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