xref: /openbmc/linux/drivers/usb/phy/phy-omap-otg.c (revision ec57fcd0)
1 /*
2  * OMAP OTG controller driver
3  *
4  * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
5  *
6  * Copyright (C) 2005-2006 Nokia Corporation
7  * Copyright (C) 2004 Texas Instruments
8  * Copyright (C) 2004 David Brownell
9  *
10  * This file is subject to the terms and conditions of the GNU General
11  * Public License. See the file "COPYING" in the main directory of this
12  * archive for more details.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  */
19 
20 #include <linux/io.h>
21 #include <linux/err.h>
22 #include <linux/extcon.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/interrupt.h>
26 #include <linux/platform_device.h>
27 #include <linux/platform_data/usb-omap1.h>
28 
29 struct otg_device {
30 	void __iomem			*base;
31 	bool				id;
32 	bool				vbus;
33 	struct extcon_dev		*extcon;
34 	struct notifier_block		vbus_nb;
35 	struct notifier_block		id_nb;
36 };
37 
38 #define OMAP_OTG_CTRL		0x0c
39 #define OMAP_OTG_ASESSVLD	(1 << 20)
40 #define OMAP_OTG_BSESSEND	(1 << 19)
41 #define OMAP_OTG_BSESSVLD	(1 << 18)
42 #define OMAP_OTG_VBUSVLD	(1 << 17)
43 #define OMAP_OTG_ID		(1 << 16)
44 #define OMAP_OTG_XCEIV_OUTPUTS \
45 	(OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
46 	 OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
47 
48 static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
49 {
50 	u32 l;
51 
52 	l = readl(otg_dev->base + OMAP_OTG_CTRL);
53 	l &= ~OMAP_OTG_XCEIV_OUTPUTS;
54 	l |= outputs;
55 	writel(l, otg_dev->base + OMAP_OTG_CTRL);
56 }
57 
58 static void omap_otg_set_mode(struct otg_device *otg_dev)
59 {
60 	if (!otg_dev->id && otg_dev->vbus)
61 		/* Set B-session valid. */
62 		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
63 	else if (otg_dev->vbus)
64 		/* Set A-session valid. */
65 		omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
66 	else if (!otg_dev->id)
67 		/* Set B-session end to indicate no VBUS. */
68 		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
69 }
70 
71 static int omap_otg_id_notifier(struct notifier_block *nb,
72 				unsigned long event, void *ptr)
73 {
74 	struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
75 
76 	otg_dev->id = event;
77 	omap_otg_set_mode(otg_dev);
78 
79 	return NOTIFY_DONE;
80 }
81 
82 static int omap_otg_vbus_notifier(struct notifier_block *nb,
83 				  unsigned long event, void *ptr)
84 {
85 	struct otg_device *otg_dev = container_of(nb, struct otg_device,
86 						  vbus_nb);
87 
88 	otg_dev->vbus = event;
89 	omap_otg_set_mode(otg_dev);
90 
91 	return NOTIFY_DONE;
92 }
93 
94 static int omap_otg_probe(struct platform_device *pdev)
95 {
96 	const struct omap_usb_config *config = pdev->dev.platform_data;
97 	struct otg_device *otg_dev;
98 	struct extcon_dev *extcon;
99 	int ret;
100 	u32 rev;
101 
102 	if (!config || !config->extcon)
103 		return -ENODEV;
104 
105 	extcon = extcon_get_extcon_dev(config->extcon);
106 	if (!extcon)
107 		return -EPROBE_DEFER;
108 
109 	otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
110 	if (!otg_dev)
111 		return -ENOMEM;
112 
113 	otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
114 	if (IS_ERR(otg_dev->base))
115 		return PTR_ERR(otg_dev->base);
116 
117 	otg_dev->extcon = extcon;
118 	otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
119 	otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;
120 
121 	ret = extcon_register_notifier(extcon, EXTCON_USB_HOST, &otg_dev->id_nb);
122 	if (ret)
123 		return ret;
124 
125 	ret = extcon_register_notifier(extcon, EXTCON_USB, &otg_dev->vbus_nb);
126 	if (ret) {
127 		extcon_unregister_notifier(extcon, EXTCON_USB_HOST,
128 					&otg_dev->id_nb);
129 		return ret;
130 	}
131 
132 	otg_dev->id = extcon_get_cable_state_(extcon, EXTCON_USB_HOST);
133 	otg_dev->vbus = extcon_get_cable_state_(extcon, EXTCON_USB);
134 	omap_otg_set_mode(otg_dev);
135 
136 	rev = readl(otg_dev->base);
137 
138 	dev_info(&pdev->dev,
139 		 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
140 		 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
141 		 otg_dev->vbus);
142 
143 	platform_set_drvdata(pdev, otg_dev);
144 
145 	return 0;
146 }
147 
148 static int omap_otg_remove(struct platform_device *pdev)
149 {
150 	struct otg_device *otg_dev = platform_get_drvdata(pdev);
151 	struct extcon_dev *edev = otg_dev->extcon;
152 
153 	extcon_unregister_notifier(edev, EXTCON_USB_HOST, &otg_dev->id_nb);
154 	extcon_unregister_notifier(edev, EXTCON_USB, &otg_dev->vbus_nb);
155 
156 	return 0;
157 }
158 
159 static struct platform_driver omap_otg_driver = {
160 	.probe		= omap_otg_probe,
161 	.remove		= omap_otg_remove,
162 	.driver		= {
163 		.name	= "omap_otg",
164 	},
165 };
166 module_platform_driver(omap_otg_driver);
167 
168 MODULE_DESCRIPTION("OMAP USB OTG controller driver");
169 MODULE_LICENSE("GPL");
170 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
171