USB: Fix double-linking of drivers/usb/otg when ULPI is selected
[linux-2.6.git] / drivers / usb / otg / nop-usb-xceiv.c
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
34 struct nop_usb_xceiv {
35         struct otg_transceiver  otg;
36         struct device           *dev;
37 };
38
39 static struct platform_device *pd;
40
41 void usb_nop_xceiv_register(void)
42 {
43         if (pd)
44                 return;
45         pd = platform_device_register_simple("nop_usb_xceiv", -1, NULL, 0);
46         if (!pd) {
47                 printk(KERN_ERR "Unable to register usb nop transceiver\n");
48                 return;
49         }
50 }
51 EXPORT_SYMBOL(usb_nop_xceiv_register);
52
53 void usb_nop_xceiv_unregister(void)
54 {
55         platform_device_unregister(pd);
56         pd = NULL;
57 }
58 EXPORT_SYMBOL(usb_nop_xceiv_unregister);
59
60 static inline struct nop_usb_xceiv *xceiv_to_nop(struct otg_transceiver *x)
61 {
62         return container_of(x, struct nop_usb_xceiv, otg);
63 }
64
65 static int nop_set_suspend(struct otg_transceiver *x, int suspend)
66 {
67         return 0;
68 }
69
70 static int nop_set_peripheral(struct otg_transceiver *x,
71                 struct usb_gadget *gadget)
72 {
73         struct nop_usb_xceiv *nop;
74
75         if (!x)
76                 return -ENODEV;
77
78         nop = xceiv_to_nop(x);
79
80         if (!gadget) {
81                 nop->otg.gadget = NULL;
82                 return -ENODEV;
83         }
84
85         nop->otg.gadget = gadget;
86         nop->otg.state = OTG_STATE_B_IDLE;
87         return 0;
88 }
89
90 static int nop_set_host(struct otg_transceiver *x, struct usb_bus *host)
91 {
92         struct nop_usb_xceiv *nop;
93
94         if (!x)
95                 return -ENODEV;
96
97         nop = xceiv_to_nop(x);
98
99         if (!host) {
100                 nop->otg.host = NULL;
101                 return -ENODEV;
102         }
103
104         nop->otg.host = host;
105         return 0;
106 }
107
108 static int __devinit nop_usb_xceiv_probe(struct platform_device *pdev)
109 {
110         struct nop_usb_xceiv    *nop;
111         int err;
112
113         nop = kzalloc(sizeof *nop, GFP_KERNEL);
114         if (!nop)
115                 return -ENOMEM;
116
117         nop->dev                = &pdev->dev;
118         nop->otg.dev            = nop->dev;
119         nop->otg.label          = "nop-xceiv";
120         nop->otg.state          = OTG_STATE_UNDEFINED;
121         nop->otg.set_host       = nop_set_host;
122         nop->otg.set_peripheral = nop_set_peripheral;
123         nop->otg.set_suspend    = nop_set_suspend;
124
125         err = otg_set_transceiver(&nop->otg);
126         if (err) {
127                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
128                         err);
129                 goto exit;
130         }
131
132         platform_set_drvdata(pdev, nop);
133
134         return 0;
135 exit:
136         kfree(nop);
137         return err;
138 }
139
140 static int __devexit nop_usb_xceiv_remove(struct platform_device *pdev)
141 {
142         struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
143
144         otg_set_transceiver(NULL);
145
146         platform_set_drvdata(pdev, NULL);
147         kfree(nop);
148
149         return 0;
150 }
151
152 static struct platform_driver nop_usb_xceiv_driver = {
153         .probe          = nop_usb_xceiv_probe,
154         .remove         = __devexit_p(nop_usb_xceiv_remove),
155         .driver         = {
156                 .name   = "nop_usb_xceiv",
157                 .owner  = THIS_MODULE,
158         },
159 };
160
161 static int __init nop_usb_xceiv_init(void)
162 {
163         return platform_driver_register(&nop_usb_xceiv_driver);
164 }
165 subsys_initcall(nop_usb_xceiv_init);
166
167 static void __exit nop_usb_xceiv_exit(void)
168 {
169         platform_driver_unregister(&nop_usb_xceiv_driver);
170 }
171 module_exit(nop_usb_xceiv_exit);
172
173 MODULE_ALIAS("platform:nop_usb_xceiv");
174 MODULE_AUTHOR("Texas Instruments Inc");
175 MODULE_DESCRIPTION("NOP USB Transceiver driver");
176 MODULE_LICENSE("GPL");