2 * This file is part of the flashrom project.
4 * Copyright (C) 2009, 2010 Carl-Daniel Hailfinger
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "programmer.h"
28 /* Note that CS# is active low, so val=0 means the chip is active. */
29 static void bitbang_spi_set_cs(const const struct bitbang_spi_master *master, int val)
34 static void bitbang_spi_set_sck(const const struct bitbang_spi_master *master, int val)
39 static void bitbang_spi_set_mosi(const const struct bitbang_spi_master *master, int val)
41 master->set_mosi(val);
44 static int bitbang_spi_get_miso(const const struct bitbang_spi_master *master)
46 return master->get_miso();
49 static void bitbang_spi_request_bus(const const struct bitbang_spi_master *master)
51 if (master->request_bus)
52 master->request_bus();
55 static void bitbang_spi_release_bus(const const struct bitbang_spi_master *master)
57 if (master->release_bus)
58 master->release_bus();
61 static int bitbang_spi_send_command(struct flashctx *flash,
62 unsigned int writecnt, unsigned int readcnt,
63 const unsigned char *writearr,
64 unsigned char *readarr);
66 static const struct spi_programmer spi_programmer_bitbang = {
67 .type = SPI_CONTROLLER_BITBANG,
68 .max_data_read = MAX_DATA_READ_UNLIMITED,
69 .max_data_write = MAX_DATA_WRITE_UNLIMITED,
70 .command = bitbang_spi_send_command,
71 .multicommand = default_spi_send_multicommand,
72 .read = default_spi_read,
73 .write_256 = default_spi_write_256,
74 .write_aai = default_spi_write_aai,
77 #if 0 // until it is needed
78 static int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
80 /* FIXME: Run bitbang_spi_release_bus here or per command? */
85 int bitbang_spi_init(const struct bitbang_spi_master *master)
87 struct spi_programmer pgm = spi_programmer_bitbang;
88 /* BITBANG_SPI_INVALID is 0, so if someone forgot to initialize ->type,
89 * we catch it here. Same goes for missing initialization of bitbanging
92 if (!master || master->type == BITBANG_SPI_INVALID || !master->set_cs ||
93 !master->set_sck || !master->set_mosi || !master->get_miso ||
94 (master->request_bus && !master->release_bus) ||
95 (!master->request_bus && master->release_bus)) {
96 msg_perr("Incomplete SPI bitbang master setting!\n"
97 "Please report a bug at flashrom@flashrom.org\n");
98 return ERROR_FLASHROM_BUG;
102 register_spi_programmer(&pgm);
104 /* Only mess with the bus if we're sure nobody else uses it. */
105 bitbang_spi_request_bus(master);
106 bitbang_spi_set_cs(master, 1);
107 bitbang_spi_set_sck(master, 0);
108 bitbang_spi_set_mosi(master, 0);
109 /* FIXME: Release SPI bus here and request it again for each command or
110 * don't release it now and only release it on programmer shutdown?
112 bitbang_spi_release_bus(master);
116 static uint8_t bitbang_spi_rw_byte(const struct bitbang_spi_master *master,
122 for (i = 7; i >= 0; i--) {
123 bitbang_spi_set_mosi(master, (val >> i) & 1);
124 programmer_delay(master->half_period);
125 bitbang_spi_set_sck(master, 1);
127 ret |= bitbang_spi_get_miso(master);
128 programmer_delay(master->half_period);
129 bitbang_spi_set_sck(master, 0);
134 static int bitbang_spi_send_command(struct flashctx *flash,
135 unsigned int writecnt, unsigned int readcnt,
136 const unsigned char *writearr,
137 unsigned char *readarr)
140 const struct bitbang_spi_master *master = flash->pgm->spi.data;
142 /* FIXME: Run bitbang_spi_request_bus here or in programmer init?
143 * Requesting and releasing the SPI bus is handled in here to allow the
144 * programmer to use its own SPI engine for native accesses.
146 bitbang_spi_request_bus(master);
147 bitbang_spi_set_cs(master, 0);
148 for (i = 0; i < writecnt; i++)
149 bitbang_spi_rw_byte(master, writearr[i]);
150 for (i = 0; i < readcnt; i++)
151 readarr[i] = bitbang_spi_rw_byte(master, 0);
153 programmer_delay(master->half_period);
154 bitbang_spi_set_cs(master, 1);
155 programmer_delay(master->half_period);
156 /* FIXME: Run bitbang_spi_release_bus here or in programmer init? */
157 bitbang_spi_release_bus(master);