This is an automated email from Gerrit.
"Tomas Vanek <van...@fbl.cz>" just uploaded a new patch set to Gerrit, which
you can find at https://review.openocd.org/c/openocd/+/7684
-- gerrit
commit 0a98920619268578c96300ae3b442da3ebc8a407
Author: Tomas Vanek <van...@fbl.cz>
Date: Tue Nov 15 09:47:43 2022 +0100
jtag/drivers/bcm2835gpio: don't touch pad setting on /dev/gpiomem
The pads were configured at a wrong memory address
if /dev/gpiomem was mapped.
The pad setting registers are not accessible in mapped /dev/gpiomem,
disable the pads setting if the driver doesn't open /dev/mem.
While on it, do not fail the driver initialization if pad mapping fails
- just emit a warning and work with unchanged pad setting.
Signed-off-by: Tomas Vanek <van...@fbl.cz>
Change-Id: I0bce76cade8f7efd75efd9087a7d9ba6511a6239
diff --git a/doc/openocd.texi b/doc/openocd.texi
index f32ef34756..f27e17ceac 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -3292,8 +3292,12 @@ configuration on exit.
GPIO numbers >= 32 can't be used for performance reasons. GPIO configuration is
handled by the generic command @ref{adapter gpio, @command{adapter gpio}}.
+/dev/gpiomem is preferred for GPIO mapping with fallback to /dev/mem.
+If /dev/mem is used GPIO 0-27 pads are set to the limited
+slew rate and drive strength is reduced to 4 mA (2 mA on RPi 4).
+
See @file{interface/raspberrypi-native.cfg} for a sample config and
-pinout.
+@file{interface/raspberrypi-gpio-connector.cfg} for pinout.
@deffn {Config Command} {bcm2835gpio speed_coeffs} @var{speed_coeff}
@var{speed_offset}
Set SPEED_COEFF and SPEED_OFFSET for delay calculations. If unspecified,
diff --git a/src/jtag/drivers/bcm2835gpio.c b/src/jtag/drivers/bcm2835gpio.c
index 879ca3c84e..16c76cdb83 100644
--- a/src/jtag/drivers/bcm2835gpio.c
+++ b/src/jtag/drivers/bcm2835gpio.c
@@ -409,10 +409,13 @@ static int bcm2835gpio_init(void)
return ERROR_JTAG_INIT_FAILED;
}
+ bool pad_mapping_possible = false;
+
dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
if (dev_mem_fd < 0) {
LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+ pad_mapping_possible = true;
}
if (dev_mem_fd < 0) {
LOG_ERROR("open: %s", strerror(errno));
@@ -428,21 +431,28 @@ static int bcm2835gpio_init(void)
return ERROR_JTAG_INIT_FAILED;
}
- pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
+ /* TODO: move pads config to a separate utility */
+ if (pad_mapping_possible) {
+ pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ |
PROT_WRITE,
MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
- if (pads_base == MAP_FAILED) {
- LOG_ERROR("mmap: %s", strerror(errno));
- bcm2835gpio_munmap();
- close(dev_mem_fd);
- return ERROR_JTAG_INIT_FAILED;
+ if (pads_base == MAP_FAILED) {
+ LOG_ERROR("mmap pads: %s", strerror(errno));
+ LOG_WARNING("Continuing with unchanged GPIO pad
settings (drive strength and slew rate)");
+ }
+ } else {
+ pads_base = MAP_FAILED;
}
close(dev_mem_fd);
- /* set 4mA drive strength, slew rate limited, hysteresis on */
- initial_drive_strength_etc = pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] &
0x1f;
- pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
+ if (pads_base != MAP_FAILED) {
+ /* set 4mA drive strength, slew rate limited, hysteresis on */
+ initial_drive_strength_etc =
pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] & 0x1f;
+LOG_INFO("initial pads conf %08x", pads_base[BCM2835_PADS_GPIO_0_27_OFFSET]);
+ pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
+LOG_INFO("pads conf set to %08x", pads_base[BCM2835_PADS_GPIO_0_27_OFFSET]);
+ }
/* Configure JTAG/SWD signals. Default directions and initial states
are handled
* by adapter.c and "adapter gpio" command.
@@ -513,8 +523,10 @@ static int bcm2835gpio_quit(void)
restore_gpio(ADAPTER_GPIO_IDX_SRST);
restore_gpio(ADAPTER_GPIO_IDX_LED);
- /* Restore drive strength. MSB is password ("5A") */
- pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5A000000 |
initial_drive_strength_etc;
+ if (pads_base != MAP_FAILED) {
+ /* Restore drive strength. MSB is password ("5A") */
+ pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5A000000 |
initial_drive_strength_etc;
+ }
bcm2835gpio_munmap();
return ERROR_OK;
--
