xref: /openbmc/u-boot/arch/x86/cpu/intel_common/lpc.c (revision ae485b54)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016 Google, Inc
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <fdtdec.h>
10 #include <pch.h>
11 #include <pci.h>
12 #include <asm/intel_regs.h>
13 #include <asm/io.h>
14 #include <asm/lpc_common.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 /* Enable Prefetching and Caching */
19 static void enable_spi_prefetch(struct udevice *pch)
20 {
21 	u8 reg8;
22 
23 	dm_pci_read_config8(pch, 0xdc, &reg8);
24 	reg8 &= ~(3 << 2);
25 	reg8 |= (2 << 2); /* Prefetching and Caching Enabled */
26 	dm_pci_write_config8(pch, 0xdc, reg8);
27 }
28 
29 static void enable_port80_on_lpc(struct udevice *pch)
30 {
31 	/* Enable port 80 POST on LPC */
32 	dm_pci_write_config32(pch, PCH_RCBA_BASE, RCB_BASE_ADDRESS | 1);
33 	clrbits_le32(RCB_REG(GCS), 4);
34 }
35 
36 /**
37  * lpc_early_init() - set up LPC serial ports and other early things
38  *
39  * @dev:	LPC device
40  * @return 0 if OK, -ve on error
41  */
42 int lpc_common_early_init(struct udevice *dev)
43 {
44 	struct udevice *pch = dev->parent;
45 	struct reg_info {
46 		u32 base;
47 		u32 size;
48 	} values[4], *ptr;
49 	int count;
50 	int i;
51 
52 	count = fdtdec_get_int_array_count(gd->fdt_blob, dev_of_offset(dev),
53 			"intel,gen-dec", (u32 *)values,
54 			sizeof(values) / sizeof(u32));
55 	if (count < 0)
56 		return -EINVAL;
57 
58 	/* Set COM1/COM2 decode range */
59 	dm_pci_write_config16(pch, LPC_IO_DEC, 0x0010);
60 
61 	/* Enable PS/2 Keyboard/Mouse, EC areas and COM1 */
62 	dm_pci_write_config16(pch, LPC_EN, KBC_LPC_EN | MC_LPC_EN |
63 			      GAMEL_LPC_EN | COMA_LPC_EN);
64 
65 	/* Write all registers but use 0 if we run out of data */
66 	count = count * sizeof(u32) / sizeof(values[0]);
67 	for (i = 0, ptr = values; i < ARRAY_SIZE(values); i++, ptr++) {
68 		u32 reg = 0;
69 
70 		if (i < count)
71 			reg = ptr->base | PCI_COMMAND_IO | (ptr->size << 16);
72 		dm_pci_write_config32(pch, LPC_GENX_DEC(i), reg);
73 	}
74 
75 	enable_spi_prefetch(pch);
76 
77 	/* This is already done in start.S, but let's do it in C */
78 	enable_port80_on_lpc(pch);
79 
80 	return 0;
81 }
82 
83 int lpc_set_spi_protect(struct udevice *dev, int bios_ctrl, bool protect)
84 {
85 	uint8_t bios_cntl;
86 
87 	/* Adjust the BIOS write protect and SMM BIOS Write Protect Disable */
88 	dm_pci_read_config8(dev, bios_ctrl, &bios_cntl);
89 	if (protect) {
90 		bios_cntl &= ~BIOS_CTRL_BIOSWE;
91 		bios_cntl |= BIT(5);
92 	} else {
93 		bios_cntl |= BIOS_CTRL_BIOSWE;
94 		bios_cntl &= ~BIT(5);
95 	}
96 	dm_pci_write_config8(dev, bios_ctrl, bios_cntl);
97 
98 	return 0;
99 }
100