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"); 356