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/string_choices.h> 23 #include <linux/usb/role.h> 24 25 #define USB_GPIO_DEB_MS 20 /* ms */ 26 #define USB_GPIO_DEB_US ((USB_GPIO_DEB_MS) * 1000) /* us */ 27 28 #define USB_CONN_IRQF \ 29 (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT) 30 31 struct usb_conn_info { 32 struct device *dev; 33 struct usb_role_switch *role_sw; 34 enum usb_role last_role; 35 struct regulator *vbus; 36 struct delayed_work dw_det; 37 unsigned long debounce_jiffies; 38 39 struct gpio_desc *id_gpiod; 40 struct gpio_desc *vbus_gpiod; 41 int id_irq; 42 int vbus_irq; 43 44 struct power_supply_desc desc; 45 struct power_supply *charger; 46 bool initial_detection; 47 }; 48 49 /* 50 * "DEVICE" = VBUS and "HOST" = !ID, so we have: 51 * Both "DEVICE" and "HOST" can't be set as active at the same time 52 * so if "HOST" is active (i.e. ID is 0) we keep "DEVICE" inactive 53 * even if VBUS is on. 54 * 55 * Role | ID | VBUS 56 * ------------------------------------ 57 * [1] DEVICE | H | H 58 * [2] NONE | H | L 59 * [3] HOST | L | H 60 * [4] HOST | L | L 61 * 62 * In case we have only one of these signals: 63 * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1 64 * - ID only - we want to distinguish between [1] and [4], so VBUS = ID 65 */ 66 static void usb_conn_detect_cable(struct work_struct *work) 67 { 68 struct usb_conn_info *info; 69 enum usb_role role; 70 int id, vbus, ret; 71 72 info = container_of(to_delayed_work(work), 73 struct usb_conn_info, dw_det); 74 75 /* check ID and VBUS */ 76 id = info->id_gpiod ? 77 gpiod_get_value_cansleep(info->id_gpiod) : 1; 78 vbus = info->vbus_gpiod ? 79 gpiod_get_value_cansleep(info->vbus_gpiod) : id; 80 81 if (!id) 82 role = USB_ROLE_HOST; 83 else if (vbus) 84 role = USB_ROLE_DEVICE; 85 else 86 role = USB_ROLE_NONE; 87 88 dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n", 89 usb_role_string(info->last_role), usb_role_string(role), id, vbus); 90 91 if (!info->initial_detection && info->last_role == role) { 92 dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role)); 93 return; 94 } 95 96 info->initial_detection = false; 97 98 if (info->last_role == USB_ROLE_HOST && info->vbus) 99 regulator_disable(info->vbus); 100 101 ret = usb_role_switch_set_role(info->role_sw, role); 102 if (ret) 103 dev_err(info->dev, "failed to set role: %d\n", ret); 104 105 if (role == USB_ROLE_HOST && info->vbus) { 106 ret = regulator_enable(info->vbus); 107 if (ret) 108 dev_err(info->dev, "enable vbus regulator failed\n"); 109 } 110 111 info->last_role = role; 112 113 if (info->vbus) 114 dev_dbg(info->dev, "vbus regulator is %s\n", 115 str_enabled_disabled(regulator_is_enabled(info->vbus))); 116 117 power_supply_changed(info->charger); 118 } 119 120 static void usb_conn_queue_dwork(struct usb_conn_info *info, 121 unsigned long delay) 122 { 123 queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay); 124 } 125 126 static irqreturn_t usb_conn_isr(int irq, void *dev_id) 127 { 128 struct usb_conn_info *info = dev_id; 129 130 usb_conn_queue_dwork(info, info->debounce_jiffies); 131 132 return IRQ_HANDLED; 133 } 134 135 static enum power_supply_property usb_charger_properties[] = { 136 POWER_SUPPLY_PROP_ONLINE, 137 }; 138 139 static int usb_charger_get_property(struct power_supply *psy, 140 enum power_supply_property psp, 141 union power_supply_propval *val) 142 { 143 struct usb_conn_info *info = power_supply_get_drvdata(psy); 144 145 switch (psp) { 146 case POWER_SUPPLY_PROP_ONLINE: 147 val->intval = info->last_role == USB_ROLE_DEVICE; 148 break; 149 default: 150 return -EINVAL; 151 } 152 153 return 0; 154 } 155 156 static int usb_conn_psy_register(struct usb_conn_info *info) 157 { 158 struct device *dev = info->dev; 159 struct power_supply_desc *desc = &info->desc; 160 struct power_supply_config cfg = { 161 .of_node = dev->of_node, 162 }; 163 164 desc->name = "usb-charger"; 165 desc->properties = usb_charger_properties; 166 desc->num_properties = ARRAY_SIZE(usb_charger_properties); 167 desc->get_property = usb_charger_get_property; 168 desc->type = POWER_SUPPLY_TYPE_USB; 169 cfg.drv_data = info; 170 171 info->charger = devm_power_supply_register(dev, desc, &cfg); 172 if (IS_ERR(info->charger)) 173 dev_err(dev, "Unable to register charger\n"); 174 175 return PTR_ERR_OR_ZERO(info->charger); 176 } 177 178 static int usb_conn_probe(struct platform_device *pdev) 179 { 180 struct device *dev = &pdev->dev; 181 struct usb_conn_info *info; 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 info->vbus = devm_regulator_get_optional(dev, "vbus"); 212 if (PTR_ERR(info->vbus) == -ENODEV) 213 info->vbus = NULL; 214 215 if (IS_ERR(info->vbus)) 216 return dev_err_probe(dev, PTR_ERR(info->vbus), "failed to get vbus\n"); 217 218 info->role_sw = usb_role_switch_get(dev); 219 if (IS_ERR(info->role_sw)) 220 return dev_err_probe(dev, PTR_ERR(info->role_sw), 221 "failed to get role switch\n"); 222 223 ret = usb_conn_psy_register(info); 224 if (ret) 225 goto put_role_sw; 226 227 if (info->id_gpiod) { 228 info->id_irq = gpiod_to_irq(info->id_gpiod); 229 if (info->id_irq < 0) { 230 dev_err(dev, "failed to get ID IRQ\n"); 231 ret = info->id_irq; 232 goto put_role_sw; 233 } 234 235 ret = devm_request_threaded_irq(dev, info->id_irq, NULL, 236 usb_conn_isr, USB_CONN_IRQF, 237 pdev->name, info); 238 if (ret < 0) { 239 dev_err(dev, "failed to request ID IRQ\n"); 240 goto put_role_sw; 241 } 242 } 243 244 if (info->vbus_gpiod) { 245 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod); 246 if (info->vbus_irq < 0) { 247 dev_err(dev, "failed to get VBUS IRQ\n"); 248 ret = info->vbus_irq; 249 goto put_role_sw; 250 } 251 252 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL, 253 usb_conn_isr, USB_CONN_IRQF, 254 pdev->name, info); 255 if (ret < 0) { 256 dev_err(dev, "failed to request VBUS IRQ\n"); 257 goto put_role_sw; 258 } 259 } 260 261 platform_set_drvdata(pdev, info); 262 device_set_wakeup_capable(&pdev->dev, true); 263 264 /* Perform initial detection */ 265 info->initial_detection = true; 266 usb_conn_queue_dwork(info, 0); 267 268 return 0; 269 270 put_role_sw: 271 usb_role_switch_put(info->role_sw); 272 return ret; 273 } 274 275 static void usb_conn_remove(struct platform_device *pdev) 276 { 277 struct usb_conn_info *info = platform_get_drvdata(pdev); 278 279 cancel_delayed_work_sync(&info->dw_det); 280 281 if (info->last_role == USB_ROLE_HOST && info->vbus) 282 regulator_disable(info->vbus); 283 284 usb_role_switch_put(info->role_sw); 285 } 286 287 static int __maybe_unused usb_conn_suspend(struct device *dev) 288 { 289 struct usb_conn_info *info = dev_get_drvdata(dev); 290 291 if (device_may_wakeup(dev)) { 292 if (info->id_gpiod) 293 enable_irq_wake(info->id_irq); 294 if (info->vbus_gpiod) 295 enable_irq_wake(info->vbus_irq); 296 return 0; 297 } 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 if (device_may_wakeup(dev)) { 314 if (info->id_gpiod) 315 disable_irq_wake(info->id_irq); 316 if (info->vbus_gpiod) 317 disable_irq_wake(info->vbus_irq); 318 return 0; 319 } 320 321 pinctrl_pm_select_default_state(dev); 322 323 if (info->id_gpiod) 324 enable_irq(info->id_irq); 325 if (info->vbus_gpiod) 326 enable_irq(info->vbus_irq); 327 328 usb_conn_queue_dwork(info, 0); 329 330 return 0; 331 } 332 333 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops, 334 usb_conn_suspend, usb_conn_resume); 335 336 static const struct of_device_id usb_conn_dt_match[] = { 337 { .compatible = "gpio-usb-b-connector", }, 338 { } 339 }; 340 MODULE_DEVICE_TABLE(of, usb_conn_dt_match); 341 342 static struct platform_driver usb_conn_driver = { 343 .probe = usb_conn_probe, 344 .remove = usb_conn_remove, 345 .driver = { 346 .name = "usb-conn-gpio", 347 .pm = &usb_conn_pm_ops, 348 .of_match_table = usb_conn_dt_match, 349 }, 350 }; 351 352 module_platform_driver(usb_conn_driver); 353 354 MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>"); 355 MODULE_DESCRIPTION("USB GPIO based connection detection driver"); 356 MODULE_LICENSE("GPL v2"); 357