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 %d/%d, gpios: id %d, vbus %d\n",
  88                 info->last_role, role, id, vbus);
  89
  90         if (!info->initial_detection && info->last_role == role) {
  91                 dev_warn(info->dev, "repeated role: %d\n", 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         bool need_vbus = true;
 182         int ret = 0;
 183
 184         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 185         if (!info)
 186                 return -ENOMEM;
 187
 188         info->dev = dev;
 189         info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
 190         if (IS_ERR(info->id_gpiod))
 191                 return PTR_ERR(info->id_gpiod);
 192
 193         info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
 194         if (IS_ERR(info->vbus_gpiod))
 195                 return PTR_ERR(info->vbus_gpiod);
 196
 197         if (!info->id_gpiod && !info->vbus_gpiod) {
 198                 dev_err(dev, "failed to get gpios\n");
 199                 return -ENODEV;
 200         }
 201
 202         if (info->id_gpiod)
 203                 ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
 204         if (!ret && info->vbus_gpiod)
 205                 ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
 206         if (ret < 0)
 207                 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
 208
 209         INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
 210
 211         /*
 212          * If the USB connector is a child of a USB port and that port already provides the VBUS
 213          * supply, there's no need for the USB connector to provide it again.
 214          */
 215         if (dev->parent && dev->parent->of_node) {
 216                 if (of_find_property(dev->parent->of_node, "vbus-supply", NULL))
 217                         need_vbus = false;
 218         }
 219
 220         if (!need_vbus) {
 221                 info->vbus = devm_regulator_get_optional(dev, "vbus");
 222                 if (PTR_ERR(info->vbus) == -ENODEV)
 223                         info->vbus = NULL;
 224         } else {
 225                 info->vbus = devm_regulator_get(dev, "vbus");
 226         }
 227
 228         if (IS_ERR(info->vbus)) {
 229                 if (PTR_ERR(info->vbus) != -EPROBE_DEFER)
 230                         dev_err(dev, "failed to get vbus: %ld\n", PTR_ERR(info->vbus));
 231                 return PTR_ERR(info->vbus);
 232         }
 233
 234         info->role_sw = usb_role_switch_get(dev);
 235         if (IS_ERR(info->role_sw)) {
 236                 if (PTR_ERR(info->role_sw) != -EPROBE_DEFER)
 237                         dev_err(dev, "failed to get role switch\n");
 238
 239                 return PTR_ERR(info->role_sw);
 240         }
 241
 242         ret = usb_conn_psy_register(info);
 243         if (ret)
 244                 goto put_role_sw;
 245
 246         if (info->id_gpiod) {
 247                 info->id_irq = gpiod_to_irq(info->id_gpiod);
 248                 if (info->id_irq < 0) {
 249                         dev_err(dev, "failed to get ID IRQ\n");
 250                         ret = info->id_irq;
 251                         goto put_role_sw;
 252                 }
 253
 254                 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 255                                                 usb_conn_isr, USB_CONN_IRQF,
 256                                                 pdev->name, info);
 257                 if (ret < 0) {
 258                         dev_err(dev, "failed to request ID IRQ\n");
 259                         goto put_role_sw;
 260                 }
 261         }
 262
 263         if (info->vbus_gpiod) {
 264                 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 265                 if (info->vbus_irq < 0) {
 266                         dev_err(dev, "failed to get VBUS IRQ\n");
 267                         ret = info->vbus_irq;
 268                         goto put_role_sw;
 269                 }
 270
 271                 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 272                                                 usb_conn_isr, USB_CONN_IRQF,
 273                                                 pdev->name, info);
 274                 if (ret < 0) {
 275                         dev_err(dev, "failed to request VBUS IRQ\n");
 276                         goto put_role_sw;
 277                 }
 278         }
 279
 280         platform_set_drvdata(pdev, info);
 281
 282         /* Perform initial detection */
 283         info->initial_detection = true;
 284         usb_conn_queue_dwork(info, 0);
 285
 286         return 0;
 287
 288 put_role_sw:
 289         usb_role_switch_put(info->role_sw);
 290         return ret;
 291 }
 292
 293 static int usb_conn_remove(struct platform_device *pdev)
 294 {
 295         struct usb_conn_info *info = platform_get_drvdata(pdev);
 296
 297         cancel_delayed_work_sync(&info->dw_det);
 298
 299         if (info->last_role == USB_ROLE_HOST && info->vbus)
 300                 regulator_disable(info->vbus);
 301
 302         usb_role_switch_put(info->role_sw);
 303
 304         return 0;
 305 }
 306
 307 static int __maybe_unused usb_conn_suspend(struct device *dev)
 308 {
 309         struct usb_conn_info *info = dev_get_drvdata(dev);
 310
 311         if (info->id_gpiod)
 312                 disable_irq(info->id_irq);
 313         if (info->vbus_gpiod)
 314                 disable_irq(info->vbus_irq);
 315
 316         pinctrl_pm_select_sleep_state(dev);
 317
 318         return 0;
 319 }
 320
 321 static int __maybe_unused usb_conn_resume(struct device *dev)
 322 {
 323         struct usb_conn_info *info = dev_get_drvdata(dev);
 324
 325         pinctrl_pm_select_default_state(dev);
 326
 327         if (info->id_gpiod)
 328                 enable_irq(info->id_irq);
 329         if (info->vbus_gpiod)
 330                 enable_irq(info->vbus_irq);
 331
 332         usb_conn_queue_dwork(info, 0);
 333
 334         return 0;
 335 }
 336
 337 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
 338                          usb_conn_suspend, usb_conn_resume);
 339
 340 static const struct of_device_id usb_conn_dt_match[] = {
 341         { .compatible = "gpio-usb-b-connector", },
 342         { }
 343 };
 344 MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
 345
 346 static struct platform_driver usb_conn_driver = {
 347         .probe          = usb_conn_probe,
 348         .remove         = usb_conn_remove,
 349         .driver         = {
 350                 .name   = "usb-conn-gpio",
 351                 .pm     = &usb_conn_pm_ops,
 352                 .of_match_table = usb_conn_dt_match,
 353         },
 354 };
 355
 356 module_platform_driver(usb_conn_driver);
 357
 358 MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
 359 MODULE_DESCRIPTION("USB GPIO based connection detection driver");
 360 MODULE_LICENSE("GPL v2");