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_generic.h>
  34 #include <linux/slab.h>
  35 #include <linux/clk.h>
  36 #include <linux/regulator/consumer.h>
  37 #include <linux/of.h>
  38 #include <linux/of_gpio.h>
  39 #include <linux/gpio.h>
  40 #include <linux/delay.h>
  41
  42 #include "phy-generic.h"
  43
  44 struct platform_device *usb_phy_generic_register(void)
  45 {
  46         return platform_device_register_simple("usb_phy_generic",
  47                         PLATFORM_DEVID_AUTO, NULL, 0);
  48 }
  49 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
  50
  51 void usb_phy_generic_unregister(struct platform_device *pdev)
  52 {
  53         platform_device_unregister(pdev);
  54 }
  55 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
  56
  57 static int nop_set_suspend(struct usb_phy *x, int suspend)
  58 {
  59         struct nop_usb_xceiv *nop = dev_get_drvdata(x->dev);
  60
  61         if (IS_ERR(nop->clk))
  62                 return 0;
  63
  64         if (suspend)
  65                 clk_disable_unprepare(nop->clk);
  66         else
  67                 clk_prepare_enable(nop->clk);
  68
  69         return 0;
  70 }
  71
  72 static void nop_reset_set(struct usb_phy_generic *nop, int asserted)
  73 {
  74         int value;
  75
  76         if (!gpio_is_valid(nop->gpio_reset))
  77                 return;
  78
  79         value = asserted;
  80         if (nop->reset_active_low)
  81                 value = !value;
  82
  83         gpio_set_value_cansleep(nop->gpio_reset, value);
  84
  85         if (!asserted)
  86                 usleep_range(10000, 20000);
  87 }
  88
  89 int usb_gen_phy_init(struct usb_phy *phy)
  90 {
  91         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
  92
  93         if (!IS_ERR(nop->vcc)) {
  94                 if (regulator_enable(nop->vcc))
  95                         dev_err(phy->dev, "Failed to enable power\n");
  96         }
  97
  98         if (!IS_ERR(nop->clk))
  99                 clk_prepare_enable(nop->clk);
 100
 101         /* De-assert RESET */
 102         nop_reset_set(nop, 0);
 103
 104         return 0;
 105 }
 106 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 107
 108 void usb_gen_phy_shutdown(struct usb_phy *phy)
 109 {
 110         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 111
 112         /* Assert RESET */
 113         nop_reset_set(nop, 1);
 114
 115         if (!IS_ERR(nop->clk))
 116                 clk_disable_unprepare(nop->clk);
 117
 118         if (!IS_ERR(nop->vcc)) {
 119                 if (regulator_disable(nop->vcc))
 120                         dev_err(phy->dev, "Failed to disable power\n");
 121         }
 122 }
 123 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 124
 125 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 126 {
 127         if (!otg)
 128                 return -ENODEV;
 129
 130         if (!gadget) {
 131                 otg->gadget = NULL;
 132                 return -ENODEV;
 133         }
 134
 135         otg->gadget = gadget;
 136         otg->phy->state = OTG_STATE_B_IDLE;
 137         return 0;
 138 }
 139
 140 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 141 {
 142         if (!otg)
 143                 return -ENODEV;
 144
 145         if (!host) {
 146                 otg->host = NULL;
 147                 return -ENODEV;
 148         }
 149
 150         otg->host = host;
 151         return 0;
 152 }
 153
 154 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
 155                 struct usb_phy_generic_platform_data *pdata)
 156 {
 157         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 158         int err;
 159
 160         u32 clk_rate = 0;
 161         bool needs_vcc = false;
 162
 163         nop->reset_active_low = true;   /* default behaviour */
 164
 165         if (dev->of_node) {
 166                 struct device_node *node = dev->of_node;
 167                 enum of_gpio_flags flags = 0;
 168
 169                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 170                         clk_rate = 0;
 171
 172                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 173                 nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios",
 174                                                                 0, &flags);
 175                 if (nop->gpio_reset == -EPROBE_DEFER)
 176                         return -EPROBE_DEFER;
 177
 178                 nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW;
 179
 180         } else if (pdata) {
 181                 type = pdata->type;
 182                 clk_rate = pdata->clk_rate;
 183                 needs_vcc = pdata->needs_vcc;
 184                 nop->gpio_reset = pdata->gpio_reset;
 185         } else {
 186                 nop->gpio_reset = -1;
 187         }
 188
 189         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 190                         GFP_KERNEL);
 191         if (!nop->phy.otg)
 192                 return -ENOMEM;
 193
 194         nop->clk = devm_clk_get(dev, "main_clk");
 195         if (IS_ERR(nop->clk)) {
 196                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 197                                         PTR_ERR(nop->clk));
 198         }
 199
 200         if (!IS_ERR(nop->clk) && clk_rate) {
 201                 err = clk_set_rate(nop->clk, clk_rate);
 202                 if (err) {
 203                         dev_err(dev, "Error setting clock rate\n");
 204                         return err;
 205                 }
 206         }
 207
 208         nop->vcc = devm_regulator_get(dev, "vcc");
 209         if (IS_ERR(nop->vcc)) {
 210                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 211                                         PTR_ERR(nop->vcc));
 212                 if (needs_vcc)
 213                         return -EPROBE_DEFER;
 214         }
 215
 216         if (gpio_is_valid(nop->gpio_reset)) {
 217                 unsigned long gpio_flags;
 218
 219                 /* Assert RESET */
 220                 if (nop->reset_active_low)
 221                         gpio_flags = GPIOF_OUT_INIT_LOW;
 222                 else
 223                         gpio_flags = GPIOF_OUT_INIT_HIGH;
 224
 225                 err = devm_gpio_request_one(dev, nop->gpio_reset,
 226                                                 gpio_flags, dev_name(dev));
 227                 if (err) {
 228                         dev_err(dev, "Error requesting RESET GPIO %d\n",
 229                                         nop->gpio_reset);
 230                         return err;
 231                 }
 232         }
 233
 234         nop->dev                = dev;
 235         nop->phy.dev            = nop->dev;
 236         nop->phy.label          = "nop-xceiv";
 237         nop->phy.set_suspend    = nop_set_suspend;
 238         nop->phy.state          = OTG_STATE_UNDEFINED;
 239         nop->phy.type           = type;
 240
 241         nop->phy.otg->phy               = &nop->phy;
 242         nop->phy.otg->set_host          = nop_set_host;
 243         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 244
 245         return 0;
 246 }
 247 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 248
 249 static int usb_phy_generic_probe(struct platform_device *pdev)
 250 {
 251         struct device *dev = &pdev->dev;
 252         struct usb_phy_generic  *nop;
 253         int err;
 254
 255         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 256         if (!nop)
 257                 return -ENOMEM;
 258
 259         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
 260         if (err)
 261                 return err;
 262
 263         nop->phy.init           = usb_gen_phy_init;
 264         nop->phy.shutdown       = usb_gen_phy_shutdown;
 265
 266         err = usb_add_phy_dev(&nop->phy);
 267         if (err) {
 268                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 269                         err);
 270                 return err;
 271         }
 272
 273         platform_set_drvdata(pdev, nop);
 274
 275         return 0;
 276 }
 277
 278 static int usb_phy_generic_remove(struct platform_device *pdev)
 279 {
 280         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 281
 282         usb_remove_phy(&nop->phy);
 283
 284         return 0;
 285 }
 286
 287 static const struct of_device_id nop_xceiv_dt_ids[] = {
 288         { .compatible = "usb-nop-xceiv" },
 289         { }
 290 };
 291
 292 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 293
 294 static struct platform_driver usb_phy_generic_driver = {
 295         .probe          = usb_phy_generic_probe,
 296         .remove         = usb_phy_generic_remove,
 297         .driver         = {
 298                 .name   = "usb_phy_generic",
 299                 .owner  = THIS_MODULE,
 300                 .of_match_table = nop_xceiv_dt_ids,
 301         },
 302 };
 303
 304 static int __init usb_phy_generic_init(void)
 305 {
 306         return platform_driver_register(&usb_phy_generic_driver);
 307 }
 308 subsys_initcall(usb_phy_generic_init);
 309
 310 static void __exit usb_phy_generic_exit(void)
 311 {
 312         platform_driver_unregister(&usb_phy_generic_driver);
 313 }
 314 module_exit(usb_phy_generic_exit);
 315
 316 MODULE_ALIAS("platform:usb_phy_generic");
 317 MODULE_AUTHOR("Texas Instruments Inc");
 318 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 319 MODULE_LICENSE("GPL");