drivers/usb/emul/sandbox_flash.c

   1 /*
   2  * (C) Copyright 2015 Google, Inc
   3  * Written by Simon Glass <sjg@chromium.org>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <os.h>
  11 #include <scsi.h>
  12 #include <usb.h>
  13
  14 DECLARE_GLOBAL_DATA_PTR;
  15
  16 /*
  17  * This driver emulates a flash stick using the UFI command specification and
  18  * the BBB (bulk/bulk/bulk) protocol. It supports only a single logical unit
  19  * number (LUN 0).
  20  */
  21
  22 enum {
  23         SANDBOX_FLASH_EP_OUT            = 1,    /* endpoints */
  24         SANDBOX_FLASH_EP_IN             = 2,
  25         SANDBOX_FLASH_BLOCK_LEN         = 512,
  26 };
  27
  28 enum cmd_phase {
  29         PHASE_START,
  30         PHASE_DATA,
  31         PHASE_STATUS,
  32 };
  33
  34 enum {
  35         STRINGID_MANUFACTURER = 1,
  36         STRINGID_PRODUCT,
  37         STRINGID_SERIAL,
  38
  39         STRINGID_COUNT,
  40 };
  41
  42 /**
  43  * struct sandbox_flash_priv - private state for this driver
  44  *
  45  * @error:      true if there is an error condition
  46  * @alloc_len:  Allocation length from the last incoming command
  47  * @transfer_len: Transfer length from CBW header
  48  * @read_len:   Number of blocks of data left in the current read command
  49  * @tag:        Tag value from last command
  50  * @fd:         File descriptor of backing file
  51  * @file_size:  Size of file in bytes
  52  * @status_buff:        Data buffer for outgoing status
  53  * @buff_used:  Number of bytes ready to transfer back to host
  54  * @buff:       Data buffer for outgoing data
  55  */
  56 struct sandbox_flash_priv {
  57         bool error;
  58         int alloc_len;
  59         int transfer_len;
  60         int read_len;
  61         enum cmd_phase phase;
  62         u32 tag;
  63         int fd;
  64         loff_t file_size;
  65         struct umass_bbb_csw status;
  66         int buff_used;
  67         u8 buff[512];
  68 };
  69
  70 struct sandbox_flash_plat {
  71         const char *pathname;
  72         struct usb_string flash_strings[STRINGID_COUNT];
  73 };
  74
  75 struct scsi_inquiry_resp {
  76         u8 type;
  77         u8 flags;
  78         u8 version;
  79         u8 data_format;
  80         u8 additional_len;
  81         u8 spare[3];
  82         char vendor[8];
  83         char product[16];
  84         char revision[4];
  85 };
  86
  87 struct scsi_read_capacity_resp {
  88         u32 last_block_addr;
  89         u32 block_len;
  90 };
  91
  92 struct __packed scsi_read10_req {
  93         u8 cmd;
  94         u8 lun_flags;
  95         u32 lba;
  96         u8 spare;
  97         u16 transfer_len;
  98         u8 spare2[3];
  99 };
 100
 101 static struct usb_device_descriptor flash_device_desc = {
 102         .bLength =              sizeof(flash_device_desc),
 103         .bDescriptorType =      USB_DT_DEVICE,
 104
 105         .bcdUSB =               __constant_cpu_to_le16(0x0200),
 106
 107         .bDeviceClass =         0,
 108         .bDeviceSubClass =      0,
 109         .bDeviceProtocol =      0,
 110
 111         .idVendor =             __constant_cpu_to_le16(0x1234),
 112         .idProduct =            __constant_cpu_to_le16(0x5678),
 113         .iManufacturer =        STRINGID_MANUFACTURER,
 114         .iProduct =             STRINGID_PRODUCT,
 115         .iSerialNumber =        STRINGID_SERIAL,
 116         .bNumConfigurations =   1,
 117 };
 118
 119 static struct usb_config_descriptor flash_config0 = {
 120         .bLength                = sizeof(flash_config0),
 121         .bDescriptorType        = USB_DT_CONFIG,
 122
 123         /* wTotalLength is set up by usb-emul-uclass */
 124         .bNumInterfaces         = 1,
 125         .bConfigurationValue    = 0,
 126         .iConfiguration         = 0,
 127         .bmAttributes           = 1 << 7,
 128         .bMaxPower              = 50,
 129 };
 130
 131 static struct usb_interface_descriptor flash_interface0 = {
 132         .bLength                = sizeof(flash_interface0),
 133         .bDescriptorType        = USB_DT_INTERFACE,
 134
 135         .bInterfaceNumber       = 0,
 136         .bAlternateSetting      = 0,
 137         .bNumEndpoints          = 2,
 138         .bInterfaceClass        = USB_CLASS_MASS_STORAGE,
 139         .bInterfaceSubClass     = US_SC_UFI,
 140         .bInterfaceProtocol     = US_PR_BULK,
 141         .iInterface             = 0,
 142 };
 143
 144 static struct usb_endpoint_descriptor flash_endpoint0_out = {
 145         .bLength                = USB_DT_ENDPOINT_SIZE,
 146         .bDescriptorType        = USB_DT_ENDPOINT,
 147
 148         .bEndpointAddress       = SANDBOX_FLASH_EP_OUT,
 149         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 150         .wMaxPacketSize         = __constant_cpu_to_le16(1024),
 151         .bInterval              = 0,
 152 };
 153
 154 static struct usb_endpoint_descriptor flash_endpoint1_in = {
 155         .bLength                = USB_DT_ENDPOINT_SIZE,
 156         .bDescriptorType        = USB_DT_ENDPOINT,
 157
 158         .bEndpointAddress       = SANDBOX_FLASH_EP_IN | USB_ENDPOINT_DIR_MASK,
 159         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 160         .wMaxPacketSize         = __constant_cpu_to_le16(1024),
 161         .bInterval              = 0,
 162 };
 163
 164 static void *flash_desc_list[] = {
 165         &flash_device_desc,
 166         &flash_config0,
 167         &flash_interface0,
 168         &flash_endpoint0_out,
 169         &flash_endpoint1_in,
 170         NULL,
 171 };
 172
 173 static int sandbox_flash_control(struct udevice *dev, struct usb_device *udev,
 174                                  unsigned long pipe, void *buff, int len,
 175                                  struct devrequest *setup)
 176 {
 177         struct sandbox_flash_priv *priv = dev_get_priv(dev);
 178
 179         if (pipe == usb_rcvctrlpipe(udev, 0)) {
 180                 switch (setup->request) {
 181                 case US_BBB_RESET:
 182                         priv->error = false;
 183                         return 0;
 184                 case US_BBB_GET_MAX_LUN:
 185                         *(char *)buff = '\0';
 186                         return 1;
 187                 default:
 188                         debug("request=%x\n", setup->request);
 189                         break;
 190                 }
 191         }
 192         debug("pipe=%lx\n", pipe);
 193
 194         return -EIO;
 195 }
 196
 197 static void setup_fail_response(struct sandbox_flash_priv *priv)
 198 {
 199         struct umass_bbb_csw *csw = &priv->status;
 200
 201         csw->dCSWSignature = CSWSIGNATURE;
 202         csw->dCSWTag = priv->tag;
 203         csw->dCSWDataResidue = 0;
 204         csw->bCSWStatus = CSWSTATUS_FAILED;
 205         priv->buff_used = 0;
 206 }
 207
 208 /**
 209  * setup_response() - set up a response to send back to the host
 210  *
 211  * @priv:       Sandbox flash private data
 212  * @resp:       Response to send, or NULL if none
 213  * @size:       Size of response
 214  */
 215 static void setup_response(struct sandbox_flash_priv *priv, void *resp,
 216                            int size)
 217 {
 218         struct umass_bbb_csw *csw = &priv->status;
 219
 220         csw->dCSWSignature = CSWSIGNATURE;
 221         csw->dCSWTag = priv->tag;
 222         csw->dCSWDataResidue = 0;
 223         csw->bCSWStatus = CSWSTATUS_GOOD;
 224
 225         assert(!resp || resp == priv->buff);
 226         priv->buff_used = size;
 227 }
 228
 229 static void handle_read(struct sandbox_flash_priv *priv, ulong lba,
 230                         ulong transfer_len)
 231 {
 232         debug("%s: lba=%lx, transfer_len=%lx\n", __func__, lba, transfer_len);
 233         if (priv->fd != -1) {
 234                 os_lseek(priv->fd, lba * SANDBOX_FLASH_BLOCK_LEN, OS_SEEK_SET);
 235                 priv->read_len = transfer_len;
 236                 setup_response(priv, priv->buff,
 237                                transfer_len * SANDBOX_FLASH_BLOCK_LEN);
 238         } else {
 239                 setup_fail_response(priv);
 240         }
 241 }
 242
 243 static int handle_ufi_command(struct sandbox_flash_plat *plat,
 244                               struct sandbox_flash_priv *priv, const void *buff,
 245                               int len)
 246 {
 247         const struct scsi_cmd *req = buff;
 248
 249         switch (*req->cmd) {
 250         case SCSI_INQUIRY: {
 251                 struct scsi_inquiry_resp *resp = (void *)priv->buff;
 252
 253                 priv->alloc_len = req->cmd[4];
 254                 memset(resp, '\0', sizeof(*resp));
 255                 resp->data_format = 1;
 256                 resp->additional_len = 0x1f;
 257                 strncpy(resp->vendor,
 258                         plat->flash_strings[STRINGID_MANUFACTURER -  1].s,
 259                         sizeof(resp->vendor));
 260                 strncpy(resp->product,
 261                         plat->flash_strings[STRINGID_PRODUCT - 1].s,
 262                         sizeof(resp->product));
 263                 strncpy(resp->revision, "1.0", sizeof(resp->revision));
 264                 setup_response(priv, resp, sizeof(*resp));
 265                 break;
 266         }
 267         case SCSI_TST_U_RDY:
 268                 setup_response(priv, NULL, 0);
 269                 break;
 270         case SCSI_RD_CAPAC: {
 271                 struct scsi_read_capacity_resp *resp = (void *)priv->buff;
 272                 uint blocks;
 273
 274                 if (priv->file_size)
 275                         blocks = priv->file_size / SANDBOX_FLASH_BLOCK_LEN - 1;
 276                 else
 277                         blocks = 0;
 278                 resp->last_block_addr = cpu_to_be32(blocks);
 279                 resp->block_len = cpu_to_be32(SANDBOX_FLASH_BLOCK_LEN);
 280                 setup_response(priv, resp, sizeof(*resp));
 281                 break;
 282         }
 283         case SCSI_READ10: {
 284                 struct scsi_read10_req *req = (void *)buff;
 285
 286                 handle_read(priv, be32_to_cpu(req->lba),
 287                             be16_to_cpu(req->transfer_len));
 288                 break;
 289         }
 290         default:
 291                 debug("Command not supported: %x\n", req->cmd[0]);
 292                 return -EPROTONOSUPPORT;
 293         }
 294
 295         priv->phase = priv->transfer_len ? PHASE_DATA : PHASE_STATUS;
 296         return 0;
 297 }
 298
 299 static int sandbox_flash_bulk(struct udevice *dev, struct usb_device *udev,
 300                               unsigned long pipe, void *buff, int len)
 301 {
 302         struct sandbox_flash_plat *plat = dev_get_platdata(dev);
 303         struct sandbox_flash_priv *priv = dev_get_priv(dev);
 304         int ep = usb_pipeendpoint(pipe);
 305         struct umass_bbb_cbw *cbw = buff;
 306
 307         debug("%s: dev=%s, pipe=%lx, ep=%x, len=%x, phase=%d\n", __func__,
 308               dev->name, pipe, ep, len, priv->phase);
 309         switch (ep) {
 310         case SANDBOX_FLASH_EP_OUT:
 311                 switch (priv->phase) {
 312                 case PHASE_START:
 313                         priv->alloc_len = 0;
 314                         priv->read_len = 0;
 315                         if (priv->error || len != UMASS_BBB_CBW_SIZE ||
 316                             cbw->dCBWSignature != CBWSIGNATURE)
 317                                 goto err;
 318                         if ((cbw->bCBWFlags & CBWFLAGS_SBZ) ||
 319                             cbw->bCBWLUN != 0)
 320                                 goto err;
 321                         if (cbw->bCDBLength < 1 || cbw->bCDBLength >= 0x10)
 322                                 goto err;
 323                         priv->transfer_len = cbw->dCBWDataTransferLength;
 324                         priv->tag = cbw->dCBWTag;
 325                         return handle_ufi_command(plat, priv, cbw->CBWCDB,
 326                                                   cbw->bCDBLength);
 327                 case PHASE_DATA:
 328                         debug("data out\n");
 329                         break;
 330                 default:
 331                         break;
 332                 }
 333         case SANDBOX_FLASH_EP_IN:
 334                 switch (priv->phase) {
 335                 case PHASE_DATA:
 336                         debug("data in, len=%x, alloc_len=%x, priv->read_len=%x\n",
 337                               len, priv->alloc_len, priv->read_len);
 338                         if (priv->read_len) {
 339                                 ulong bytes_read;
 340
 341                                 bytes_read = os_read(priv->fd, buff, len);
 342                                 if (bytes_read != len)
 343                                         return -EIO;
 344                                 priv->read_len -= len / SANDBOX_FLASH_BLOCK_LEN;
 345                                 if (!priv->read_len)
 346                                         priv->phase = PHASE_STATUS;
 347                         } else {
 348                                 if (priv->alloc_len && len > priv->alloc_len)
 349                                         len = priv->alloc_len;
 350                                 memcpy(buff, priv->buff, len);
 351                                 priv->phase = PHASE_STATUS;
 352                         }
 353                         return len;
 354                 case PHASE_STATUS:
 355                         debug("status in, len=%x\n", len);
 356                         if (len > sizeof(priv->status))
 357                                 len = sizeof(priv->status);
 358                         memcpy(buff, &priv->status, len);
 359                         priv->phase = PHASE_START;
 360                         return len;
 361                 default:
 362                         break;
 363                 }
 364         }
 365 err:
 366         priv->error = true;
 367         debug("%s: Detected transfer error\n", __func__);
 368         return 0;
 369 }
 370
 371 static int sandbox_flash_ofdata_to_platdata(struct udevice *dev)
 372 {
 373         struct sandbox_flash_plat *plat = dev_get_platdata(dev);
 374
 375         plat->pathname = dev_read_string(dev, "sandbox,filepath");
 376
 377         return 0;
 378 }
 379
 380 static int sandbox_flash_bind(struct udevice *dev)
 381 {
 382         struct sandbox_flash_plat *plat = dev_get_platdata(dev);
 383         struct usb_string *fs;
 384
 385         fs = plat->flash_strings;
 386         fs[0].id = STRINGID_MANUFACTURER;
 387         fs[0].s = "sandbox";
 388         fs[1].id = STRINGID_PRODUCT;
 389         fs[1].s = "flash";
 390         fs[2].id = STRINGID_SERIAL;
 391         fs[2].s = dev->name;
 392
 393         return usb_emul_setup_device(dev, PACKET_SIZE_64, plat->flash_strings,
 394                                      flash_desc_list);
 395 }
 396
 397 static int sandbox_flash_probe(struct udevice *dev)
 398 {
 399         struct sandbox_flash_plat *plat = dev_get_platdata(dev);
 400         struct sandbox_flash_priv *priv = dev_get_priv(dev);
 401
 402         priv->fd = os_open(plat->pathname, OS_O_RDONLY);
 403         if (priv->fd != -1)
 404                 return os_get_filesize(plat->pathname, &priv->file_size);
 405
 406         return 0;
 407 }
 408
 409 static const struct dm_usb_ops sandbox_usb_flash_ops = {
 410         .control        = sandbox_flash_control,
 411         .bulk           = sandbox_flash_bulk,
 412 };
 413
 414 static const struct udevice_id sandbox_usb_flash_ids[] = {
 415         { .compatible = "sandbox,usb-flash" },
 416         { }
 417 };
 418
 419 U_BOOT_DRIVER(usb_sandbox_flash) = {
 420         .name   = "usb_sandbox_flash",
 421         .id     = UCLASS_USB_EMUL,
 422         .of_match = sandbox_usb_flash_ids,
 423         .bind   = sandbox_flash_bind,
 424         .probe  = sandbox_flash_probe,
 425         .ofdata_to_platdata = sandbox_flash_ofdata_to_platdata,
 426         .ops    = &sandbox_usb_flash_ops,
 427         .priv_auto_alloc_size = sizeof(struct sandbox_flash_priv),
 428         .platdata_auto_alloc_size = sizeof(struct sandbox_flash_plat),
 429 };