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"); 353