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mirror of git://projects.qi-hardware.com/ben-blinkenlights.git synced 2024-07-01 02:44:32 +03:00

ubb-patgen/: add DMA-based pattern transfer (WIP)

Works for some patterns but seems to have issues at the edge of
transfers. Clock selection also needs more work.
This commit is contained in:
Werner Almesberger 2013-01-14 03:55:51 -03:00
parent 8d59f8a206
commit 09bf9c23ab

View File

@ -14,11 +14,18 @@
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <assert.h>
#include <ubb/ubb.h>
#include <ubb/regs4740.h>
#include <ubb/mmcclk.h>
#include <ubb/physmem.h>
#define DMA 5
/* ----- List available bus clock frequencies ------------------------------ */
@ -122,6 +129,142 @@ static int select_freq(struct mmcclk *res, int hz, int rel)
}
/* ----- DMA the pattern --------------------------------------------------- */
static uint32_t old_dmac;
static void dma_stop(void)
{
DCS(DMA) = (1 << 3) | (1 << 2); /* halt DMA channel */
DCS(DMA) = 0; /* reset DMA channel */
}
static void dma_init(void)
{
old_dmac = DMAC;
DMAC = 1; /* activate the DMA controller (in case it's off) */
dma_stop();
DCM(DMA) =
(1 << 23) | /* source address increment */
(4 << 8); /* transfer size is 32 bytes */
DRT(DMA) = 26; /* MSC transmit-fifo-empty transfer request */
}
static void dma_cleanup(void)
{
DMAC = old_dmac;
dma_stop();
}
static void dma_setup(unsigned long buf, int nibbles)
{
assert(!(nibbles & 63));
DCS(DMA) = 1 << 31; /* no-descriptor transfer */
DSA(DMA) = buf; /* source */
DTA(DMA) = REG_PADDR(MSC_TXFIFO); /* MUST set this each time */
DTC(DMA) = nibbles >> 6; /* 32 bytes per transfer */
}
static void mmc_buffer(const struct mmcclk *clk,
unsigned long buf, int nibbles)
{
MSC_STRPCL = 1 << 3; /* reset the MSC */
while (MSC_STAT & (1 << 15)); /* wait until reset finishes */
dma_setup(buf, nibbles);
MSC_CLKRT = clk->clkrt; /* cleared by MSC reset */
MSC_STRPCL = 2; /* start the bus clock */
MSC_RESTO = 0xffff; /* maximum response time-out */
MSC_CMDAT =
(2 << 9) | /* 4 bit bus */
(1 << 8) | /* DMA */
(1 << 4) | /* write */
(1 << 3) | /* with data transfer */
1; /* R1 response */
MSC_STRPCL = 4; /* START_OP */
DCS(DMA) =
(1 << 31) | /* no descriptor */
1; /* enable transfer */
usleep(100);
sleep(1);
printf("MSC_STAT 0x%x\n", MSC_STAT);
}
static void send_buffer(const struct mmcclk *clk,
const uint8_t *buf, int nibbles)
{
unsigned long phys;
phys = physmem_xlat((void *) buf);
mmc_buffer(clk, phys, nibbles);
}
static int dma_pattern(const struct mmcclk *clk,
const char *pattern, uint32_t mask)
{
int n = strlen(pattern);
int rounded = (n+63) & ~63;
uint8_t *buf = physmem_malloc(rounded >> 1);
uint8_t *tmp = physmem_malloc(32);
int i;
if (!n)
return 1;
memset(buf, 0, rounded);
for (i = 0; i != rounded; i++) {
char ch[2] = { pattern[i < n ? i : n-1], 0 };
char *end;
buf[i >> 1] |= strtoul(ch, &end, 16) << 4*(~i & 1);
if (*end)
return 0;
}
dma_init();
PDDATC = ~((buf[0] >> 4) << 10) & mask;
PDDATS = (buf[0] >> 4) << 10;
PDDIRS = mask;
memset(tmp, (buf[0] >> 4)*0x11, 64);
send_buffer(clk, tmp, 64);
PDFUNS = mask;
send_buffer(clk, buf, rounded);
PDDATC = ~((buf[(rounded >> 1)-1] & 0xf) << 10) & mask;
PDDATS = (buf[(rounded >> 1)-1] & 0xf) << 10;
PDFUNC = mask;
dma_cleanup();
return 1;
}
/* ----- Command-line processing ------------------------------------------- */
@ -174,15 +317,18 @@ static void usage(const char *name)
{
fprintf(stderr,
"usage: %s\n"
"usage: %s [-b freq_hz] [-c] [-q] active_s\n\n"
"usage: %s [-b freq_hz] [-f freq_hz] [-c] [-q] [pattern] active_s\n\n"
" -b freq_hz set bus clock to the specified frequency (default: 1 MHz)\n"
" -c output bus clock on CLK\n"
" -f freq_hz set pattern rate (default: same as bus clock)\n"
" -q quiet. Don't report clock differences.\n\n"
" active_s keep running that many seconds after setting the clock\n\n"
" active_s keep running that many seconds after setting the clock\n"
" pattern send the specified pattern on DAT0 through DAT3\n\n"
"Frequency: the frequency in Hz, optionally followed by \"M\" or \"k\",\n"
" optionally followed by \"Hz\", optionally followed by \"+\" or \"-\".\n"
" \"+\" selects a frequency >= the specified one, \"-\" one <=.\n"
" Without +/-, the closest available frequency is selected.\n"
"Pattern: hex digits corresponding to 1 for DAT0, 2 for DAT1, etc.\n"
, name, name);
exit(1);
}
@ -191,7 +337,9 @@ static void usage(const char *name)
int main(int argc, char **argv)
{
struct mmcclk clk;
int bus_hz = 1000000, clkout = 0, rel = 0;
int bus_hz = 0, clkout = 0, bus_rel = 0;
int pattern_hz = 0, pattern_rel = 0;
const char *pattern = NULL;
int quiet = 0;
double active_s;
struct timespec active_ns;
@ -201,7 +349,11 @@ int main(int argc, char **argv)
while ((c = getopt(argc, argv, "b:cq")) != EOF)
switch (c) {
case 'b':
if (!frequency(optarg, &bus_hz, &rel))
if (!frequency(optarg, &bus_hz, &bus_rel))
usage(*argv);
break;
case 'f':
if (!frequency(optarg, &pattern_hz, &pattern_rel))
usage(*argv);
break;
case 'c':
@ -221,8 +373,11 @@ int main(int argc, char **argv)
ubb_open(UBB_ALL);
show_frequencies();
return 1;
case 2:
pattern = argv[optind];
/* fall through */
case 1:
active_s = strtod(argv[optind], &end);
active_s = strtod(argv[argc-1], &end);
if (*end)
usage(*argv);
active_ns.tv_sec = (int) active_s;
@ -234,7 +389,12 @@ int main(int argc, char **argv)
ubb_open(UBB_ALL);
if (!select_freq(&clk, bus_hz, rel)) {
PDFUNS = UBB_CMD;
if (!bus_hz)
bus_hz = 1000000;
if (!select_freq(&clk, bus_hz, bus_rel)) {
fprintf(stderr, "no suitable frequency found\n");
exit(1);
}
@ -254,12 +414,17 @@ int main(int argc, char **argv)
PDFUNS = UBB_CLK;
mmcclk_start(&clk);
if (pattern)
if (!dma_pattern(&clk, pattern,
UBB_DAT0 | UBB_DAT1 | UBB_DAT2 | UBB_DAT3))
usage(*argv);
if (nanosleep(&active_ns, NULL))
perror("nanosleep");
mmcclk_stop();
ubb_close(0);
ubb_close(UBB_DAT0 | UBB_DAT1 | UBB_DAT2 | UBB_DAT3);
return 0;
}