xref: /openbmc/linux/drivers/usb/phy/phy-omap-otg.c (revision 449d2ba6)
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_specific_cable_nb	vbus_dev;
34 	struct extcon_specific_cable_nb	id_dev;
35 	struct notifier_block		vbus_nb;
36 	struct notifier_block		id_nb;
37 };
38 
39 #define OMAP_OTG_CTRL		0x0c
40 #define OMAP_OTG_ASESSVLD	(1 << 20)
41 #define OMAP_OTG_BSESSEND	(1 << 19)
42 #define OMAP_OTG_BSESSVLD	(1 << 18)
43 #define OMAP_OTG_VBUSVLD	(1 << 17)
44 #define OMAP_OTG_ID		(1 << 16)
45 #define OMAP_OTG_XCEIV_OUTPUTS \
46 	(OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
47 	 OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
48 
49 static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
50 {
51 	u32 l;
52 
53 	l = readl(otg_dev->base + OMAP_OTG_CTRL);
54 	l &= ~OMAP_OTG_XCEIV_OUTPUTS;
55 	l |= outputs;
56 	writel(l, otg_dev->base + OMAP_OTG_CTRL);
57 }
58 
59 static void omap_otg_set_mode(struct otg_device *otg_dev)
60 {
61 	if (!otg_dev->id && otg_dev->vbus)
62 		/* Set B-session valid. */
63 		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
64 	else if (otg_dev->vbus)
65 		/* Set A-session valid. */
66 		omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
67 	else if (!otg_dev->id)
68 		/* Set B-session end to indicate no VBUS. */
69 		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
70 }
71 
72 static int omap_otg_id_notifier(struct notifier_block *nb,
73 				unsigned long event, void *ptr)
74 {
75 	struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
76 
77 	otg_dev->id = event;
78 	omap_otg_set_mode(otg_dev);
79 
80 	return NOTIFY_DONE;
81 }
82 
83 static int omap_otg_vbus_notifier(struct notifier_block *nb,
84 				  unsigned long event, void *ptr)
85 {
86 	struct otg_device *otg_dev = container_of(nb, struct otg_device,
87 						  vbus_nb);
88 
89 	otg_dev->vbus = event;
90 	omap_otg_set_mode(otg_dev);
91 
92 	return NOTIFY_DONE;
93 }
94 
95 static int omap_otg_probe(struct platform_device *pdev)
96 {
97 	const struct omap_usb_config *config = pdev->dev.platform_data;
98 	struct otg_device *otg_dev;
99 	struct extcon_dev *extcon;
100 	int ret;
101 	u32 rev;
102 
103 	if (!config || !config->extcon)
104 		return -ENODEV;
105 
106 	extcon = extcon_get_extcon_dev(config->extcon);
107 	if (!extcon)
108 		return -EPROBE_DEFER;
109 
110 	otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
111 	if (!otg_dev)
112 		return -ENOMEM;
113 
114 	otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
115 	if (IS_ERR(otg_dev->base))
116 		return PTR_ERR(otg_dev->base);
117 
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_interest(&otg_dev->id_dev, config->extcon,
122 				       "USB-HOST", &otg_dev->id_nb);
123 	if (ret)
124 		return ret;
125 
126 	ret = extcon_register_interest(&otg_dev->vbus_dev, config->extcon,
127 				       "USB", &otg_dev->vbus_nb);
128 	if (ret) {
129 		extcon_unregister_interest(&otg_dev->id_dev);
130 		return ret;
131 	}
132 
133 	otg_dev->id = extcon_get_cable_state(extcon, "USB-HOST");
134 	otg_dev->vbus = extcon_get_cable_state(extcon, "USB");
135 	omap_otg_set_mode(otg_dev);
136 
137 	rev = readl(otg_dev->base);
138 
139 	dev_info(&pdev->dev,
140 		 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
141 		 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
142 		 otg_dev->vbus);
143 
144 	return 0;
145 }
146 
147 static int omap_otg_remove(struct platform_device *pdev)
148 {
149 	struct otg_device *otg_dev = platform_get_drvdata(pdev);
150 
151 	extcon_unregister_interest(&otg_dev->id_dev);
152 	extcon_unregister_interest(&otg_dev->vbus_dev);
153 
154 	return 0;
155 }
156 
157 static struct platform_driver omap_otg_driver = {
158 	.probe		= omap_otg_probe,
159 	.remove		= omap_otg_remove,
160 	.driver		= {
161 		.owner	= THIS_MODULE,
162 		.name	= "omap_otg",
163 	},
164 };
165 module_platform_driver(omap_otg_driver);
166 
167 MODULE_DESCRIPTION("OMAP USB OTG controller driver");
168 MODULE_LICENSE("GPL");
169 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
170