drivers/scsi/scsi_emul.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Emulation of enough SCSI commands to find and read from a unit
   4  *
   5  * Copyright 2022 Google LLC
   6  * Written by Simon Glass <sjg@chromium.org>
   7  *
   8  * implementation of SCSI functions required so that CONFIG_SCSI can be enabled
   9  * for sandbox.
  10  */
  11
  12 #define LOG_CATEGORY UCLASS_SCSI
  13
  14 #include <common.h>
  15 #include <dm.h>
  16 #include <log.h>
  17 #include <scsi.h>
  18 #include <scsi_emul.h>
  19
  20 int sb_scsi_emul_command(struct scsi_emul_info *info,
  21                          const struct scsi_cmd *req, int len)
  22 {
  23         int ret = 0;
  24
  25         info->buff_used = 0;
  26         log_debug("emul %x\n", *req->cmd);
  27         switch (*req->cmd) {
  28         case SCSI_INQUIRY: {
  29                 struct scsi_inquiry_resp *resp = (void *)info->buff;
  30
  31                 info->alloc_len = req->cmd[4];
  32                 memset(resp, '\0', sizeof(*resp));
  33                 resp->data_format = 1;
  34                 resp->additional_len = 0x1f;
  35                 strncpy(resp->vendor, info->vendor, sizeof(resp->vendor));
  36                 strncpy(resp->product, info->product, sizeof(resp->product));
  37                 strncpy(resp->revision, "1.0", sizeof(resp->revision));
  38                 info->buff_used = sizeof(*resp);
  39                 break;
  40         }
  41         case SCSI_TST_U_RDY:
  42                 break;
  43         case SCSI_RD_CAPAC: {
  44                 struct scsi_read_capacity_resp *resp = (void *)info->buff;
  45                 uint blocks;
  46
  47                 if (info->file_size)
  48                         blocks = info->file_size / info->block_size - 1;
  49                 else
  50                         blocks = 0;
  51                 resp->last_block_addr = cpu_to_be32(blocks);
  52                 resp->block_len = cpu_to_be32(info->block_size);
  53                 info->buff_used = sizeof(*resp);
  54                 break;
  55         }
  56         case SCSI_READ10: {
  57                 const struct scsi_read10_req *read_req = (void *)req;
  58
  59                 info->seek_block = be32_to_cpu(read_req->lba);
  60                 info->read_len = be16_to_cpu(read_req->xfer_len);
  61                 info->buff_used = info->read_len * info->block_size;
  62                 ret = SCSI_EMUL_DO_READ;
  63                 break;
  64         }
  65         default:
  66                 debug("Command not supported: %x\n", req->cmd[0]);
  67                 ret = -EPROTONOSUPPORT;
  68         }
  69         if (ret >= 0)
  70                 info->phase = info->transfer_len ? SCSIPH_DATA : SCSIPH_STATUS;
  71         log_debug("   - done %x: ret=%d\n", *req->cmd, ret);
  72
  73         return ret;
  74 }