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 is to add "nop" transceiver for all those phy which is
  26  *      autonomous such as isp1504 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 u64 nop_xceiv_dmamask = DMA_BIT_MASK(32);
  40
  41 static struct platform_device nop_xceiv_device = {
  42         .name           = "nop_usb_xceiv",
  43         .id             = -1,
  44         .dev = {
  45                 .dma_mask               = &nop_xceiv_dmamask,
  46                 .coherent_dma_mask      = DMA_BIT_MASK(32),
  47                 .platform_data          = NULL,
  48         },
  49 };
  50
  51 void usb_nop_xceiv_register(void)
  52 {
  53         if (platform_device_register(&nop_xceiv_device) < 0) {
  54                 printk(KERN_ERR "Unable to register usb nop transceiver\n");
  55                 return;
  56         }
  57 }
  58
  59 void usb_nop_xceiv_unregister(void)
  60 {
  61         platform_device_unregister(&nop_xceiv_device);
  62 }
  63
  64 static inline struct nop_usb_xceiv *xceiv_to_nop(struct otg_transceiver *x)
  65 {
  66         return container_of(x, struct nop_usb_xceiv, otg);
  67 }
  68
  69 static int nop_set_suspend(struct otg_transceiver *x, int suspend)
  70 {
  71         return 0;
  72 }
  73
  74 static int nop_set_peripheral(struct otg_transceiver *x,
  75                 struct usb_gadget *gadget)
  76 {
  77         struct nop_usb_xceiv *nop;
  78
  79         if (!x)
  80                 return -ENODEV;
  81
  82         nop = xceiv_to_nop(x);
  83
  84         if (!gadget) {
  85                 nop->otg.gadget = NULL;
  86                 return -ENODEV;
  87         }
  88
  89         nop->otg.gadget = gadget;
  90         nop->otg.state = OTG_STATE_B_IDLE;
  91         return 0;
  92 }
  93
  94 static int nop_set_host(struct otg_transceiver *x, struct usb_bus *host)
  95 {
  96         struct nop_usb_xceiv *nop;
  97
  98         if (!x)
  99                 return -ENODEV;
 100
 101         nop = xceiv_to_nop(x);
 102
 103         if (!host) {
 104                 nop->otg.host = NULL;
 105                 return -ENODEV;
 106         }
 107
 108         nop->otg.host = host;
 109         return 0;
 110 }
 111
 112 static int __devinit nop_usb_xceiv_probe(struct platform_device *pdev)
 113 {
 114         struct nop_usb_xceiv    *nop;
 115         int err;
 116
 117         nop = kzalloc(sizeof *nop, GFP_KERNEL);
 118         if (!nop)
 119                 return -ENOMEM;
 120
 121         nop->dev                = &pdev->dev;
 122         nop->otg.dev            = nop->dev;
 123         nop->otg.label          = "nop-xceiv";
 124         nop->otg.state          = OTG_STATE_UNDEFINED;
 125         nop->otg.set_host       = nop_set_host;
 126         nop->otg.set_peripheral = nop_set_peripheral;
 127         nop->otg.set_suspend    = nop_set_suspend;
 128
 129         err = otg_set_transceiver(&nop->otg);
 130         if (err) {
 131                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 132                         err);
 133                 goto exit;
 134         }
 135
 136         platform_set_drvdata(pdev, nop);
 137
 138         return 0;
 139 exit:
 140         kfree(nop);
 141         return err;
 142 }
 143
 144 static int __devexit nop_usb_xceiv_remove(struct platform_device *pdev)
 145 {
 146         struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
 147
 148         otg_set_transceiver(NULL);
 149
 150         platform_set_drvdata(pdev, NULL);
 151         kfree(nop);
 152
 153         return 0;
 154 }
 155
 156 static struct platform_driver nop_usb_xceiv_driver = {
 157         .probe          = nop_usb_xceiv_probe,
 158         .remove         = __devexit_p(nop_usb_xceiv_remove),
 159         .driver         = {
 160                 .name   = "nop_usb_xceiv",
 161                 .owner  = THIS_MODULE,
 162         },
 163 };
 164
 165 static int __init nop_usb_xceiv_init(void)
 166 {
 167         return platform_driver_register(&nop_usb_xceiv_driver);
 168 }
 169 subsys_initcall(nop_usb_xceiv_init);
 170
 171 static void __exit nop_usb_xceiv_exit(void)
 172 {
 173         platform_driver_unregister(&nop_usb_xceiv_driver);
 174 }
 175 module_exit(nop_usb_xceiv_exit);
 176
 177 MODULE_ALIAS("platform:nop_usb_xceiv");
 178 MODULE_AUTHOR("Texas Instruments Inc");
 179 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 180 MODULE_LICENSE("GPL");