diff options
| author | Tomas Vanek <vanekt@fbl.cz> | 2017-04-09 10:59:57 +0200 |
|---|---|---|
| committer | Paul Fertser <fercerpav@gmail.com> | 2018-01-03 10:56:32 +0000 |
| commit | bb976e3c387bc82e20ab7304f0cfac3e5eede3a1 (patch) | |
| tree | ce1fddfeee5bfa2a44b720e72f435aede83b4b8f /src/jtag/drivers | |
| parent | 1c2e3d41de30c5e47d3fc8eda3de0a0a8229895a (diff) | |
jtag/drivers/cmsis-dap: fix connect under reset
Commit ef02b69b14d133b061217a91add5a028a77e86bc included
a call to cmsis_dap_cmd_DAP_Connect() before calling
cmsis_dap_cmd_DAP_SWJ_Sequence(). According to comment
it is necessary for at least Keil ULINK-ME.
Commit 72c3464be42088dc75245cf2fcc8f5c6e6959b4b added
a cmsis_dap_cmd_DAP_Disconnect() before connect call to pair
connection/disconnection. It solves some problems on Atmel EDBG.
Unfortunately calling either of cmsis_dap_cmd_DAP_Connect()
or cmsis_dap_cmd_DAP_Disconnect() deasserts reset signal.
So these workarounds break ability to connect under reset.
Use cmsis_dap_cmd_DAP_Disconnect() and cmsis_dap_cmd_DAP_Connect()
pair only if both SRST and TRST are deasserted.
Change-Id: I0914dae0a1360b8c7fe48231ff3867caedfb2dbe
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reported-by: Leonardo Sabino dos Santos <leonardo.sabino@gmail.com>
Reviewed-on: http://openocd.zylin.com/4100
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
Diffstat (limited to 'src/jtag/drivers')
| -rw-r--r-- | src/jtag/drivers/cmsis_dap_usb.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/src/jtag/drivers/cmsis_dap_usb.c b/src/jtag/drivers/cmsis_dap_usb.c index 345c1fd7..b8181d6a 100644 --- a/src/jtag/drivers/cmsis_dap_usb.c +++ b/src/jtag/drivers/cmsis_dap_usb.c @@ -206,6 +206,8 @@ static uint8_t queued_seq_buf[1024]; /* TODO: make dynamic / move into cmsis obj static int queued_retval; +static uint8_t output_pins = SWJ_PIN_SRST | SWJ_PIN_TRST; + static struct cmsis_dap *cmsis_dap_handle; static int cmsis_dap_usb_open(void) @@ -790,15 +792,21 @@ static int cmsis_dap_swd_switch_seq(enum swd_special_seq seq) unsigned int s_len; int retval; - /* First disconnect before connecting, Atmel EDBG needs it for SAMD/R/L/C */ - cmsis_dap_cmd_DAP_Disconnect(); + if ((output_pins & (SWJ_PIN_SRST | SWJ_PIN_TRST)) == (SWJ_PIN_SRST | SWJ_PIN_TRST)) { + /* Following workaround deasserts reset on most adapters. + * Do not reconnect if a reset line is active! + * Reconnecting would break connecting under reset. */ - /* When we are reconnecting, DAP_Connect needs to be rerun, at - * least on Keil ULINK-ME */ - retval = cmsis_dap_cmd_DAP_Connect(seq == LINE_RESET || seq == JTAG_TO_SWD ? + /* First disconnect before connecting, Atmel EDBG needs it for SAMD/R/L/C */ + cmsis_dap_cmd_DAP_Disconnect(); + + /* When we are reconnecting, DAP_Connect needs to be rerun, at + * least on Keil ULINK-ME */ + retval = cmsis_dap_cmd_DAP_Connect(seq == LINE_RESET || seq == JTAG_TO_SWD ? CONNECT_SWD : CONNECT_JTAG); - if (retval != ERROR_OK) - return retval; + if (retval != ERROR_OK) + return retval; + } switch (seq) { case LINE_RESET: @@ -1010,14 +1018,14 @@ static void cmsis_dap_execute_reset(struct jtag_command *cmd) { /* Set both TRST and SRST even if they're not enabled as * there's no way to tristate them */ - uint8_t pins = 0; + output_pins = 0; if (!cmd->cmd.reset->srst) - pins |= SWJ_PIN_SRST; + output_pins |= SWJ_PIN_SRST; if (!cmd->cmd.reset->trst) - pins |= SWJ_PIN_TRST; + output_pins |= SWJ_PIN_TRST; - int retval = cmsis_dap_cmd_DAP_SWJ_Pins(pins, + int retval = cmsis_dap_cmd_DAP_SWJ_Pins(output_pins, SWJ_PIN_TRST | SWJ_PIN_SRST, 0, NULL); if (retval != ERROR_OK) LOG_ERROR("CMSIS-DAP: Interface reset failed"); |