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-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");