY_TYPE_USB;
 165         cfg.drv_data = info;
 166
 167         info->charger = devm_power_supply_register(dev, desc, &cfg);
 168         if (IS_ERR(info->charger))
 169                 dev_err(dev, "Unable to register charger\n");
 170
 171         return PTR_ERR_OR_ZERO(info->charger);
 172 }
 173
 174 static int usb_conn_probe(struct platform_device *pdev)
 175 {
 176         struct device *dev = &pdev->dev;
 177         struct usb_conn_info *info;
 178         int ret = 0;
 179
 180         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 181         if (!info)
 182                 return -ENOMEM;
 183
 184         info->dev = dev;
 185         info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
 186         if (IS_ERR(info->id_gpiod))
 187                 return PTR_ERR(info->id_gpiod);
 188
 189         info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
 190         if (IS_ERR(info->vbus_gpiod))
 191                 return PTR_ERR(info->vbus_gpiod);
 192
 193         if (!info->id_gpiod && !info->vbus_gpiod) {
 194                 dev_err(dev, "failed to get gpios\n");
 195                 return -ENODEV;
 196         }
 197
 198         if (info->id_gpiod)
 199                 ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
 200         if (!ret && info->vbus_gpiod)
 201                 ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
 202         if (ret < 0)
 203                 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
 204
 205         INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
 206
 207         info->vbus = devm_regulator_get_optional(dev, "vbus");
 208         if (PTR_ERR(info->vbus) == -ENODEV)
 209                 info->vbus = NULL;
 210
 211         if (IS_ERR(info->vbus)) {
 212                 ret = PTR_ERR(info->vbus);
 213                 return dev_err_probe(dev, ret, "failed to get vbus :%d\n", ret);
 214         }
 215
 216         info->role_sw = usb_role_switch_get(dev);
 217         if (IS_ERR(info->role_sw))
 218                 return dev_err_probe(dev, PTR_ERR(info->role_sw),
 219                                      "failed to get role switch\n");
 220
 221         ret = usb_conn_psy_register(info);
 222         if (ret)
 223                 goto put_role_sw;
 224
 225         if (info->id_gpiod) {
 226                 info->id_irq = gpiod_to_irq(info->id_gpiod);
 227                 if (info->id_irq < 0) {
 228                         dev_err(dev, "failed to get ID IRQ\n");
 229                         ret = info->id_irq;
 230                         goto put_role_sw;
 231                 }
 232
 233                 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 234                                                 usb_conn_isr, USB_CONN_IRQF,
 235                                                 pdev->name, info);
 236                 if (ret < 0) {
 237                         dev_err(dev, "failed to request ID IRQ\n");
 238                         goto put_role_sw;
 239                 }
 240         }
 241
 242         if (info->vbus_gpiod) {
 243                 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 244                 if (info->vbus_irq < 0) {
 245                         dev_err(dev, "failed to get VBUS IRQ\n");
 246                         ret = info->vbus_irq;
 247                         goto put_role_sw;
 248                 }
 249
 250                 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 251                                                 usb_conn_isr, USB_CONN_IRQF,
 252                                                 pdev->name, info);
 253                 if (ret < 0) {
 254                         dev_err(dev, "failed to request VBUS IRQ\n");
 255                         goto put_role_sw;
 256                 }
 257         }
 258
 259         platform_set_drvdata(pdev, info);
 260         device_set_wakeup_capable(&pdev->dev, true);
 261
 262         /* Perform initial detection */
 263         usb_conn_queue_dwork(info, 0);
 264
 265         return 0;
 266
 267 put_role_sw:
 268         usb_role_switch_put(info->role_sw);
 269         return ret;
 270 }
 271
 272 static int usb_conn_remove(struct platform_device *pdev)
 273 {
 274         struct usb_conn_info *info = platform_get_drvdata(pdev);
 275
 276         cancel_delayed_work_sync(&info->dw_det);
 277
 278         if (info->last_role == USB_ROLE_HOST && info->vbus)
 279                 regulator_disable(info->vbus);
 280
 281         usb_role_switch_put(info->role_sw);
 282
 283         return 0;
 284 }
 285
 286 static int __maybe_unused usb_conn_suspend(struct device *dev)
 287 {
 288         struct usb_conn_info *info = dev_get_drvdata(dev);
 289
 290         if (device_may_wakeup(dev)) {
 291                 if (info->id_gpiod)
 292                         enable_irq_wake(info->id_irq);
 293                 if (info->vbus_gpiod)
 294                         enable_irq_wake(info->vbus_irq);
 295                 return 0;
 296         }
 297
 298         if (info->id_gpiod)
 299                 disable_irq(info->id_irq);
 300         if (info->vbus_gpiod)
 301                 disable_irq(info->vbus_irq);
 302
 303         pinctrl_pm_select_sleep_state(dev);
 304
 305         return 0;
 306 }
 307
 308 static int __maybe_unused usb_conn_resume(struct device *dev)
 309 {
 310         struct usb_conn_info *info = dev_get_drvdata(dev);
 311
 312         if (device_may_wakeup(dev)) {
 313                 if (info->id_gpiod)
 314                         disable_irq_wake(info->id_irq);
 315                 if (info->vbus_gpiod)
 316                         disable_irq_wake(info->vbus_irq);
 317                 return 0;
 318         }
 319
 320         pinctrl_pm_select_default_state(dev);
 321
 322         if (info->id_gpiod)
 323                 enable_irq(info->id_irq);
 324         if (info->vbus_gpiod)
 325                 enable_irq(info->vbus_irq);
 326
 327         usb_conn_queue_dwork(info, 0);
 328
 329         return 0;
 330 }
 331
 332 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
 333                          usb_conn_suspend, usb_conn_resume);
 334
 335 static const struct of_device_id usb_conn_dt_match[] = {
 336         { .compatible = "gpio-usb-b-connector", },
 337         { }
 338 };
 339 MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
 340
 341 static struct platform_driver usb_conn_driver = {
 342         .probe          = usb_conn_probe,
 343         .remove         = usb_conn_remove,
 344         .driver         = {
 345                 .name   = "usb-conn-gpio",
 346                 .pm     = &usb_conn_pm_ops,
 347                 .of_match_table = usb_conn_dt_match,
 348         },
 349 };
 350
 351 module_platform_driver(usb_conn_driver);
 352
 353 MODULE_AUTHOR("Chunfeng Yun <[email protected]>");
 354 MODULE_DESCRIPTION("USB GPIO based connection detection driver");
 355 MODULE_LICENSE("GPL v2");