at91samd: handle reset run/halt in DSU

[fw/openocd] / src / flash / nor / at91samd.c

diff --git a/src/flash/nor/at91samd.c b/src/flash/nor/at91samd.c
index a4cc51d21d39019eb106296ae1cebb03f269bc49..9b0f7eebe56ce4816202efb8686eda75155397b8 100644 (file)
--- a/src/flash/nor/at91samd.c
+++ b/src/flash/nor/at91samd.c
@@ -25,6 +25,8 @@
 #include "imp.h"
 #include "helper/binarybuffer.h"
 
+#include <target/cortex_m.h>
+
 #define SAMD_NUM_SECTORS       16
 #define SAMD_PAGE_SIZE_MAX     1024
 
@@ -34,6 +36,7 @@
 #define SAMD_DSU                       0x41002000      /* Device Service Unit */
 #define SAMD_NVMCTRL           0x41004000      /* Non-volatile memory controller */
 
+#define SAMD_DSU_STATUSA        1               /* DSU status register */
 #define SAMD_DSU_DID           0x18            /* Device ID register */
 
 #define SAMD_NVMCTRL_CTRLA             0x00    /* NVM control A register */
@@ -1038,7 +1041,46 @@ COMMAND_HANDLER(samd_handle_bootloader_command)
        return res;
 }
 
+
+
+COMMAND_HANDLER(samd_handle_reset_deassert)
+{
+       struct target *target = get_current_target(CMD_CTX);
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = armv7m->arm.dap;
+       int retval = ERROR_OK;
+       enum reset_types jtag_reset_config = jtag_get_reset_config();
+
+       /* In case of sysresetreq, debug retains state set in cortex_m_assert_reset()
+        * so we just release reset held by DSU
+        *
+        * n_RESET (srst) clears the DP, so reenable debug and set vector catch here
+        *
+        * After vectreset DSU release is not needed however makes no harm
+        */
+       if (target->reset_halt && (jtag_reset_config & RESET_HAS_SRST)) {
+               retval = mem_ap_write_u32(swjdp, DCB_DHCSR, DBGKEY | C_HALT | C_DEBUGEN);
+               if (retval == ERROR_OK)
+                       retval = mem_ap_write_u32(swjdp, DCB_DEMCR,
+                               TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET);
+               /* do not return on error here, releasing DSU reset is more important */
+       }
+
+       /* clear CPU Reset Phase Extension bit */
+       int retval2 = target_write_u8(target, SAMD_DSU + SAMD_DSU_STATUSA, (1<<1));
+       if (retval2 != ERROR_OK)
+               return retval2;
+
+       return retval;
+}
+
 static const struct command_registration at91samd_exec_command_handlers[] = {
+       {
+               .name = "dsu_reset_deassert",
+               .handler = samd_handle_reset_deassert,
+               .mode = COMMAND_EXEC,
+               .help = "deasert internal reset held by DSU"
+       },
        {
                .name = "info",
                .handler = samd_handle_info_command,