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 #include <linux/clk.h>
  36 #include <linux/regulator/consumer.h>
  37
  38 struct nop_usb_xceiv {
  39         struct usb_phy          phy;
  40         struct device           *dev;
  41         struct clk              *clk;
  42         struct regulator        *vcc;
  43 };
  44
  45 static struct platform_device *pd;
  46
  47 void usb_nop_xceiv_register(void)
  48 {
  49         if (pd)
  50                 return;
  51         pd = platform_device_register_simple("nop_usb_xceiv", -1, NULL, 0);
  52         if (!pd) {
  53                 printk(KERN_ERR "Unable to register usb nop transceiver\n");
  54                 return;
  55         }
  56 }
  57 EXPORT_SYMBOL(usb_nop_xceiv_register);
  58
  59 void usb_nop_xceiv_unregister(void)
  60 {
  61         platform_device_unregister(pd);
  62         pd = NULL;
  63 }
  64 EXPORT_SYMBOL(usb_nop_xceiv_unregister);
  65
  66 static int nop_set_suspend(struct usb_phy *x, int suspend)
  67 {
  68         return 0;
  69 }
  70
  71 static int nop_init(struct usb_phy *phy)
  72 {
  73         struct nop_usb_xceiv *nop = dev_get_drvdata(phy->dev);
  74
  75         if (!IS_ERR(nop->vcc)) {
  76                 if (regulator_enable(nop->vcc))
  77                         dev_err(phy->dev, "Failed to enable power\n");
  78         }
  79
  80         if (!IS_ERR(nop->clk))
  81                 clk_enable(nop->clk);
  82
  83         return 0;
  84 }
  85
  86 static void nop_shutdown(struct usb_phy *phy)
  87 {
  88         struct nop_usb_xceiv *nop = dev_get_drvdata(phy->dev);
  89
  90         if (!IS_ERR(nop->clk))
  91                 clk_disable(nop->clk);
  92
  93         if (!IS_ERR(nop->vcc)) {
  94                 if (regulator_disable(nop->vcc))
  95                         dev_err(phy->dev, "Failed to disable power\n");
  96         }
  97 }
  98
  99 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 100 {
 101         if (!otg)
 102                 return -ENODEV;
 103
 104         if (!gadget) {
 105                 otg->gadget = NULL;
 106                 return -ENODEV;
 107         }
 108
 109         otg->gadget = gadget;
 110         otg->phy->state = OTG_STATE_B_IDLE;
 111         return 0;
 112 }
 113
 114 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 115 {
 116         if (!otg)
 117                 return -ENODEV;
 118
 119         if (!host) {
 120                 otg->host = NULL;
 121                 return -ENODEV;
 122         }
 123
 124         otg->host = host;
 125         return 0;
 126 }
 127
 128 static int nop_usb_xceiv_probe(struct platform_device *pdev)
 129 {
 130         struct nop_usb_xceiv_platform_data *pdata = pdev->dev.platform_data;
 131         struct nop_usb_xceiv    *nop;
 132         enum usb_phy_type       type = USB_PHY_TYPE_USB2;
 133         int err;
 134
 135         nop = devm_kzalloc(&pdev->dev, sizeof(*nop), GFP_KERNEL);
 136         if (!nop)
 137                 return -ENOMEM;
 138
 139         nop->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*nop->phy.otg),
 140                                                         GFP_KERNEL);
 141         if (!nop->phy.otg)
 142                 return -ENOMEM;
 143
 144         if (pdata)
 145                 type = pdata->type;
 146
 147         nop->clk = devm_clk_get(&pdev->dev, "main_clk");
 148         if (IS_ERR(nop->clk)) {
 149                 dev_dbg(&pdev->dev, "Can't get phy clock: %ld\n",
 150                                         PTR_ERR(nop->clk));
 151         }
 152
 153         if (!IS_ERR(nop->clk) && pdata && pdata->clk_rate) {
 154                 err = clk_set_rate(nop->clk, pdata->clk_rate);
 155                 if (err) {
 156                         dev_err(&pdev->dev, "Error setting clock rate\n");
 157                         return err;
 158                 }
 159         }
 160
 161         if (!IS_ERR(nop->clk)) {
 162                 err = clk_prepare(nop->clk);
 163                 if (err) {
 164                         dev_err(&pdev->dev, "Error preparing clock\n");
 165                         return err;
 166                 }
 167         }
 168
 169         nop->vcc = devm_regulator_get(&pdev->dev, "vcc");
 170         if (IS_ERR(nop->vcc)) {
 171                 dev_dbg(&pdev->dev, "Error getting vcc regulator: %ld\n",
 172                                         PTR_ERR(nop->vcc));
 173         }
 174
 175         nop->dev                = &pdev->dev;
 176         nop->phy.dev            = nop->dev;
 177         nop->phy.label          = "nop-xceiv";
 178         nop->phy.set_suspend    = nop_set_suspend;
 179         nop->phy.init           = nop_init;
 180         nop->phy.shutdown       = nop_shutdown;
 181         nop->phy.state          = OTG_STATE_UNDEFINED;
 182
 183         nop->phy.otg->phy               = &nop->phy;
 184         nop->phy.otg->set_host          = nop_set_host;
 185         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 186
 187         err = usb_add_phy(&nop->phy, type);
 188         if (err) {
 189                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 190                         err);
 191                 goto err_add;
 192         }
 193
 194         platform_set_drvdata(pdev, nop);
 195
 196         ATOMIC_INIT_NOTIFIER_HEAD(&nop->phy.notifier);
 197
 198         return 0;
 199
 200 err_add:
 201         if (!IS_ERR(nop->clk))
 202                 clk_unprepare(nop->clk);
 203         return err;
 204 }
 205
 206 static int nop_usb_xceiv_remove(struct platform_device *pdev)
 207 {
 208         struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
 209
 210         if (!IS_ERR(nop->clk))
 211                 clk_unprepare(nop->clk);
 212
 213         usb_remove_phy(&nop->phy);
 214
 215         platform_set_drvdata(pdev, NULL);
 216
 217         return 0;
 218 }
 219
 220 static struct platform_driver nop_usb_xceiv_driver = {
 221         .probe          = nop_usb_xceiv_probe,
 222         .remove         = nop_usb_xceiv_remove,
 223         .driver         = {
 224                 .name   = "nop_usb_xceiv",
 225                 .owner  = THIS_MODULE,
 226         },
 227 };
 228
 229 static int __init nop_usb_xceiv_init(void)
 230 {
 231         return platform_driver_register(&nop_usb_xceiv_driver);
 232 }
 233 subsys_initcall(nop_usb_xceiv_init);
 234
 235 static void __exit nop_usb_xceiv_exit(void)
 236 {
 237         platform_driver_unregister(&nop_usb_xceiv_driver);
 238 }
 239 module_exit(nop_usb_xceiv_exit);
 240
 241 MODULE_ALIAS("platform:nop_usb_xceiv");
 242 MODULE_AUTHOR("Texas Instruments Inc");
 243 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 244 MODULE_LICENSE("GPL");