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.otg->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.otg->state = OTG_STATE_B_PERIPHERAL;
  90                         usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED);
  91                         break;
  92                 case OTG_STATE_A_IDLE:
  93                         /*
  94                          * Session is now valid assuming the USB hub is driving
  95                          * Vbus.
  96                          */
  97                         tu->phy.otg->state = OTG_STATE_A_HOST;
  98                         break;
  99                 default:
 100                         break;
 101                 }
 102                 dev_info(&tu->pt_dev->dev, "USB cable connected\n");
 103         } else {
 104                 switch (tu->phy.otg->state) {
 105                 case OTG_STATE_B_PERIPHERAL:
 106                         if (tu->phy.otg->gadget)
 107                                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 108                         tu->phy.otg->state = OTG_STATE_B_IDLE;
 109                         usb_phy_set_event(&tu->phy, USB_EVENT_NONE);
 110                         break;
 111                 case OTG_STATE_A_HOST:
 112                         tu->phy.otg->state = OTG_STATE_A_IDLE;
 113                         break;
 114                 default:
 115                         break;
 116                 }
 117                 dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
 118         }
 119
 120         prev_state = tu->vbus_state;
 121         tu->vbus_state = reg & TAHVO_STAT_VBUS;
 122         if (prev_state != tu->vbus_state) {
 123                 extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
 124                 sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
 125         }
 126 }
 127
 128 static void tahvo_usb_become_host(struct tahvo_usb *tu)
 129 {
 130         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 131
 132         extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
 133
 134         /* Power up the transceiver in USB host mode */
 135         retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
 136                    USBR_MASTER_SW2 | USBR_MASTER_SW1);
 137         tu->phy.otg->state = OTG_STATE_A_IDLE;
 138
 139         check_vbus_state(tu);
 140 }
 141
 142 static void tahvo_usb_stop_host(struct tahvo_usb *tu)
 143 {
 144         tu->phy.otg->state = OTG_STATE_A_IDLE;
 145 }
 146
 147 static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
 148 {
 149         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 150
 151         extcon_set_cable_state(&tu->extcon, "USB-HOST", false);
 152
 153         /* Power up transceiver and set it in USB peripheral mode */
 154         retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
 155                    USBR_NSUSPEND | USBR_SLAVE_SW);
 156         tu->phy.otg->state = OTG_STATE_B_IDLE;
 157
 158         check_vbus_state(tu);
 159 }
 160
 161 static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
 162 {
 163         if (tu->phy.otg->gadget)
 164                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 165         tu->phy.otg->state = OTG_STATE_B_IDLE;
 166 }
 167
 168 static void tahvo_usb_power_off(struct tahvo_usb *tu)
 169 {
 170         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 171
 172         /* Disable gadget controller if any */
 173         if (tu->phy.otg->gadget)
 174                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 175
 176         /* Power off transceiver */
 177         retu_write(rdev, TAHVO_REG_USBR, 0);
 178         tu->phy.otg->state = OTG_STATE_UNDEFINED;
 179 }
 180
 181 static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
 182 {
 183         struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
 184         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 185         u16 w;
 186
 187         dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
 188
 189         w = retu_read(rdev, TAHVO_REG_USBR);
 190         if (suspend)
 191                 w &= ~USBR_NSUSPEND;
 192         else
 193                 w |= USBR_NSUSPEND;
 194         retu_write(rdev, TAHVO_REG_USBR, w);
 195
 196         return 0;
 197 }
 198
 199 static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
 200 {
 201         struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
 202                                             phy);
 203
 204         dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
 205
 206         mutex_lock(&tu->serialize);
 207
 208         if (host == NULL) {
 209                 if (tu->tahvo_mode == TAHVO_MODE_HOST)
 210                         tahvo_usb_power_off(tu);
 211                 otg->host = NULL;
 212                 mutex_unlock(&tu->serialize);
 213                 return 0;
 214         }
 215
 216         if (tu->tahvo_mode == TAHVO_MODE_HOST) {
 217                 otg->host = NULL;
 218                 tahvo_usb_become_host(tu);
 219         }
 220
 221         otg->host = host;
 222
 223         mutex_unlock(&tu->serialize);
 224
 225         return 0;
 226 }
 227
 228 static int tahvo_usb_set_peripheral(struct usb_otg *otg,
 229                                     struct usb_gadget *gadget)
 230 {
 231         struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
 232                                             phy);
 233
 234         dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
 235
 236         mutex_lock(&tu->serialize);
 237
 238         if (!gadget) {
 239                 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 240                         tahvo_usb_power_off(tu);
 241                 tu->phy.otg->gadget = NULL;
 242                 mutex_unlock(&tu->serialize);
 243                 return 0;
 244         }
 245
 246         tu->phy.otg->gadget = gadget;
 247         if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 248                 tahvo_usb_become_peripheral(tu);
 249
 250         mutex_unlock(&tu->serialize);
 251
 252         return 0;
 253 }
 254
 255 static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
 256 {
 257         struct tahvo_usb *tu = _tu;
 258
 259         mutex_lock(&tu->serialize);
 260         check_vbus_state(tu);
 261         mutex_unlock(&tu->serialize);
 262
 263         return IRQ_HANDLED;
 264 }
 265
 266 static ssize_t otg_mode_show(struct device *device,
 267                              struct device_attribute *attr, char *buf)
 268 {
 269         struct tahvo_usb *tu = dev_get_drvdata(device);
 270
 271         switch (tu->tahvo_mode) {
 272         case TAHVO_MODE_HOST:
 273                 return sprintf(buf, "host\n");
 274         case TAHVO_MODE_PERIPHERAL:
 275                 return sprintf(buf, "peripheral\n");
 276         }
 277
 278         return -EINVAL;
 279 }
 280
 281 static ssize_t otg_mode_store(struct device *device,
 282                               struct device_attribute *attr,
 283                               const char *buf, size_t count)
 284 {
 285         struct tahvo_usb *tu = dev_get_drvdata(device);
 286         int r;
 287
 288         mutex_lock(&tu->serialize);
 289         if (count >= 4 && strncmp(buf, "host", 4) == 0) {
 290                 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 291                         tahvo_usb_stop_peripheral(tu);
 292                 tu->tahvo_mode = TAHVO_MODE_HOST;
 293                 if (tu->phy.otg->host) {
 294                         dev_info(device, "HOST mode: host controller present\n");
 295                         tahvo_usb_become_host(tu);
 296                 } else {
 297                         dev_info(device, "HOST mode: no host controller, powering off\n");
 298                         tahvo_usb_power_off(tu);
 299                 }
 300                 r = strlen(buf);
 301         } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
 302                 if (tu->tahvo_mode == TAHVO_MODE_HOST)
 303                         tahvo_usb_stop_host(tu);
 304                 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
 305                 if (tu->phy.otg->gadget) {
 306                         dev_info(device, "PERIPHERAL mode: gadget driver present\n");
 307                         tahvo_usb_become_peripheral(tu);
 308                 } else {
 309                         dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
 310                         tahvo_usb_power_off(tu);
 311                 }
 312                 r = strlen(buf);
 313         } else {
 314                 r = -EINVAL;
 315         }
 316         mutex_unlock(&tu->serialize);
 317
 318         return r;
 319 }
 320 static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
 321
 322 static struct attribute *tahvo_attributes[] = {
 323         &dev_attr_vbus.attr,
 324         &dev_attr_otg_mode.attr,
 325         NULL
 326 };
 327
 328 static struct attribute_group tahvo_attr_group = {
 329         .attrs = tahvo_attributes,
 330 };
 331
 332 static int tahvo_usb_probe(struct platform_device *pdev)
 333 {
 334         struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
 335         struct tahvo_usb *tu;
 336         int ret;
 337
 338         tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
 339         if (!tu)
 340                 return -ENOMEM;
 341
 342         tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
 343                                    GFP_KERNEL);
 344         if (!tu->phy.otg)
 345                 return -ENOMEM;
 346
 347         tu->pt_dev = pdev;
 348
 349         /* Default mode */
 350 #ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
 351         tu->tahvo_mode = TAHVO_MODE_HOST;
 352 #else
 353         tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
 354 #endif
 355
 356         mutex_init(&tu->serialize);
 357
 358         tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
 359         if (!IS_ERR(tu->ick))
 360                 clk_enable(tu->ick);
 361
 362         /*
 363          * Set initial state, so that we generate kevents only on state changes.
 364          */
 365         tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
 366
 367         tu->extcon.name = DRIVER_NAME;
 368         tu->extcon.supported_cable = tahvo_cable;
 369         tu->extcon.dev.parent = &pdev->dev;
 370
 371         ret = extcon_dev_register(&tu->extcon);
 372         if (ret) {
 373                 dev_err(&pdev->dev, "could not register extcon device: %d\n",
 374                         ret);
 375                 goto err_disable_clk;
 376         }
 377
 378         /* Set the initial cable state. */
 379         extcon_set_cable_state(&tu->extcon, "USB-HOST",
 380                                tu->tahvo_mode == TAHVO_MODE_HOST);
 381         extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
 382
 383         /* Create OTG interface */
 384         tahvo_usb_power_off(tu);
 385         tu->phy.dev = &pdev->dev;
 386         tu->phy.otg->state = OTG_STATE_UNDEFINED;
 387         tu->phy.label = DRIVER_NAME;
 388         tu->phy.set_suspend = tahvo_usb_set_suspend;
 389
 390         tu->phy.otg->usb_phy = &tu->phy;
 391         tu->phy.otg->set_host = tahvo_usb_set_host;
 392         tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
 393
 394         ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
 395         if (ret < 0) {
 396                 dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
 397                         ret);
 398                 goto err_extcon_unreg;
 399         }
 400
 401         dev_set_drvdata(&pdev->dev, tu);
 402
 403         tu->irq = platform_get_irq(pdev, 0);
 404         ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
 405                                    "tahvo-vbus", tu);
 406         if (ret) {
 407                 dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
 408                         ret);
 409                 goto err_remove_phy;
 410         }
 411
 412         /* Attributes */
 413         ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
 414         if (ret) {
 415                 dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
 416                 goto err_free_irq;
 417         }
 418
 419         return 0;
 420
 421 err_free_irq:
 422         free_irq(tu->irq, tu);
 423 err_remove_phy:
 424         usb_remove_phy(&tu->phy);
 425 err_extcon_unreg:
 426         extcon_dev_unregister(&tu->extcon);
 427 err_disable_clk:
 428         if (!IS_ERR(tu->ick))
 429                 clk_disable(tu->ick);
 430
 431         return ret;
 432 }
 433
 434 static int tahvo_usb_remove(struct platform_device *pdev)
 435 {
 436         struct tahvo_usb *tu = platform_get_drvdata(pdev);
 437
 438         sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
 439         free_irq(tu->irq, tu);
 440         usb_remove_phy(&tu->phy);
 441         extcon_dev_unregister(&tu->extcon);
 442         if (!IS_ERR(tu->ick))
 443                 clk_disable(tu->ick);
 444
 445         return 0;
 446 }
 447
 448 static struct platform_driver tahvo_usb_driver = {
 449         .probe          = tahvo_usb_probe,
 450         .remove         = tahvo_usb_remove,
 451         .driver         = {
 452                 .name   = "tahvo-usb",
 453         },
 454 };
 455 module_platform_driver(tahvo_usb_driver);
 456
 457 MODULE_DESCRIPTION("Tahvo USB transceiver driver");
 458 MODULE_LICENSE("GPL");
 459 MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
 460 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");