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>
This commit is contained in:
Simon Glass 2019-12-19 17:58:20 -07:00 committed by Bin Meng
parent 8c3ccb3f6d
commit 44482e8a2a
3 changed files with 58 additions and 0 deletions

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@ -542,6 +542,17 @@ config BCM6345_SERIAL
help
Select this to enable UART on BCM6345 SoCs.
config COREBOOT_SERIAL
bool "Coreboot UART support"
depends on DM_SERIAL
default y if SYS_COREBOOT
select SYS_NS16550
help
Select this to enable a ns16550-style UART where the platform data
comes from the coreboot 'sysinfo' tables. This allows U-Boot to have
a serial console on any platform without needing to change the
device tree, etc.
config FSL_LINFLEXUART
bool "Freescale Linflex UART support"
depends on DM_SERIAL

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@ -35,6 +35,7 @@ obj-$(CONFIG_AR933X_UART) += serial_ar933x.o
obj-$(CONFIG_ARM_DCC) += arm_dcc.o
obj-$(CONFIG_ATMEL_USART) += atmel_usart.o
obj-$(CONFIG_BCM6345_SERIAL) += serial_bcm6345.o
obj-$(CONFIG_COREBOOT_SERIAL) += serial_coreboot.o
obj-$(CONFIG_EFI_APP) += serial_efi.o
obj-$(CONFIG_LPC32XX_HSUART) += lpc32xx_hsuart.o
obj-$(CONFIG_MCFUART) += mcfuart.o

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@ -0,0 +1,46 @@
// 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,
};