LXR linux/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#include <linux/slab.h>
  34
  35struct nop_usb_xceiv {
  36        struct otg_transceiver  otg;
  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 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
  66static int nop_set_suspend(struct otg_transceiver *x, int suspend)
  67{
  68        return 0;
  69}
  70
  71static 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
  91static 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
 109static 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        BLOCKING_INIT_NOTIFIER_HEAD(&nop->otg.notifier);
 136
 137        return 0;
 138exit:
 139        kfree(nop);
 140        return err;
 141}
 142
 143static 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
 155static 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
 164static int __init nop_usb_xceiv_init(void)
 165{
 166        return platform_driver_register(&nop_usb_xceiv_driver);
 167}
 168subsys_initcall(nop_usb_xceiv_init);
 169
 170static void __exit nop_usb_xceiv_exit(void)
 171{
 172        platform_driver_unregister(&nop_usb_xceiv_driver);
 173}
 174module_exit(nop_usb_xceiv_exit);
 175
 176MODULE_ALIAS("platform:nop_usb_xceiv");
 177MODULE_AUTHOR("Texas Instruments Inc");
 178MODULE_DESCRIPTION("NOP USB Transceiver driver");
 179MODULE_LICENSE("GPL");
 180