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) 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) { 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 dev_dbg(info->dev, "vbus regulator is %s\n", 110 regulator_is_enabled(info->vbus) ? "enabled" : "disabled"); 111 112 power_supply_changed(info->charger); 113 } 114 115 static void usb_conn_queue_dwork(struct usb_conn_info *info, 116 unsigned long delay) 117 { 118 queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay); 119 } 120 121 static irqreturn_t usb_conn_isr(int irq, void *dev_id) 122 { 123 struct usb_conn_info *info = dev_id; 124 125 usb_conn_queue_dwork(info, info->debounce_jiffies); 126 127 return IRQ_HANDLED; 128 } 129 130 static enum power_supply_property usb_charger_properties[] = { 131 POWER_SUPPLY_PROP_ONLINE, 132 }; 133 134 static int usb_charger_get_property(struct power_supply *psy, 135 enum power_supply_property psp, 136 union power_supply_propval *val) 137 { 138 struct usb_conn_info *info = power_supply_get_drvdata(psy); 139 140 switch (psp) { 141 case POWER_SUPPLY_PROP_ONLINE: 142 val->intval = info->last_role == USB_ROLE_DEVICE; 143 break; 144 default: 145 return -EINVAL; 146 } 147 148 return 0; 149 } 150 151 static int usb_conn_probe(struct platform_device *pdev) 152 { 153 struct device *dev = &pdev->dev; 154 struct power_supply_desc *desc; 155 struct usb_conn_info *info; 156 struct power_supply_config cfg = { 157 .of_node = dev->of_node, 158 }; 159 int ret = 0; 160 161 info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); 162 if (!info) 163 return -ENOMEM; 164 165 info->dev = dev; 166 info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN); 167 if (IS_ERR(info->id_gpiod)) 168 return PTR_ERR(info->id_gpiod); 169 170 info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN); 171 if (IS_ERR(info->vbus_gpiod)) 172 return PTR_ERR(info->vbus_gpiod); 173 174 if (!info->id_gpiod && !info->vbus_gpiod) { 175 dev_err(dev, "failed to get gpios\n"); 176 return -ENODEV; 177 } 178 179 if (info->id_gpiod) 180 ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US); 181 if (!ret && info->vbus_gpiod) 182 ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US); 183 if (ret < 0) 184 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS); 185 186 INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable); 187 188 info->vbus = devm_regulator_get(dev, "vbus"); 189 if (IS_ERR(info->vbus)) { 190 if (PTR_ERR(info->vbus) != -EPROBE_DEFER) 191 dev_err(dev, "failed to get vbus\n"); 192 return PTR_ERR(info->vbus); 193 } 194 195 info->role_sw = usb_role_switch_get(dev); 196 if (IS_ERR(info->role_sw)) { 197 if (PTR_ERR(info->role_sw) != -EPROBE_DEFER) 198 dev_err(dev, "failed to get role switch\n"); 199 200 return PTR_ERR(info->role_sw); 201 } 202 203 if (info->id_gpiod) { 204 info->id_irq = gpiod_to_irq(info->id_gpiod); 205 if (info->id_irq < 0) { 206 dev_err(dev, "failed to get ID IRQ\n"); 207 ret = info->id_irq; 208 goto put_role_sw; 209 } 210 211 ret = devm_request_threaded_irq(dev, info->id_irq, NULL, 212 usb_conn_isr, USB_CONN_IRQF, 213 pdev->name, info); 214 if (ret < 0) { 215 dev_err(dev, "failed to request ID IRQ\n"); 216 goto put_role_sw; 217 } 218 } 219 220 if (info->vbus_gpiod) { 221 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod); 222 if (info->vbus_irq < 0) { 223 dev_err(dev, "failed to get VBUS IRQ\n"); 224 ret = info->vbus_irq; 225 goto put_role_sw; 226 } 227 228 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL, 229 usb_conn_isr, USB_CONN_IRQF, 230 pdev->name, info); 231 if (ret < 0) { 232 dev_err(dev, "failed to request VBUS IRQ\n"); 233 goto put_role_sw; 234 } 235 } 236 237 desc = &info->desc; 238 desc->name = "usb-charger"; 239 desc->properties = usb_charger_properties; 240 desc->num_properties = ARRAY_SIZE(usb_charger_properties); 241 desc->get_property = usb_charger_get_property; 242 desc->type = POWER_SUPPLY_TYPE_USB; 243 cfg.drv_data = info; 244 245 info->charger = devm_power_supply_register(dev, desc, &cfg); 246 if (IS_ERR(info->charger)) { 247 dev_err(dev, "Unable to register charger\n"); 248 return PTR_ERR(info->charger); 249 } 250 251 platform_set_drvdata(pdev, info); 252 253 /* Perform initial detection */ 254 usb_conn_queue_dwork(info, 0); 255 256 return 0; 257 258 put_role_sw: 259 usb_role_switch_put(info->role_sw); 260 return ret; 261 } 262 263 static int usb_conn_remove(struct platform_device *pdev) 264 { 265 struct usb_conn_info *info = platform_get_drvdata(pdev); 266 267 cancel_delayed_work_sync(&info->dw_det); 268 269 if (info->last_role == USB_ROLE_HOST) 270 regulator_disable(info->vbus); 271 272 usb_role_switch_put(info->role_sw); 273 274 return 0; 275 } 276 277 static int __maybe_unused usb_conn_suspend(struct device *dev) 278 { 279 struct usb_conn_info *info = dev_get_drvdata(dev); 280 281 if (info->id_gpiod) 282 disable_irq(info->id_irq); 283 if (info->vbus_gpiod) 284 disable_irq(info->vbus_irq); 285 286 pinctrl_pm_select_sleep_state(dev); 287 288 return 0; 289 } 290 291 static int __maybe_unused usb_conn_resume(struct device *dev) 292 { 293 struct usb_conn_info *info = dev_get_drvdata(dev); 294 295 pinctrl_pm_select_default_state(dev); 296 297 if (info->id_gpiod) 298 enable_irq(info->id_irq); 299 if (info->vbus_gpiod) 300 enable_irq(info->vbus_irq); 301 302 usb_conn_queue_dwork(info, 0); 303 304 return 0; 305 } 306 307 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops, 308 usb_conn_suspend, usb_conn_resume); 309 310 static const struct of_device_id usb_conn_dt_match[] = { 311 { .compatible = "gpio-usb-b-connector", }, 312 { } 313 }; 314 MODULE_DEVICE_TABLE(of, usb_conn_dt_match); 315 316 static struct platform_driver usb_conn_driver = { 317 .probe = usb_conn_probe, 318 .remove = usb_conn_remove, 319 .driver = { 320 .name = "usb-conn-gpio", 321 .pm = &usb_conn_pm_ops, 322 .of_match_table = usb_conn_dt_match, 323 }, 324 }; 325 326 module_platform_driver(usb_conn_driver); 327 328 MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>"); 329 MODULE_DESCRIPTION("USB GPIO based connection detection driver"); 330 MODULE_LICENSE("GPL v2"); 331