mips32: Added CP0 coprocessor R/W routines
[fw/openocd] / src / target / mips32_pracc.c
index 7d91d42ecade704405655245359f468441bb3ed6..1986e5ca21701ca4bacbf827c50916dff2db2f48 100644 (file)
@@ -6,6 +6,9 @@
  *                                                                         *
  *   Copyright (C) 2009 by David N. Claffey <dnclaffey@gmail.com>          *
  *                                                                         *
+ *   Copyright (C) 2011 by Drasko DRASKOVIC                                *
+ *   drasko.draskovic@gmail.com                                            *
+ *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
@@ -74,6 +77,8 @@ Nico Coesel
 #include "config.h"
 #endif
 
+#include <helper/time_support.h>
+
 #include "mips32.h"
 #include "mips32_pracc.h"
 
@@ -90,19 +95,49 @@ struct mips32_pracc_context
        struct mips_ejtag *ejtag_info;
 };
 
+static int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info,
+               uint32_t addr, int count, uint8_t *buf);
+static int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info,
+               uint32_t addr, int count, uint16_t *buf);
+static int mips32_pracc_read_mem32(struct mips_ejtag *ejtag_info,
+               uint32_t addr, int count, uint32_t *buf);
+static int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info,
+               uint32_t addr, uint32_t *buf);
+
+static int mips32_pracc_write_mem8(struct mips_ejtag *ejtag_info,
+               uint32_t addr, int count, uint8_t *buf);
+static int mips32_pracc_write_mem16(struct mips_ejtag *ejtag_info,
+               uint32_t addr, int count, uint16_t *buf);
+static int mips32_pracc_write_mem32(struct mips_ejtag *ejtag_info,
+               uint32_t addr, int count, uint32_t *buf);
+static int mips32_pracc_write_u32(struct mips_ejtag *ejtag_info,
+               uint32_t addr, uint32_t *buf);
+
 static int wait_for_pracc_rw(struct mips_ejtag *ejtag_info, uint32_t *ctrl)
 {
        uint32_t ejtag_ctrl;
+       long long then = timeval_ms();
+       int timeout;
+       int retval;
+
+       /* wait for the PrAcc to become "1" */
+       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
+       ejtag_ctrl = ejtag_info->ejtag_ctrl;
 
        while (1)
        {
-               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
-               ejtag_ctrl = ejtag_info->ejtag_ctrl;
-               mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
+               retval = mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
+               if (retval != ERROR_OK)
+                       return retval;
+
                if (ejtag_ctrl & EJTAG_CTRL_PRACC)
                        break;
-               LOG_DEBUG("DEBUGMODULE: No memory access in progress!\n");
-               return ERROR_JTAG_DEVICE_ERROR;
+
+               if ( (timeout = timeval_ms()-then) > 1000 )
+               {
+                       LOG_DEBUG("DEBUGMODULE: No memory access in progress!");
+                       return ERROR_JTAG_DEVICE_ERROR;
+               }
        }
 
        *ctrl = ejtag_ctrl;
@@ -149,18 +184,15 @@ static int mips32_pracc_exec_read(struct mips32_pracc_context *ctx, uint32_t add
        }
 
        /* Send the data out */
-       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_DATA, NULL);
-       mips_ejtag_drscan_32(ctx->ejtag_info, &data);
+       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_DATA);
+       mips_ejtag_drscan_32_out(ctx->ejtag_info, data);
 
        /* Clear the access pending bit (let the processor eat!) */
        ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
-       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_CONTROL, NULL);
-       mips_ejtag_drscan_32(ctx->ejtag_info, &ejtag_ctrl);
-
-       jtag_add_clocks(5);
-       jtag_execute_queue();
+       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_CONTROL);
+       mips_ejtag_drscan_32_out(ctx->ejtag_info, ejtag_ctrl);
 
-       return ERROR_OK;
+       return jtag_execute_queue();
 }
 
 static int mips32_pracc_exec_write(struct mips32_pracc_context *ctx, uint32_t address)
@@ -168,17 +200,21 @@ static int mips32_pracc_exec_write(struct mips32_pracc_context *ctx, uint32_t ad
        uint32_t ejtag_ctrl,data;
        int offset;
        struct mips_ejtag *ejtag_info = ctx->ejtag_info;
+       int retval;
 
-       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_DATA, NULL);
-       mips_ejtag_drscan_32(ctx->ejtag_info, &data);
+       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_DATA);
+       retval = mips_ejtag_drscan_32(ctx->ejtag_info, &data);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* Clear access pending bit */
        ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
-       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_CONTROL, NULL);
-       mips_ejtag_drscan_32(ctx->ejtag_info, &ejtag_ctrl);
+       mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_CONTROL);
+       mips_ejtag_drscan_32_out(ctx->ejtag_info, ejtag_ctrl);
 
-       jtag_add_clocks(5);
-       jtag_execute_queue();
+       retval = jtag_execute_queue();
+       if (retval != ERROR_OK)
+               return retval;
 
        if ((address >= MIPS32_PRACC_PARAM_IN)
                && (address <= MIPS32_PRACC_PARAM_IN + ctx->num_iparam * 4))
@@ -206,7 +242,8 @@ static int mips32_pracc_exec_write(struct mips32_pracc_context *ctx, uint32_t ad
        return ERROR_OK;
 }
 
-int mips32_pracc_exec(struct mips_ejtag *ejtag_info, int code_len, const uint32_t *code, int num_param_in, uint32_t *param_in, int num_param_out, uint32_t *param_out, int cycle)
+int mips32_pracc_exec(struct mips_ejtag *ejtag_info, int code_len, const uint32_t *code,
+               int num_param_in, uint32_t *param_in, int num_param_out, uint32_t *param_out, int cycle)
 {
        uint32_t ejtag_ctrl;
        uint32_t address, data;
@@ -229,8 +266,10 @@ int mips32_pracc_exec(struct mips_ejtag *ejtag_info, int code_len, const uint32_
                        return retval;
 
                address = data = 0;
-               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS, NULL);
-               mips_ejtag_drscan_32(ejtag_info, &address);
+               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
+               retval = mips_ejtag_drscan_32(ejtag_info, &address);
+               if (retval != ERROR_OK)
+                       return retval;
 
                /* Check for read or write */
                if (ejtag_ctrl & EJTAG_CTRL_PRNW)
@@ -283,7 +322,7 @@ int mips32_pracc_read_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size
        return ERROR_OK;
 }
 
-int mips32_pracc_read_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint32_t *buf)
+static int mips32_pracc_read_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint32_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -353,7 +392,7 @@ int mips32_pracc_read_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int co
        return retval;
 }
 
-int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
+static int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -386,7 +425,7 @@ int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t
        return retval;
 }
 
-int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint16_t *buf)
+static int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint16_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -429,13 +468,10 @@ int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int co
        uint32_t *param_out = malloc(count * sizeof(uint32_t));
        int i;
 
-//     int retval;
+       int retval = ERROR_OK;
        int blocksize;
-       int bytesread;
        uint32_t param_in[2];
 
-       bytesread = 0;
-
        //while (count > 0)
        {
                blocksize = count;
@@ -445,12 +481,11 @@ int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int co
                param_in[0] = addr;
                param_in[1] = blocksize;
 
-               mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+               retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                        ARRAY_SIZE(param_in), param_in, count, param_out, 1);
 
 //             count -= blocksize;
 //             addr += blocksize;
-//             bytesread += blocksize;
        }
 
        for (i = 0; i < count; i++)
@@ -460,10 +495,10 @@ int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int co
 
        free(param_out);
 
-       return ERROR_OK;
+       return retval;
 }
 
-int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint8_t *buf)
+static int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint8_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -506,13 +541,10 @@ int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int cou
        uint32_t *param_out = malloc(count * sizeof(uint32_t));
        int i;
 
-//     int retval;
+       int retval = ERROR_OK;
        int blocksize;
-       int bytesread;
        uint32_t param_in[2];
 
-       bytesread = 0;
-
 //     while (count > 0)
        {
                blocksize = count;
@@ -522,12 +554,11 @@ int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int cou
                param_in[0] = addr;
                param_in[1] = blocksize;
 
-               mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+               retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                        ARRAY_SIZE(param_in), param_in, count, param_out, 1);
 
 //             count -= blocksize;
 //             addr += blocksize;
-//             bytesread += blocksize;
        }
 
        for (i = 0; i < count; i++)
@@ -537,7 +568,99 @@ int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int cou
 
        free(param_out);
 
-       return ERROR_OK;
+       return retval;
+}
+
+int mips32_cp0_read(struct mips_ejtag *ejtag_info, uint32_t *val, uint32_t cp0_reg, uint32_t cp0_sel)
+{
+       /**
+        * Do not make this code static, but regenerate it every time,
+        * as 5th element has to be changed to add parameters
+        */
+       uint32_t code[] = {
+                                                                                                                       /* start: */
+               MIPS32_MTC0(15,31,0),                                                           /* move $15 to COP0 DeSave */
+               MIPS32_LUI(15,UPPER16(MIPS32_PRACC_STACK)),                     /* $15 = MIPS32_PRACC_STACK */
+               MIPS32_ORI(15,15,LOWER16(MIPS32_PRACC_STACK)),
+               MIPS32_SW(8,0,15),                                                                      /* sw $8,($15) */
+               MIPS32_SW(9,0,15),                                                                      /* sw $9,($15) */
+
+               /* 5 */ MIPS32_MFC0(8,0,0),                                                     /* move COP0 [cp0_reg select] to $8 */
+
+               MIPS32_LUI(9,UPPER16(MIPS32_PRACC_PARAM_OUT)),          /* $11 = MIPS32_PRACC_PARAM_OUT */
+               MIPS32_ORI(9,9,LOWER16(MIPS32_PRACC_PARAM_OUT)),
+               MIPS32_SW(8,0,9),                                                                       /* sw $8,0($9) */
+
+               MIPS32_LW(9,0,15),                                                                      /* lw $9,($15) */
+               MIPS32_LW(8,0,15),                                                                      /* lw $8,($15) */
+               MIPS32_B(NEG16(12)),                                                            /* b start */
+               MIPS32_MFC0(15,31,0),                                                           /* move COP0 DeSave to $15 */
+       };
+
+       /**
+        * Note that our input parametes cp0_reg and cp0_sel
+        * are numbers (not gprs) which make part of mfc0 instruction opcode.
+        *
+        * These are not fix, but can be different for each mips32_cp0_read() function call,
+        * and that is why we must insert them directly into opcode,
+        * i.e. we can not pass it on EJTAG microprogram stack (via param_in),
+        * and put them into the gprs later from MIPS32_PRACC_STACK
+        * because mfc0 do not use gpr as a parameter for the cp0_reg and select part,
+        * but plain (immediate) number.
+        *
+        * MIPS32_MTC0 is implemented via MIPS32_R_INST macro.
+        * In order to insert our parameters, we must change rd and funct fields.
+        */
+       code[5] |= (cp0_reg << 11) | cp0_sel;  /* change rd and funct of MIPS32_R_INST macro */
+
+       /* TODO remove array */
+       uint32_t *param_out = val;
+       int retval;
+
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 0, NULL, 1, param_out, 1);
+
+       return retval;
+}
+
+int mips32_cp0_write(struct mips_ejtag *ejtag_info,
+                                                                                       uint32_t val, uint32_t cp0_reg, uint32_t cp0_sel)
+{
+       uint32_t code[] = {
+                                                                                                                       /* start: */
+               MIPS32_MTC0(15,31,0),                                                           /* move $15 to COP0 DeSave */
+               MIPS32_LUI(15,UPPER16(MIPS32_PRACC_STACK)),                     /* $15 = MIPS32_PRACC_STACK */
+               MIPS32_ORI(15,15,LOWER16(MIPS32_PRACC_STACK)),
+               MIPS32_SW(8,0,15),                                                                      /* sw $8,($15) */
+               MIPS32_SW(9,0,15),                                                                      /* sw $9,($15) */
+
+               MIPS32_LUI(8,UPPER16(MIPS32_PRACC_PARAM_IN)),           /* $8 = MIPS32_PRACC_PARAM_IN */
+               MIPS32_ORI(8,8,LOWER16(MIPS32_PRACC_PARAM_IN)),
+               MIPS32_LW(9,0,8),                                                                       /* Load write val to $9 */
+
+               /* 8 */ MIPS32_MTC0(9,0,0),                                                     /* move $9 to COP0 [cp0_reg select] */
+
+               MIPS32_LW(9,0,15),                                                                      /* lw $9,($15) */
+               MIPS32_LW(8,0,15),                                                                      /* lw $8,($15) */
+               MIPS32_B(NEG16(12)),                                                            /* b start */
+               MIPS32_MFC0(15,31,0),                                                           /* move COP0 DeSave to $15 */
+       };
+
+       /**
+        * Note that MIPS32_MTC0 macro is implemented via MIPS32_R_INST macro.
+        * In order to insert our parameters, we must change rd and funct fields.
+        */
+       code[8] |= (cp0_reg << 11) | cp0_sel;  /* change rd and funct fields of MIPS32_R_INST macro */
+
+       /* TODO remove array */
+       uint32_t *param_in = malloc(1 * sizeof(uint32_t));
+       int retval;
+       param_in[0] = val;
+
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 1, param_in, 0, NULL, 1);
+
+       free(param_in);
+
+       return retval;
 }
 
 int mips32_pracc_write_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, void *buf)
@@ -558,7 +681,7 @@ int mips32_pracc_write_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int siz
        return ERROR_OK;
 }
 
-int mips32_pracc_write_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint32_t *buf)
+static int mips32_pracc_write_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint32_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -599,15 +722,16 @@ int mips32_pracc_write_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int c
 
        memcpy(&param_in[2], buf, count * sizeof(uint32_t));
 
-       mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+       int retval;
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                count + 2, param_in, 0, NULL, 1);
 
        free(param_in);
 
-       return ERROR_OK;
+       return retval;
 }
 
-int mips32_pracc_write_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
+static int mips32_pracc_write_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -633,13 +757,11 @@ int mips32_pracc_write_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_
        param_in[0] = addr;
        param_in[1] = *buf;
 
-       mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+       return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                ARRAY_SIZE(param_in), param_in, 0, NULL, 1);
-
-       return ERROR_OK;
 }
 
-int mips32_pracc_write_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint16_t *buf)
+static int mips32_pracc_write_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint16_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -689,15 +811,16 @@ int mips32_pracc_write_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int c
                param_in[i + 2] = buf[i];
        }
 
-       mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+       int retval;
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                count + 2, param_in, 0, NULL, 1);
 
        free(param_in);
 
-       return ERROR_OK;
+       return retval;
 }
 
-int mips32_pracc_write_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint8_t *buf)
+static int mips32_pracc_write_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint8_t *buf)
 {
        static const uint32_t code[] = {
                                                                                                                        /* start: */
@@ -748,7 +871,7 @@ int mips32_pracc_write_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int co
                param_in[i + 2] = buf[i];
        }
 
-       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                count + 2, param_in, 0, NULL, 1);
 
        free(param_in);
@@ -820,7 +943,7 @@ int mips32_pracc_write_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
 
        int retval;
 
-       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                        MIPS32NUMCOREREGS, regs, 0, NULL, 1);
 
        return retval;
@@ -895,7 +1018,7 @@ int mips32_pracc_read_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
 
        int retval;
 
-       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, \
+       retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
                0, NULL, MIPS32NUMCOREREGS, regs, 1);
 
        return retval;
@@ -909,7 +1032,7 @@ int mips32_pracc_read_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
  * 3. data ...
  */
 int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_area *source,
-                                                               int write, uint32_t addr, int count, uint32_t *buf)
+                                                               int write_t, uint32_t addr, int count, uint32_t *buf)
 {
        uint32_t handler_code[] = {
                /* caution when editing, table is modified below */
@@ -954,7 +1077,7 @@ int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_are
        if (source->size < MIPS32_FASTDATA_HANDLER_SIZE)
                return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 
-       if (write)
+       if (write_t)
        {
                handler_code[8] = MIPS32_LW(11,0,8);    /* load data from probe at fastdata area */
                handler_code[9] = MIPS32_SW(11,0,9);    /* store data to RAM @ r9 */
@@ -966,9 +1089,14 @@ int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_are
        }
 
        /* write program into RAM */
-       mips32_pracc_write_mem32(ejtag_info, source->address, ARRAY_SIZE(handler_code), handler_code);
+       if (write_t != ejtag_info->fast_access_save)
+       {
+               mips32_pracc_write_mem32(ejtag_info, source->address, ARRAY_SIZE(handler_code), handler_code);
+               /* save previous operation to speed to any consecutive read/writes */
+               ejtag_info->fast_access_save = write_t;
+       }
 
-       LOG_DEBUG("%s using 0x%.8" PRIx32 " for write handler\n", __func__, source->address);
+       LOG_DEBUG("%s using 0x%.8" PRIx32 " for write handler", __func__, source->address);
 
        jmp_code[1] |= UPPER16(source->address);
        jmp_code[2] |= LOWER16(source->address);
@@ -978,13 +1106,13 @@ int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_are
                if ((retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl)) != ERROR_OK)
                        return retval;
 
-               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA, NULL);
-               mips_ejtag_drscan_32(ejtag_info, &jmp_code[i]);
+               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
+               mips_ejtag_drscan_32_out(ejtag_info, jmp_code[i]);
 
                /* Clear the access pending bit (let the processor eat!) */
                ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
-               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
-               mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
+               mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
+               mips_ejtag_drscan_32_out(ejtag_info, ejtag_ctrl);
        }
 
        if ((retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl)) != ERROR_OK)
@@ -992,26 +1120,30 @@ int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_are
 
        /* next fetch to dmseg should be in FASTDATA_AREA, check */
        address = 0;
-       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS, NULL);
-       mips_ejtag_drscan_32(ejtag_info, &address);
+       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
+       retval = mips_ejtag_drscan_32(ejtag_info, &address);
+       if (retval != ERROR_OK)
+               return retval;
 
        if (address != MIPS32_PRACC_FASTDATA_AREA)
                return ERROR_FAIL;
 
+       /* wait PrAcc pending bit for FASTDATA write */
+       if ((retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl)) != ERROR_OK)
+               return retval;
+
        /* Send the load start address */
        val = addr;
-       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_FASTDATA, NULL);
+       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_FASTDATA);
        mips_ejtag_fastdata_scan(ejtag_info, 1, &val);
 
        /* Send the load end address */
        val = addr + (count - 1) * 4;
-       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_FASTDATA, NULL);
        mips_ejtag_fastdata_scan(ejtag_info, 1, &val);
 
        for (i = 0; i < count; i++)
        {
-               /* Send the data out using fastdata (clears the access pending bit) */
-               if ((retval = mips_ejtag_fastdata_scan(ejtag_info, write, buf++)) != ERROR_OK)
+               if ((retval = mips_ejtag_fastdata_scan(ejtag_info, write_t, buf++)) != ERROR_OK)
                        return retval;
        }
 
@@ -1025,11 +1157,13 @@ int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_are
                return retval;
 
        address = 0;
-       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS, NULL);
-       mips_ejtag_drscan_32(ejtag_info, &address);
+       mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
+       retval = mips_ejtag_drscan_32(ejtag_info, &address);
+       if (retval != ERROR_OK)
+               return retval;
 
        if (address != MIPS32_PRACC_TEXT)
-               LOG_ERROR("mini program did not return to start\n");
+               LOG_ERROR("mini program did not return to start");
 
        return retval;
 }