summaryrefslogtreecommitdiffstats
path: root/sb600spi.c
blob: c853f420e6dfcabed242f094b2110233f7b5a625 (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
/*
 * This file is part of the flashrom project.
 *
 * Copyright (C) 2008 Wang Qingpei <Qingpei.Wang@amd.com>
 * Copyright (C) 2008 Joe Bao <Zheng.Bao@amd.com>
 * Copyright (C) 2008 Advanced Micro Devices, 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 <string.h>
#include "flash.h"
#include "spi.h"

/* This struct is unused, but helps visualize the SB600 SPI BAR layout.
 *struct sb600_spi_controller {
 *	unsigned int spi_cntrl0;	/ * 00h * /
 *	unsigned int restrictedcmd1;	/ * 04h * /
 *	unsigned int restrictedcmd2;	/ * 08h * /
 *	unsigned int spi_cntrl1;	/ * 0ch * /
 *	unsigned int spi_cmdvalue0;	/ * 10h * /
 *	unsigned int spi_cmdvalue1;	/ * 14h * /
 *	unsigned int spi_cmdvalue2;	/ * 18h * /
 *	unsigned int spi_fakeid;	/ * 1Ch * /
 *};
 */

uint8_t *sb600_spibar = NULL;

int sb600_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len)
{
	/* Maximum read length is 8 bytes. */
	return spi_read_chunked(flash, buf, start, len, 8);
}

/* FIXME: SB600 can write 5 bytes per transaction. */
int sb600_spi_write_1(struct flashchip *flash, uint8_t *buf)
{
	int rc = 0, i;
	int total_size = flash->total_size * 1024;
	int result;

	spi_disable_blockprotect();
	/* Erase first */
	printf("Erasing flash before programming... ");
	if (flash->erase(flash)) {
		fprintf(stderr, "ERASE FAILED!\n");
		return -1;
	}
	printf("done.\n");

	printf("Programming flash");
	for (i = 0; i < total_size; i++, buf++) {
		result = spi_byte_program(i, *buf);
		/* wait program complete. */
		if (i % 0x8000 == 0)
			printf(".");
		while (spi_read_status_register() & JEDEC_RDSR_BIT_WIP)
			;
	}
	printf(" done.\n");
	return rc;
}

static void reset_internal_fifo_pointer(void)
{
	mmio_writeb(mmio_readb(sb600_spibar + 2) | 0x10, sb600_spibar + 2);

	while (mmio_readb(sb600_spibar + 0xD) & 0x7)
		printf("reset\n");
}

static void execute_command(void)
{
	mmio_writeb(mmio_readb(sb600_spibar + 2) | 1, sb600_spibar + 2);

	while (mmio_readb(sb600_spibar + 2) & 1)
		;
}

int sb600_spi_send_command(unsigned int writecnt, unsigned int readcnt,
		      const unsigned char *writearr, unsigned char *readarr)
{
	int count;
	/* First byte is cmd which can not being sent through FIFO. */
	unsigned char cmd = *writearr++;
	unsigned int readoffby1;

	writecnt--;

	printf_debug("%s, cmd=%x, writecnt=%x, readcnt=%x\n",
		     __func__, cmd, writecnt, readcnt);

	if (readcnt > 8) {
		printf("%s, SB600 SPI controller can not receive %d bytes, "
		       "it is limited to 8 bytes\n", __func__, readcnt);
		return SPI_INVALID_LENGTH;
	}

	if (writecnt > 8) {
		printf("%s, SB600 SPI controller can not send %d bytes, "
		       "it is limited to 8 bytes\n", __func__, writecnt);
		return SPI_INVALID_LENGTH;
	}

	/* This is a workaround for a bug in SB600 and SB700. If we only send
	 * an opcode and no additional data/address, the SPI controller will
	 * read one byte too few from the chip. Basically, the last byte of
	 * the chip response is discarded and will not end up in the FIFO.
	 * It is unclear if the CS# line is set high too early as well.
	 */
	readoffby1 = (writecnt) ? 0 : 1;
	mmio_writeb((readcnt + readoffby1) << 4 | (writecnt), sb600_spibar + 1);
	mmio_writeb(cmd, sb600_spibar + 0);

	/* Before we use the FIFO, reset it first. */
	reset_internal_fifo_pointer();

	/* Send the write byte to FIFO. */
	for (count = 0; count < writecnt; count++, writearr++) {
		printf_debug(" [%x]", *writearr);
		mmio_writeb(*writearr, sb600_spibar + 0xC);
	}
	printf_debug("\n");

	/*
	 * We should send the data by sequence, which means we need to reset
	 * the FIFO pointer to the first byte we want to send.
	 */
	reset_internal_fifo_pointer();

	execute_command();

	/*
	 * After the command executed, we should find out the index of the
	 * received byte. Here we just reset the FIFO pointer and skip the
	 * writecnt.
	 * It would be possible to increase the FIFO pointer by one instead
	 * of reading and discarding one byte from the FIFO.
	 * The FIFO is implemented on top of an 8 byte ring buffer and the
	 * buffer is never cleared. For every byte that is shifted out after
	 * the opcode, the FIFO already stores the response from the chip.
	 * Usually, the chip will respond with 0x00 or 0xff.
	 */
	reset_internal_fifo_pointer();

	/* Skip the bytes we sent. */
	for (count = 0; count < writecnt; count++) {
		cmd = mmio_readb(sb600_spibar + 0xC);
		printf_debug("[ %2x]", cmd);
	}

	printf_debug("The FIFO pointer after skipping is %d.\n",
		     mmio_readb(sb600_spibar + 0xd) & 0x07);
	for (count = 0; count < readcnt; count++, readarr++) {
		*readarr = mmio_readb(sb600_spibar + 0xC);
		printf_debug("[%02x]", *readarr);
	}
	printf_debug("\n");

	return 0;
}
OpenPOWER on IntegriCloud