u-boot/arch/x86/cpu/intel_common/fast_spi.c
Simon Glass 8e2922e357 x86: spi: Add a way to access the SPI mapping via registers
At present the PCI BDF (bus/device/function) is needed to access the SPI
mapping, since the registers are at BAR0. This doesn't work when PCI
auto-config has not been done yet, since BARs are unassigned.

Add another way to find the mapping, using the MMIO base, if the caller
knows this.

Also add a missing function comment.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00

82 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 Google LLC
*/
#include <common.h>
#include <asm/io.h>
#include <asm/cpu_common.h>
#include <asm/fast_spi.h>
#include <asm/pci.h>
/*
* Returns bios_start and fills in size of the BIOS region.
*/
static ulong fast_spi_get_bios_region(struct fast_spi_regs *regs,
uint *bios_size)
{
ulong bios_start, bios_end;
/*
* BIOS_BFPREG provides info about BIOS-Flash Primary Region Base and
* Limit. Base and Limit fields are in units of 4K.
*/
u32 val = readl(&regs->bfp);
bios_start = (val & SPIBAR_BFPREG_PRB_MASK) << 12;
bios_end = (((val & SPIBAR_BFPREG_PRL_MASK) >>
SPIBAR_BFPREG_PRL_SHIFT) + 1) << 12;
*bios_size = bios_end - bios_start;
return bios_start;
}
int fast_spi_get_bios_mmap_regs(struct fast_spi_regs *regs, ulong *map_basep,
uint *map_sizep, uint *offsetp)
{
ulong base;
base = fast_spi_get_bios_region(regs, map_sizep);
*map_basep = (u32)-*map_sizep - base;
*offsetp = base;
return 0;
}
int fast_spi_get_bios_mmap(pci_dev_t pdev, ulong *map_basep, uint *map_sizep,
uint *offsetp)
{
struct fast_spi_regs *regs;
ulong bar, mmio_base;
/* Special case to find mapping without probing the device */
pci_x86_read_config(pdev, PCI_BASE_ADDRESS_0, &bar, PCI_SIZE_32);
mmio_base = bar & PCI_BASE_ADDRESS_MEM_MASK;
regs = (struct fast_spi_regs *)mmio_base;
return fast_spi_get_bios_mmap_regs(regs, map_basep, map_sizep, offsetp);
}
int fast_spi_early_init(pci_dev_t pdev, ulong mmio_base)
{
/* Program Temporary BAR for SPI */
pci_x86_write_config(pdev, PCI_BASE_ADDRESS_0,
mmio_base | PCI_BASE_ADDRESS_SPACE_MEMORY,
PCI_SIZE_32);
/* Enable Bus Master and MMIO Space */
pci_x86_clrset_config(pdev, PCI_COMMAND, 0, PCI_COMMAND_MASTER |
PCI_COMMAND_MEMORY, PCI_SIZE_8);
/*
* Disable the BIOS write protect so write commands are allowed.
* Enable Prefetching and caching.
*/
pci_x86_clrset_config(pdev, SPIBAR_BIOS_CONTROL,
SPIBAR_BIOS_CONTROL_EISS |
SPIBAR_BIOS_CONTROL_CACHE_DISABLE,
SPIBAR_BIOS_CONTROL_WPD |
SPIBAR_BIOS_CONTROL_PREFETCH_ENABLE, PCI_SIZE_8);
return 0;
}