system76-coreboot/src/soc/intel/apollolake/bootblock/bootblock.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2016 Intel Corp.
 * (Written by Andrey Petrov <andrey.petrov@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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <arch/cpu.h>
#include <bootblock_common.h>
#include <cpu/x86/mtrr.h>
#include <device/pci.h>
#include <lib.h>
#include <soc/iomap.h>
#include <soc/cpu.h>
#include <soc/gpio.h>
#include <soc/iosf.h>
#include <soc/mmap_boot.h>
#include <soc/northbridge.h>
#include <soc/pci_devs.h>
#include <soc/pm.h>
#include <soc/uart.h>
#include <spi-generic.h>
#include <timestamp.h>

static const struct pad_config tpm_spi_configs[] = {
	PAD_CFG_NF(GPIO_106, NATIVE, DEEP, NF3),	/* FST_SPI_CS2_N */
};

static void tpm_enable(void)
{
	/* Configure gpios */
	gpio_configure_pads(tpm_spi_configs, ARRAY_SIZE(tpm_spi_configs));
}

static void enable_pm_timer(void)
{
	/* ACPI PM timer emulation */
	msr_t msr;
	/*
	 * The derived frequency is calculated as follows:
	 *    (CTC_FREQ * msr[63:32]) >> 32 = target frequency.
	 * Back solve the multiplier so the 3.579545MHz ACPI timer
	 * frequency is used.
	 */
	msr.hi = (3579545ULL << 32) / CTC_FREQ;
	/* Set PM1 timer IO port and enable*/
	msr.lo = EMULATE_PM_TMR_EN | (ACPI_PMIO_BASE + R_ACPI_PM1_TMR);
	wrmsr(MSR_EMULATE_PM_TMR, msr);
}

static void enable_cmos_upper_bank(void)
{
	uint32_t reg = iosf_read(IOSF_RTC_PORT_ID, RTC_CONFIG);
	reg |= RTC_CONFIG_UCMOS_ENABLE;
	iosf_write(IOSF_RTC_PORT_ID, RTC_CONFIG, reg);
}

void asmlinkage bootblock_c_entry(uint64_t base_timestamp)
{
	device_t dev = NB_DEV_ROOT;

	/* Set PCI Express BAR */
	pci_io_write_config32(dev, PCIEXBAR, CONFIG_MMCONF_BASE_ADDRESS | 1);
	/*
	 * Clear TSEG register - TSEG register comes out of reset with a
	 * non-zero default value. Clear this register to ensure that there are
	 * no surprises in CBMEM handling.
	 */
	pci_write_config32(dev, TSEG, 0);

	dev = P2SB_DEV;
	/* BAR and MMIO enable for IOSF, so that GPIOs can be configured */
	pci_write_config32(dev, PCI_BASE_ADDRESS_0, CONFIG_IOSF_BASE_ADDRESS);
	pci_write_config32(dev, PCI_BASE_ADDRESS_1, 0);
	pci_write_config16(dev, PCI_COMMAND,
				PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);

	/* Decode the ACPI I/O port range for early firmware verification.*/
	dev = PMC_DEV;
	pci_write_config16(dev, PCI_BASE_ADDRESS_4, ACPI_PMIO_BASE);
	pci_write_config16(dev, PCI_COMMAND,
				PCI_COMMAND_IO | PCI_COMMAND_MASTER);

	enable_cmos_upper_bank();

	/* Call lib/bootblock.c main */
	bootblock_main_with_timestamp(base_timestamp);
}

static void cache_bios_region(void)
{
	int mtrr;
	size_t rom_size;
	uint32_t alignment;

	mtrr = get_free_var_mtrr();

	if (mtrr==-1)
		return;

	/* Only the IFD BIOS region is memory mapped (at top of 4G) */
	rom_size = get_bios_size();

	if (!rom_size)
		return;

	/* Round to power of two */
	alignment = 1 << (log2_ceil(rom_size));
	rom_size = ALIGN_UP(rom_size, alignment);
	set_var_mtrr(mtrr, 4ULL*GiB - rom_size, rom_size, MTRR_TYPE_WRPROT);
}

/*
 * Program temporary BAR for SPI in case any of the stages before ramstage need
 * to access SPI MMIO regs. Ramstage will assign a new BAR during PCI
 * enumeration.
 */
static void enable_spibar(void)
{
	device_t dev = SPI_DEV;
	uint8_t val;

	/* Disable Bus Master and MMIO space. */
	val = pci_read_config8(dev, PCI_COMMAND);
	val &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
	pci_write_config8(dev, PCI_COMMAND, val);

	/* Program Temporary BAR for SPI */
	pci_write_config32(dev, PCI_BASE_ADDRESS_0,
			   PRERAM_SPI_BASE_ADDRESS |
			   PCI_BASE_ADDRESS_SPACE_MEMORY);

	/* Enable Bus Master and MMIO Space */
	val = pci_read_config8(dev, PCI_COMMAND);
	val |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
	pci_write_config8(dev, PCI_COMMAND, val);

	/* Initialize SPI to allow BIOS to write/erase on flash. */
	spi_init();
}

static void enable_pmcbar(void)
{
	device_t pmc = PMC_DEV;

	/* Set PMC base addresses and enable decoding. */
	pci_write_config32(pmc, PCI_BASE_ADDRESS_0, PMC_BAR0);
	pci_write_config32(pmc, PCI_BASE_ADDRESS_1, 0);	/* 64-bit BAR */
	pci_write_config32(pmc, PCI_BASE_ADDRESS_2, PMC_BAR1);
	pci_write_config32(pmc, PCI_BASE_ADDRESS_3, 0);	/* 64-bit BAR */
	pci_write_config16(pmc, PCI_BASE_ADDRESS_4, ACPI_PMIO_BASE);
	pci_write_config16(pmc, PCI_COMMAND,
				PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
				PCI_COMMAND_MASTER);
}

void bootblock_soc_early_init(void)
{
	enable_pmcbar();

	/* Clear global reset promotion bit */
	global_reset_enable(0);

	/* Prepare UART for serial console. */
	if (IS_ENABLED(CONFIG_SOC_UART_DEBUG))
		soc_console_uart_init();

	if (IS_ENABLED(CONFIG_TPM_ON_FAST_SPI))
		tpm_enable();

	enable_pm_timer();

	enable_spibar();

	cache_bios_region();
}