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common/swdptap.c: Speed up by "unrolling" swd.._seq_...() for GPIO. 

Try to have sensible setup/hold times by evenntually duplicated or
logically useless port commands.
Loading code to RAM on a STM32L476 got up from 46 to 83 kB/sec.
This commit is contained in:
Uwe Bonnes 2018-01-23 20:15:16 +01:00
parent d4d24c256c
commit e54a826745
1 changed files with 103 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

104
src/platforms/common/swdptap.c
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@ -18,7 +18,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* This file implements the low-level SW-DP interface. */
/* This file implements the SW-DP interface. */
#include "general.h"
#include "swdptap.h"
@ -43,6 +43,7 @@ static void swdptap_turnaround(uint8_t dir)
if(dir)
SWDIO_MODE_FLOAT();
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_clear(SWCLK_PORT, SWCLK_PIN);
if(!dir)
SWDIO_MODE_DRIVE();
@ -56,6 +57,7 @@ bool swdptap_bit_in(void)
ret = gpio_get(SWDIO_PORT, SWDIO_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_clear(SWCLK_PORT, SWCLK_PIN);
#ifdef DEBUG_SWD_BITS
@ -65,6 +67,64 @@ bool swdptap_bit_in(void)
return ret != 0;
}
uint32_t
swdptap_seq_in(int ticks)
{
uint32_t index = 1;
uint32_t ret = 0;
int len = ticks;
swdptap_turnaround(1);
while (len--) {
int res;
res = gpio_get(SWDIO_PORT, SWDIO_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
if (res)
ret |= index;
index <<= 1;
gpio_clear(SWCLK_PORT, SWCLK_PIN);
}
#ifdef DEBUG_SWD_BITS
for (int i = 0; i < len; i++)
DEBUG("%d", (ret & (1 << i)) ? 1 : 0);
#endif
return ret;
}
bool
swdptap_seq_in_parity(uint32_t *ret, int ticks)
{
uint32_t index = 1;
uint8_t parity = 0;
uint32_t res = 0;
bool bit;
int len = ticks;
swdptap_turnaround(1);
while (len--) {
bit = gpio_get(SWDIO_PORT, SWDIO_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
if (bit) {
res |= index;
parity ^= 1;
}
index <<= 1;
gpio_clear(SWCLK_PORT, SWCLK_PIN);
}
bit = gpio_get(SWDIO_PORT, SWDIO_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
if (bit)
parity ^= 1;
gpio_clear(SWCLK_PORT, SWCLK_PIN);
#ifdef DEBUG_SWD_BITS
for (int i = 0; i < len; i++)
DEBUG("%d", (res & (1 << i)) ? 1 : 0);
#endif
*ret = res;
return parity;
}
void swdptap_bit_out(bool val)
{
#ifdef DEBUG_SWD_BITS
@ -75,6 +135,48 @@ void swdptap_bit_out(bool val)
gpio_set_val(SWDIO_PORT, SWDIO_PIN, val);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_clear(SWCLK_PORT, SWCLK_PIN);
}
void
swdptap_seq_out(uint32_t MS, int ticks)
{
int data = MS & 1;
#ifdef DEBUG_SWD_BITS
for (int i = 0; i < ticks; i++)
DEBUG("%d", (MS & (1 << i)) ? 1 : 0);
#endif
swdptap_turnaround(0);
while (ticks--) {
gpio_set_val(SWDIO_PORT, SWDIO_PIN, data);
gpio_set(SWCLK_PORT, SWCLK_PIN);
MS >>= 1;
data = MS & 1;
gpio_clear(SWCLK_PORT, SWCLK_PIN);
}
}
void
swdptap_seq_out_parity(uint32_t MS, int ticks)
{
uint8_t parity = 0;
int data = MS & 1;
#ifdef DEBUG_SWD_BITS
for (int i = 0; i < ticks; i++)
DEBUG("%d", (MS & (1 << i)) ? 1 : 0);
#endif
swdptap_turnaround(0);
while (ticks--) {
gpio_set_val(SWDIO_PORT, SWDIO_PIN, data);
gpio_set(SWCLK_PORT, SWCLK_PIN);
parity ^= MS;
MS >>= 1;
data = MS & 1;
gpio_clear(SWCLK_PORT, SWCLK_PIN);
}
gpio_set_val(SWDIO_PORT, SWDIO_PIN, parity & 1);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_set(SWCLK_PORT, SWCLK_PIN);
gpio_clear(SWCLK_PORT, SWCLK_PIN);
}