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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 Google LLC
*
* From coreboot Apollo Lake support lpc.c
*/
#include <common.h>
#include <dm.h>
#include <spl.h>
#include <asm/lpc_common.h>
#include <asm/pci.h>
#include <asm/arch/iomap.h>
#include <asm/arch/lpc.h>
#include <linux/log2.h>
void lpc_enable_fixed_io_ranges(uint io_enables)
{
pci_x86_clrset_config(PCH_DEV_LPC, LPC_IO_ENABLES, 0, io_enables,
PCI_SIZE_16);
}
/*
* Find the first unused IO window.
* Returns -1 if not found, 0 for reg 0x84, 1 for reg 0x88 ...
*/
static int find_unused_pmio_window(void)
{
int i;
ulong lgir;
for (i = 0; i < LPC_NUM_GENERIC_IO_RANGES; i++) {
pci_x86_read_config(PCH_DEV_LPC, LPC_GENERIC_IO_RANGE(i),
&lgir, PCI_SIZE_32);
if (!(lgir & LPC_LGIR_EN))
return i;
}
return -1;
}
int lpc_open_pmio_window(uint base, uint size)
{
int i, lgir_reg_num;
u32 lgir_reg_offset, lgir, window_size, alignment;
ulong bridged_size, bridge_base;
ulong reg;
log_debug("LPC: Trying to open IO window from %x size %x\n", base,
size);
bridged_size = 0;
bridge_base = base;
while (bridged_size < size) {
/* Each IO range register can only open a 256-byte window */
window_size = min(size, (uint)LPC_LGIR_MAX_WINDOW_SIZE);
/* Window size must be a power of two for the AMASK to work */
alignment = 1UL << (order_base_2(window_size));
window_size = ALIGN(window_size, alignment);
/* Address[15:2] in LGIR[15:12] and Mask[7:2] in LGIR[23:18] */
lgir = (bridge_base & LPC_LGIR_ADDR_MASK) | LPC_LGIR_EN;
lgir |= ((window_size - 1) << 16) & LPC_LGIR_AMASK_MASK;
/* Skip programming if same range already programmed */
for (i = 0; i < LPC_NUM_GENERIC_IO_RANGES; i++) {
pci_x86_read_config(PCH_DEV_LPC,
LPC_GENERIC_IO_RANGE(i), ®,
PCI_SIZE_32);
if (lgir == reg)
return -EALREADY;
}
lgir_reg_num = find_unused_pmio_window();
if (lgir_reg_num < 0) {
log_err("LPC: Cannot open IO window: %lx size %lx\n",
bridge_base, size - bridged_size);
log_err("No more IO windows\n");
return -ENOSPC;
}
lgir_reg_offset = LPC_GENERIC_IO_RANGE(lgir_reg_num);
pci_x86_write_config(PCH_DEV_LPC, lgir_reg_offset, lgir,
PCI_SIZE_32);
log_debug("LPC: Opened IO window LGIR%d: base %lx size %x\n",
lgir_reg_num, bridge_base, window_size);
bridged_size += window_size;
bridge_base += window_size;
}
return 0;
}
void lpc_io_setup_comm_a_b(void)
{
/* ComA Range 3F8h-3FFh [2:0] */
u16 com_ranges = LPC_IOD_COMA_RANGE;
u16 com_enable = LPC_IOE_COMA_EN;
/* Setup I/O Decode Range Register for LPC */
pci_write_config16(PCH_DEV_LPC, LPC_IO_DECODE, com_ranges);
/* Enable ComA and ComB Port */
lpc_enable_fixed_io_ranges(com_enable);
}
static const struct udevice_id apl_lpc_ids[] = {
{ .compatible = "intel,apl-lpc" },
{ }
};
/* All pads are LPC already configured by the hostbridge, so no probing here */
U_BOOT_DRIVER(apl_lpc_drv) = {
.name = "intel_apl_lpc",
.id = UCLASS_LPC,
.of_match = apl_lpc_ids,
};
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