drivers/usb/phy/phy-tahvo.c

   1 /*
   2  * Tahvo USB transceiver driver
   3  *
   4  * Copyright (C) 2005-2006 Nokia Corporation
   5  *
   6  * Parts copied from isp1301_omap.c.
   7  * Copyright (C) 2004 Texas Instruments
   8  * Copyright (C) 2004 David Brownell
   9  *
  10  * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
  11  * Modified for Retu/Tahvo MFD by Aaro Koskinen.
  12  *
  13  * This file is subject to the terms and conditions of the GNU General
  14  * Public License. See the file "COPYING" in the main directory of this
  15  * archive for more details.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU General Public License for more details.
  21  */
  22
  23 #include <linux/io.h>
  24 #include <linux/clk.h>
  25 #include <linux/usb.h>
  26 #include <linux/extcon.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/usb/otg.h>
  30 #include <linux/mfd/retu.h>
  31 #include <linux/usb/gadget.h>
  32 #include <linux/platform_device.h>
  33
  34 #define DRIVER_NAME     "tahvo-usb"
  35
  36 #define TAHVO_REG_IDSR  0x02
  37 #define TAHVO_REG_USBR  0x06
  38
  39 #define USBR_SLAVE_CONTROL      (1 << 8)
  40 #define USBR_VPPVIO_SW          (1 << 7)
  41 #define USBR_SPEED              (1 << 6)
  42 #define USBR_REGOUT             (1 << 5)
  43 #define USBR_MASTER_SW2         (1 << 4)
  44 #define USBR_MASTER_SW1         (1 << 3)
  45 #define USBR_SLAVE_SW           (1 << 2)
  46 #define USBR_NSUSPEND           (1 << 1)
  47 #define USBR_SEMODE             (1 << 0)
  48
  49 #define TAHVO_MODE_HOST         0
  50 #define TAHVO_MODE_PERIPHERAL   1
  51
  52 struct tahvo_usb {
  53         struct platform_device  *pt_dev;
  54         struct usb_phy          phy;
  55         int                     vbus_state;
  56         struct mutex            serialize;
  57         struct clk              *ick;
  58         int                     irq;
  59         int                     tahvo_mode;
  60         struct extcon_dev       extcon;
  61 };
  62
  63 static const char *tahvo_cable[] = {
  64         "USB-HOST",
  65         "USB",
  66         NULL,
  67 };
  68
  69 static ssize_t vbus_state_show(struct device *device,
  70                                struct device_attribute *attr, char *buf)
  71 {
  72         struct tahvo_usb *tu = dev_get_drvdata(device);
  73         return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
  74 }
  75 static DEVICE_ATTR(vbus, 0444, vbus_state_show, NULL);
  76
  77 static void check_vbus_state(struct tahvo_usb *tu)
  78 {
  79         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
  80         int reg, prev_state;
  81
  82         reg = retu_read(rdev, TAHVO_REG_IDSR);
  83         if (reg & TAHVO_STAT_VBUS) {
  84                 switch (tu->phy.state) {
  85                 case OTG_STATE_B_IDLE:
  86                         /* Enable the gadget driver */
  87                         if (tu->phy.otg->gadget)
  88                                 usb_gadget_vbus_connect(tu->phy.otg->gadget);
  89                         tu->phy.state = OTG_STATE_B_PERIPHERAL;
  90                         break;
  91                 case OTG_STATE_A_IDLE:
  92                         /*
  93                          * Session is now valid assuming the USB hub is driving
  94                          * Vbus.
  95                          */
  96                         tu->phy.state = OTG_STATE_A_HOST;
  97                         break;
  98                 default:
  99                         break;
 100                 }
 101                 dev_info(&tu->pt_dev->dev, "USB cable connected\n");
 102         } else {
 103                 switch (tu->phy.state) {
 104                 case OTG_STATE_B_PERIPHERAL:
 105                         if (tu->phy.otg->gadget)
 106                                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 107                         tu->phy.state = OTG_STATE_B_IDLE;
 108                         break;
 109                 case OTG_STATE_A_HOST:
 110                         tu->phy.state = OTG_STATE_A_IDLE;
 111                         break;
 112                 default:
 113                         break;
 114                 }
 115                 dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
 116         }
 117
 118         prev_state = tu->vbus_state;
 119         tu->vbus_state = reg & TAHVO_STAT_VBUS;
 120         if (prev_state != tu->vbus_state) {
 121                 extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
 122                 sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
 123         }
 124 }
 125
 126 static void tahvo_usb_become_host(struct tahvo_usb *tu)
 127 {
 128         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 129
 130         extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
 131
 132         /* Power up the transceiver in USB host mode */
 133         retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
 134                    USBR_MASTER_SW2 | USBR_MASTER_SW1);
 135         tu->phy.state = OTG_STATE_A_IDLE;
 136
 137         check_vbus_state(tu);
 138 }
 139
 140 static void tahvo_usb_stop_host(struct tahvo_usb *tu)
 141 {
 142         tu->phy.state = OTG_STATE_A_IDLE;
 143 }
 144
 145 static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
 146 {
 147         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 148
 149         extcon_set_cable_state(&tu->extcon, "USB-HOST", false);
 150
 151         /* Power up transceiver and set it in USB peripheral mode */
 152         retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
 153                    USBR_NSUSPEND | USBR_SLAVE_SW);
 154         tu->phy.state = OTG_STATE_B_IDLE;
 155
 156         check_vbus_state(tu);
 157 }
 158
 159 static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
 160 {
 161         if (tu->phy.otg->gadget)
 162                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 163         tu->phy.state = OTG_STATE_B_IDLE;
 164 }
 165
 166 static void tahvo_usb_power_off(struct tahvo_usb *tu)
 167 {
 168         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 169
 170         /* Disable gadget controller if any */
 171         if (tu->phy.otg->gadget)
 172                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 173
 174         /* Power off transceiver */
 175         retu_write(rdev, TAHVO_REG_USBR, 0);
 176         tu->phy.state = OTG_STATE_UNDEFINED;
 177 }
 178
 179 static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
 180 {
 181         struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
 182         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 183         u16 w;
 184
 185         dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
 186
 187         w = retu_read(rdev, TAHVO_REG_USBR);
 188         if (suspend)
 189                 w &= ~USBR_NSUSPEND;
 190         else
 191                 w |= USBR_NSUSPEND;
 192         retu_write(rdev, TAHVO_REG_USBR, w);
 193
 194         return 0;
 195 }
 196
 197 static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
 198 {
 199         struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
 200
 201         dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
 202
 203         mutex_lock(&tu->serialize);
 204
 205         if (host == NULL) {
 206                 if (tu->tahvo_mode == TAHVO_MODE_HOST)
 207                         tahvo_usb_power_off(tu);
 208                 otg->host = NULL;
 209                 mutex_unlock(&tu->serialize);
 210                 return 0;
 211         }
 212
 213         if (tu->tahvo_mode == TAHVO_MODE_HOST) {
 214                 otg->host = NULL;
 215                 tahvo_usb_become_host(tu);
 216         }
 217
 218         otg->host = host;
 219
 220         mutex_unlock(&tu->serialize);
 221
 222         return 0;
 223 }
 224
 225 static int tahvo_usb_set_peripheral(struct usb_otg *otg,
 226                                     struct usb_gadget *gadget)
 227 {
 228         struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
 229
 230         dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
 231
 232         mutex_lock(&tu->serialize);
 233
 234         if (!gadget) {
 235                 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 236                         tahvo_usb_power_off(tu);
 237                 tu->phy.otg->gadget = NULL;
 238                 mutex_unlock(&tu->serialize);
 239                 return 0;
 240         }
 241
 242         tu->phy.otg->gadget = gadget;
 243         if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 244                 tahvo_usb_become_peripheral(tu);
 245
 246         mutex_unlock(&tu->serialize);
 247
 248         return 0;
 249 }
 250
 251 static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
 252 {
 253         struct tahvo_usb *tu = _tu;
 254
 255         mutex_lock(&tu->serialize);
 256         check_vbus_state(tu);
 257         mutex_unlock(&tu->serialize);
 258
 259         return IRQ_HANDLED;
 260 }
 261
 262 static ssize_t otg_mode_show(struct device *device,
 263                              struct device_attribute *attr, char *buf)
 264 {
 265         struct tahvo_usb *tu = dev_get_drvdata(device);
 266
 267         switch (tu->tahvo_mode) {
 268         case TAHVO_MODE_HOST:
 269                 return sprintf(buf, "host\n");
 270         case TAHVO_MODE_PERIPHERAL:
 271                 return sprintf(buf, "peripheral\n");
 272         }
 273
 274         return -EINVAL;
 275 }
 276
 277 static ssize_t otg_mode_store(struct device *device,
 278                               struct device_attribute *attr,
 279                               const char *buf, size_t count)
 280 {
 281         struct tahvo_usb *tu = dev_get_drvdata(device);
 282         int r;
 283
 284         mutex_lock(&tu->serialize);
 285         if (count >= 4 && strncmp(buf, "host", 4) == 0) {
 286                 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 287                         tahvo_usb_stop_peripheral(tu);
 288                 tu->tahvo_mode = TAHVO_MODE_HOST;
 289                 if (tu->phy.otg->host) {
 290                         dev_info(device, "HOST mode: host controller present\n");
 291                         tahvo_usb_become_host(tu);
 292                 } else {
 293                         dev_info(device, "HOST mode: no host controller, powering off\n");
 294                         tahvo_usb_power_off(tu);
 295                 }
 296                 r = strlen(buf);
 297         } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
 298                 if (tu->tahvo_mode == TAHVO_MODE_HOST)
 299                         tahvo_usb_stop_host(tu);
 300                 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
 301                 if (tu->phy.otg->gadget) {
 302                         dev_info(device, "PERIPHERAL mode: gadget driver present\n");
 303                         tahvo_usb_become_peripheral(tu);
 304                 } else {
 305                         dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
 306                         tahvo_usb_power_off(tu);
 307                 }
 308                 r = strlen(buf);
 309         } else {
 310                 r = -EINVAL;
 311         }
 312         mutex_unlock(&tu->serialize);
 313
 314         return r;
 315 }
 316 static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
 317
 318 static struct attribute *tahvo_attributes[] = {
 319         &dev_attr_vbus.attr,
 320         &dev_attr_otg_mode.attr,
 321         NULL
 322 };
 323
 324 static struct attribute_group tahvo_attr_group = {
 325         .attrs = tahvo_attributes,
 326 };
 327
 328 static int tahvo_usb_probe(struct platform_device *pdev)
 329 {
 330         struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
 331         struct tahvo_usb *tu;
 332         int ret;
 333
 334         tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
 335         if (!tu)
 336                 return -ENOMEM;
 337
 338         tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
 339                                    GFP_KERNEL);
 340         if (!tu->phy.otg)
 341                 return -ENOMEM;
 342
 343         tu->pt_dev = pdev;
 344
 345         /* Default mode */
 346 #ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
 347         tu->tahvo_mode = TAHVO_MODE_HOST;
 348 #else
 349         tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
 350 #endif
 351
 352         mutex_init(&tu->serialize);
 353
 354         tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
 355         if (!IS_ERR(tu->ick))
 356                 clk_enable(tu->ick);
 357
 358         /*
 359          * Set initial state, so that we generate kevents only on state changes.
 360          */
 361         tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
 362
 363         tu->extcon.name = DRIVER_NAME;
 364         tu->extcon.supported_cable = tahvo_cable;
 365         tu->extcon.dev.parent = &pdev->dev;
 366
 367         ret = extcon_dev_register(&tu->extcon);
 368         if (ret) {
 369                 dev_err(&pdev->dev, "could not register extcon device: %d\n",
 370                         ret);
 371                 goto err_disable_clk;
 372         }
 373
 374         /* Set the initial cable state. */
 375         extcon_set_cable_state(&tu->extcon, "USB-HOST",
 376                                tu->tahvo_mode == TAHVO_MODE_HOST);
 377         extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
 378
 379         /* Create OTG interface */
 380         tahvo_usb_power_off(tu);
 381         tu->phy.dev = &pdev->dev;
 382         tu->phy.state = OTG_STATE_UNDEFINED;
 383         tu->phy.label = DRIVER_NAME;
 384         tu->phy.set_suspend = tahvo_usb_set_suspend;
 385
 386         tu->phy.otg->phy = &tu->phy;
 387         tu->phy.otg->set_host = tahvo_usb_set_host;
 388         tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
 389
 390         ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
 391         if (ret < 0) {
 392                 dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
 393                         ret);
 394                 goto err_extcon_unreg;
 395         }
 396
 397         dev_set_drvdata(&pdev->dev, tu);
 398
 399         tu->irq = platform_get_irq(pdev, 0);
 400         ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
 401                                    "tahvo-vbus", tu);
 402         if (ret) {
 403                 dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
 404                         ret);
 405                 goto err_remove_phy;
 406         }
 407
 408         /* Attributes */
 409         ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
 410         if (ret) {
 411                 dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
 412                 goto err_free_irq;
 413         }
 414
 415         return 0;
 416
 417 err_free_irq:
 418         free_irq(tu->irq, tu);
 419 err_remove_phy:
 420         usb_remove_phy(&tu->phy);
 421 err_extcon_unreg:
 422         extcon_dev_unregister(&tu->extcon);
 423 err_disable_clk:
 424         if (!IS_ERR(tu->ick))
 425                 clk_disable(tu->ick);
 426
 427         return ret;
 428 }
 429
 430 static int tahvo_usb_remove(struct platform_device *pdev)
 431 {
 432         struct tahvo_usb *tu = platform_get_drvdata(pdev);
 433
 434         sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
 435         free_irq(tu->irq, tu);
 436         usb_remove_phy(&tu->phy);
 437         extcon_dev_unregister(&tu->extcon);
 438         if (!IS_ERR(tu->ick))
 439                 clk_disable(tu->ick);
 440
 441         return 0;
 442 }
 443
 444 static struct platform_driver tahvo_usb_driver = {
 445         .probe          = tahvo_usb_probe,
 446         .remove         = tahvo_usb_remove,
 447         .driver         = {
 448                 .name   = "tahvo-usb",
 449                 .owner  = THIS_MODULE,
 450         },
 451 };
 452 module_platform_driver(tahvo_usb_driver);
 453
 454 MODULE_DESCRIPTION("Tahvo USB transceiver driver");
 455 MODULE_LICENSE("GPL");
 456 MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
 457 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");