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 unsigned int tahvo_cable[] = {
  64         EXTCON_USB,
  65         EXTCON_USB_HOST,
  66
  67         EXTCON_NONE,
  68 };
  69
  70 static ssize_t vbus_state_show(struct device *device,
  71                                struct device_attribute *attr, char *buf)
  72 {
  73         struct tahvo_usb *tu = dev_get_drvdata(device);
  74         return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
  75 }
  76 static DEVICE_ATTR(vbus, 0444, vbus_state_show, NULL);
  77
  78 static void check_vbus_state(struct tahvo_usb *tu)
  79 {
  80         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
  81         int reg, prev_state;
  82
  83         reg = retu_read(rdev, TAHVO_REG_IDSR);
  84         if (reg & TAHVO_STAT_VBUS) {
  85                 switch (tu->phy.otg->state) {
  86                 case OTG_STATE_B_IDLE:
  87                         /* Enable the gadget driver */
  88                         if (tu->phy.otg->gadget)
  89                                 usb_gadget_vbus_connect(tu->phy.otg->gadget);
  90                         tu->phy.otg->state = OTG_STATE_B_PERIPHERAL;
  91                         usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED);
  92                         break;
  93                 case OTG_STATE_A_IDLE:
  94                         /*
  95                          * Session is now valid assuming the USB hub is driving
  96                          * Vbus.
  97                          */
  98                         tu->phy.otg->state = OTG_STATE_A_HOST;
  99                         break;
 100                 default:
 101                         break;
 102                 }
 103                 dev_info(&tu->pt_dev->dev, "USB cable connected\n");
 104         } else {
 105                 switch (tu->phy.otg->state) {
 106                 case OTG_STATE_B_PERIPHERAL:
 107                         if (tu->phy.otg->gadget)
 108                                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 109                         tu->phy.otg->state = OTG_STATE_B_IDLE;
 110                         usb_phy_set_event(&tu->phy, USB_EVENT_NONE);
 111                         break;
 112                 case OTG_STATE_A_HOST:
 113                         tu->phy.otg->state = OTG_STATE_A_IDLE;
 114                         break;
 115                 default:
 116                         break;
 117                 }
 118                 dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
 119         }
 120
 121         prev_state = tu->vbus_state;
 122         tu->vbus_state = reg & TAHVO_STAT_VBUS;
 123         if (prev_state != tu->vbus_state) {
 124                 extcon_set_cable_state_(tu->extcon, EXTCON_USB, tu->vbus_state);
 125                 sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
 126         }
 127 }
 128
 129 static void tahvo_usb_become_host(struct tahvo_usb *tu)
 130 {
 131         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 132
 133         extcon_set_cable_state_(tu->extcon, EXTCON_USB_HOST, true);
 134
 135         /* Power up the transceiver in USB host mode */
 136         retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
 137                    USBR_MASTER_SW2 | USBR_MASTER_SW1);
 138         tu->phy.otg->state = OTG_STATE_A_IDLE;
 139
 140         check_vbus_state(tu);
 141 }
 142
 143 static void tahvo_usb_stop_host(struct tahvo_usb *tu)
 144 {
 145         tu->phy.otg->state = OTG_STATE_A_IDLE;
 146 }
 147
 148 static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
 149 {
 150         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 151
 152         extcon_set_cable_state_(tu->extcon, EXTCON_USB_HOST, false);
 153
 154         /* Power up transceiver and set it in USB peripheral mode */
 155         retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
 156                    USBR_NSUSPEND | USBR_SLAVE_SW);
 157         tu->phy.otg->state = OTG_STATE_B_IDLE;
 158
 159         check_vbus_state(tu);
 160 }
 161
 162 static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
 163 {
 164         if (tu->phy.otg->gadget)
 165                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 166         tu->phy.otg->state = OTG_STATE_B_IDLE;
 167 }
 168
 169 static void tahvo_usb_power_off(struct tahvo_usb *tu)
 170 {
 171         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 172
 173         /* Disable gadget controller if any */
 174         if (tu->phy.otg->gadget)
 175                 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 176
 177         /* Power off transceiver */
 178         retu_write(rdev, TAHVO_REG_USBR, 0);
 179         tu->phy.otg->state = OTG_STATE_UNDEFINED;
 180 }
 181
 182 static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
 183 {
 184         struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
 185         struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 186         u16 w;
 187
 188         dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
 189
 190         w = retu_read(rdev, TAHVO_REG_USBR);
 191         if (suspend)
 192                 w &= ~USBR_NSUSPEND;
 193         else
 194                 w |= USBR_NSUSPEND;
 195         retu_write(rdev, TAHVO_REG_USBR, w);
 196
 197         return 0;
 198 }
 199
 200 static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
 201 {
 202         struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
 203                                             phy);
 204
 205         dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
 206
 207         mutex_lock(&tu->serialize);
 208
 209         if (host == NULL) {
 210                 if (tu->tahvo_mode == TAHVO_MODE_HOST)
 211                         tahvo_usb_power_off(tu);
 212                 otg->host = NULL;
 213                 mutex_unlock(&tu->serialize);
 214                 return 0;
 215         }
 216
 217         if (tu->tahvo_mode == TAHVO_MODE_HOST) {
 218                 otg->host = NULL;
 219                 tahvo_usb_become_host(tu);
 220         }
 221
 222         otg->host = host;
 223
 224         mutex_unlock(&tu->serialize);
 225
 226         return 0;
 227 }
 228
 229 static int tahvo_usb_set_peripheral(struct usb_otg *otg,
 230                                     struct usb_gadget *gadget)
 231 {
 232         struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
 233                                             phy);
 234
 235         dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
 236
 237         mutex_lock(&tu->serialize);
 238
 239         if (!gadget) {
 240                 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 241                         tahvo_usb_power_off(tu);
 242                 tu->phy.otg->gadget = NULL;
 243                 mutex_unlock(&tu->serialize);
 244                 return 0;
 245         }
 246
 247         tu->phy.otg->gadget = gadget;
 248         if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 249                 tahvo_usb_become_peripheral(tu);
 250
 251         mutex_unlock(&tu->serialize);
 252
 253         return 0;
 254 }
 255
 256 static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
 257 {
 258         struct tahvo_usb *tu = _tu;
 259
 260         mutex_lock(&tu->serialize);
 261         check_vbus_state(tu);
 262         mutex_unlock(&tu->serialize);
 263
 264         return IRQ_HANDLED;
 265 }
 266
 267 static ssize_t otg_mode_show(struct device *device,
 268                              struct device_attribute *attr, char *buf)
 269 {
 270         struct tahvo_usb *tu = dev_get_drvdata(device);
 271
 272         switch (tu->tahvo_mode) {
 273         case TAHVO_MODE_HOST:
 274                 return sprintf(buf, "host\n");
 275         case TAHVO_MODE_PERIPHERAL:
 276                 return sprintf(buf, "peripheral\n");
 277         }
 278
 279         return -EINVAL;
 280 }
 281
 282 static ssize_t otg_mode_store(struct device *device,
 283                               struct device_attribute *attr,
 284                               const char *buf, size_t count)
 285 {
 286         struct tahvo_usb *tu = dev_get_drvdata(device);
 287         int r;
 288
 289         mutex_lock(&tu->serialize);
 290         if (count >= 4 && strncmp(buf, "host", 4) == 0) {
 291                 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
 292                         tahvo_usb_stop_peripheral(tu);
 293                 tu->tahvo_mode = TAHVO_MODE_HOST;
 294                 if (tu->phy.otg->host) {
 295                         dev_info(device, "HOST mode: host controller present\n");
 296                         tahvo_usb_become_host(tu);
 297                 } else {
 298                         dev_info(device, "HOST mode: no host controller, powering off\n");
 299                         tahvo_usb_power_off(tu);
 300                 }
 301                 r = strlen(buf);
 302         } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
 303                 if (tu->tahvo_mode == TAHVO_MODE_HOST)
 304                         tahvo_usb_stop_host(tu);
 305                 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
 306                 if (tu->phy.otg->gadget) {
 307                         dev_info(device, "PERIPHERAL mode: gadget driver present\n");
 308                         tahvo_usb_become_peripheral(tu);
 309                 } else {
 310                         dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
 311                         tahvo_usb_power_off(tu);
 312                 }
 313                 r = strlen(buf);
 314         } else {
 315                 r = -EINVAL;
 316         }
 317         mutex_unlock(&tu->serialize);
 318
 319         return r;
 320 }
 321 static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
 322
 323 static struct attribute *tahvo_attributes[] = {
 324         &dev_attr_vbus.attr,
 325         &dev_attr_otg_mode.attr,
 326         NULL
 327 };
 328
 329 static struct attribute_group tahvo_attr_group = {
 330         .attrs = tahvo_attributes,
 331 };
 332
 333 static int tahvo_usb_probe(struct platform_device *pdev)
 334 {
 335         struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
 336         struct tahvo_usb *tu;
 337         int ret;
 338
 339         tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
 340         if (!tu)
 341                 return -ENOMEM;
 342
 343         tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
 344                                    GFP_KERNEL);
 345         if (!tu->phy.otg)
 346                 return -ENOMEM;
 347
 348         tu->pt_dev = pdev;
 349
 350         /* Default mode */
 351 #ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
 352         tu->tahvo_mode = TAHVO_MODE_HOST;
 353 #else
 354         tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
 355 #endif
 356
 357         mutex_init(&tu->serialize);
 358
 359         tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
 360         if (!IS_ERR(tu->ick))
 361                 clk_enable(tu->ick);
 362
 363         /*
 364          * Set initial state, so that we generate kevents only on state changes.
 365          */
 366         tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
 367
 368         tu->extcon = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable);
 369         if (IS_ERR(tu->extcon)) {
 370                 dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
 371                 ret = PTR_ERR(tu->extcon);
 372                 goto err_disable_clk;
 373         }
 374
 375         ret = devm_extcon_dev_register(&pdev->dev, tu->extcon);
 376         if (ret) {
 377                 dev_err(&pdev->dev, "could not register extcon device: %d\n",
 378                         ret);
 379                 goto err_disable_clk;
 380         }
 381
 382         /* Set the initial cable state. */
 383         extcon_set_cable_state_(tu->extcon, EXTCON_USB_HOST,
 384                                tu->tahvo_mode == TAHVO_MODE_HOST);
 385         extcon_set_cable_state_(tu->extcon, EXTCON_USB, tu->vbus_state);
 386
 387         /* Create OTG interface */
 388         tahvo_usb_power_off(tu);
 389         tu->phy.dev = &pdev->dev;
 390         tu->phy.otg->state = OTG_STATE_UNDEFINED;
 391         tu->phy.label = DRIVER_NAME;
 392         tu->phy.set_suspend = tahvo_usb_set_suspend;
 393
 394         tu->phy.otg->usb_phy = &tu->phy;
 395         tu->phy.otg->set_host = tahvo_usb_set_host;
 396         tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
 397
 398         ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
 399         if (ret < 0) {
 400                 dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
 401                         ret);
 402                 goto err_disable_clk;
 403         }
 404
 405         dev_set_drvdata(&pdev->dev, tu);
 406
 407         tu->irq = platform_get_irq(pdev, 0);
 408         ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt,
 409                                    IRQF_ONESHOT,
 410                                    "tahvo-vbus", tu);
 411         if (ret) {
 412                 dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
 413                         ret);
 414                 goto err_remove_phy;
 415         }
 416
 417         /* Attributes */
 418         ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
 419         if (ret) {
 420                 dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
 421                 goto err_free_irq;
 422         }
 423
 424         return 0;
 425
 426 err_free_irq:
 427         free_irq(tu->irq, tu);
 428 err_remove_phy:
 429         usb_remove_phy(&tu->phy);
 430 err_disable_clk:
 431         if (!IS_ERR(tu->ick))
 432                 clk_disable(tu->ick);
 433
 434         return ret;
 435 }
 436
 437 static int tahvo_usb_remove(struct platform_device *pdev)
 438 {
 439         struct tahvo_usb *tu = platform_get_drvdata(pdev);
 440
 441         sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
 442         free_irq(tu->irq, tu);
 443         usb_remove_phy(&tu->phy);
 444         if (!IS_ERR(tu->ick))
 445                 clk_disable(tu->ick);
 446
 447         return 0;
 448 }
 449
 450 static struct platform_driver tahvo_usb_driver = {
 451         .probe          = tahvo_usb_probe,
 452         .remove         = tahvo_usb_remove,
 453         .driver         = {
 454                 .name   = "tahvo-usb",
 455         },
 456 };
 457 module_platform_driver(tahvo_usb_driver);
 458
 459 MODULE_DESCRIPTION("Tahvo USB transceiver driver");
 460 MODULE_LICENSE("GPL");
 461 MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
 462 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");