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"); 349