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mirror of https://review.coreboot.org/flashrom.git synced 2025-04-27 15:12:36 +02:00

linux_spi: Dynamically detect max buffer size

Read max buffer size from sysfs if available.

Change-Id: Ic541e548ced8488f074d388f1c92174cad123064
Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: David Hendricks <dhendricks@fb.com>
Reviewed-on: https://review.coreboot.org/22441
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
This commit is contained in:
Keno Fischer 2015-11-15 14:58:25 +00:00 committed by David Hendricks
parent 22f2dc5ec0
commit 1f33cb5800

View File

@ -42,6 +42,8 @@
*/
static int fd = -1;
#define BUF_SIZE_FROM_SYSFS "/sys/module/spidev/parameters/bufsiz"
static size_t max_kernel_buf_size;
static int linux_spi_shutdown(void *data);
static int linux_spi_send_command(struct flashctx *flash, unsigned int writecnt,
@ -127,8 +129,45 @@ int linux_spi_init(void)
return 1;
}
register_spi_master(&spi_master_linux);
/* Read max buffer size from sysfs, or use page size as fallback. */
FILE *fp;
fp = fopen(BUF_SIZE_FROM_SYSFS, "r");
if (!fp) {
msg_pwarn("Cannot open %s: %s.\n", BUF_SIZE_FROM_SYSFS, strerror(errno));
goto out;
}
char buf[10];
memset(buf, 0, sizeof(buf));
if (!fread(buf, 1, sizeof(buf) - 1, fp)) {
if (feof(fp))
msg_pwarn("Cannot read %s: file is empty.\n", BUF_SIZE_FROM_SYSFS);
else
msg_pwarn("Cannot read %s: %s.\n", BUF_SIZE_FROM_SYSFS, strerror(errno));
goto out;
}
long int tmp;
errno = 0;
tmp = strtol(buf, NULL, 0);
if ((tmp < 0) || errno) {
msg_pwarn("Buffer size %ld from %s seems wrong.\n", tmp, BUF_SIZE_FROM_SYSFS);
} else {
msg_pdbg("%s: Using value from %s as max buffer size.\n", __func__, BUF_SIZE_FROM_SYSFS);
max_kernel_buf_size = (size_t)tmp;
}
out:
if (fp)
fclose(fp);
if (!max_kernel_buf_size) {
msg_pdbg("%s: Using page size as max buffer size.\n", __func__);
max_kernel_buf_size = (size_t)getpagesize();
}
msg_pdbg("%s: max_kernel_buf_size: %zu\n", __func__, max_kernel_buf_size);
register_spi_master(&spi_master_linux);
return 0;
}
@ -179,17 +218,16 @@ static int linux_spi_send_command(struct flashctx *flash, unsigned int writecnt,
return 0;
}
static int linux_spi_read(struct flashctx *flash, uint8_t *buf,
unsigned int start, unsigned int len)
static int linux_spi_read(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len)
{
return spi_read_chunked(flash, buf, start, len,
(unsigned int)getpagesize());
/* Read buffer is fully utilized for data. */
return spi_read_chunked(flash, buf, start, len, max_kernel_buf_size);
}
static int linux_spi_write_256(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len)
{
return spi_write_chunked(flash, buf, start, len,
((unsigned int)getpagesize()) - 4);
/* 5 bytes must be reserved for longest possible command + address. */
return spi_write_chunked(flash, buf, start, len, max_kernel_buf_size - 5);
}
#endif // CONFIG_LINUX_SPI == 1