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/platform_device.h>
 24#include <linux/slab.h>
 25#include <linux/workqueue.h>
 26
 27#define USB_ID_DEBOUNCE_MS	5	/* ms */
 28
 29struct 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
 36static const unsigned int qcom_usb_extcon_cable[] = {
 37	EXTCON_USB_HOST,
 38	EXTCON_NONE,
 39};
 40
 41static 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
 57static 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
 67static 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
115static 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
125static 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
136static 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
148static SIMPLE_DEV_PM_OPS(qcom_usb_extcon_pm_ops,
149			 qcom_usb_extcon_suspend, qcom_usb_extcon_resume);
150
151static const struct of_device_id qcom_usb_extcon_dt_match[] = {
152	{ .compatible = "qcom,pm8941-misc", },
153	{ }
154};
155MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match);
156
157static 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};
166module_platform_driver(qcom_usb_extcon_driver);
167
168MODULE_DESCRIPTION("QCOM USB ID extcon driver");
169MODULE_AUTHOR("Stephen Boyd <stephen.boyd@linaro.org>");
170MODULE_LICENSE("GPL v2");