drivers/usb/phy/phy-generic.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/usb_phy_gen_xceiv.h>
  34 #include <linux/slab.h>
  35 #include <linux/clk.h>
  36 #include <linux/regulator/consumer.h>
  37 #include <linux/of.h>
  38
  39 #include "phy-generic.h"
  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("usb_phy_gen_xceiv", -1, NULL, 0);
  48         if (!pd) {
  49                 pr_err("Unable to register generic usb 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 int usb_gen_phy_init(struct usb_phy *phy)
  68 {
  69         struct usb_phy_gen_xceiv *nop = dev_get_drvdata(phy->dev);
  70
  71         if (!IS_ERR(nop->vcc)) {
  72                 if (regulator_enable(nop->vcc))
  73                         dev_err(phy->dev, "Failed to enable power\n");
  74         }
  75
  76         if (!IS_ERR(nop->clk))
  77                 clk_enable(nop->clk);
  78
  79         if (!IS_ERR(nop->reset)) {
  80                 /* De-assert RESET */
  81                 if (regulator_enable(nop->reset))
  82                         dev_err(phy->dev, "Failed to de-assert reset\n");
  83         }
  84
  85         return 0;
  86 }
  87 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
  88
  89 void usb_gen_phy_shutdown(struct usb_phy *phy)
  90 {
  91         struct usb_phy_gen_xceiv *nop = dev_get_drvdata(phy->dev);
  92
  93         if (!IS_ERR(nop->reset)) {
  94                 /* Assert RESET */
  95                 if (regulator_disable(nop->reset))
  96                         dev_err(phy->dev, "Failed to assert reset\n");
  97         }
  98
  99         if (!IS_ERR(nop->clk))
 100                 clk_disable(nop->clk);
 101
 102         if (!IS_ERR(nop->vcc)) {
 103                 if (regulator_disable(nop->vcc))
 104                         dev_err(phy->dev, "Failed to disable power\n");
 105         }
 106 }
 107 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 108
 109 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 110 {
 111         if (!otg)
 112                 return -ENODEV;
 113
 114         if (!gadget) {
 115                 otg->gadget = NULL;
 116                 return -ENODEV;
 117         }
 118
 119         otg->gadget = gadget;
 120         otg->phy->state = OTG_STATE_B_IDLE;
 121         return 0;
 122 }
 123
 124 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 125 {
 126         if (!otg)
 127                 return -ENODEV;
 128
 129         if (!host) {
 130                 otg->host = NULL;
 131                 return -ENODEV;
 132         }
 133
 134         otg->host = host;
 135         return 0;
 136 }
 137
 138 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_gen_xceiv *nop,
 139                 enum usb_phy_type type, u32 clk_rate, bool needs_vcc,
 140                 bool needs_reset)
 141 {
 142         int err;
 143
 144         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 145                         GFP_KERNEL);
 146         if (!nop->phy.otg)
 147                 return -ENOMEM;
 148
 149         nop->clk = devm_clk_get(dev, "main_clk");
 150         if (IS_ERR(nop->clk)) {
 151                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 152                                         PTR_ERR(nop->clk));
 153         }
 154
 155         if (!IS_ERR(nop->clk) && clk_rate) {
 156                 err = clk_set_rate(nop->clk, clk_rate);
 157                 if (err) {
 158                         dev_err(dev, "Error setting clock rate\n");
 159                         return err;
 160                 }
 161         }
 162
 163         if (!IS_ERR(nop->clk)) {
 164                 err = clk_prepare(nop->clk);
 165                 if (err) {
 166                         dev_err(dev, "Error preparing clock\n");
 167                         return err;
 168                 }
 169         }
 170
 171         nop->vcc = devm_regulator_get(dev, "vcc");
 172         if (IS_ERR(nop->vcc)) {
 173                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 174                                         PTR_ERR(nop->vcc));
 175                 if (needs_vcc)
 176                         return -EPROBE_DEFER;
 177         }
 178
 179         nop->reset = devm_regulator_get(dev, "reset");
 180         if (IS_ERR(nop->reset)) {
 181                 dev_dbg(dev, "Error getting reset regulator: %ld\n",
 182                                         PTR_ERR(nop->reset));
 183                 if (needs_reset)
 184                         return -EPROBE_DEFER;
 185         }
 186
 187         nop->dev                = dev;
 188         nop->phy.dev            = nop->dev;
 189         nop->phy.label          = "nop-xceiv";
 190         nop->phy.set_suspend    = nop_set_suspend;
 191         nop->phy.state          = OTG_STATE_UNDEFINED;
 192         nop->phy.type           = type;
 193
 194         nop->phy.otg->phy               = &nop->phy;
 195         nop->phy.otg->set_host          = nop_set_host;
 196         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 197
 198         ATOMIC_INIT_NOTIFIER_HEAD(&nop->phy.notifier);
 199         return 0;
 200 }
 201 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 202
 203 void usb_phy_gen_cleanup_phy(struct usb_phy_gen_xceiv *nop)
 204 {
 205         if (!IS_ERR(nop->clk))
 206                 clk_unprepare(nop->clk);
 207 }
 208 EXPORT_SYMBOL_GPL(usb_phy_gen_cleanup_phy);
 209
 210 static int usb_phy_gen_xceiv_probe(struct platform_device *pdev)
 211 {
 212         struct device *dev = &pdev->dev;
 213         struct usb_phy_gen_xceiv_platform_data *pdata =
 214                         dev_get_platdata(&pdev->dev);
 215         struct usb_phy_gen_xceiv        *nop;
 216         enum usb_phy_type       type = USB_PHY_TYPE_USB2;
 217         int err;
 218         u32 clk_rate = 0;
 219         bool needs_vcc = false;
 220         bool needs_reset = false;
 221
 222         if (dev->of_node) {
 223                 struct device_node *node = dev->of_node;
 224
 225                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 226                         clk_rate = 0;
 227
 228                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 229                 needs_reset = of_property_read_bool(node, "reset-supply");
 230
 231         } else if (pdata) {
 232                 type = pdata->type;
 233                 clk_rate = pdata->clk_rate;
 234                 needs_vcc = pdata->needs_vcc;
 235                 needs_reset = pdata->needs_reset;
 236         }
 237
 238         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 239         if (!nop)
 240                 return -ENOMEM;
 241
 242
 243         err = usb_phy_gen_create_phy(dev, nop, type, clk_rate, needs_vcc,
 244                         needs_reset);
 245         if (err)
 246                 return err;
 247
 248         nop->phy.init           = usb_gen_phy_init;
 249         nop->phy.shutdown       = usb_gen_phy_shutdown;
 250
 251         err = usb_add_phy_dev(&nop->phy);
 252         if (err) {
 253                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 254                         err);
 255                 goto err_add;
 256         }
 257
 258         platform_set_drvdata(pdev, nop);
 259
 260         return 0;
 261
 262 err_add:
 263         usb_phy_gen_cleanup_phy(nop);
 264         return err;
 265 }
 266
 267 static int usb_phy_gen_xceiv_remove(struct platform_device *pdev)
 268 {
 269         struct usb_phy_gen_xceiv *nop = platform_get_drvdata(pdev);
 270
 271         usb_phy_gen_cleanup_phy(nop);
 272         usb_remove_phy(&nop->phy);
 273
 274         return 0;
 275 }
 276
 277 static const struct of_device_id nop_xceiv_dt_ids[] = {
 278         { .compatible = "usb-nop-xceiv" },
 279         { }
 280 };
 281
 282 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 283
 284 static struct platform_driver usb_phy_gen_xceiv_driver = {
 285         .probe          = usb_phy_gen_xceiv_probe,
 286         .remove         = usb_phy_gen_xceiv_remove,
 287         .driver         = {
 288                 .name   = "usb_phy_gen_xceiv",
 289                 .owner  = THIS_MODULE,
 290                 .of_match_table = nop_xceiv_dt_ids,
 291         },
 292 };
 293
 294 static int __init usb_phy_gen_xceiv_init(void)
 295 {
 296         return platform_driver_register(&usb_phy_gen_xceiv_driver);
 297 }
 298 subsys_initcall(usb_phy_gen_xceiv_init);
 299
 300 static void __exit usb_phy_gen_xceiv_exit(void)
 301 {
 302         platform_driver_unregister(&usb_phy_gen_xceiv_driver);
 303 }
 304 module_exit(usb_phy_gen_xceiv_exit);
 305
 306 MODULE_ALIAS("platform:usb_phy_gen_xceiv");
 307 MODULE_AUTHOR("Texas Instruments Inc");
 308 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 309 MODULE_LICENSE("GPL");