drivers/usb/phy/phy-generic.c

   1 /*
   2  * NOP USB transceiver for all USB transceiver which are either built-in
   3  * into USB IP or which are mostly autonomous.
   4  *
   5  * Copyright (C) 2009 Texas Instruments Inc
   6  * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  * Current status:
  23  *      This provides a "nop" transceiver for PHYs which are
  24  *      autonomous such as isp1504, isp1707, etc.
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/usb/gadget.h>
  31 #include <linux/usb/otg.h>
  32 #include <linux/usb/usb_phy_generic.h>
  33 #include <linux/slab.h>
  34 #include <linux/clk.h>
  35 #include <linux/regulator/consumer.h>
  36 #include <linux/of.h>
  37 #include <linux/of_gpio.h>
  38 #include <linux/gpio.h>
  39 #include <linux/delay.h>
  40
  41 #include "phy-generic.h"
  42
  43 #define VBUS_IRQ_FLAGS \
  44         (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
  45                 IRQF_ONESHOT)
  46
  47 struct platform_device *usb_phy_generic_register(void)
  48 {
  49         return platform_device_register_simple("usb_phy_generic",
  50                         PLATFORM_DEVID_AUTO, NULL, 0);
  51 }
  52 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
  53
  54 void usb_phy_generic_unregister(struct platform_device *pdev)
  55 {
  56         platform_device_unregister(pdev);
  57 }
  58 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
  59
  60 static int nop_set_suspend(struct usb_phy *x, int suspend)
  61 {
  62         struct usb_phy_generic *nop = dev_get_drvdata(x->dev);
  63
  64         if (!IS_ERR(nop->clk)) {
  65                 if (suspend)
  66                         clk_disable_unprepare(nop->clk);
  67                 else
  68                         clk_prepare_enable(nop->clk);
  69         }
  70
  71         return 0;
  72 }
  73
  74 static void nop_reset(struct usb_phy_generic *nop)
  75 {
  76         if (!nop->gpiod_reset)
  77                 return;
  78
  79         gpiod_set_value(nop->gpiod_reset, 1);
  80         usleep_range(10000, 20000);
  81         gpiod_set_value(nop->gpiod_reset, 0);
  82 }
  83
  84 /* interface to regulator framework */
  85 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
  86 {
  87         struct regulator *vbus_draw = nop->vbus_draw;
  88         int enabled;
  89         int ret;
  90
  91         if (!vbus_draw)
  92                 return;
  93
  94         enabled = nop->vbus_draw_enabled;
  95         if (mA) {
  96                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
  97                 if (!enabled) {
  98                         ret = regulator_enable(vbus_draw);
  99                         if (ret < 0)
 100                                 return;
 101                         nop->vbus_draw_enabled = 1;
 102                 }
 103         } else {
 104                 if (enabled) {
 105                         ret = regulator_disable(vbus_draw);
 106                         if (ret < 0)
 107                                 return;
 108                         nop->vbus_draw_enabled = 0;
 109                 }
 110         }
 111         nop->mA = mA;
 112 }
 113
 114
 115 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 116 {
 117         struct usb_phy_generic *nop = data;
 118         struct usb_otg *otg = nop->phy.otg;
 119         int vbus, status;
 120
 121         vbus = gpiod_get_value(nop->gpiod_vbus);
 122         if ((vbus ^ nop->vbus) == 0)
 123                 return IRQ_HANDLED;
 124         nop->vbus = vbus;
 125
 126         if (vbus) {
 127                 status = USB_EVENT_VBUS;
 128                 otg->state = OTG_STATE_B_PERIPHERAL;
 129                 nop->phy.last_event = status;
 130
 131                 /* drawing a "unit load" is *always* OK, except for OTG */
 132                 nop_set_vbus_draw(nop, 100);
 133
 134                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 135                                            otg->gadget);
 136         } else {
 137                 nop_set_vbus_draw(nop, 0);
 138
 139                 status = USB_EVENT_NONE;
 140                 otg->state = OTG_STATE_B_IDLE;
 141                 nop->phy.last_event = status;
 142
 143                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 144                                            otg->gadget);
 145         }
 146         return IRQ_HANDLED;
 147 }
 148
 149 int usb_gen_phy_init(struct usb_phy *phy)
 150 {
 151         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 152         int ret;
 153
 154         if (!IS_ERR(nop->vcc)) {
 155                 if (regulator_enable(nop->vcc))
 156                         dev_err(phy->dev, "Failed to enable power\n");
 157         }
 158
 159         if (!IS_ERR(nop->clk)) {
 160                 ret = clk_prepare_enable(nop->clk);
 161                 if (ret)
 162                         return ret;
 163         }
 164
 165         nop_reset(nop);
 166
 167         return 0;
 168 }
 169 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 170
 171 void usb_gen_phy_shutdown(struct usb_phy *phy)
 172 {
 173         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 174
 175         gpiod_set_value(nop->gpiod_reset, 1);
 176
 177         if (!IS_ERR(nop->clk))
 178                 clk_disable_unprepare(nop->clk);
 179
 180         if (!IS_ERR(nop->vcc)) {
 181                 if (regulator_disable(nop->vcc))
 182                         dev_err(phy->dev, "Failed to disable power\n");
 183         }
 184 }
 185 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 186
 187 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 188 {
 189         if (!otg)
 190                 return -ENODEV;
 191
 192         if (!gadget) {
 193                 otg->gadget = NULL;
 194                 return -ENODEV;
 195         }
 196
 197         otg->gadget = gadget;
 198         if (otg->state == OTG_STATE_B_PERIPHERAL)
 199                 atomic_notifier_call_chain(&otg->usb_phy->notifier,
 200                                            USB_EVENT_VBUS, otg->gadget);
 201         else
 202                 otg->state = OTG_STATE_B_IDLE;
 203         return 0;
 204 }
 205
 206 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 207 {
 208         if (!otg)
 209                 return -ENODEV;
 210
 211         if (!host) {
 212                 otg->host = NULL;
 213                 return -ENODEV;
 214         }
 215
 216         otg->host = host;
 217         return 0;
 218 }
 219
 220 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
 221                 struct usb_phy_generic_platform_data *pdata)
 222 {
 223         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 224         int err = 0;
 225
 226         u32 clk_rate = 0;
 227         bool needs_vcc = false;
 228
 229         if (dev->of_node) {
 230                 struct device_node *node = dev->of_node;
 231
 232                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 233                         clk_rate = 0;
 234
 235                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 236                 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
 237                                                            GPIOD_ASIS);
 238                 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
 239                 if (!err) {
 240                         nop->gpiod_vbus = devm_gpiod_get_optional(dev,
 241                                                          "vbus-detect",
 242                                                          GPIOD_ASIS);
 243                         err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
 244                 }
 245         } else if (pdata) {
 246                 type = pdata->type;
 247                 clk_rate = pdata->clk_rate;
 248                 needs_vcc = pdata->needs_vcc;
 249                 if (gpio_is_valid(pdata->gpio_reset)) {
 250                         err = devm_gpio_request_one(dev, pdata->gpio_reset,
 251                                                     GPIOF_ACTIVE_LOW,
 252                                                     dev_name(dev));
 253                         if (!err)
 254                                 nop->gpiod_reset =
 255                                         gpio_to_desc(pdata->gpio_reset);
 256                 }
 257                 nop->gpiod_vbus = pdata->gpiod_vbus;
 258         }
 259
 260         if (err == -EPROBE_DEFER)
 261                 return -EPROBE_DEFER;
 262         if (err) {
 263                 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
 264                 return err;
 265         }
 266         if (nop->gpiod_reset)
 267                 gpiod_direction_output(nop->gpiod_reset, 1);
 268
 269         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 270                         GFP_KERNEL);
 271         if (!nop->phy.otg)
 272                 return -ENOMEM;
 273
 274         nop->clk = devm_clk_get(dev, "main_clk");
 275         if (IS_ERR(nop->clk)) {
 276                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 277                                         PTR_ERR(nop->clk));
 278         }
 279
 280         if (!IS_ERR(nop->clk) && clk_rate) {
 281                 err = clk_set_rate(nop->clk, clk_rate);
 282                 if (err) {
 283                         dev_err(dev, "Error setting clock rate\n");
 284                         return err;
 285                 }
 286         }
 287
 288         nop->vcc = devm_regulator_get(dev, "vcc");
 289         if (IS_ERR(nop->vcc)) {
 290                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 291                                         PTR_ERR(nop->vcc));
 292                 if (needs_vcc)
 293                         return -EPROBE_DEFER;
 294         }
 295
 296         nop->dev                = dev;
 297         nop->phy.dev            = nop->dev;
 298         nop->phy.label          = "nop-xceiv";
 299         nop->phy.set_suspend    = nop_set_suspend;
 300         nop->phy.type           = type;
 301
 302         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
 303         nop->phy.otg->usb_phy           = &nop->phy;
 304         nop->phy.otg->set_host          = nop_set_host;
 305         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 306
 307         return 0;
 308 }
 309 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 310
 311 static int usb_phy_generic_probe(struct platform_device *pdev)
 312 {
 313         struct device *dev = &pdev->dev;
 314         struct usb_phy_generic  *nop;
 315         int err;
 316
 317         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 318         if (!nop)
 319                 return -ENOMEM;
 320
 321         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
 322         if (err)
 323                 return err;
 324         if (nop->gpiod_vbus) {
 325                 err = devm_request_threaded_irq(&pdev->dev,
 326                                                 gpiod_to_irq(nop->gpiod_vbus),
 327                                                 NULL, nop_gpio_vbus_thread,
 328                                                 VBUS_IRQ_FLAGS, "vbus_detect",
 329                                                 nop);
 330                 if (err) {
 331                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
 332                                 gpiod_to_irq(nop->gpiod_vbus), err);
 333                         return err;
 334                 }
 335                 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
 336                         OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
 337         }
 338
 339         nop->phy.init           = usb_gen_phy_init;
 340         nop->phy.shutdown       = usb_gen_phy_shutdown;
 341
 342         err = usb_add_phy_dev(&nop->phy);
 343         if (err) {
 344                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 345                         err);
 346                 return err;
 347         }
 348
 349         platform_set_drvdata(pdev, nop);
 350
 351         return 0;
 352 }
 353
 354 static int usb_phy_generic_remove(struct platform_device *pdev)
 355 {
 356         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 357
 358         usb_remove_phy(&nop->phy);
 359
 360         return 0;
 361 }
 362
 363 static const struct of_device_id nop_xceiv_dt_ids[] = {
 364         { .compatible = "usb-nop-xceiv" },
 365         { }
 366 };
 367
 368 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 369
 370 static struct platform_driver usb_phy_generic_driver = {
 371         .probe          = usb_phy_generic_probe,
 372         .remove         = usb_phy_generic_remove,
 373         .driver         = {
 374                 .name   = "usb_phy_generic",
 375                 .of_match_table = nop_xceiv_dt_ids,
 376         },
 377 };
 378
 379 static int __init usb_phy_generic_init(void)
 380 {
 381         return platform_driver_register(&usb_phy_generic_driver);
 382 }
 383 subsys_initcall(usb_phy_generic_init);
 384
 385 static void __exit usb_phy_generic_exit(void)
 386 {
 387         platform_driver_unregister(&usb_phy_generic_driver);
 388 }
 389 module_exit(usb_phy_generic_exit);
 390
 391 MODULE_ALIAS("platform:usb_phy_generic");
 392 MODULE_AUTHOR("Texas Instruments Inc");
 393 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 394 MODULE_LICENSE("GPL");