u-boot/arch/x86/cpu/braswell/early_uart.c
Bin Meng de9ac9a1b9 x86: Add Intel Braswell SoC support
This adds initial Intel Braswell SoC support. It uses Intel FSP
to initialize the chipset.

Similar to its predecessor BayTrail, there are some work to do to
enable the legacy UART integrated in the Braswell SoC.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-16 14:57:44 +08:00

82 lines
1.8 KiB
C

/*
* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#define PCI_DEV_CONFIG(segbus, dev, fn) ( \
(((segbus) & 0xfff) << 20) | \
(((dev) & 0x1f) << 15) | \
(((fn) & 0x07) << 12))
/* Platform Controller Unit */
#define LPC_DEV 0x1f
#define LPC_FUNC 0
/* Enable UART */
#define UART_CONT 0x80
/* UART PAD definitions */
#define UART_RXD_COMMUITY 1
#define UART_TXD_COMMUITY 1
#define UART_RXD_FAMILY 4
#define UART_TXD_FAMILY 4
#define UART_RXD_PAD 2
#define UART_TXD_PAD 7
#define UART_RXD_FUNC 3
#define UART_TXD_FUNC 3
/* IO Memory */
#define IO_BASE_ADDRESS 0xfed80000
static inline uint32_t gpio_pconf0(int community, int family, int pad)
{
return IO_BASE_ADDRESS + community * 0x8000 + 0x4400 +
family * 0x400 + pad * 8;
}
static void gpio_select_func(int community, int family, int pad, int func)
{
uint32_t pconf0_addr = gpio_pconf0(community, family, pad);
clrsetbits_le32(pconf0_addr, 0xf << 16, func << 16);
}
static void x86_pci_write_config32(int dev, unsigned int where, u32 value)
{
unsigned long addr;
addr = CONFIG_PCIE_ECAM_BASE | dev | (where & ~3);
writel(value, addr);
}
/* This can be called after memory-mapped PCI is working */
int setup_internal_uart(int enable)
{
/* Enable or disable the legacy UART hardware */
x86_pci_write_config32(PCI_DEV_CONFIG(0, LPC_DEV, LPC_FUNC), UART_CONT,
enable);
/* All done for the disable part, so just return */
if (!enable)
return 0;
/*
* Set up the pads to the UART function. This allows the signals to
* leave the chip
*/
gpio_select_func(UART_RXD_COMMUITY, UART_RXD_FAMILY,
UART_RXD_PAD, UART_RXD_FUNC);
gpio_select_func(UART_TXD_COMMUITY, UART_TXD_FAMILY,
UART_TXD_PAD, UART_TXD_FUNC);
return 0;
}
void board_debug_uart_init(void)
{
setup_internal_uart(1);
}