interesting
/
riscv-openocd
mirror of https://github.com/riscv/riscv-openocd.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

jtag/drivers/bcm2835gpio: use rounding in delay math 

After setting adapter speed to some values, the driver
shows the real speed little bit higher.
Although it does not impose a problem from technical point
of view because the difference is smaller than usual speed error,
it looks at least strange to the user. The documentation reads
that real frequency should be same or lower than requested.

Use proper rounding in speed -> delay and delay -> speed
conversions.

Change-Id: I1831112cc58681875548d2aeb688391fb79fa37f
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7261
Tested-by: jenkins
Reviewed-by: Jonathan Bell <jonathan@raspberrypi.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
This commit is contained in:
Tomas Vanek 2022-10-13 16:46:31 +02:00 committed by Antonio Borneo
parent 148bc7e215
commit b4dd8dbc37
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/jtag/drivers/bcm2835gpio.c
View File

@ -264,7 +264,8 @@ static int bcm2835gpio_khz(int khz, int *jtag_speed)
LOG_DEBUG("BCM2835 GPIO: RCLK not supported");
return ERROR_FAIL;
}
*jtag_speed = speed_coeff/khz - speed_offset;
*jtag_speed = DIV_ROUND_UP(speed_coeff, khz) - speed_offset;
LOG_DEBUG("jtag_delay %d", *jtag_speed);
if (*jtag_speed < 0)
*jtag_speed = 0;
return ERROR_OK;
@ -272,7 +273,9 @@ static int bcm2835gpio_khz(int khz, int *jtag_speed)
static int bcm2835gpio_speed_div(int speed, int *khz)
{
*khz = speed_coeff/(speed + speed_offset);
int divisor = speed + speed_offset;
/* divide with roundig to the closest */
*khz = (speed_coeff + divisor / 2) / divisor;
return ERROR_OK;
}