1 // SPDX-License-Identifier: GPL-2.0-only
2 /**
3  * extcon-qcom-spmi-misc.c - Qualcomm USB extcon driver to support USB ID
4  *				detection based on extcon-usb-gpio.c.
5  *
6  * Copyright (C) 2016 Linaro, Ltd.
7  * Stephen Boyd <stephen.boyd@linaro.org>
8  */
9 
10 #include <linux/extcon-provider.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/workqueue.h>
19 
20 #define USB_ID_DEBOUNCE_MS	5	/* ms */
21 
22 struct qcom_usb_extcon_info {
23 	struct extcon_dev *edev;
24 	int irq;
25 	struct delayed_work wq_detcable;
26 	unsigned long debounce_jiffies;
27 };
28 
29 static const unsigned int qcom_usb_extcon_cable[] = {
30 	EXTCON_USB_HOST,
31 	EXTCON_NONE,
32 };
33 
34 static void qcom_usb_extcon_detect_cable(struct work_struct *work)
35 {
36 	bool id;
37 	int ret;
38 	struct qcom_usb_extcon_info *info = container_of(to_delayed_work(work),
39 						    struct qcom_usb_extcon_info,
40 						    wq_detcable);
41 
42 	/* check ID and update cable state */
43 	ret = irq_get_irqchip_state(info->irq, IRQCHIP_STATE_LINE_LEVEL, &id);
44 	if (ret)
45 		return;
46 
47 	extcon_set_state_sync(info->edev, EXTCON_USB_HOST, !id);
48 }
49 
50 static irqreturn_t qcom_usb_irq_handler(int irq, void *dev_id)
51 {
52 	struct qcom_usb_extcon_info *info = dev_id;
53 
54 	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
55 			   info->debounce_jiffies);
56 
57 	return IRQ_HANDLED;
58 }
59 
60 static int qcom_usb_extcon_probe(struct platform_device *pdev)
61 {
62 	struct device *dev = &pdev->dev;
63 	struct qcom_usb_extcon_info *info;
64 	int ret;
65 
66 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
67 	if (!info)
68 		return -ENOMEM;
69 
70 	info->edev = devm_extcon_dev_allocate(dev, qcom_usb_extcon_cable);
71 	if (IS_ERR(info->edev)) {
72 		dev_err(dev, "failed to allocate extcon device\n");
73 		return -ENOMEM;
74 	}
75 
76 	ret = devm_extcon_dev_register(dev, info->edev);
77 	if (ret < 0) {
78 		dev_err(dev, "failed to register extcon device\n");
79 		return ret;
80 	}
81 
82 	info->debounce_jiffies = msecs_to_jiffies(USB_ID_DEBOUNCE_MS);
83 	INIT_DELAYED_WORK(&info->wq_detcable, qcom_usb_extcon_detect_cable);
84 
85 	info->irq = platform_get_irq_byname(pdev, "usb_id");
86 	if (info->irq < 0)
87 		return info->irq;
88 
89 	ret = devm_request_threaded_irq(dev, info->irq, NULL,
90 					qcom_usb_irq_handler,
91 					IRQF_TRIGGER_RISING |
92 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
93 					pdev->name, info);
94 	if (ret < 0) {
95 		dev_err(dev, "failed to request handler for ID IRQ\n");
96 		return ret;
97 	}
98 
99 	platform_set_drvdata(pdev, info);
100 	device_init_wakeup(dev, 1);
101 
102 	/* Perform initial detection */
103 	qcom_usb_extcon_detect_cable(&info->wq_detcable.work);
104 
105 	return 0;
106 }
107 
108 static int qcom_usb_extcon_remove(struct platform_device *pdev)
109 {
110 	struct qcom_usb_extcon_info *info = platform_get_drvdata(pdev);
111 
112 	cancel_delayed_work_sync(&info->wq_detcable);
113 
114 	return 0;
115 }
116 
117 #ifdef CONFIG_PM_SLEEP
118 static int qcom_usb_extcon_suspend(struct device *dev)
119 {
120 	struct qcom_usb_extcon_info *info = dev_get_drvdata(dev);
121 	int ret = 0;
122 
123 	if (device_may_wakeup(dev))
124 		ret = enable_irq_wake(info->irq);
125 
126 	return ret;
127 }
128 
129 static int qcom_usb_extcon_resume(struct device *dev)
130 {
131 	struct qcom_usb_extcon_info *info = dev_get_drvdata(dev);
132 	int ret = 0;
133 
134 	if (device_may_wakeup(dev))
135 		ret = disable_irq_wake(info->irq);
136 
137 	return ret;
138 }
139 #endif
140 
141 static SIMPLE_DEV_PM_OPS(qcom_usb_extcon_pm_ops,
142 			 qcom_usb_extcon_suspend, qcom_usb_extcon_resume);
143 
144 static const struct of_device_id qcom_usb_extcon_dt_match[] = {
145 	{ .compatible = "qcom,pm8941-misc", },
146 	{ }
147 };
148 MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match);
149 
150 static struct platform_driver qcom_usb_extcon_driver = {
151 	.probe		= qcom_usb_extcon_probe,
152 	.remove		= qcom_usb_extcon_remove,
153 	.driver		= {
154 		.name	= "extcon-pm8941-misc",
155 		.pm	= &qcom_usb_extcon_pm_ops,
156 		.of_match_table = qcom_usb_extcon_dt_match,
157 	},
158 };
159 module_platform_driver(qcom_usb_extcon_driver);
160 
161 MODULE_DESCRIPTION("QCOM USB ID extcon driver");
162 MODULE_AUTHOR("Stephen Boyd <stephen.boyd@linaro.org>");
163 MODULE_LICENSE("GPL v2");
164