asix-sigma: Cleanup the bit2bitbang

Rework the bit2bitbang function. Remarkable changes are:
- The function was renamed to sigma_fw_2_bitbang()
- We use glib function calls to work with the file
- We mmap the file containing firmware instead of opening the file
  and then reading it into a buffer.
- The magic firmware transformation is now type-safe.
- Documentation and comments were added where applicable.

Signed-off-by: Marek Vasut <marex@denx.de>
This commit is contained in:
Marek Vasut 2014-04-20 19:19:33 +02:00 committed by Bert Vermeulen
parent 8bbf7627df
commit d485d44361
1 changed files with 57 additions and 66 deletions

View File

@ -299,85 +299,76 @@ static int sigma_write_trigger_lut(struct triggerlut *lut, struct dev_context *d
return SR_OK;
}
/* Generate the bitbang stream for programming the FPGA. */
static int bin2bitbang(const char *filename,
unsigned char **buf, size_t *buf_size)
/*
* Read the firmware from a file and transform it into a series of bitbang
* pulses used to program the FPGA. Note that the *bb_cmd must be free()'d
* by the caller of this function.
*/
static int sigma_fw_2_bitbang(const char *filename,
uint8_t **bb_cmd, gsize *bb_cmd_size)
{
FILE *f;
unsigned long file_size;
unsigned long offset = 0;
unsigned char *p;
uint8_t *firmware;
unsigned long fwsize = 0;
const int buffer_size = 65536;
size_t i;
int c, bit, v;
uint32_t imm = 0x3f6df2ab;
GMappedFile *file;
GError *error;
gsize i, file_size, bb_size;
gchar *firmware;
uint8_t *bb_stream, *bbs;
uint32_t imm;
int bit, v;
int ret = SR_OK;
f = g_fopen(filename, "rb");
if (!f) {
sr_err("g_fopen(\"%s\", \"rb\")", filename);
return SR_ERR;
}
/*
* Map the file and make the mapped buffer writable.
* NOTE: Using writable=TRUE does _NOT_ mean that file that is mapped
* will be modified. It will not be modified until someone uses
* g_file_set_contents() on it.
*/
error = NULL;
file = g_mapped_file_new(filename, TRUE, &error);
g_assert_no_error(error);
if (-1 == fseek(f, 0, SEEK_END)) {
sr_err("fseek on %s failed", filename);
fclose(f);
return SR_ERR;
}
file_size = g_mapped_file_get_length(file);
firmware = g_mapped_file_get_contents(file);
g_assert(firmware);
file_size = ftell(f);
fseek(f, 0, SEEK_SET);
if (!(firmware = g_try_malloc(buffer_size))) {
sr_err("%s: firmware malloc failed", __func__);
fclose(f);
return SR_ERR_MALLOC;
}
while ((c = getc(f)) != EOF) {
/* Weird magic transformation below, I have no idea what it does. */
imm = 0x3f6df2ab;
for (i = 0; i < file_size; i++) {
imm = (imm + 0xa853753) % 177 + (imm * 0x8034052);
firmware[fwsize++] = c ^ imm;
}
fclose(f);
if(fwsize != file_size) {
sr_err("%s: Error reading firmware", filename);
fclose(f);
g_free(firmware);
return SR_ERR;
firmware[i] ^= imm & 0xff;
}
*buf_size = fwsize * 2 * 8;
/*
* Now that the firmware is "transformed", we will transcribe the
* firmware blob into a sequence of toggles of the Dx wires. This
* sequence will be fed directly into the Sigma, which must be in
* the FPGA bitbang programming mode.
*/
*buf = p = (unsigned char *)g_try_malloc(*buf_size);
if (!p) {
sr_err("%s: buf/p malloc failed", __func__);
g_free(firmware);
return SR_ERR_MALLOC;
/* Each bit of firmware is transcribed as two toggles of Dx wires. */
bb_size = file_size * 8 * 2;
bb_stream = (uint8_t *)g_try_malloc(bb_size);
if (!bb_stream) {
sr_err("%s: Failed to allocate bitbang stream", __func__);
ret = SR_ERR_MALLOC;
goto exit;
}
for (i = 0; i < fwsize; ++i) {
for (bit = 7; bit >= 0; --bit) {
v = firmware[i] & 1 << bit ? 0x40 : 0x00;
p[offset++] = v | 0x01;
p[offset++] = v;
bbs = bb_stream;
for (i = 0; i < file_size; i++) {
for (bit = 7; bit >= 0; bit--) {
v = (firmware[i] & (1 << bit)) ? 0x40 : 0x00;
*bbs++ = v | 0x01;
*bbs++ = v;
}
}
g_free(firmware);
/* The transformation completed successfully, return the result. */
*bb_cmd = bb_stream;
*bb_cmd_size = bb_size;
if (offset != *buf_size) {
g_free(*buf);
sr_err("Error reading firmware %s "
"offset=%ld, file_size=%ld, buf_size=%zd.",
filename, offset, file_size, *buf_size);
return SR_ERR;
}
return SR_OK;
exit:
g_mapped_file_unref(file);
return ret;
}
static void clear_helper(void *priv)
@ -575,7 +566,7 @@ static int upload_firmware(int firmware_idx, struct dev_context *devc)
return ret;
/* Prepare firmware. */
ret = bin2bitbang(firmware, &buf, &buf_size);
ret = sigma_fw_2_bitbang(firmware, &buf, &buf_size);
if (ret != SR_OK) {
sr_err("An error occured while reading the firmware: %s",
firmware);