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