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 };
  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 %d/%d, gpios: id %d, vbus %d\n",
  87                 info->last_role, role, id, vbus);
  88
  89         if (info->last_role == role) {
  90                 dev_warn(info->dev, "repeated role: %d\n", 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_probe(struct platform_device *pdev)
 153 {
 154         struct device *dev = &pdev->dev;
 155         struct power_supply_desc *desc;
 156         struct usb_conn_info *info;
 157         struct power_supply_config cfg = {
 158                 .of_node = dev->of_node,
 159         };
 160         bool need_vbus = true;
 161         int ret = 0;
 162
 163         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 164         if (!info)
 165                 return -ENOMEM;
 166
 167         info->dev = dev;
 168         info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
 169         if (IS_ERR(info->id_gpiod))
 170                 return PTR_ERR(info->id_gpiod);
 171
 172         info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
 173         if (IS_ERR(info->vbus_gpiod))
 174                 return PTR_ERR(info->vbus_gpiod);
 175
 176         if (!info->id_gpiod && !info->vbus_gpiod) {
 177                 dev_err(dev, "failed to get gpios\n");
 178                 return -ENODEV;
 179         }
 180
 181         if (info->id_gpiod)
 182                 ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
 183         if (!ret && info->vbus_gpiod)
 184                 ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
 185         if (ret < 0)
 186                 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
 187
 188         INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
 189
 190         /*
 191          * If the USB connector is a child of a USB port and that port already provides the VBUS
 192          * supply, there's no need for the USB connector to provide it again.
 193          */
 194         if (dev->parent && dev->parent->of_node) {
 195                 if (of_find_property(dev->parent->of_node, "vbus-supply", NULL))
 196                         need_vbus = false;
 197         }
 198
 199         if (!need_vbus) {
 200                 info->vbus = devm_regulator_get_optional(dev, "vbus");
 201                 if (PTR_ERR(info->vbus) == -ENODEV)
 202                         info->vbus = NULL;
 203         } else {
 204                 info->vbus = devm_regulator_get(dev, "vbus");
 205         }
 206
 207         if (IS_ERR(info->vbus)) {
 208                 if (PTR_ERR(info->vbus) != -EPROBE_DEFER)
 209                         dev_err(dev, "failed to get vbus: %ld\n", PTR_ERR(info->vbus));
 210                 return PTR_ERR(info->vbus);
 211         }
 212
 213         info->role_sw = usb_role_switch_get(dev);
 214         if (IS_ERR(info->role_sw)) {
 215                 if (PTR_ERR(info->role_sw) != -EPROBE_DEFER)
 216                         dev_err(dev, "failed to get role switch\n");
 217
 218                 return PTR_ERR(info->role_sw);
 219         }
 220
 221         if (info->id_gpiod) {
 222                 info->id_irq = gpiod_to_irq(info->id_gpiod);
 223                 if (info->id_irq < 0) {
 224                         dev_err(dev, "failed to get ID IRQ\n");
 225                         ret = info->id_irq;
 226                         goto put_role_sw;
 227                 }
 228
 229                 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 230                                                 usb_conn_isr, USB_CONN_IRQF,
 231                                                 pdev->name, info);
 232                 if (ret < 0) {
 233                         dev_err(dev, "failed to request ID IRQ\n");
 234                         goto put_role_sw;
 235                 }
 236         }
 237
 238         if (info->vbus_gpiod) {
 239                 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 240                 if (info->vbus_irq < 0) {
 241                         dev_err(dev, "failed to get VBUS IRQ\n");
 242                         ret = info->vbus_irq;
 243                         goto put_role_sw;
 244                 }
 245
 246                 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 247                                                 usb_conn_isr, USB_CONN_IRQF,
 248                                                 pdev->name, info);
 249                 if (ret < 0) {
 250                         dev_err(dev, "failed to request VBUS IRQ\n");
 251                         goto put_role_sw;
 252                 }
 253         }
 254
 255         desc = &info->desc;
 256         desc->name = "usb-charger";
 257         desc->properties = usb_charger_properties;
 258         desc->num_properties = ARRAY_SIZE(usb_charger_properties);
 259         desc->get_property = usb_charger_get_property;
 260         desc->type = POWER_SUPPLY_TYPE_USB;
 261         cfg.drv_data = info;
 262
 263         info->charger = devm_power_supply_register(dev, desc, &cfg);
 264         if (IS_ERR(info->charger)) {
 265                 dev_err(dev, "Unable to register charger\n");
 266                 return PTR_ERR(info->charger);
 267         }
 268
 269         platform_set_drvdata(pdev, info);
 270
 271         /* Perform initial detection */
 272         usb_conn_queue_dwork(info, 0);
 273
 274         return 0;
 275
 276 put_role_sw:
 277         usb_role_switch_put(info->role_sw);
 278         return ret;
 279 }
 280
 281 static int usb_conn_remove(struct platform_device *pdev)
 282 {
 283         struct usb_conn_info *info = platform_get_drvdata(pdev);
 284
 285         cancel_delayed_work_sync(&info->dw_det);
 286
 287         if (info->last_role == USB_ROLE_HOST && info->vbus)
 288                 regulator_disable(info->vbus);
 289
 290         usb_role_switch_put(info->role_sw);
 291
 292         return 0;
 293 }
 294
 295 static int __maybe_unused usb_conn_suspend(struct device *dev)
 296 {
 297         struct usb_conn_info *info = dev_get_drvdata(dev);
 298
 299         if (info->id_gpiod)
 300                 disable_irq(info->id_irq);
 301         if (info->vbus_gpiod)
 302                 disable_irq(info->vbus_irq);
 303
 304         pinctrl_pm_select_sleep_state(dev);
 305
 306         return 0;
 307 }
 308
 309 static int __maybe_unused usb_conn_resume(struct device *dev)
 310 {
 311         struct usb_conn_info *info = dev_get_drvdata(dev);
 312
 313         pinctrl_pm_select_default_state(dev);
 314
 315         if (info->id_gpiod)
 316                 enable_irq(info->id_irq);
 317         if (info->vbus_gpiod)
 318                 enable_irq(info->vbus_irq);
 319
 320         usb_conn_queue_dwork(info, 0);
 321
 322         return 0;
 323 }
 324
 325 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
 326                          usb_conn_suspend, usb_conn_resume);
 327
 328 static const struct of_device_id usb_conn_dt_match[] = {
 329         { .compatible = "gpio-usb-b-connector", },
 330         { }
 331 };
 332 MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
 333
 334 static struct platform_driver usb_conn_driver = {
 335         .probe          = usb_conn_probe,
 336         .remove         = usb_conn_remove,
 337         .driver         = {
 338                 .name   = "usb-conn-gpio",
 339                 .pm     = &usb_conn_pm_ops,
 340                 .of_match_table = usb_conn_dt_match,
 341         },
 342 };
 343
 344 module_platform_driver(usb_conn_driver);
 345
 346 MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
 347 MODULE_DESCRIPTION("USB GPIO based connection detection driver");
 348 MODULE_LICENSE("GPL v2");