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 %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         bool need_vbus = true;
 179         int ret = 0;
 180
 181         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 182         if (!info)
 183                 return -ENOMEM;
 184
 185         info->dev = dev;
 186         info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
 187         if (IS_ERR(info->id_gpiod))
 188                 return PTR_ERR(info->id_gpiod);
 189
 190         info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
 191         if (IS_ERR(info->vbus_gpiod))
 192                 return PTR_ERR(info->vbus_gpiod);
 193
 194         if (!info->id_gpiod && !info->vbus_gpiod) {
 195                 dev_err(dev, "failed to get gpios\n");
 196                 return -ENODEV;
 197         }
 198
 199         if (info->id_gpiod)
 200                 ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
 201         if (!ret && info->vbus_gpiod)
 202                 ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
 203         if (ret < 0)
 204                 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
 205
 206         INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
 207
 208         /*
 209          * If the USB connector is a child of a USB port and that port already provides the VBUS
 210          * supply, there's no need for the USB connector to provide it again.
 211          */
 212         if (dev->parent && dev->parent->of_node) {
 213                 if (of_find_property(dev->parent->of_node, "vbus-supply", NULL))
 214                         need_vbus = false;
 215         }
 216
 217         if (!need_vbus) {
 218                 info->vbus = devm_regulator_get_optional(dev, "vbus");
 219                 if (PTR_ERR(info->vbus) == -ENODEV)
 220                         info->vbus = NULL;
 221         } else {
 222                 info->vbus = devm_regulator_get(dev, "vbus");
 223         }
 224
 225         if (IS_ERR(info->vbus)) {
 226                 ret = PTR_ERR(info->vbus);
 227                 return dev_err_probe(dev, ret, "failed to get vbus :%d\n", ret);
 228         }
 229
 230         info->role_sw = usb_role_switch_get(dev);
 231         if (IS_ERR(info->role_sw))
 232                 return dev_err_probe(dev, PTR_ERR(info->role_sw),
 233                                      "failed to get role switch\n");
 234
 235         ret = usb_conn_psy_register(info);
 236         if (ret)
 237                 goto put_role_sw;
 238
 239         if (info->id_gpiod) {
 240                 info->id_irq = gpiod_to_irq(info->id_gpiod);
 241                 if (info->id_irq < 0) {
 242                         dev_err(dev, "failed to get ID IRQ\n");
 243                         ret = info->id_irq;
 244                         goto put_role_sw;
 245                 }
 246
 247                 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 248                                                 usb_conn_isr, USB_CONN_IRQF,
 249                                                 pdev->name, info);
 250                 if (ret < 0) {
 251                         dev_err(dev, "failed to request ID IRQ\n");
 252                         goto put_role_sw;
 253                 }
 254         }
 255
 256         if (info->vbus_gpiod) {
 257                 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 258                 if (info->vbus_irq < 0) {
 259                         dev_err(dev, "failed to get VBUS IRQ\n");
 260                         ret = info->vbus_irq;
 261                         goto put_role_sw;
 262                 }
 263
 264                 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 265                                                 usb_conn_isr, USB_CONN_IRQF,
 266                                                 pdev->name, info);
 267                 if (ret < 0) {
 268                         dev_err(dev, "failed to request VBUS IRQ\n");
 269                         goto put_role_sw;
 270                 }
 271         }
 272
 273         platform_set_drvdata(pdev, info);
 274
 275         /* Perform initial detection */
 276         usb_conn_queue_dwork(info, 0);
 277
 278         return 0;
 279
 280 put_role_sw:
 281         usb_role_switch_put(info->role_sw);
 282         return ret;
 283 }
 284
 285 static int usb_conn_remove(struct platform_device *pdev)
 286 {
 287         struct usb_conn_info *info = platform_get_drvdata(pdev);
 288
 289         cancel_delayed_work_sync(&info->dw_det);
 290
 291         if (info->last_role == USB_ROLE_HOST && info->vbus)
 292                 regulator_disable(info->vbus);
 293
 294         usb_role_switch_put(info->role_sw);
 295
 296         return 0;
 297 }
 298
 299 static int __maybe_unused usb_conn_suspend(struct device *dev)
 300 {
 301         struct usb_conn_info *info = dev_get_drvdata(dev);
 302
 303         if (info->id_gpiod)
 304                 disable_irq(info->id_irq);
 305         if (info->vbus_gpiod)
 306                 disable_irq(info->vbus_irq);
 307
 308         pinctrl_pm_select_sleep_state(dev);
 309
 310         return 0;
 311 }
 312
 313 static int __maybe_unused usb_conn_resume(struct device *dev)
 314 {
 315         struct usb_conn_info *info = dev_get_drvdata(dev);
 316
 317         pinctrl_pm_select_default_state(dev);
 318
 319         if (info->id_gpiod)
 320                 enable_irq(info->id_irq);
 321         if (info->vbus_gpiod)
 322                 enable_irq(info->vbus_irq);
 323
 324         usb_conn_queue_dwork(info, 0);
 325
 326         return 0;
 327 }
 328
 329 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
 330                          usb_conn_suspend, usb_conn_resume);
 331
 332 static const struct of_device_id usb_conn_dt_match[] = {
 333         { .compatible = "gpio-usb-b-connector", },
 334         { }
 335 };
 336 MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
 337
 338 static struct platform_driver usb_conn_driver = {
 339         .probe          = usb_conn_probe,
 340         .remove         = usb_conn_remove,
 341         .driver         = {
 342                 .name   = "usb-conn-gpio",
 343                 .pm     = &usb_conn_pm_ops,
 344                 .of_match_table = usb_conn_dt_match,
 345         },
 346 };
 347
 348 module_platform_driver(usb_conn_driver);
 349
 350 MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
 351 MODULE_DESCRIPTION("USB GPIO based connection detection driver");
 352 MODULE_LICENSE("GPL v2");