drivers/extcon/extcon-qcom-spmi-misc.c

   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");