summaryrefslogtreecommitdiff
path: root/src/soc/intel/skylake/bootblock/i2c.c
blob: 64b1fb57e799531988c7621b08cf527e2c64f695 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
/*
 * This file is part of the coreboot project.
 *
 * Copyright 2016 Google Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <arch/io.h>
#include <commonlib/helpers.h>
#include <device/device.h>
#include <device/i2c.h>
#include <device/pci_def.h>
#include <soc/intel/common/lpss_i2c.h>
#include <soc/iomap.h>
#include <soc/pci_devs.h>
#include <soc/bootblock.h>
#include <soc/serialio.h>
#include "chip.h"

uintptr_t lpss_i2c_base_address(unsigned bus)
{
	int devfn;
	pci_devfn_t dev;

	/* Find device+function for this controller */
	devfn = i2c_bus_to_devfn(bus);
	if (devfn < 0)
		return 0;

	/* Form a PCI address for this device */
	dev = PCI_DEV(0, PCI_SLOT(devfn), PCI_FUNC(devfn));

	/* Read the first base address for this device */
	return ALIGN_DOWN(pci_read_config32(dev, PCI_BASE_ADDRESS_0), 16);
}

static void i2c_early_init_bus(unsigned bus)
{
	ROMSTAGE_CONST struct soc_intel_skylake_config *config;
	ROMSTAGE_CONST struct device *tree_dev;
	const struct lpss_i2c_speed_config *sptr;
	enum i2c_speed speed;
	pci_devfn_t dev;
	int devfn;
	uintptr_t base;
	uint32_t value;
	void *reg;

	/* Find the PCI device for this bus controller */
	devfn = i2c_bus_to_devfn(bus);
	if (devfn < 0)
		return;

	/* Look up the controller device in the devicetree */
	dev = PCI_DEV(0, PCI_SLOT(devfn), PCI_FUNC(devfn));
	tree_dev = dev_find_slot(0, devfn);
	if (!tree_dev || !tree_dev->enabled)
		return;

	/* Skip if not enabled for early init */
	config = tree_dev->chip_info;
	if (!config)
		return;
	if (!config->i2c[bus].early_init)
		return;

	/* Prepare early base address for access before memory */
	base = EARLY_I2C_BASE(bus);
	pci_write_config32(dev, PCI_BASE_ADDRESS_0, base);
	pci_write_config32(dev, PCI_COMMAND,
			   PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);

	/* Take device out of reset */
	reg = (void *)(base + SIO_REG_PPR_RESETS);
	value = read32(reg);
	value |= SIO_REG_PPR_RESETS_FUNC | SIO_REG_PPR_RESETS_APB |
		SIO_REG_PPR_RESETS_IDMA;
	write32(reg, value);

	/* Initialize the controller */
	speed = config->i2c[bus].speed ? : I2C_SPEED_FAST;
	lpss_i2c_init(bus, speed);

	/* Apply custom speed config if it has been set by the board */
	for (value = 0; value < LPSS_I2C_SPEED_CONFIG_COUNT; value++) {
		sptr = &config->i2c[bus].speed_config[value];
		if (sptr->speed == speed) {
			lpss_i2c_set_speed_config(bus, sptr);
			break;
		}
	}
}

void i2c_early_init(void)
{
	int bus;

	/* Initialize I2C controllers that are enabled in devicetree */
	for (bus = 0; bus < SKYLAKE_I2C_DEV_MAX; bus++)
		i2c_early_init_bus(bus);
}