1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2015 Google, Inc
4 */
5
6#include <common.h>
7#include <errno.h>
8#include <asm/io.h>
9
10#define PCI_DEV_CONFIG(segbus, dev, fn) ( \
11		(((segbus) & 0xfff) << 20) | \
12		(((dev) & 0x1f) << 15) | \
13		(((fn)  & 0x07) << 12))
14
15/* Platform Controller Unit */
16#define LPC_DEV			0x1f
17#define LPC_FUNC		0
18
19/* Enable UART */
20#define UART_CONT		0x80
21
22/* SCORE Pad definitions */
23#define UART_RXD_PAD			82
24#define UART_TXD_PAD			83
25
26/* Pad base: PAD_CONF0[n]= PAD_BASE + 16 * n */
27#define GPSCORE_PAD_BASE	(IO_BASE_ADDRESS + IO_BASE_OFFSET_GPSCORE)
28
29/* IO Memory */
30#define IO_BASE_ADDRESS			0xfed0c000
31#define  IO_BASE_OFFSET_GPSCORE		0x0000
32#define  IO_BASE_OFFSET_GPNCORE		0x1000
33#define  IO_BASE_OFFSET_GPSSUS		0x2000
34#define IO_BASE_SIZE			0x4000
35
36static inline unsigned int score_pconf0(int pad_num)
37{
38	return GPSCORE_PAD_BASE + pad_num * 16;
39}
40
41static void score_select_func(int pad, int func)
42{
43	uint32_t reg;
44	uint32_t pconf0_addr = score_pconf0(pad);
45
46	reg = readl(pconf0_addr);
47	reg &= ~0x7;
48	reg |= func & 0x7;
49	writel(reg, pconf0_addr);
50}
51
52static void x86_pci_write_config32(int dev, unsigned int where, u32 value)
53{
54	unsigned long addr;
55
56	addr = CONFIG_PCIE_ECAM_BASE | dev | (where & ~3);
57	writel(value, addr);
58}
59
60/* This can be called after memory-mapped PCI is working */
61int setup_internal_uart(int enable)
62{
63	/* Enable or disable the legacy UART hardware */
64	x86_pci_write_config32(PCI_DEV_CONFIG(0, LPC_DEV, LPC_FUNC), UART_CONT,
65			       enable);
66
67	/* All done for the disable part, so just return */
68	if (!enable)
69		return 0;
70
71	/*
72	 * Set up the pads to the UART function. This allows the signals to
73	 * leave the chip
74	 */
75	score_select_func(UART_RXD_PAD, 1);
76	score_select_func(UART_TXD_PAD, 1);
77
78	/* TODO(sjg@chromium.org): Call debug_uart_init() */
79
80	return 0;
81}
82
83void board_debug_uart_init(void)
84{
85	setup_internal_uart(1);
86}
87