summaryrefslogtreecommitdiff
path: root/src/northbridge/via/vx800/early_smbus.c
blob: 3894d67c01d8f531c31c6c24791ebf91881873dc (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
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2009 One Laptop per Child, Association, 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <device/pci_ids.h>
#include "vx800.h"

#define SMBUS_IO_BASE		0x0500	//from award bios
#define PMIO_BASE		VX800_ACPI_IO_BASE	//might as well set this while we're here

#define SMBHSTSTAT		SMBUS_IO_BASE + 0x0
#define SMBSLVSTAT		SMBUS_IO_BASE + 0x1
#define SMBHSTCTL		SMBUS_IO_BASE + 0x2
#define SMBHSTCMD		SMBUS_IO_BASE + 0x3
#define SMBXMITADD		SMBUS_IO_BASE + 0x4
#define SMBHSTDAT0		SMBUS_IO_BASE + 0x5
#define SMBHSTDAT1		SMBUS_IO_BASE + 0x6
/* Rest of these aren't currently used... */
#define SMBBLKDAT		SMBUS_IO_BASE + 0x7
#define SMBSLVCTL		SMBUS_IO_BASE + 0x8
#define SMBTRNSADD		SMBUS_IO_BASE + 0x9
#define SMBSLVDATA 		SMBUS_IO_BASE + 0xa
#define SMLINK_PIN_CTL		SMBUS_IO_BASE + 0xe
#define SMBUS_PIN_CTL		SMBUS_IO_BASE + 0xf

/* Define register settings */
#define HOST_RESET	0xff
#define READ_CMD		0x01	// 1 in the 0 bit of SMBHSTADD states to READ

#define SMBUS_TIMEOUT		(100*1000*10)

#define I2C_TRANS_CMD		0x40
#define CLOCK_SLAVE_ADDRESS	0x69

#define SMBUS_DELAY()		outb(0x80, 0x80)

#if CONFIG_DEBUG_SMBUS
#define PRINT_DEBUG(x)		print_debug(x)
#define PRINT_DEBUG_HEX16(x)	print_debug_hex16(x)
#else
#define PRINT_DEBUG(x)
#define PRINT_DEBUG_HEX16(x)
#endif

/* Internal functions */
static void smbus_print_error(unsigned char host_status_register, int loops)
{
//              print_err("some i2c error\n");
	/* Check if there actually was an error */
	if (host_status_register == 0x00 || host_status_register == 0x40 ||
	    host_status_register == 0x42)
		return;
	print_err("smbus_error: ");
	print_err_hex8(host_status_register);
	print_err("\n");
	if (loops >= SMBUS_TIMEOUT) {
		print_err("SMBus Timout\n");
	}
	if (host_status_register & (1 << 4)) {
		print_err("Interrup/SMI# was Failed Bus Transaction\n");
	}
	if (host_status_register & (1 << 3)) {
		print_err("Bus Error\n");
	}
	if (host_status_register & (1 << 2)) {
		print_err("Device Error\n");
	}
	if (host_status_register & (1 << 1)) {
		/* This isn't a real error... */
		print_debug("Interrupt/SMI# was Successful Completion\n");
	}
	if (host_status_register & (1 << 0)) {
		print_err("Host Busy\n");
	}
}

static void smbus_wait_until_ready(void)
{
	int loops;

	loops = 0;
	/* Yes, this is a mess, but it's the easiest way to do it */
	while (((inb(SMBHSTSTAT) & 1) == 1) && (loops <= SMBUS_TIMEOUT)) {
		SMBUS_DELAY();
		++loops;
	}
	smbus_print_error(inb(SMBHSTSTAT), loops);
}

static void smbus_reset(void)
{
	outb(HOST_RESET, SMBHSTSTAT);
}

/* Public functions */

static unsigned int get_spd_data(unsigned int dimm, unsigned int offset)
{
	unsigned int val;

	smbus_reset();
	/* clear host data port */
	outb(0x00, SMBHSTDAT0);
	SMBUS_DELAY();
	smbus_wait_until_ready();

	/* Do some mathmatic magic */
	dimm = (DIMM0 + dimm) << 1;

	outb(dimm | 0x1, SMBXMITADD);
	outb(offset, SMBHSTCMD);
	outb(0x48, SMBHSTCTL);

	SMBUS_DELAY();

	smbus_wait_until_ready();

	val = inb(SMBHSTDAT0);
	smbus_reset();
	return val;
}

void enable_smbus(void)
{
	device_t dev;

	dev = pci_locate_device(PCI_ID(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855_LPC), 0);

	if (dev == PCI_DEV_INVALID) {
		/* This won't display text if enable_smbus() is before serial init */
		die("Power Managment Controller not found\n");
	}

	/* Set clock source */
	pci_write_config8(dev, 0x94, 0x20);

	/* Write SMBus IO base to 0xd0, and enable SMBus */
	pci_write_config16(dev, 0xd0, SMBUS_IO_BASE | 1);

	/* Set to Award value */
	pci_write_config8(dev, 0xd2, 0x05);

	/* Make it work for I/O ... */
	pci_write_config16(dev, 0x04, 0x0003);

	smbus_reset();
	/* clear host data port */
	outb(0x00, SMBHSTDAT0);
	SMBUS_DELAY();
	smbus_wait_until_ready();
}

/**
 * A fixup for some systems that need time for the SMBus to "warm up". This is
 * needed on some VT823x based systems, where the SMBus spurts out bad data for
 * a short time after power on. This has been seen on the VIA Epia series and
 * Jetway J7F2-series. It reads the ID byte from SMBus, looking for
 * known-good data from a slot/address. Exits on either good data or a timeout.
 *
 * TODO: This should probably go into some global file, but one would need to
 *       be created just for it. If some other chip needs/wants it, we can
 *       worry about it then.
 *
 * @param mem_ctrl The memory controller and SMBus addresses.
 */
void smbus_fixup(const struct mem_controller *mem_ctrl)
{
	int i, ram_slots, current_slot = 0;
	u8 result = 0;

	ram_slots = ARRAY_SIZE(mem_ctrl->channel0);
	if (!ram_slots) {
		print_err("smbus_fixup() thinks there are no RAM slots!\n");
		return;
	}

	PRINT_DEBUG("Waiting for SMBus to warm up");

	/*
	 * Bad SPD data should be either 0 or 0xff, but YMMV. So we look for
	 * the ID bytes of SDRAM, DDR, DDR2, and DDR3 (and anything in between).
	 * VT8237R has only been seen on DDR and DDR2 based systems, so far.
	 */
	for (i = 0; (i < SMBUS_TIMEOUT && ((result < SPD_MEMORY_TYPE_SDRAM) ||
					   (result >
					    SPD_MEMORY_TYPE_SDRAM_DDR3)));
	     i++) {

		if (current_slot > ram_slots)
			current_slot = 0;

		result = get_spd_data(mem_ctrl->channel0[current_slot],
				      SPD_MEMORY_TYPE);
		current_slot++;
		PRINT_DEBUG(".");
	}

	if (i >= SMBUS_TIMEOUT)
		print_err("SMBus timed out while warming up\n");
	else
		PRINT_DEBUG("Done\n");
}

/* Debugging Function */
#if CONFIG_DEBUG_SMBUS
static void dump_spd_data(void)
{
	int dimm, offset, regs;
	unsigned int val;

	for (dimm = 0; dimm < 8; dimm++) {
		print_debug("SPD Data for DIMM ");
		print_debug_hex8(dimm);
		print_debug("\n");

		val = get_spd_data(dimm, 0);
		if (val == 0xff) {
			regs = 256;
		} else if (val == 0x80) {
			regs = 128;
		} else {
			print_debug("No DIMM present\n");
			regs = 0;
		}
		for (offset = 0; offset < regs; offset++) {
			print_debug("  Offset ");
			print_debug_hex8(offset);
			print_debug(" = 0x");
			print_debug_hex8(get_spd_data(dimm, offset));
			print_debug("\n");
		}
	}
}
#else
#define dump_spd_data()
#endif