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-provider.h> 19 #include <linux/init.h> 20 #include <linux/interrupt.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/mod_devicetable.h> 24 #include <linux/platform_device.h> 25 #include <linux/slab.h> 26 #include <linux/workqueue.h> 27 28 #define USB_ID_DEBOUNCE_MS 5 /* ms */ 29 30 struct qcom_usb_extcon_info { 31 struct extcon_dev *edev; 32 int irq; 33 struct delayed_work wq_detcable; 34 unsigned long debounce_jiffies; 35 }; 36 37 static const unsigned int qcom_usb_extcon_cable[] = { 38 EXTCON_USB_HOST, 39 EXTCON_NONE, 40 }; 41 42 static void qcom_usb_extcon_detect_cable(struct work_struct *work) 43 { 44 bool id; 45 int ret; 46 struct qcom_usb_extcon_info *info = container_of(to_delayed_work(work), 47 struct qcom_usb_extcon_info, 48 wq_detcable); 49 50 /* check ID and update cable state */ 51 ret = irq_get_irqchip_state(info->irq, IRQCHIP_STATE_LINE_LEVEL, &id); 52 if (ret) 53 return; 54 55 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, !id); 56 } 57 58 static irqreturn_t qcom_usb_irq_handler(int irq, void *dev_id) 59 { 60 struct qcom_usb_extcon_info *info = dev_id; 61 62 queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, 63 info->debounce_jiffies); 64 65 return IRQ_HANDLED; 66 } 67 68 static int qcom_usb_extcon_probe(struct platform_device *pdev) 69 { 70 struct device *dev = &pdev->dev; 71 struct qcom_usb_extcon_info *info; 72 int ret; 73 74 info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); 75 if (!info) 76 return -ENOMEM; 77 78 info->edev = devm_extcon_dev_allocate(dev, qcom_usb_extcon_cable); 79 if (IS_ERR(info->edev)) { 80 dev_err(dev, "failed to allocate extcon device\n"); 81 return -ENOMEM; 82 } 83 84 ret = devm_extcon_dev_register(dev, info->edev); 85 if (ret < 0) { 86 dev_err(dev, "failed to register extcon device\n"); 87 return ret; 88 } 89 90 info->debounce_jiffies = msecs_to_jiffies(USB_ID_DEBOUNCE_MS); 91 INIT_DELAYED_WORK(&info->wq_detcable, qcom_usb_extcon_detect_cable); 92 93 info->irq = platform_get_irq_byname(pdev, "usb_id"); 94 if (info->irq < 0) 95 return info->irq; 96 97 ret = devm_request_threaded_irq(dev, info->irq, NULL, 98 qcom_usb_irq_handler, 99 IRQF_TRIGGER_RISING | 100 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 101 pdev->name, info); 102 if (ret < 0) { 103 dev_err(dev, "failed to request handler for ID IRQ\n"); 104 return ret; 105 } 106 107 platform_set_drvdata(pdev, info); 108 device_init_wakeup(dev, 1); 109 110 /* Perform initial detection */ 111 qcom_usb_extcon_detect_cable(&info->wq_detcable.work); 112 113 return 0; 114 } 115 116 static int qcom_usb_extcon_remove(struct platform_device *pdev) 117 { 118 struct qcom_usb_extcon_info *info = platform_get_drvdata(pdev); 119 120 cancel_delayed_work_sync(&info->wq_detcable); 121 122 return 0; 123 } 124 125 #ifdef CONFIG_PM_SLEEP 126 static int qcom_usb_extcon_suspend(struct device *dev) 127 { 128 struct qcom_usb_extcon_info *info = dev_get_drvdata(dev); 129 int ret = 0; 130 131 if (device_may_wakeup(dev)) 132 ret = enable_irq_wake(info->irq); 133 134 return ret; 135 } 136 137 static int qcom_usb_extcon_resume(struct device *dev) 138 { 139 struct qcom_usb_extcon_info *info = dev_get_drvdata(dev); 140 int ret = 0; 141 142 if (device_may_wakeup(dev)) 143 ret = disable_irq_wake(info->irq); 144 145 return ret; 146 } 147 #endif 148 149 static SIMPLE_DEV_PM_OPS(qcom_usb_extcon_pm_ops, 150 qcom_usb_extcon_suspend, qcom_usb_extcon_resume); 151 152 static const struct of_device_id qcom_usb_extcon_dt_match[] = { 153 { .compatible = "qcom,pm8941-misc", }, 154 { } 155 }; 156 MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match); 157 158 static struct platform_driver qcom_usb_extcon_driver = { 159 .probe = qcom_usb_extcon_probe, 160 .remove = qcom_usb_extcon_remove, 161 .driver = { 162 .name = "extcon-pm8941-misc", 163 .pm = &qcom_usb_extcon_pm_ops, 164 .of_match_table = qcom_usb_extcon_dt_match, 165 }, 166 }; 167 module_platform_driver(qcom_usb_extcon_driver); 168 169 MODULE_DESCRIPTION("QCOM USB ID extcon driver"); 170 MODULE_AUTHOR("Stephen Boyd <stephen.boyd@linaro.org>"); 171 MODULE_LICENSE("GPL v2"); 172