// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * altera-jtag.c
 *
 * altera FPGA driver
 *
 * Copyright (C) Altera Corporation 1998-2001
 * Copyright (C) 2010 NetUP Inc.
 * Copyright (C) 2010 Igor M. Liplianin <liplianin@netup.ru>
 */

#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/slab.h>
#include <misc/altera.h>
#include "altera-exprt.h"
#include "altera-jtag.h"

#define alt_jtag_io(a, b, c)\
                astate->config->jtag_io(astate->config->dev, a, b, c);

#define alt_malloc(a)   kzalloc(a, GFP_KERNEL);

/*
 * This structure shows, for each JTAG state, which state is reached after
 * a single TCK clock cycle with TMS high or TMS low, respectively.  This
 * describes all possible state transitions in the JTAG state machine.
 */
struct altera_jtag_machine {
        enum altera_jtag_state tms_high;
        enum altera_jtag_state tms_low;
};

static const struct altera_jtag_machine altera_transitions[] = {
        /* RESET     */ { RESET,        IDLE },
        /* IDLE      */ { DRSELECT,     IDLE },
        /* DRSELECT  */ { IRSELECT,     DRCAPTURE },
        /* DRCAPTURE */ { DREXIT1,      DRSHIFT },
        /* DRSHIFT   */ { DREXIT1,      DRSHIFT },
        /* DREXIT1   */ { DRUPDATE,     DRPAUSE },
        /* DRPAUSE   */ { DREXIT2,      DRPAUSE },
        /* DREXIT2   */ { DRUPDATE,     DRSHIFT },
        /* DRUPDATE  */ { DRSELECT,     IDLE },
        /* IRSELECT  */ { RESET,        IRCAPTURE },
        /* IRCAPTURE */ { IREXIT1,      IRSHIFT },
        /* IRSHIFT   */ { IREXIT1,      IRSHIFT },
        /* IREXIT1   */ { IRUPDATE,     IRPAUSE },
        /* IRPAUSE   */ { IREXIT2,      IRPAUSE },
        /* IREXIT2   */ { IRUPDATE,     IRSHIFT },
        /* IRUPDATE  */ { DRSELECT,     IDLE }
};

/*
 * This table contains the TMS value to be used to take the NEXT STEP on
 * the path to the desired state.  The array index is the current state,
 * and the bit position is the desired endstate.  To find out which state
 * is used as the intermediate state, look up the TMS value in the
 * altera_transitions[] table.
 */
static const u16 altera_jtag_path_map[16] = {
        /* RST  RTI     SDRS    CDR     SDR     E1DR    PDR     E2DR */
        0x0001, 0xFFFD, 0xFE01, 0xFFE7, 0xFFEF, 0xFF0F, 0xFFBF, 0xFFFF,
        /* UDR  SIRS    CIR     SIR     E1IR    PIR     E2IR    UIR */
        0xFEFD, 0x0001, 0xF3FF, 0xF7FF, 0x87FF, 0xDFFF, 0xFFFF, 0x7FFD
};

/* Flag bits for alt_jtag_io() function */
#define TMS_HIGH   1
#define TMS_LOW    0
#define TDI_HIGH   1
#define TDI_LOW    0
#define READ_TDO   1
#define IGNORE_TDO 0

int altera_jinit(struct altera_state *astate)
{
        struct altera_jtag *js = &astate->js;

        /* initial JTAG state is unknown */
        js->jtag_state = ILLEGAL_JTAG_STATE;

        /* initialize to default state */
        js->drstop_state = IDLE;
        js->irstop_state = IDLE;
        js->dr_pre  = 0;
        js->dr_post = 0;
        js->ir_pre  = 0;
        js->ir_post = 0;
        js->dr_length    = 0;
        js->ir_length    = 0;

        js->dr_pre_data  = NULL;
        js->dr_post_data = NULL;
        js->ir_pre_data  = NULL;
        js->ir_post_data = NULL;
        js->dr_buffer    = NULL;
        js->ir_buffer    = NULL;

        return 0;
}

int altera_set_drstop(struct altera_jtag *js, enum altera_jtag_state state)
{
        js->drstop_state = state;

        return 0;
}

int altera_set_irstop(struct altera_jtag *js, enum altera_jtag_state state)
{
        js->irstop_state = state;

        return 0;
}

int altera_set_dr_pre(struct altera_jtag *js,
                                u32 count, u32 start_index,
                                u8 *preamble_data)
{
        int status = 0;
        u32 i;
        u32 j;

        if (count > js->dr_pre) {
                kfree(js->dr_pre_data);
                js->dr_pre_data = (u8 *)alt_malloc((count + 7) >> 3);
                if (js->dr_pre_data == NULL)
                        status = -ENOMEM;
                else
                        js->dr_pre = count;
        } else
                js->dr_pre = count;

        if (status == 0) {
                for (i = 0; i < count; ++i) {
                        j = i + start_index;

                        if (preamble_data == NULL)
                                js->dr_pre_data[i >> 3] |= (1 << (i & 7));
                        else {
                                if (preamble_data[j >> 3] & (1 << (j & 7)))
                                        js->dr_pre_data[i >> 3] |=
                                                        (1 << (i & 7));
                                else
                                        js->dr_pre_data[i >> 3] &=
                                                        ~(u32)(1 << (i & 7));

                        }
                }
        }

        return status;
}

int altera_set_ir_pre(struct altera_jtag *js, u32 count, u32 start_index,
                                                        u8 *preamble_data)
{
        int status = 0;
        u32 i;
        u32 j;

        if (count > js->ir_pre) {
                kfree(js->ir_pre_data);
                js->ir_pre_data = (u8 *)alt_malloc((count + 7) >> 3);
                if (js->ir_pre_data == NULL)
                        status = -ENOMEM;
                else
                        js->ir_pre = count;

        } else
                js->ir_pre = count;

        if (status == 0) {
                for (i = 0; i < count; ++i) {
                        j = i + start_index;
                        if (preamble_data == NULL)
                                js->ir_pre_data[i >> 3] |= (1 << (i & 7));
                        else {
                                if (preamble_data[j >> 3] & (1 << (j & 7)))
                                        js->ir_pre_data[i >> 3] |=
                                                        (1 << (i & 7));
                                else
                                        js->ir_pre_data[i >> 3] &=
                                                        ~(u32)(1 << (i & 7));

                        }
                }
        }

        return status;
}

int altera_set_dr_post(struct altera_jtag *js, u32 count, u32 start_index,
                                                u8 *postamble_data)
{
        int status = 0;
        u32 i;
        u32 j;

        if (count > js->dr_post) {
                kfree(js->dr_post_data);
                js->dr_post_data = (u8 *)alt_malloc((count + 7) >> 3);

                if (js->dr_post_data == NULL)
                        status = -ENOMEM;
                else
                        js->dr_post = count;

        } else
                js->dr_post = count;

        if (status == 0) {
                for (i = 0; i < count; ++i) {
                        j = i + start_index;

                        if (postamble_data == NULL)
                                js->dr_post_data[i >> 3] |= (1 << (i & 7));
                        else {
                                if (postamble_data[j >> 3] & (1 << (j & 7)))
                                        js->dr_post_data[i >> 3] |=
                                                                (1 << (i & 7));
                                else
                                        js->dr_post_data[i >> 3] &=
                                            ~(u32)(1 << (i & 7));

                        }
                }
        }

        return status;
}

int altera_set_ir_post(struct altera_jtag *js, u32 count, u32 start_index,
                                                u8 *postamble_data)
{
        int status = 0;
        u32 i;
        u32 j;

        if (count > js->ir_post) {
                kfree(js->ir_post_data);
                js->ir_post_data = (u8 *)alt_malloc((count + 7) >> 3);
                if (js->ir_post_data == NULL)
                        status = -ENOMEM;
                else
                        js->ir_post = count;

        } else
                js->ir_post = count;

        if (status != 0)
                return status;

        for (i = 0; i < count; ++i) {
                j = i + start_index;

                if (postamble_data == NULL)
                        js->ir_post_data[i >> 3] |= (1 << (i & 7));
                else {
                        if (postamble_data[j >> 3] & (1 << (j & 7)))
                                js->ir_post_data[i >> 3] |= (1 << (i & 7));
                        else
                                js->ir_post_data[i >> 3] &=
                                    ~(u32)(1 << (i & 7));

                }
        }

        return status;
}

static void altera_jreset_idle(struct altera_state *astate)
{
        struct altera_jtag *js = &astate->js;
        int i;
        /* Go to Test Logic Reset (no matter what the starting state may be) */
        for (i = 0; i < 5; ++i)
                alt_jtag_io(TMS_HIGH, TDI_LOW, IGNORE_TDO);

        /* Now step to Run Test / Idle */
        alt_jtag_io(TMS_LOW, TDI_LOW, IGNORE_TDO);
        js->jtag_state = IDLE;
}

int altera_goto_jstate(struct altera_state *astate,
                                        enum altera_jtag_state state)
{
        struct altera_jtag *js = &astate->js;
        int tms;
        int count = 0;
        int status = 0;

        if (js->jtag_state == ILLEGAL_JTAG_STATE)
                /* initialize JTAG chain to known state */
                altera_jreset_idle(astate);

        if (js->jtag_state == state) {
                /*
                 * We are already in the desired state.
                 * If it is a stable state, loop here.
                 * Otherwise do nothing (no clock cycles).
                 */
                if ((state == IDLE) || (state == DRSHIFT) ||
                        (state == DRPAUSE) || (state == IRSHIFT) ||
                                (state == IRPAUSE)) {
                        alt_jtag_io(TMS_LOW, TDI_LOW, IGNORE_TDO);
                } else if (state == RESET)
                        alt_jtag_io(TMS_HIGH, TDI_LOW, IGNORE_TDO);

        } else {
                while ((js->jtag_state != state) && (count < 9)) {
                        /* Get TMS value to take a step toward desired state */
                        tms = (altera_jtag_path_map[js->jtag_state] &
                                                        (1 << state))
                                                        ? TMS_HIGH : TMS_LOW;

                        /* Take a step */
                        alt_jtag_io(tms, TDI_LOW, IGNORE_TDO);

                        if (tms)
                                js->jtag_state =
                                        altera_transitions[js->jtag_state].tms_high;
                        else
                                js->jtag_state =
                                        altera_transitions[js->jtag_state].tms_low;

                        ++count;
                }
        }

        if (js->jtag_state != state)
                status = -EREMOTEIO;

        return status;
}

int altera_wait_cycles(struct altera_state *astate,
                                        s32 cycles,
                                        enum altera_jtag_state wait_state)
{
        struct altera_jtag *js = &astate->js;
        int tms;
        s32 count;
        int status = 0;

        if (js->jtag_state != wait_state)
                status = altera_goto_jstate(astate, wait_state);

        if (status == 0) {
                /*
                 * Set TMS high to loop in RESET state
                 * Set TMS low to loop in any other stable state
                 */
                tms = (wait_state == RESET) ? TMS_HIGH : TMS_LOW;

                for (count = 0L; count < cycles; count++)
                        alt_jtag_io(tms, TDI_LOW, IGNORE_TDO);

        }

        return status;
}

int altera_wait_msecs(struct altera_state *astate,
                        s32 microseconds, enum altera_jtag_state wait_state)
/*
 * Causes JTAG hardware to sit in the specified stable
 * state for the specified duration of real time.  If
 * no JTAG operations have been performed yet, then only
 * a delay is performed.  This permits the WAIT USECS
 * statement to be used in VECTOR programs without causing
 * any JTAG operations.
 * Returns 0 for success, else appropriate error code.
 */
{
        struct altera_jtag *js = &astate->js;
        int status = 0;

        if ((js->jtag_state != ILLEGAL_JTAG_STATE) &&
            (js->jtag_state != wait_state))
                status = altera_goto_jstate(astate, wait_state);

        if (status == 0)
                /* Wait for specified time interval */
                udelay(microseconds);

        return status;
}

static void altera_concatenate_data(u8 *buffer,
                                u8 *preamble_data,
                                u32 preamble_count,
                                u8 *target_data,
                                u32 start_index,
                                u32 target_count,
                                u8 *postamble_data,
                                u32 postamble_count)
/*
 * Copies preamble data, target data, and postamble data
 * into one buffer for IR or DR scans.
 */
{
        u32 i, j, k;

        for (i = 0L; i < preamble_count; ++i) {
                if (preamble_data[i >> 3L] & (1L << (i & 7L)))
                        buffer[i >> 3L] |= (1L << (i & 7L));
                else
                        buffer[i >> 3L] &= ~(u32)(1L << (i & 7L));

        }

        j = start_index;
        k = preamble_count + target_count;
        for (; i < k; ++i, ++j) {
                if (target_data[j >> 3L] & (1L << (j & 7L)))
                        buffer[i >> 3L] |= (1L << (i & 7L));
                else
                        buffer[i >> 3L] &= ~(u32)(1L << (i & 7L));

        }

        j = 0L;
        k = preamble_count + target_count + postamble_count;
        for (; i < k; ++i, ++j) {
                if (postamble_data[j >> 3L] & (1L << (j & 7L)))
                        buffer[i >> 3L] |= (1L << (i & 7L));
                else
                        buffer[i >> 3L] &= ~(u32)(1L << (i & 7L));

        }
}

static int alt_jtag_drscan(struct altera_state *astate,
                        int start_state,
                        int count,
                        u8 *tdi,
                        u8 *tdo)
{
        int i = 0;
        int tdo_bit = 0;
        int status = 1;

        /* First go to DRSHIFT state */
        switch (start_state) {
        case 0:                                         /* IDLE */
                alt_jtag_io(1, 0, 0);   /* DRSELECT */
                alt_jtag_io(0, 0, 0);   /* DRCAPTURE */
                alt_jtag_io(0, 0, 0);   /* DRSHIFT */
                break;

        case 1:                                         /* DRPAUSE */
                alt_jtag_io(1, 0, 0);   /* DREXIT2 */
                alt_jtag_io(1, 0, 0);   /* DRUPDATE */
                alt_jtag_io(1, 0, 0);   /* DRSELECT */
                alt_jtag_io(0, 0, 0);   /* DRCAPTURE */
                alt_jtag_io(0, 0, 0);   /* DRSHIFT */
                break;

        case 2:                                         /* IRPAUSE */
                alt_jtag_io(1, 0, 0);   /* IREXIT2 */
                alt_jtag_io(1, 0, 0);   /* IRUPDATE */
                alt_jtag_io(1, 0, 0);   /* DRSELECT */
                alt_jtag_io(0, 0, 0);   /* DRCAPTURE */
                alt_jtag_io(0, 0, 0);   /* DRSHIFT */
                break;

        default:
                status = 0;
        }

        if (status) {
                /* loop in the SHIFT-DR state */
                for (i = 0; i < count; i++) {
                        tdo_bit = alt_jtag_io(
                                        (i == count - 1),
                                        tdi[i >> 3] & (1 << (i & 7)),
                                        (tdo != NULL));

                        if (tdo != NULL) {
                                if (tdo_bit)
                                        tdo[i >> 3] |= (1 << (i & 7));
                                else
                                        tdo[i >> 3] &= ~(u32)(1 << (i & 7));

                        }
                }

                alt_jtag_io(0, 0, 0);   /* DRPAUSE */
        }

        return status;
}

static int alt_jtag_irscan(struct altera_state *astate,
                    int start_state,
                    int count,
                    u8 *tdi,
                    u8 *tdo)
{
        int i = 0;
        int tdo_bit = 0;
        int status = 1;

        /* First go to IRSHIFT state */
        switch (start_state) {
        case 0:                                         /* IDLE */
                alt_jtag_io(1, 0, 0);   /* DRSELECT */
                alt_jtag_io(1, 0, 0);   /* IRSELECT */
                alt_jtag_io(0, 0, 0);   /* IRCAPTURE */
                alt_jtag_io(0, 0, 0);   /* IRSHIFT */
                break;

        case 1:                                         /* DRPAUSE */
                alt_jtag_io(1, 0, 0);   /* DREXIT2 */
                alt_jtag_io(1, 0, 0);   /* DRUPDATE */
                alt_jtag_io(1, 0, 0);   /* DRSELECT */
                alt_jtag_io(1, 0, 0);   /* IRSELECT */
                alt_jtag_io(0, 0, 0);   /* IRCAPTURE */
                alt_jtag_io(0, 0, 0);   /* IRSHIFT */
                break;

        case 2:                                         /* IRPAUSE */
                alt_jtag_io(1, 0, 0);   /* IREXIT2 */
                alt_jtag_io(1, 0, 0);   /* IRUPDATE */
                alt_jtag_io(1, 0, 0);   /* DRSELECT */
                alt_jtag_io(1, 0, 0);   /* IRSELECT */
                alt_jtag_io(0, 0, 0);   /* IRCAPTURE */
                alt_jtag_io(0, 0, 0);   /* IRSHIFT */
                break;

        default:
                status = 0;
        }

        if (status) {
                /* loop in the SHIFT-IR state */
                for (i = 0; i < count; i++) {
                        tdo_bit = alt_jtag_io(
                                      (i == count - 1),
                                      tdi[i >> 3] & (1 << (i & 7)),
                                      (tdo != NULL));
                        if (tdo != NULL) {
                                if (tdo_bit)
                                        tdo[i >> 3] |= (1 << (i & 7));
                                else
                                        tdo[i >> 3] &= ~(u32)(1 << (i & 7));

                        }
                }

                alt_jtag_io(0, 0, 0);   /* IRPAUSE */
        }

        return status;
}

static void altera_extract_target_data(u8 *buffer,
                                u8 *target_data,
                                u32 start_index,
                                u32 preamble_count,
                                u32 target_count)
/*
 * Copies target data from scan buffer, filtering out
 * preamble and postamble data.
 */
{
        u32 i;
        u32 j;
        u32 k;

        j = preamble_count;
        k = start_index + target_count;
        for (i = start_index; i < k; ++i, ++j) {
                if (buffer[j >> 3] & (1 << (j & 7)))
                        target_data[i >> 3] |= (1 << (i & 7));
                else
                        target_data[i >> 3] &= ~(u32)(1 << (i & 7));

        }
}

int altera_irscan(struct altera_state *astate,
                                u32 count,
                                u8 *tdi_data,
                                u32 start_index)
/* Shifts data into instruction register */
{
        struct altera_jtag *js = &astate->js;
        int start_code = 0;
        u32 alloc_chars = 0;
        u32 shift_count = js->ir_pre + count + js->ir_post;
        int status = 0;
        enum altera_jtag_state start_state = ILLEGAL_JTAG_STATE;

        switch (js->jtag_state) {
        case ILLEGAL_JTAG_STATE:
        case RESET:
        case IDLE:
                start_code = 0;
                start_state = IDLE;
                break;

        case DRSELECT:
        case DRCAPTURE:
        case DRSHIFT:
        case DREXIT1:
        case DRPAUSE:
        case DREXIT2:
        case DRUPDATE:
                start_code = 1;
                start_state = DRPAUSE;
                break;

        case IRSELECT:
        case IRCAPTURE:
        case IRSHIFT:
        case IREXIT1:
        case IRPAUSE:
        case IREXIT2:
        case IRUPDATE:
                start_code = 2;
                start_state = IRPAUSE;
                break;

        default:
                status = -EREMOTEIO;
                break;
        }

        if (status == 0)
                if (js->jtag_state != start_state)
                        status = altera_goto_jstate(astate, start_state);

        if (status == 0) {
                if (shift_count > js->ir_length) {
                        alloc_chars = (shift_count + 7) >> 3;
                        kfree(js->ir_buffer);
                        js->ir_buffer = (u8 *)alt_malloc(alloc_chars);
                        if (js->ir_buffer == NULL)
                                status = -ENOMEM;
                        else
                                js->ir_length = alloc_chars * 8;

                }
        }

        if (status == 0) {
                /*
                 * Copy preamble data, IR data,
                 * and postamble data into a buffer
                 */
                altera_concatenate_data(js->ir_buffer,
                                        js->ir_pre_data,
                                        js->ir_pre,
                                        tdi_data,
                                        start_index,
                                        count,
                                        js->ir_post_data,
                                        js->ir_post);
                /* Do the IRSCAN */
                alt_jtag_irscan(astate,
                                start_code,
                                shift_count,
                                js->ir_buffer,
                                NULL);

                /* alt_jtag_irscan() always ends in IRPAUSE state */
                js->jtag_state = IRPAUSE;
        }

        if (status == 0)
                if (js->irstop_state != IRPAUSE)
                        status = altera_goto_jstate(astate, js->irstop_state);


        return status;
}

int altera_swap_ir(struct altera_state *astate,
                            u32 count,
                            u8 *in_data,
                            u32 in_index,
                            u8 *out_data,
                            u32 out_index)
/* Shifts data into instruction register, capturing output data */
{
        struct altera_jtag *js = &astate->js;
        int start_code = 0;
        u32 alloc_chars = 0;
        u32 shift_count = js->ir_pre + count + js->ir_post;
        int status = 0;
        enum altera_jtag_state start_state = ILLEGAL_JTAG_STATE;

        switch (js->jtag_state) {
        case ILLEGAL_JTAG_STATE:
        case RESET:
        case IDLE:
                start_code = 0;
                start_state = IDLE;
                break;

        case DRSELECT:
        case DRCAPTURE:
        case DRSHIFT:
        case DREXIT1:
        case DRPAUSE:
        case DREXIT2:
        case DRUPDATE:
                start_code = 1;
                start_state = DRPAUSE;
                break;

        case IRSELECT:
        case IRCAPTURE:
        case IRSHIFT:
        case IREXIT1:
        case IRPAUSE:
        case IREXIT2:
        case IRUPDATE:
                start_code = 2;
                start_state = IRPAUSE;
                break;

        default:
                status = -EREMOTEIO;
                break;
        }

        if (status == 0)
                if (js->jtag_state != start_state)
                        status = altera_goto_jstate(astate, start_state);

        if (status == 0) {
                if (shift_count > js->ir_length) {
                        alloc_chars = (shift_count + 7) >> 3;
                        kfree(js->ir_buffer);
                        js->ir_buffer = (u8 *)alt_malloc(alloc_chars);
                        if (js->ir_buffer == NULL)
                                status = -ENOMEM;
                        else
                                js->ir_length = alloc_chars * 8;

                }
        }

        if (status == 0) {
                /*
                 * Copy preamble data, IR data,
                 * and postamble data into a buffer
                 */
                altera_concatenate_data(js->ir_buffer,
                                        js->ir_pre_data,
                                        js->ir_pre,
                                        in_data,
                                        in_index,
                                        count,
                                        js->ir_post_data,
                                        js->ir_post);

                /* Do the IRSCAN */
                alt_jtag_irscan(astate,
                                start_code,
                                shift_count,
                                js->ir_buffer,
                                js->ir_buffer);

                /* alt_jtag_irscan() always ends in IRPAUSE state */
                js->jtag_state = IRPAUSE;
        }

        if (status == 0)
                if (js->irstop_state != IRPAUSE)
                        status = altera_goto_jstate(astate, js->irstop_state);


        if (status == 0)
                /* Now extract the returned data from the buffer */
                altera_extract_target_data(js->ir_buffer,
                                        out_data, out_index,
                                        js->ir_pre, count);

        return status;
}

int altera_drscan(struct altera_state *astate,
                                u32 count,
                                u8 *tdi_data,
                                u32 start_index)
/* Shifts data into data register (ignoring output data) */
{
        struct altera_jtag *js = &astate->js;
        int start_code = 0;
        u32 alloc_chars = 0;
        u32 shift_count = js->dr_pre + count + js->dr_post;
        int status = 0;
        enum altera_jtag_state start_state = ILLEGAL_JTAG_STATE;

        switch (js->jtag_state) {
        case ILLEGAL_JTAG_STATE:
        case RESET:
        case IDLE:
                start_code = 0;
                start_state = IDLE;
                break;

        case DRSELECT:
        case DRCAPTURE:
        case DRSHIFT:
        case DREXIT1:
        case DRPAUSE:
        case DREXIT2:
        case DRUPDATE:
                start_code = 1;
                start_state = DRPAUSE;
                break;

        case IRSELECT:
        case IRCAPTURE:
        case IRSHIFT:
        case IREXIT1:
        case IRPAUSE:
        case IREXIT2:
        case IRUPDATE:
                start_code = 2;
                start_state = IRPAUSE;
                break;

        default:
                status = -EREMOTEIO;
                break;
        }

        if (status == 0)
                if (js->jtag_state != start_state)
                        status = altera_goto_jstate(astate, start_state);

        if (status == 0) {
                if (shift_count > js->dr_length) {
                        alloc_chars = (shift_count + 7) >> 3;
                        kfree(js->dr_buffer);
                        js->dr_buffer = (u8 *)alt_malloc(alloc_chars);
                        if (js->dr_buffer == NULL)
                                status = -ENOMEM;
                        else
                                js->dr_length = alloc_chars * 8;

                }
        }

        if (status == 0) {
                /*
                 * Copy preamble data, DR data,
                 * and postamble data into a buffer
                 */
                altera_concatenate_data(js->dr_buffer,
                                        js->dr_pre_data,
                                        js->dr_pre,
                                        tdi_data,
                                        start_index,
                                        count,
                                        js->dr_post_data,
                                        js->dr_post);
                /* Do the DRSCAN */
                alt_jtag_drscan(astate, start_code, shift_count,
                                js->dr_buffer, NULL);
                /* alt_jtag_drscan() always ends in DRPAUSE state */
                js->jtag_state = DRPAUSE;
        }

        if (status == 0)
                if (js->drstop_state != DRPAUSE)
                        status = altera_goto_jstate(astate, js->drstop_state);

        return status;
}

int altera_swap_dr(struct altera_state *astate, u32 count,
                                u8 *in_data, u32 in_index,
                                u8 *out_data, u32 out_index)
/* Shifts data into data register, capturing output data */
{
        struct altera_jtag *js = &astate->js;
        int start_code = 0;
        u32 alloc_chars = 0;
        u32 shift_count = js->dr_pre + count + js->dr_post;
        int status = 0;
        enum altera_jtag_state start_state = ILLEGAL_JTAG_STATE;

        switch (js->jtag_state) {
        case ILLEGAL_JTAG_STATE:
        case RESET:
        case IDLE:
                start_code = 0;
                start_state = IDLE;
                break;

        case DRSELECT:
        case DRCAPTURE:
        case DRSHIFT:
        case DREXIT1:
        case DRPAUSE:
        case DREXIT2:
        case DRUPDATE:
                start_code = 1;
                start_state = DRPAUSE;
                break;

        case IRSELECT:
        case IRCAPTURE:
        case IRSHIFT:
        case IREXIT1:
        case IRPAUSE:
        case IREXIT2:
        case IRUPDATE:
                start_code = 2;
                start_state = IRPAUSE;
                break;

        default:
                status = -EREMOTEIO;
                break;
        }

        if (status == 0)
                if (js->jtag_state != start_state)
                        status = altera_goto_jstate(astate, start_state);

        if (status == 0) {
                if (shift_count > js->dr_length) {
                        alloc_chars = (shift_count + 7) >> 3;
                        kfree(js->dr_buffer);
                        js->dr_buffer = (u8 *)alt_malloc(alloc_chars);

                        if (js->dr_buffer == NULL)
                                status = -ENOMEM;
                        else
                                js->dr_length = alloc_chars * 8;

                }
        }

        if (status == 0) {
                /*
                 * Copy preamble data, DR data,
                 * and postamble data into a buffer
                 */
                altera_concatenate_data(js->dr_buffer,
                                js->dr_pre_data,
                                js->dr_pre,
                                in_data,
                                in_index,
                                count,
                                js->dr_post_data,
                                js->dr_post);

                /* Do the DRSCAN */
                alt_jtag_drscan(astate,
                                start_code,
                                shift_count,
                                js->dr_buffer,
                                js->dr_buffer);

                /* alt_jtag_drscan() always ends in DRPAUSE state */
                js->jtag_state = DRPAUSE;
        }

        if (status == 0)
                if (js->drstop_state != DRPAUSE)
                        status = altera_goto_jstate(astate, js->drstop_state);

        if (status == 0)
                /* Now extract the returned data from the buffer */
                altera_extract_target_data(js->dr_buffer,
                                        out_data,
                                        out_index,
                                        js->dr_pre,
                                        count);

        return status;
}

void altera_free_buffers(struct altera_state *astate)
{
        struct altera_jtag *js = &astate->js;
        /* If the JTAG interface was used, reset it to TLR */
        if (js->jtag_state != ILLEGAL_JTAG_STATE)
                altera_jreset_idle(astate);

        kfree(js->dr_pre_data);
        js->dr_pre_data = NULL;

        kfree(js->dr_post_data);
        js->dr_post_data = NULL;

        kfree(js->dr_buffer);
        js->dr_buffer = NULL;

        kfree(js->ir_pre_data);
        js->ir_pre_data = NULL;

        kfree(js->ir_post_data);
        js->ir_post_data = NULL;

        kfree(js->ir_buffer);
        js->ir_buffer = NULL;
}