xref: /openbmc/u-boot/arch/x86/cpu/intel_common/lpc.c (revision 77f29293)
1 /*
2  * Copyright (c) 2016 Google, Inc
3  *
4  * SPDX-License-Identifier:	GPL-2.0
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <fdtdec.h>
11 #include <pch.h>
12 #include <pci.h>
13 #include <asm/intel_regs.h>
14 #include <asm/io.h>
15 #include <asm/lpc_common.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 /* Enable Prefetching and Caching */
20 static void enable_spi_prefetch(struct udevice *pch)
21 {
22 	u8 reg8;
23 
24 	dm_pci_read_config8(pch, 0xdc, &reg8);
25 	reg8 &= ~(3 << 2);
26 	reg8 |= (2 << 2); /* Prefetching and Caching Enabled */
27 	dm_pci_write_config8(pch, 0xdc, reg8);
28 }
29 
30 static void enable_port80_on_lpc(struct udevice *pch)
31 {
32 	/* Enable port 80 POST on LPC */
33 	dm_pci_write_config32(pch, PCH_RCBA_BASE, RCB_BASE_ADDRESS | 1);
34 	clrbits_le32(RCB_REG(GCS), 4);
35 }
36 
37 /**
38  * lpc_early_init() - set up LPC serial ports and other early things
39  *
40  * @dev:	LPC device
41  * @return 0 if OK, -ve on error
42  */
43 int lpc_common_early_init(struct udevice *dev)
44 {
45 	struct udevice *pch = dev->parent;
46 	struct reg_info {
47 		u32 base;
48 		u32 size;
49 	} values[4], *ptr;
50 	int count;
51 	int i;
52 
53 	count = fdtdec_get_int_array_count(gd->fdt_blob, dev_of_offset(dev),
54 			"intel,gen-dec", (u32 *)values,
55 			sizeof(values) / sizeof(u32));
56 	if (count < 0)
57 		return -EINVAL;
58 
59 	/* Set COM1/COM2 decode range */
60 	dm_pci_write_config16(pch, LPC_IO_DEC, 0x0010);
61 
62 	/* Enable PS/2 Keyboard/Mouse, EC areas and COM1 */
63 	dm_pci_write_config16(pch, LPC_EN, KBC_LPC_EN | MC_LPC_EN |
64 			      GAMEL_LPC_EN | COMA_LPC_EN);
65 
66 	/* Write all registers but use 0 if we run out of data */
67 	count = count * sizeof(u32) / sizeof(values[0]);
68 	for (i = 0, ptr = values; i < ARRAY_SIZE(values); i++, ptr++) {
69 		u32 reg = 0;
70 
71 		if (i < count)
72 			reg = ptr->base | PCI_COMMAND_IO | (ptr->size << 16);
73 		dm_pci_write_config32(pch, LPC_GENX_DEC(i), reg);
74 	}
75 
76 	enable_spi_prefetch(pch);
77 
78 	/* This is already done in start.S, but let's do it in C */
79 	enable_port80_on_lpc(pch);
80 
81 	return 0;
82 }
83 
84 int lpc_set_spi_protect(struct udevice *dev, int bios_ctrl, bool protect)
85 {
86 	uint8_t bios_cntl;
87 
88 	/* Adjust the BIOS write protect and SMM BIOS Write Protect Disable */
89 	dm_pci_read_config8(dev, bios_ctrl, &bios_cntl);
90 	if (protect) {
91 		bios_cntl &= ~BIOS_CTRL_BIOSWE;
92 		bios_cntl |= BIT(5);
93 	} else {
94 		bios_cntl |= BIOS_CTRL_BIOSWE;
95 		bios_cntl &= ~BIT(5);
96 	}
97 	dm_pci_write_config8(dev, bios_ctrl, bios_cntl);
98 
99 	return 0;
100 }
101