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
  35 struct nop_usb_xceiv {
  36         struct usb_phy          phy;
  37         struct device           *dev;
  38 };
  39
  40 static struct platform_device *pd;
  41
  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
  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
  61 static int nop_set_suspend(struct usb_phy *x, int suspend)
  62 {
  63         return 0;
  64 }
  65
  66 static 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
  81 static 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
  95 static 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;
 132 exit:
 133         kfree(nop->phy.otg);
 134         kfree(nop);
 135         return err;
 136 }
 137
 138 static 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
 151 static 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
 160 static int __init nop_usb_xceiv_init(void)
 161 {
 162         return platform_driver_register(&nop_usb_xceiv_driver);
 163 }
 164 subsys_initcall(nop_usb_xceiv_init);
 165
 166 static void __exit nop_usb_xceiv_exit(void)
 167 {
 168         platform_driver_unregister(&nop_usb_xceiv_driver);
 169 }
 170 module_exit(nop_usb_xceiv_exit);
 171
 172 MODULE_ALIAS("platform:nop_usb_xceiv");
 173 MODULE_AUTHOR("Texas Instruments Inc");
 174 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 175 MODULE_LICENSE("GPL");