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