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 <chunfeng.yun@mediatek.com>
   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         bool initial_detection;
  46 };
  47
  48 /*
  49  * "DEVICE" = VBUS and "HOST" = !ID, so we have:
  50  * Both "DEVICE" and "HOST" can't be set as active at the same time
  51  * so if "HOST" is active (i.e. ID is 0)  we keep "DEVICE" inactive
  52  * even if VBUS is on.
  53  *
  54  *  Role          |   ID  |  VBUS
  55  * ------------------------------------
  56  *  [1] DEVICE    |   H   |   H
  57  *  [2] NONE      |   H   |   L
  58  *  [3] HOST      |   L   |   H
  59  *  [4] HOST      |   L   |   L
  60  *
  61  * In case we have only one of these signals:
  62  * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1
  63  * - ID only - we want to distinguish between [1] and [4], so VBUS = ID
  64  */
  65 static void usb_conn_detect_cable(struct work_struct *work)
  66 {
  67         struct usb_conn_info *info;
  68         enum usb_role role;
  69         int id, vbus, ret;
  70
  71         info = container_of(to_delayed_work(work),
  72                             struct usb_conn_info, dw_det);
  73
  74         /* check ID and VBUS */
  75         id = info->id_gpiod ?
  76                 gpiod_get_value_cansleep(info->id_gpiod) : 1;
  77         vbus = info->vbus_gpiod ?
  78                 gpiod_get_value_cansleep(info->vbus_gpiod) : id;
  79
  80         if (!id)
  81                 role = USB_ROLE_HOST;
  82         else if (vbus)
  83                 role = USB_ROLE_DEVICE;
  84         else
  85                 role = USB_ROLE_NONE;
  86
  87         dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n",
  88                 usb_role_string(info->last_role), usb_role_string(role), id, vbus);
  89
  90         if (!info->initial_detection && info->last_role == role) {
  91                 dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role));
  92                 return;
  93         }
  94
  95         info->initial_detection = false;
  96
  97         if (info->last_role == USB_ROLE_HOST && info->vbus)
  98                 regulator_disable(info->vbus);
  99
 100         ret = usb_role_switch_set_role(info->role_sw, role);
 101         if (ret)
 102                 dev_err(info->dev, "failed to set role: %d\n", ret);
 103
 104         if (role == USB_ROLE_HOST && info->vbus) {
 105                 ret = regulator_enable(info->vbus);
 106                 if (ret)
 107                         dev_err(info->dev, "enable vbus regulator failed\n");
 108         }
 109
 110         info->last_role = role;
 111
 112         if (info->vbus)
 113                 dev_dbg(info->dev, "vbus regulator is %s\n",
 114                         regulator_is_enabled(info->vbus) ? "enabled" : "disabled");
 115
 116         power_supply_changed(info->charger);
 117 }
 118
 119 static void usb_conn_queue_dwork(struct usb_conn_info *info,
 120                                  unsigned long delay)
 121 {
 122         queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
 123 }
 124
 125 static irqreturn_t usb_conn_isr(int irq, void *dev_id)
 126 {
 127         struct usb_conn_info *info = dev_id;
 128
 129         usb_conn_queue_dwork(info, info->debounce_jiffies);
 130
 131         return IRQ_HANDLED;
 132 }
 133
 134 static enum power_supply_property usb_charger_properties[] = {
 135         POWER_SUPPLY_PROP_ONLINE,
 136 };
 137
 138 static int usb_charger_get_property(struct power_supply *psy,
 139                                     enum power_supply_property psp,
 140                                     union power_supply_propval *val)
 141 {
 142         struct usb_conn_info *info = power_supply_get_drvdata(psy);
 143
 144         switch (psp) {
 145         case POWER_SUPPLY_PROP_ONLINE:
 146                 val->intval = info->last_role == USB_ROLE_DEVICE;
 147                 break;
 148         default:
 149                 return -EINVAL;
 150         }
 151
 152         return 0;
 153 }
 154
 155 static int usb_conn_psy_register(struct usb_conn_info *info)
 156 {
 157         struct device *dev = info->dev;
 158         struct power_supply_desc *desc = &info->desc;
 159         struct power_supply_config cfg = {
 160                 .of_node = dev->of_node,
 161         };
 162
 163         desc->name = "usb-charger";
 164         desc->properties = usb_charger_properties;
 165         desc->num_properties = ARRAY_SIZE(usb_charger_properties);
 166         desc->get_property = usb_charger_get_property;
 167         desc->type = POWER_SUPPLY_TYPE_USB;
 168         cfg.drv_data = info;
 169
 170         info->charger = devm_power_supply_register(dev, desc, &cfg);
 171         if (IS_ERR(info->charger))
 172                 dev_err(dev, "Unable to register charger\n");
 173
 174         return PTR_ERR_OR_ZERO(info->charger);
 175 }
 176
 177 static int usb_conn_probe(struct platform_device *pdev)
 178 {
 179         struct device *dev = &pdev->dev;
 180         struct usb_conn_info *info;
 181         int ret = 0;
 182
 183         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 184         if (!info)
 185                 return -ENOMEM;
 186
 187         info->dev = dev;
 188         info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
 189         if (IS_ERR(info->id_gpiod))
 190                 return PTR_ERR(info->id_gpiod);
 191
 192         info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
 193         if (IS_ERR(info->vbus_gpiod))
 194                 return PTR_ERR(info->vbus_gpiod);
 195
 196         if (!info->id_gpiod && !info->vbus_gpiod) {
 197                 dev_err(dev, "failed to get gpios\n");
 198                 return -ENODEV;
 199         }
 200
 201         if (info->id_gpiod)
 202                 ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
 203         if (!ret && info->vbus_gpiod)
 204                 ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
 205         if (ret < 0)
 206                 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
 207
 208         INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
 209
 210         info->vbus = devm_regulator_get_optional(dev, "vbus");
 211         if (PTR_ERR(info->vbus) == -ENODEV)
 212                 info->vbus = NULL;
 213
 214         if (IS_ERR(info->vbus))
 215                 return dev_err_probe(dev, PTR_ERR(info->vbus), "failed to get vbus\n");
 216
 217         info->role_sw = usb_role_switch_get(dev);
 218         if (IS_ERR(info->role_sw))
 219                 return dev_err_probe(dev, PTR_ERR(info->role_sw),
 220                                      "failed to get role switch\n");
 221
 222         ret = usb_conn_psy_register(info);
 223         if (ret)
 224                 goto put_role_sw;
 225
 226         if (info->id_gpiod) {
 227                 info->id_irq = gpiod_to_irq(info->id_gpiod);
 228                 if (info->id_irq < 0) {
 229                         dev_err(dev, "failed to get ID IRQ\n");
 230                         ret = info->id_irq;
 231                         goto put_role_sw;
 232                 }
 233
 234                 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 235                                                 usb_conn_isr, USB_CONN_IRQF,
 236                                                 pdev->name, info);
 237                 if (ret < 0) {
 238                         dev_err(dev, "failed to request ID IRQ\n");
 239                         goto put_role_sw;
 240                 }
 241         }
 242
 243         if (info->vbus_gpiod) {
 244                 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 245                 if (info->vbus_irq < 0) {
 246                         dev_err(dev, "failed to get VBUS IRQ\n");
 247                         ret = info->vbus_irq;
 248                         goto put_role_sw;
 249                 }
 250
 251                 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 252                                                 usb_conn_isr, USB_CONN_IRQF,
 253                                                 pdev->name, info);
 254                 if (ret < 0) {
 255                         dev_err(dev, "failed to request VBUS IRQ\n");
 256                         goto put_role_sw;
 257                 }
 258         }
 259
 260         platform_set_drvdata(pdev, info);
 261         device_set_wakeup_capable(&pdev->dev, true);
 262
 263         /* Perform initial detection */
 264         info->initial_detection = true;
 265         usb_conn_queue_dwork(info, 0);
 266
 267         return 0;
 268
 269 put_role_sw:
 270         usb_role_switch_put(info->role_sw);
 271         return ret;
 272 }
 273
 274 static void usb_conn_remove(struct platform_device *pdev)
 275 {
 276         struct usb_conn_info *info = platform_get_drvdata(pdev);
 277
 278         cancel_delayed_work_sync(&info->dw_det);
 279
 280         if (info->last_role == USB_ROLE_HOST && info->vbus)
 281                 regulator_disable(info->vbus);
 282
 283         usb_role_switch_put(info->role_sw);
 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_new     = 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 <chunfeng.yun@mediatek.com>");
 354 MODULE_DESCRIPTION("USB GPIO based connection detection driver");
 355 MODULE_LICENSE("GPL v2");