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| author | Tomas Vanek <vanekt@fbl.cz> | 2022-11-15 09:47:43 +0100 |
|---|---|---|
| committer | Tomas Vanek <vanekt@fbl.cz> | 2023-05-24 05:25:28 +0000 |
| commit | c164906420521546849d03a26977fb91838aca8e (patch) | |
| tree | 1fd15d6064ca291ca8e4825ddcdf9d3bd42e575e /src | |
| parent | 30b0e9af8d1e68ee051ac62dd0e27c920fb396bd (diff) | |
| download | riscv-openocd-c164906420521546849d03a26977fb91838aca8e.zip riscv-openocd-c164906420521546849d03a26977fb91838aca8e.tar.gz riscv-openocd-c164906420521546849d03a26977fb91838aca8e.tar.bz2 | |
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 <vanekt@fbl.cz>
Change-Id: I0bce76cade8f7efd75efd9087a7d9ba6511a6239
Reviewed-on: https://review.openocd.org/c/openocd/+/7684
Tested-by: jenkins
Reviewed-by: Jonathan Bell <jonathan@raspberrypi.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/jtag/drivers/bcm2835gpio.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/src/jtag/drivers/bcm2835gpio.c b/src/jtag/drivers/bcm2835gpio.c index 879ca3c..16c76cd 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; |