drivers/serial/serial_coreboot.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * UART support for U-Boot when launched from Coreboot
   4  *
   5  * Copyright 2019 Google LLC
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <ns16550.h>
  11 #include <serial.h>
  12 #include <asm/arch/sysinfo.h>
  13
  14 static int coreboot_ofdata_to_platdata(struct udevice *dev)
  15 {
  16         struct ns16550_platdata *plat = dev_get_platdata(dev);
  17         struct cb_serial *cb_info = lib_sysinfo.serial;
  18
  19         plat->base = cb_info->baseaddr;
  20         plat->reg_shift = cb_info->regwidth == 4 ? 2 : 0;
  21         plat->reg_width = cb_info->regwidth;
  22         plat->clock = cb_info->input_hertz;
  23         plat->fcr = UART_FCR_DEFVAL;
  24         plat->flags = 0;
  25         if (cb_info->type == CB_SERIAL_TYPE_IO_MAPPED)
  26                 plat->flags |= NS16550_FLAG_IO;
  27
  28         return 0;
  29 }
  30
  31 static const struct udevice_id coreboot_serial_ids[] = {
  32         { .compatible = "coreboot-serial" },
  33         { },
  34 };
  35
  36 U_BOOT_DRIVER(coreboot_uart) = {
  37         .name   = "coreboot_uart",
  38         .id     = UCLASS_SERIAL,
  39         .of_match       = coreboot_serial_ids,
  40         .priv_auto_alloc_size = sizeof(struct NS16550),
  41         .platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
  42         .ofdata_to_platdata  = coreboot_ofdata_to_platdata,
  43         .probe  = ns16550_serial_probe,
  44         .ops    = &ns16550_serial_ops,
  45         .flags  = DM_FLAG_PRE_RELOC,
  46 };