u-boot/drivers/serial/serial_coreboot.c
Simon Glass 44482e8a2a x86: serial: Add a coreboot serial driver
Coreboot can provide information about the serial device in use on a
platform. Add a driver that uses this information to produce a working
UART.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-02-04 01:19:25 +08:00

47 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* UART support for U-Boot when launched from Coreboot
*
* Copyright 2019 Google LLC
*/
#include <common.h>
#include <dm.h>
#include <ns16550.h>
#include <serial.h>
#include <asm/arch/sysinfo.h>
static int coreboot_ofdata_to_platdata(struct udevice *dev)
{
struct ns16550_platdata *plat = dev_get_platdata(dev);
struct cb_serial *cb_info = lib_sysinfo.serial;
plat->base = cb_info->baseaddr;
plat->reg_shift = cb_info->regwidth == 4 ? 2 : 0;
plat->reg_width = cb_info->regwidth;
plat->clock = cb_info->input_hertz;
plat->fcr = UART_FCR_DEFVAL;
plat->flags = 0;
if (cb_info->type == CB_SERIAL_TYPE_IO_MAPPED)
plat->flags |= NS16550_FLAG_IO;
return 0;
}
static const struct udevice_id coreboot_serial_ids[] = {
{ .compatible = "coreboot-serial" },
{ },
};
U_BOOT_DRIVER(coreboot_uart) = {
.name = "coreboot_uart",
.id = UCLASS_SERIAL,
.of_match = coreboot_serial_ids,
.priv_auto_alloc_size = sizeof(struct NS16550),
.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
.ofdata_to_platdata = coreboot_ofdata_to_platdata,
.probe = ns16550_serial_probe,
.ops = &ns16550_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};