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/usb/nop-usb-xceiv.h>
  34 #include <linux/slab.h>
  35
  36 struct nop_usb_xceiv {
  37         struct usb_phy          phy;
  38         struct device           *dev;
  39 };
  40
  41 static struct platform_device *pd;
  42
  43 void usb_nop_xceiv_register(void)
  44 {
  45         if (pd)
  46                 return;
  47         pd = platform_device_register_simple("nop_usb_xceiv", -1, NULL, 0);
  48         if (!pd) {
  49                 printk(KERN_ERR "Unable to register usb nop transceiver\n");
  50                 return;
  51         }
  52 }
  53 EXPORT_SYMBOL(usb_nop_xceiv_register);
  54
  55 void usb_nop_xceiv_unregister(void)
  56 {
  57         platform_device_unregister(pd);
  58         pd = NULL;
  59 }
  60 EXPORT_SYMBOL(usb_nop_xceiv_unregister);
  61
  62 static int nop_set_suspend(struct usb_phy *x, int suspend)
  63 {
  64         return 0;
  65 }
  66
  67 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
  68 {
  69         if (!otg)
  70                 return -ENODEV;
  71
  72         if (!gadget) {
  73                 otg->gadget = NULL;
  74                 return -ENODEV;
  75         }
  76
  77         otg->gadget = gadget;
  78         otg->phy->state = OTG_STATE_B_IDLE;
  79         return 0;
  80 }
  81
  82 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
  83 {
  84         if (!otg)
  85                 return -ENODEV;
  86
  87         if (!host) {
  88                 otg->host = NULL;
  89                 return -ENODEV;
  90         }
  91
  92         otg->host = host;
  93         return 0;
  94 }
  95
  96 static int nop_usb_xceiv_probe(struct platform_device *pdev)
  97 {
  98         struct nop_usb_xceiv_platform_data *pdata = pdev->dev.platform_data;
  99         struct nop_usb_xceiv    *nop;
 100         enum usb_phy_type       type = USB_PHY_TYPE_USB2;
 101         int err;
 102
 103         nop = kzalloc(sizeof *nop, GFP_KERNEL);
 104         if (!nop)
 105                 return -ENOMEM;
 106
 107         nop->phy.otg = kzalloc(sizeof *nop->phy.otg, GFP_KERNEL);
 108         if (!nop->phy.otg) {
 109                 kfree(nop);
 110                 return -ENOMEM;
 111         }
 112
 113         if (pdata)
 114                 type = pdata->type;
 115
 116         nop->dev                = &pdev->dev;
 117         nop->phy.dev            = nop->dev;
 118         nop->phy.label          = "nop-xceiv";
 119         nop->phy.set_suspend    = nop_set_suspend;
 120         nop->phy.state          = OTG_STATE_UNDEFINED;
 121
 122         nop->phy.otg->phy               = &nop->phy;
 123         nop->phy.otg->set_host          = nop_set_host;
 124         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 125
 126         err = usb_add_phy(&nop->phy, type);
 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->phy.notifier);
 136
 137         return 0;
 138 exit:
 139         kfree(nop->phy.otg);
 140         kfree(nop);
 141         return err;
 142 }
 143
 144 static int nop_usb_xceiv_remove(struct platform_device *pdev)
 145 {
 146         struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
 147
 148         usb_remove_phy(&nop->phy);
 149
 150         platform_set_drvdata(pdev, NULL);
 151         kfree(nop->phy.otg);
 152         kfree(nop);
 153
 154         return 0;
 155 }
 156
 157 static struct platform_driver nop_usb_xceiv_driver = {
 158         .probe          = nop_usb_xceiv_probe,
 159         .remove         = nop_usb_xceiv_remove,
 160         .driver         = {
 161                 .name   = "nop_usb_xceiv",
 162                 .owner  = THIS_MODULE,
 163         },
 164 };
 165
 166 static int __init nop_usb_xceiv_init(void)
 167 {
 168         return platform_driver_register(&nop_usb_xceiv_driver);
 169 }
 170 subsys_initcall(nop_usb_xceiv_init);
 171
 172 static void __exit nop_usb_xceiv_exit(void)
 173 {
 174         platform_driver_unregister(&nop_usb_xceiv_driver);
 175 }
 176 module_exit(nop_usb_xceiv_exit);
 177
 178 MODULE_ALIAS("platform:nop_usb_xceiv");
 179 MODULE_AUTHOR("Texas Instruments Inc");
 180 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 181 MODULE_LICENSE("GPL");