1 /*
2 * drivers/usb/otg/nop-usb-xceiv.c
3 *
4 * NOP USB transceiver for all USB transceiver which are either built-in
5 * into USB IP or which are mostly autonomous.
6 *
7 * Copyright (C) 2009 Texas Instruments Inc
8 * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 *
24 * Current status:
25 * This provides a "nop" transceiver for PHYs which are
26 * autonomous such as isp1504, isp1707, etc.
27 */
28
29 #include <linux/module.h>
30 #include <linux/platform_device.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/usb/otg.h>
33 #include <linux/slab.h>
34
35 struct nop_usb_xceiv {
36 struct otg_transceiver otg;
37 struct device *dev;
38 };
39
40 static struct platform_device *pd;
41
usb_nop_xceiv_register(void)42 void usb_nop_xceiv_register(void)
43 {
44 if (pd)
45 return;
46 pd = platform_device_register_simple("nop_usb_xceiv", -1, NULL, 0);
47 if (!pd) {
48 printk(KERN_ERR "Unable to register usb nop transceiver\n");
49 return;
50 }
51 }
52 EXPORT_SYMBOL(usb_nop_xceiv_register);
53
usb_nop_xceiv_unregister(void)54 void usb_nop_xceiv_unregister(void)
55 {
56 platform_device_unregister(pd);
57 pd = NULL;
58 }
59 EXPORT_SYMBOL(usb_nop_xceiv_unregister);
60
xceiv_to_nop(struct otg_transceiver * x)61 static inline struct nop_usb_xceiv *xceiv_to_nop(struct otg_transceiver *x)
62 {
63 return container_of(x, struct nop_usb_xceiv, otg);
64 }
65
nop_set_suspend(struct otg_transceiver * x,int suspend)66 static int nop_set_suspend(struct otg_transceiver *x, int suspend)
67 {
68 return 0;
69 }
70
nop_set_peripheral(struct otg_transceiver * x,struct usb_gadget * gadget)71 static int nop_set_peripheral(struct otg_transceiver *x,
72 struct usb_gadget *gadget)
73 {
74 struct nop_usb_xceiv *nop;
75
76 if (!x)
77 return -ENODEV;
78
79 nop = xceiv_to_nop(x);
80
81 if (!gadget) {
82 nop->otg.gadget = NULL;
83 return -ENODEV;
84 }
85
86 nop->otg.gadget = gadget;
87 nop->otg.state = OTG_STATE_B_IDLE;
88 return 0;
89 }
90
nop_set_host(struct otg_transceiver * x,struct usb_bus * host)91 static int nop_set_host(struct otg_transceiver *x, struct usb_bus *host)
92 {
93 struct nop_usb_xceiv *nop;
94
95 if (!x)
96 return -ENODEV;
97
98 nop = xceiv_to_nop(x);
99
100 if (!host) {
101 nop->otg.host = NULL;
102 return -ENODEV;
103 }
104
105 nop->otg.host = host;
106 return 0;
107 }
108
nop_usb_xceiv_probe(struct platform_device * pdev)109 static int __devinit nop_usb_xceiv_probe(struct platform_device *pdev)
110 {
111 struct nop_usb_xceiv *nop;
112 int err;
113
114 nop = kzalloc(sizeof *nop, GFP_KERNEL);
115 if (!nop)
116 return -ENOMEM;
117
118 nop->dev = &pdev->dev;
119 nop->otg.dev = nop->dev;
120 nop->otg.label = "nop-xceiv";
121 nop->otg.state = OTG_STATE_UNDEFINED;
122 nop->otg.set_host = nop_set_host;
123 nop->otg.set_peripheral = nop_set_peripheral;
124 nop->otg.set_suspend = nop_set_suspend;
125
126 err = otg_set_transceiver(&nop->otg);
127 if (err) {
128 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
129 err);
130 goto exit;
131 }
132
133 platform_set_drvdata(pdev, nop);
134
135 ATOMIC_INIT_NOTIFIER_HEAD(&nop->otg.notifier);
136
137 return 0;
138 exit:
139 kfree(nop);
140 return err;
141 }
142
nop_usb_xceiv_remove(struct platform_device * pdev)143 static int __devexit nop_usb_xceiv_remove(struct platform_device *pdev)
144 {
145 struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
146
147 otg_set_transceiver(NULL);
148
149 platform_set_drvdata(pdev, NULL);
150 kfree(nop);
151
152 return 0;
153 }
154
155 static struct platform_driver nop_usb_xceiv_driver = {
156 .probe = nop_usb_xceiv_probe,
157 .remove = __devexit_p(nop_usb_xceiv_remove),
158 .driver = {
159 .name = "nop_usb_xceiv",
160 .owner = THIS_MODULE,
161 },
162 };
163
nop_usb_xceiv_init(void)164 static int __init nop_usb_xceiv_init(void)
165 {
166 return platform_driver_register(&nop_usb_xceiv_driver);
167 }
168 subsys_initcall(nop_usb_xceiv_init);
169
nop_usb_xceiv_exit(void)170 static void __exit nop_usb_xceiv_exit(void)
171 {
172 platform_driver_unregister(&nop_usb_xceiv_driver);
173 }
174 module_exit(nop_usb_xceiv_exit);
175
176 MODULE_ALIAS("platform:nop_usb_xceiv");
177 MODULE_AUTHOR("Texas Instruments Inc");
178 MODULE_DESCRIPTION("NOP USB Transceiver driver");
179 MODULE_LICENSE("GPL");
180