diff options
Diffstat (limited to 'src/target/adi_v5_swd.c')
-rw-r--r-- | src/target/adi_v5_swd.c | 69 |
1 files changed, 56 insertions, 13 deletions
diff --git a/src/target/adi_v5_swd.c b/src/target/adi_v5_swd.c index ee30ff7..b25181e 100644 --- a/src/target/adi_v5_swd.c +++ b/src/target/adi_v5_swd.c @@ -118,26 +118,69 @@ static int swd_connect(struct adiv5_dap *dap) } } - /* Note, debugport_init() does setup too */ - swd->switch_seq(JTAG_TO_SWD); - /* Clear link state, including the SELECT cache. */ - dap->do_reconnect = false; - dap_invalidate_cache(dap); + int64_t timeout = timeval_ms() + 500; - swd_queue_dp_read(dap, DP_DPIDR, &dpidr); + do { + /* Note, debugport_init() does setup too */ + swd->switch_seq(JTAG_TO_SWD); - /* force clear all sticky faults */ - swd_clear_sticky_errors(dap); + /* Clear link state, including the SELECT cache. */ + dap->do_reconnect = false; + dap_invalidate_cache(dap); + + status = swd_queue_dp_read(dap, DP_DPIDR, &dpidr); + if (status == ERROR_OK) { + status = swd_run_inner(dap); + if (status == ERROR_OK) + break; + } + + alive_sleep(1); + + } while (timeval_ms() < timeout); + + if (status != ERROR_OK) { + LOG_ERROR("Error connecting DP: cannot read IDR"); + return status; + } + + LOG_INFO("SWD DPIDR %#8.8" PRIx32, dpidr); + + do { + dap->do_reconnect = false; - status = swd_run_inner(dap); + /* force clear all sticky faults */ + swd_clear_sticky_errors(dap); + + status = swd_run_inner(dap); + if (status != ERROR_WAIT) + break; + + alive_sleep(10); + + } while (timeval_ms() < timeout); + + /* IHI 0031E B4.3.2: + * "A WAIT response must not be issued to the ... + * ... writes to the ABORT register" + * swd_clear_sticky_errors() writes to the ABORT register only. + * + * Unfortunately at least Microchip SAMD51/E53/E54 returns WAIT + * in a corner case. Just try if ABORT resolves the problem. + */ + if (status == ERROR_WAIT) { + LOG_WARNING("Connecting DP: stalled AP operation, issuing ABORT"); - if (status == ERROR_OK) { - LOG_INFO("SWD DPIDR %#8.8" PRIx32, dpidr); dap->do_reconnect = false; + + swd->write_reg(swd_cmd(false, false, DP_ABORT), + DAPABORT | STKCMPCLR | STKERRCLR | WDERRCLR | ORUNERRCLR, 0); + status = swd_run_inner(dap); + } + + if (status == ERROR_OK) status = dap_dp_init(dap); - } else - dap->do_reconnect = true; return status; } |