diff options
Diffstat (limited to 'src/soc/intel/skylake/romstage/uart.c')
| -rw-r--r-- | src/soc/intel/skylake/romstage/uart.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/soc/intel/skylake/romstage/uart.c b/src/soc/intel/skylake/romstage/uart.c new file mode 100644 index 0000000000..96c96343f1 --- /dev/null +++ b/src/soc/intel/skylake/romstage/uart.c @@ -0,0 +1,85 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2014 Google Inc. + * + * 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; version 2 of the License. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <arch/early_variables.h> +#include <arch/io.h> +#include <delay.h> +#include <device/pci_def.h> +#include <reg_script.h> +#include <stdint.h> +#include <uart8250.h> +#include <soc/iobp.h> +#include <soc/serialio.h> + +const struct reg_script uart_init[] = { + /* Set MMIO BAR */ + REG_PCI_WRITE32(PCI_BASE_ADDRESS_0, CONFIG_TTYS0_BASE), + /* Enable Memory access and Bus Master */ + REG_PCI_OR32(PCI_COMMAND, PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER), + /* Initialize LTR */ + REG_MMIO_RMW32(CONFIG_TTYS0_BASE + SIO_REG_PPR_GEN, + ~SIO_REG_PPR_GEN_LTR_MODE_MASK, 0), + REG_MMIO_RMW32(CONFIG_TTYS0_BASE + SIO_REG_PPR_RST, + ~(SIO_REG_PPR_RST_ASSERT), 0), + /* Take UART out of reset */ + REG_MMIO_OR32(CONFIG_TTYS0_BASE + SIO_REG_PPR_RST, + SIO_REG_PPR_RST_ASSERT), + /* Set M and N divisor inputs and enable clock */ + REG_MMIO_WRITE32(CONFIG_TTYS0_BASE + SIO_REG_PPR_CLOCK, + SIO_REG_PPR_CLOCK_EN | SIO_REG_PPR_CLOCK_UPDATE | + (SIO_REG_PPR_CLOCK_N_DIV << 16) | + (SIO_REG_PPR_CLOCK_M_DIV << 1)), + REG_SCRIPT_END +}; + +void pch_uart_init(void) +{ + /* Program IOBP CB000154h[12,9:8,4:0] = 1001100011111b */ + u32 gpiodf = 0x131f; + device_t dev; + + /* Put UART in byte access mode for 16550 compatibility */ + switch (CONFIG_INTEL_PCH_UART_CONSOLE_NUMBER) { + case 0: + dev = PCH_DEV_UART0; + gpiodf |= SIO_IOBP_GPIODF_UART0_BYTE_ACCESS; + break; + case 1: + dev = PCH_DEV_UART1; + gpiodf |= SIO_IOBP_GPIODF_UART1_BYTE_ACCESS; + break; + default: + return; + } + + /* Program IOBP GPIODF */ + pch_iobp_update(SIO_IOBP_GPIODF, ~gpiodf, gpiodf); + + /* Program IOBP CB000180h[5:0] = 111111b (undefined register) */ + pch_iobp_update(0xcb000180, ~0x0000003f, 0x0000003f); + + /* Initialize chipset uart interface */ + reg_script_run_on_dev(dev, uart_init); + + /* + * Perform standard UART initialization + * Divisor 1 is 115200 BAUD + */ + uart8250_mem_init(CONFIG_TTYS0_BASE, 1); +} |