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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2015 Intel Corp.
* (Written by Alexandru Gagniuc <alexandrux.gagniuc@intel.com> for Intel Corp.)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <console/uart.h>
#include <device/pci.h>
#include <soc/gpio.h>
#include <soc/uart.h>
#include <soc/pci_devs.h>
static void lpss_uart_write(uint16_t reg, uint32_t val)
{
uintptr_t base = CONFIG_CONSOLE_UART_BASE_ADDRESS | reg;
write32((void *)base, val);
}
void lpss_console_uart_init(void)
{
uint32_t clk_sel;
device_t uart = _LPSS_PCI_DEV(UART, CONFIG_UART_FOR_CONSOLE & 3);
if (CONFIG_UART_FOR_CONSOLE > 2)
return;
/* Enable BAR0 for the UART -- this is where the 8250 registers hide */
pci_write_config32(uart, PCI_BASE_ADDRESS_0,
CONFIG_CONSOLE_UART_BASE_ADDRESS);
/* Enable memory access and bus master */
pci_write_config32(uart, PCI_COMMAND,
PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
/* Take UART out of reset */
lpss_uart_write(UART_RESET, UART_RESET_UART_EN);
/* These values get us a 1.836 MHz clock (ideally we want 1.843 MHz) */
clk_sel = UART_CLK_DIV_N(0x7fff) | UART_CLK_DIV_M(0x025a);
/* Set M and N divisor inputs and enable clock */
lpss_uart_write(UART_CLK, clk_sel | UART_CLK_UPDATE);
lpss_uart_write(UART_CLK, clk_sel | UART_CLK_EN);
}
uintptr_t uart_platform_base(int idx)
{
return (CONFIG_CONSOLE_UART_BASE_ADDRESS);
}
unsigned int uart_platform_refclk(void)
{
/* That's within 0.5% of the actual value we've set earlier */
return 115200 * 16;
}
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