1 /** 2 * extcon-qcom-spmi-misc.c - Qualcomm USB extcon driver to support USB ID 3 * detection based on extcon-usb-gpio.c. 4 * 5 * Copyright (C) 2016 Linaro, Ltd. 6 * Stephen Boyd <stephen.boyd@linaro.org> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include <linux/extcon.h> 19 #include <linux/init.h> 20 #include <linux/interrupt.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/platform_device.h> 24 #include <linux/slab.h> 25 #include <linux/workqueue.h> 26 27 #define USB_ID_DEBOUNCE_MS 5 /* ms */ 28 29 struct qcom_usb_extcon_info { 30 struct extcon_dev *edev; 31 int irq; 32 struct delayed_work wq_detcable; 33 unsigned long debounce_jiffies; 34 }; 35 36 static const unsigned int qcom_usb_extcon_cable[] = { 37 EXTCON_USB_HOST, 38 EXTCON_NONE, 39 }; 40 41 static void qcom_usb_extcon_detect_cable(struct work_struct *work) 42 { 43 bool id; 44 int ret; 45 struct qcom_usb_extcon_info *info = container_of(to_delayed_work(work), 46 struct qcom_usb_extcon_info, 47 wq_detcable); 48 49 /* check ID and update cable state */ 50 ret = irq_get_irqchip_state(info->irq, IRQCHIP_STATE_LINE_LEVEL, &id); 51 if (ret) 52 return; 53 54 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, !id); 55 } 56 57 static irqreturn_t qcom_usb_irq_handler(int irq, void *dev_id) 58 { 59 struct qcom_usb_extcon_info *info = dev_id; 60 61 queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, 62 info->debounce_jiffies); 63 64 return IRQ_HANDLED; 65 } 66 67 static int qcom_usb_extcon_probe(struct platform_device *pdev) 68 { 69 struct device *dev = &pdev->dev; 70 struct qcom_usb_extcon_info *info; 71 int ret; 72 73 info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); 74 if (!info) 75 return -ENOMEM; 76 77 info->edev = devm_extcon_dev_allocate(dev, qcom_usb_extcon_cable); 78 if (IS_ERR(info->edev)) { 79 dev_err(dev, "failed to allocate extcon device\n"); 80 return -ENOMEM; 81 } 82 83 ret = devm_extcon_dev_register(dev, info->edev); 84 if (ret < 0) { 85 dev_err(dev, "failed to register extcon device\n"); 86 return ret; 87 } 88 89 info->debounce_jiffies = msecs_to_jiffies(USB_ID_DEBOUNCE_MS); 90 INIT_DELAYED_WORK(&info->wq_detcable, qcom_usb_extcon_detect_cable); 91 92 info->irq = platform_get_irq_byname(pdev, "usb_id"); 93 if (info->irq < 0) 94 return info->irq; 95 96 ret = devm_request_threaded_irq(dev, info->irq, NULL, 97 qcom_usb_irq_handler, 98 IRQF_TRIGGER_RISING | 99 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 100 pdev->name, info); 101 if (ret < 0) { 102 dev_err(dev, "failed to request handler for ID IRQ\n"); 103 return ret; 104 } 105 106 platform_set_drvdata(pdev, info); 107 device_init_wakeup(dev, 1); 108 109 /* Perform initial detection */ 110 qcom_usb_extcon_detect_cable(&info->wq_detcable.work); 111 112 return 0; 113 } 114 115 static int qcom_usb_extcon_remove(struct platform_device *pdev) 116 { 117 struct qcom_usb_extcon_info *info = platform_get_drvdata(pdev); 118 119 cancel_delayed_work_sync(&info->wq_detcable); 120 121 return 0; 122 } 123 124 #ifdef CONFIG_PM_SLEEP 125 static int qcom_usb_extcon_suspend(struct device *dev) 126 { 127 struct qcom_usb_extcon_info *info = dev_get_drvdata(dev); 128 int ret = 0; 129 130 if (device_may_wakeup(dev)) 131 ret = enable_irq_wake(info->irq); 132 133 return ret; 134 } 135 136 static int qcom_usb_extcon_resume(struct device *dev) 137 { 138 struct qcom_usb_extcon_info *info = dev_get_drvdata(dev); 139 int ret = 0; 140 141 if (device_may_wakeup(dev)) 142 ret = disable_irq_wake(info->irq); 143 144 return ret; 145 } 146 #endif 147 148 static SIMPLE_DEV_PM_OPS(qcom_usb_extcon_pm_ops, 149 qcom_usb_extcon_suspend, qcom_usb_extcon_resume); 150 151 static const struct of_device_id qcom_usb_extcon_dt_match[] = { 152 { .compatible = "qcom,pm8941-misc", }, 153 { } 154 }; 155 MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match); 156 157 static struct platform_driver qcom_usb_extcon_driver = { 158 .probe = qcom_usb_extcon_probe, 159 .remove = qcom_usb_extcon_remove, 160 .driver = { 161 .name = "extcon-pm8941-misc", 162 .pm = &qcom_usb_extcon_pm_ops, 163 .of_match_table = qcom_usb_extcon_dt_match, 164 }, 165 }; 166 module_platform_driver(qcom_usb_extcon_driver); 167 168 MODULE_DESCRIPTION("QCOM USB ID extcon driver"); 169 MODULE_AUTHOR("Stephen Boyd <stephen.boyd@linaro.org>"); 170 MODULE_LICENSE("GPL v2"); 171