1 /*
2 * This file is part of the flashrom project.
3 *
4 * Copyright (C) 2011 Sven Schnelle <[email protected]>
5 *
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.
9 *
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.
14 */
15
16 #include <stdio.h>
17 #include <string.h>
18 #include <stdlib.h>
19 #include <stdint.h>
20 #include <inttypes.h>
21 #include <fcntl.h>
22 #include <errno.h>
23 #include <ctype.h>
24 #include <unistd.h>
25 #include <sys/ioctl.h>
26 #include <linux/types.h>
27 #include "flash.h"
28 #include "chipdrivers.h"
29 #include "programmer.h"
30 #include "spi.h"
31 /*
32 * Linux versions prior to v4.14-rc7 may need linux/ioctl.h included here due
33 * to missing from linux/spi/spidev.h. This was fixed in the following commit:
34 * a2b4a79b88b2 spi: uapi: spidev: add missing ioctl header
35 */
36 #include <linux/ioctl.h>
37 #include <linux/spi/spidev.h>
38
39 /* Devices known to work with this module (FIXME: export as struct dev_entry):
40 * Beagle Bone Black
41 * Raspberry Pi
42 * HummingBoard
43 */
44
45 #define BUF_SIZE_FROM_SYSFS "/sys/module/spidev/parameters/bufsiz"
46
47 struct linux_spi_data {
48 int fd;
49 size_t max_kernel_buf_size;
50 };
51
linux_spi_read(struct flashctx * flash,uint8_t * buf,unsigned int start,unsigned int len)52 static int linux_spi_read(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len)
53 {
54 struct linux_spi_data *spi_data = flash->mst->spi.data;
55 /* Older kernels use a single buffer for combined input and output
56 data. So account for longest possible command + address, too. */
57 return spi_read_chunked(flash, buf, start, len, spi_data->max_kernel_buf_size - 5);
58 }
59
linux_spi_write_256(struct flashctx * flash,const uint8_t * buf,unsigned int start,unsigned int len)60 static int linux_spi_write_256(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len)
61 {
62 struct linux_spi_data *spi_data = flash->mst->spi.data;
63 /* 5 bytes must be reserved for longest possible command + address. */
64 return spi_write_chunked(flash, buf, start, len, spi_data->max_kernel_buf_size - 5);
65 }
66
linux_spi_shutdown(void * data)67 static int linux_spi_shutdown(void *data)
68 {
69 struct linux_spi_data *spi_data = data;
70 close(spi_data->fd);
71 free(spi_data);
72 return 0;
73 }
74
linux_spi_send_command(const struct flashctx * flash,unsigned int writecnt,unsigned int readcnt,const unsigned char * txbuf,unsigned char * rxbuf)75 static int linux_spi_send_command(const struct flashctx *flash, unsigned int writecnt,
76 unsigned int readcnt,
77 const unsigned char *txbuf,
78 unsigned char *rxbuf)
79 {
80 struct linux_spi_data *spi_data = flash->mst->spi.data;
81 int iocontrol_code;
82 struct spi_ioc_transfer msg[2] = {
83 {
84 .tx_buf = (uint64_t)(uintptr_t)txbuf,
85 .len = writecnt,
86 },
87 {
88 .rx_buf = (uint64_t)(uintptr_t)rxbuf,
89 .len = readcnt,
90 },
91 };
92
93 if (spi_data->fd == -1)
94 return -1;
95 /* The implementation currently does not support requests that
96 don't start with sending a command. */
97 if (writecnt == 0)
98 return SPI_INVALID_LENGTH;
99
100 /* Just submit the first (write) request in case there is nothing
101 to read. Otherwise submit both requests. */
102 if (readcnt == 0)
103 iocontrol_code = SPI_IOC_MESSAGE(1);
104 else
105 iocontrol_code = SPI_IOC_MESSAGE(2);
106
107 if (ioctl(spi_data->fd, iocontrol_code, msg) == -1) {
108 msg_cerr("%s: ioctl: %s\n", __func__, strerror(errno));
109 return -1;
110 }
111 return 0;
112 }
113
114 static const struct spi_master spi_master_linux = {
115 .features = SPI_MASTER_4BA,
116 .max_data_read = MAX_DATA_UNSPECIFIED, /* TODO? */
117 .max_data_write = MAX_DATA_UNSPECIFIED, /* TODO? */
118 .command = linux_spi_send_command,
119 .read = linux_spi_read,
120 .write_256 = linux_spi_write_256,
121 .shutdown = linux_spi_shutdown,
122 };
123
124 /* Read max buffer size from sysfs, or use page size as fallback. */
get_max_kernel_buf_size()125 static size_t get_max_kernel_buf_size()
126 {
127 size_t result = 0;
128 FILE *fp;
129 fp = fopen(BUF_SIZE_FROM_SYSFS, "r");
130 if (!fp) {
131 msg_pwarn("Cannot open %s: %s.\n", BUF_SIZE_FROM_SYSFS, strerror(errno));
132 goto out;
133 }
134
135 char buf[10];
136 if (!fgets(buf, sizeof(buf), fp)) {
137 if (feof(fp))
138 msg_pwarn("Cannot read %s: file is empty.\n", BUF_SIZE_FROM_SYSFS);
139 else
140 msg_pwarn("Cannot read %s: %s.\n", BUF_SIZE_FROM_SYSFS, strerror(errno));
141 goto out;
142 }
143
144 long int tmp;
145 errno = 0;
146 tmp = strtol(buf, NULL, 0);
147 if ((tmp < 0) || errno) {
148 msg_pwarn("Buffer size %ld from %s seems wrong.\n", tmp, BUF_SIZE_FROM_SYSFS);
149 } else {
150 msg_pdbg("%s: Using value from %s as max buffer size.\n", __func__, BUF_SIZE_FROM_SYSFS);
151 result = (size_t)tmp;
152 }
153
154 out:
155 if (fp)
156 fclose(fp);
157
158 if (!result) {
159 msg_pdbg("%s: Using page size as max buffer size.\n", __func__);
160 result = (size_t)getpagesize();
161 }
162 return result;
163 }
164
linux_spi_init(const struct programmer_cfg * cfg)165 static int linux_spi_init(const struct programmer_cfg *cfg)
166 {
167 char *param_str, *endp;
168 uint32_t speed_hz = 2 * 1000 * 1000;
169 /* FIXME: make the following configurable by CLI options. */
170 /* SPI mode 0 (beware this also includes: MSB first, CS active low and others */
171 const uint8_t mode = SPI_MODE_0;
172 const uint8_t bits = 8;
173 int fd;
174 size_t max_kernel_buf_size;
175 struct linux_spi_data *spi_data;
176
177 param_str = extract_programmer_param_str(cfg, "spispeed");
178 if (param_str && strlen(param_str)) {
179 speed_hz = (uint32_t)strtoul(param_str, &endp, 10) * 1000;
180 if (param_str == endp || speed_hz == 0) {
181 msg_perr("%s: invalid clock: %s kHz\n", __func__, param_str);
182 free(param_str);
183 return 1;
184 }
185 } else {
186 msg_pinfo("Using default %"PRIu32
187 "kHz clock. Use 'spispeed' parameter to override.\n",
188 speed_hz / 1000);
189 }
190 free(param_str);
191
192 param_str = extract_programmer_param_str(cfg, "dev");
193 if (!param_str || !strlen(param_str)) {
194 msg_perr("No SPI device given. Use flashrom -p "
195 "linux_spi:dev=/dev/spidevX.Y\n");
196 free(param_str);
197 return 1;
198 }
199
200 msg_pdbg("Using device %s\n", param_str);
201 if ((fd = open(param_str, O_RDWR)) == -1) {
202 msg_perr("%s: failed to open %s: %s\n", __func__,
203 param_str, strerror(errno));
204 free(param_str);
205 return 1;
206 }
207 free(param_str);
208
209 if (ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed_hz) == -1) {
210 msg_perr("%s: failed to set speed to %"PRIu32"Hz: %s\n",
211 __func__, speed_hz, strerror(errno));
212 goto init_err;
213 }
214 msg_pdbg("Using %"PRIu32"kHz clock\n", speed_hz / 1000);
215
216 if (ioctl(fd, SPI_IOC_WR_MODE, &mode) == -1) {
217 msg_perr("%s: failed to set SPI mode to 0x%02x: %s\n",
218 __func__, mode, strerror(errno));
219 goto init_err;
220 }
221
222 if (ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits) == -1) {
223 msg_perr("%s: failed to set the number of bits per SPI word to %u: %s\n",
224 __func__, bits == 0 ? 8 : bits, strerror(errno));
225 goto init_err;
226 }
227
228 max_kernel_buf_size = get_max_kernel_buf_size();
229 msg_pdbg("%s: max_kernel_buf_size: %zu\n", __func__, max_kernel_buf_size);
230
231 spi_data = calloc(1, sizeof(*spi_data));
232 if (!spi_data) {
233 msg_perr("Unable to allocated space for SPI master data\n");
234 goto init_err;
235 }
236 spi_data->fd = fd;
237 spi_data->max_kernel_buf_size = max_kernel_buf_size;
238
239 return register_spi_master(&spi_master_linux, spi_data);
240
241 init_err:
242 close(fd);
243 return 1;
244 }
245
246 const struct programmer_entry programmer_linux_spi = {
247 .name = "linux_spi",
248 .type = OTHER,
249 .devs.note = "Device files /dev/spidev*.*\n",
250 .init = linux_spi_init,
251 };
252