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         return 0;
  63 }
  64
  65 static void nop_reset(struct usb_phy_generic *nop)
  66 {
  67         if (!nop->gpiod_reset)
  68                 return;
  69
  70         gpiod_set_value(nop->gpiod_reset, 1);
  71         usleep_range(10000, 20000);
  72         gpiod_set_value(nop->gpiod_reset, 0);
  73 }
  74
  75 /* interface to regulator framework */
  76 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
  77 {
  78         struct regulator *vbus_draw = nop->vbus_draw;
  79         int enabled;
  80         int ret;
  81
  82         if (!vbus_draw)
  83                 return;
  84
  85         enabled = nop->vbus_draw_enabled;
  86         if (mA) {
  87                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
  88                 if (!enabled) {
  89                         ret = regulator_enable(vbus_draw);
  90                         if (ret < 0)
  91                                 return;
  92                         nop->vbus_draw_enabled = 1;
  93                 }
  94         } else {
  95                 if (enabled) {
  96                         ret = regulator_disable(vbus_draw);
  97                         if (ret < 0)
  98                                 return;
  99                         nop->vbus_draw_enabled = 0;
 100                 }
 101         }
 102         nop->mA = mA;
 103 }
 104
 105
 106 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 107 {
 108         struct usb_phy_generic *nop = data;
 109         struct usb_otg *otg = nop->phy.otg;
 110         int vbus, status;
 111
 112         vbus = gpiod_get_value(nop->gpiod_vbus);
 113         if ((vbus ^ nop->vbus) == 0)
 114                 return IRQ_HANDLED;
 115         nop->vbus = vbus;
 116
 117         if (vbus) {
 118                 status = USB_EVENT_VBUS;
 119                 otg->state = OTG_STATE_B_PERIPHERAL;
 120                 nop->phy.last_event = status;
 121                 usb_gadget_vbus_connect(otg->gadget);
 122
 123                 /* drawing a "unit load" is *always* OK, except for OTG */
 124                 nop_set_vbus_draw(nop, 100);
 125
 126                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 127                                            otg->gadget);
 128         } else {
 129                 nop_set_vbus_draw(nop, 0);
 130
 131                 usb_gadget_vbus_disconnect(otg->gadget);
 132                 status = USB_EVENT_NONE;
 133                 otg->state = OTG_STATE_B_IDLE;
 134                 nop->phy.last_event = status;
 135
 136                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 137                                            otg->gadget);
 138         }
 139         return IRQ_HANDLED;
 140 }
 141
 142 int usb_gen_phy_init(struct usb_phy *phy)
 143 {
 144         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 145
 146         if (!IS_ERR(nop->vcc)) {
 147                 if (regulator_enable(nop->vcc))
 148                         dev_err(phy->dev, "Failed to enable power\n");
 149         }
 150
 151         if (!IS_ERR(nop->clk))
 152                 clk_prepare_enable(nop->clk);
 153
 154         nop_reset(nop);
 155
 156         return 0;
 157 }
 158 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 159
 160 void usb_gen_phy_shutdown(struct usb_phy *phy)
 161 {
 162         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 163
 164         gpiod_set_value(nop->gpiod_reset, 1);
 165
 166         if (!IS_ERR(nop->clk))
 167                 clk_disable_unprepare(nop->clk);
 168
 169         if (!IS_ERR(nop->vcc)) {
 170                 if (regulator_disable(nop->vcc))
 171                         dev_err(phy->dev, "Failed to disable power\n");
 172         }
 173 }
 174 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 175
 176 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 177 {
 178         if (!otg)
 179                 return -ENODEV;
 180
 181         if (!gadget) {
 182                 otg->gadget = NULL;
 183                 return -ENODEV;
 184         }
 185
 186         otg->gadget = gadget;
 187         otg->state = OTG_STATE_B_IDLE;
 188         return 0;
 189 }
 190
 191 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 192 {
 193         if (!otg)
 194                 return -ENODEV;
 195
 196         if (!host) {
 197                 otg->host = NULL;
 198                 return -ENODEV;
 199         }
 200
 201         otg->host = host;
 202         return 0;
 203 }
 204
 205 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
 206                 struct usb_phy_generic_platform_data *pdata)
 207 {
 208         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 209         int err = 0;
 210
 211         u32 clk_rate = 0;
 212         bool needs_vcc = false;
 213
 214         if (dev->of_node) {
 215                 struct device_node *node = dev->of_node;
 216
 217                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 218                         clk_rate = 0;
 219
 220                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 221                 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
 222                                                            GPIOD_ASIS);
 223                 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
 224                 if (!err) {
 225                         nop->gpiod_vbus = devm_gpiod_get_optional(dev,
 226                                                          "vbus-detect",
 227                                                          GPIOD_ASIS);
 228                         err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
 229                 }
 230         } else if (pdata) {
 231                 type = pdata->type;
 232                 clk_rate = pdata->clk_rate;
 233                 needs_vcc = pdata->needs_vcc;
 234                 if (gpio_is_valid(pdata->gpio_reset)) {
 235                         err = devm_gpio_request_one(dev, pdata->gpio_reset,
 236                                                     GPIOF_ACTIVE_LOW,
 237                                                     dev_name(dev));
 238                         if (!err)
 239                                 nop->gpiod_reset =
 240                                         gpio_to_desc(pdata->gpio_reset);
 241                 }
 242                 nop->gpiod_vbus = pdata->gpiod_vbus;
 243         }
 244
 245         if (err == -EPROBE_DEFER)
 246                 return -EPROBE_DEFER;
 247         if (err) {
 248                 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
 249                 return err;
 250         }
 251         if (nop->gpiod_reset)
 252                 gpiod_direction_output(nop->gpiod_reset, 1);
 253
 254         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 255                         GFP_KERNEL);
 256         if (!nop->phy.otg)
 257                 return -ENOMEM;
 258
 259         nop->clk = devm_clk_get(dev, "main_clk");
 260         if (IS_ERR(nop->clk)) {
 261                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 262                                         PTR_ERR(nop->clk));
 263         }
 264
 265         if (!IS_ERR(nop->clk) && clk_rate) {
 266                 err = clk_set_rate(nop->clk, clk_rate);
 267                 if (err) {
 268                         dev_err(dev, "Error setting clock rate\n");
 269                         return err;
 270                 }
 271         }
 272
 273         nop->vcc = devm_regulator_get(dev, "vcc");
 274         if (IS_ERR(nop->vcc)) {
 275                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 276                                         PTR_ERR(nop->vcc));
 277                 if (needs_vcc)
 278                         return -EPROBE_DEFER;
 279         }
 280
 281         nop->dev                = dev;
 282         nop->phy.dev            = nop->dev;
 283         nop->phy.label          = "nop-xceiv";
 284         nop->phy.set_suspend    = nop_set_suspend;
 285         nop->phy.type           = type;
 286
 287         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
 288         nop->phy.otg->usb_phy           = &nop->phy;
 289         nop->phy.otg->set_host          = nop_set_host;
 290         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 291
 292         return 0;
 293 }
 294 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 295
 296 static int usb_phy_generic_probe(struct platform_device *pdev)
 297 {
 298         struct device *dev = &pdev->dev;
 299         struct usb_phy_generic  *nop;
 300         int err;
 301
 302         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 303         if (!nop)
 304                 return -ENOMEM;
 305
 306         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
 307         if (err)
 308                 return err;
 309         if (nop->gpiod_vbus) {
 310                 err = devm_request_threaded_irq(&pdev->dev,
 311                                                 gpiod_to_irq(nop->gpiod_vbus),
 312                                                 NULL, nop_gpio_vbus_thread,
 313                                                 VBUS_IRQ_FLAGS, "vbus_detect",
 314                                                 nop);
 315                 if (err) {
 316                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
 317                                 gpiod_to_irq(nop->gpiod_vbus), err);
 318                         return err;
 319                 }
 320         }
 321
 322         nop->phy.init           = usb_gen_phy_init;
 323         nop->phy.shutdown       = usb_gen_phy_shutdown;
 324
 325         err = usb_add_phy_dev(&nop->phy);
 326         if (err) {
 327                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 328                         err);
 329                 return err;
 330         }
 331
 332         platform_set_drvdata(pdev, nop);
 333
 334         return 0;
 335 }
 336
 337 static int usb_phy_generic_remove(struct platform_device *pdev)
 338 {
 339         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 340
 341         usb_remove_phy(&nop->phy);
 342
 343         return 0;
 344 }
 345
 346 static const struct of_device_id nop_xceiv_dt_ids[] = {
 347         { .compatible = "usb-nop-xceiv" },
 348         { }
 349 };
 350
 351 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 352
 353 static struct platform_driver usb_phy_generic_driver = {
 354         .probe          = usb_phy_generic_probe,
 355         .remove         = usb_phy_generic_remove,
 356         .driver         = {
 357                 .name   = "usb_phy_generic",
 358                 .of_match_table = nop_xceiv_dt_ids,
 359         },
 360 };
 361
 362 static int __init usb_phy_generic_init(void)
 363 {
 364         return platform_driver_register(&usb_phy_generic_driver);
 365 }
 366 subsys_initcall(usb_phy_generic_init);
 367
 368 static void __exit usb_phy_generic_exit(void)
 369 {
 370         platform_driver_unregister(&usb_phy_generic_driver);
 371 }
 372 module_exit(usb_phy_generic_exit);
 373
 374 MODULE_ALIAS("platform:usb_phy_generic");
 375 MODULE_AUTHOR("Texas Instruments Inc");
 376 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 377 MODULE_LICENSE("GPL");