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