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 
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