xref: /OK3568_Linux_fs/u-boot/arch/x86/cpu/baytrail/early_uart.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (C) 2015 Google, Inc
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <errno.h>
9*4882a593Smuzhiyun #include <asm/io.h>
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #define PCI_DEV_CONFIG(segbus, dev, fn) ( \
12*4882a593Smuzhiyun 		(((segbus) & 0xfff) << 20) | \
13*4882a593Smuzhiyun 		(((dev) & 0x1f) << 15) | \
14*4882a593Smuzhiyun 		(((fn)  & 0x07) << 12))
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun /* Platform Controller Unit */
17*4882a593Smuzhiyun #define LPC_DEV			0x1f
18*4882a593Smuzhiyun #define LPC_FUNC		0
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun /* Enable UART */
21*4882a593Smuzhiyun #define UART_CONT		0x80
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun /* SCORE Pad definitions */
24*4882a593Smuzhiyun #define UART_RXD_PAD			82
25*4882a593Smuzhiyun #define UART_TXD_PAD			83
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun /* Pad base: PAD_CONF0[n]= PAD_BASE + 16 * n */
28*4882a593Smuzhiyun #define GPSCORE_PAD_BASE	(IO_BASE_ADDRESS + IO_BASE_OFFSET_GPSCORE)
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun /* IO Memory */
31*4882a593Smuzhiyun #define IO_BASE_ADDRESS			0xfed0c000
32*4882a593Smuzhiyun #define  IO_BASE_OFFSET_GPSCORE		0x0000
33*4882a593Smuzhiyun #define  IO_BASE_OFFSET_GPNCORE		0x1000
34*4882a593Smuzhiyun #define  IO_BASE_OFFSET_GPSSUS		0x2000
35*4882a593Smuzhiyun #define IO_BASE_SIZE			0x4000
36*4882a593Smuzhiyun 
score_pconf0(int pad_num)37*4882a593Smuzhiyun static inline unsigned int score_pconf0(int pad_num)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun 	return GPSCORE_PAD_BASE + pad_num * 16;
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun 
score_select_func(int pad,int func)42*4882a593Smuzhiyun static void score_select_func(int pad, int func)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun 	uint32_t reg;
45*4882a593Smuzhiyun 	uint32_t pconf0_addr = score_pconf0(pad);
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun 	reg = readl(pconf0_addr);
48*4882a593Smuzhiyun 	reg &= ~0x7;
49*4882a593Smuzhiyun 	reg |= func & 0x7;
50*4882a593Smuzhiyun 	writel(reg, pconf0_addr);
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun 
x86_pci_write_config32(int dev,unsigned int where,u32 value)53*4882a593Smuzhiyun static void x86_pci_write_config32(int dev, unsigned int where, u32 value)
54*4882a593Smuzhiyun {
55*4882a593Smuzhiyun 	unsigned long addr;
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun 	addr = CONFIG_PCIE_ECAM_BASE | dev | (where & ~3);
58*4882a593Smuzhiyun 	writel(value, addr);
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun 
61*4882a593Smuzhiyun /* This can be called after memory-mapped PCI is working */
setup_internal_uart(int enable)62*4882a593Smuzhiyun int setup_internal_uart(int enable)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun 	/* Enable or disable the legacy UART hardware */
65*4882a593Smuzhiyun 	x86_pci_write_config32(PCI_DEV_CONFIG(0, LPC_DEV, LPC_FUNC), UART_CONT,
66*4882a593Smuzhiyun 			       enable);
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun 	/* All done for the disable part, so just return */
69*4882a593Smuzhiyun 	if (!enable)
70*4882a593Smuzhiyun 		return 0;
71*4882a593Smuzhiyun 
72*4882a593Smuzhiyun 	/*
73*4882a593Smuzhiyun 	 * Set up the pads to the UART function. This allows the signals to
74*4882a593Smuzhiyun 	 * leave the chip
75*4882a593Smuzhiyun 	 */
76*4882a593Smuzhiyun 	score_select_func(UART_RXD_PAD, 1);
77*4882a593Smuzhiyun 	score_select_func(UART_TXD_PAD, 1);
78*4882a593Smuzhiyun 
79*4882a593Smuzhiyun 	/* TODO(sjg@chromium.org): Call debug_uart_init() */
80*4882a593Smuzhiyun 
81*4882a593Smuzhiyun 	return 0;
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun 
board_debug_uart_init(void)84*4882a593Smuzhiyun void board_debug_uart_init(void)
85*4882a593Smuzhiyun {
86*4882a593Smuzhiyun 	setup_internal_uart(1);
87*4882a593Smuzhiyun }
88