src/target/openrisc/or1k_tap_vjtag.c

   1 /***************************************************************************
   2  *   Copyright (C) 2013 by Franck Jullien                                  *
   3  *   elec4fun@gmail.com                                                    *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24
  25 #include "or1k_tap.h"
  26 #include "or1k.h"
  27
  28 #include <jtag/jtag.h>
  29
  30 /* Contains constants relevant to the Altera Virtual JTAG
  31  * device, which are not included in the BSDL.
  32  * As of this writing, these are constant across every
  33  * device which supports virtual JTAG.
  34  */
  35
  36 /* These are commands for the FPGA's IR. */
  37 #define ALTERA_CYCLONE_CMD_USER1        0x0E
  38 #define ALTERA_CYCLONE_CMD_USER0        0x0C
  39
  40 /* These defines are for the virtual IR (not the FPGA's)
  41  * The virtual TAP was defined in hardware to match the OpenCores native
  42  * TAP in both IR size and DEBUG command.
  43  */
  44 #define ALT_VJTAG_IR_SIZE               4
  45 #define ALT_VJTAG_CMD_DEBUG             0x8
  46
  47 /* SLD node ID. */
  48 #define JTAG_TO_AVALON_NODE_ID          0x84
  49 #define VJTAG_NODE_ID                   0x08
  50 #define SIGNAL_TAP_NODE_ID              0x00
  51 #define SERIAL_FLASH_LOADER_NODE_ID     0x04
  52
  53 #define VER(x)                          ((x >> 27) & 0x1f)
  54 #define NB_NODES(x)                     ((x >> 19) & 0xff)
  55 #define ID(x)                           ((x >> 19) & 0xff)
  56 #define MANUF(x)                        ((x >> 8)  & 0x7ff)
  57 #define M_WIDTH(x)                      ((x >> 0)  & 0xff)
  58 #define INST_ID(x)                      ((x >> 0)  & 0xff)
  59
  60 /* tap instructions - Mohor JTAG TAP */
  61 #define OR1K_TAP_INST_IDCODE 0x2
  62 #define OR1K_TAP_INST_DEBUG 0x8
  63
  64 static char *id_to_string(unsigned char id)
  65 {
  66         switch (id) {
  67         case VJTAG_NODE_ID:
  68                 return "Virtual JTAG";
  69         case JTAG_TO_AVALON_NODE_ID:
  70                 return "JTAG to avalon bridge";
  71         case SIGNAL_TAP_NODE_ID:
  72                 return "Signal TAP";
  73         case SERIAL_FLASH_LOADER_NODE_ID:
  74                 return "Serial Flash Loader";
  75         }
  76         return "unknown";
  77 }
  78
  79 static unsigned char guess_addr_width(unsigned char number_of_nodes)
  80 {
  81         unsigned char width = 0;
  82
  83         while (number_of_nodes) {
  84                 number_of_nodes >>= 1;
  85                 width++;
  86         }
  87
  88         return width;
  89 }
  90
  91 static int or1k_tap_vjtag_init(struct or1k_jtag *jtag_info)
  92 {
  93         LOG_DEBUG("Initialising Altera Virtual JTAG TAP");
  94
  95         /* Put TAP into state where it can talk to the debug interface
  96          * by shifting in correct value to IR.
  97          */
  98
  99         /* Ensure TAP is reset - maybe not necessary*/
 100         jtag_add_tlr();
 101
 102         /* You can use a custom JTAG controller to discover transactions
 103          * necessary to enumerate all Virtual JTAG megafunction instances
 104          * from your design atruntime. All SLD nodes and the virtual JTAG
 105          * registers that they contain are targeted by two Instruction Register
 106          * values, USER0 and USER1.
 107          *
 108          * The USER1 instruction targets the virtual IR of either the sld_hub
 109          * or a SLD node. That is,when the USER1 instruction is issued to
 110          * the device, the subsequent DR scans target a specific virtual
 111          * IR chain based on an address field contained within the DR scan.
 112          * The table below shows how the virtual IR, the DR target of the
 113          * USER1 instruction is interpreted.
 114          *
 115          * The VIR_VALUE in the table below is the virtual IR value for the
 116          * target SLD node. The width of this field is m bits in length,
 117          * where m is the length of the largest VIR for all of the SLD nodes
 118          * in the design. All SLD nodes with VIR lengths of fewer than m
 119          * bits must pad VIR_VALUE with zeros up to a length of m.
 120          *
 121          * -------------------------------+-------------------------------
 122          * m + n - 1                   m  |  m -1                       0
 123          * -------------------------------+-------------------------------
 124          *     ADDR [(n – 1)..0]          |     VIR_VALUE [(m – 1)..0]
 125          * -------------------------------+-------------------------------
 126          *
 127          * The ADDR bits act as address values to signal the active SLD node
 128          * that the virtual IR shift targets. ADDR is n bits in length, where
 129          * n bits must be long enough to encode all SLD nodes within the design,
 130          * as shown below.
 131          *
 132          * n = CEIL(log2(Number of SLD_nodes +1))
 133          *
 134          * The SLD hub is always 0 in the address map.
 135          *
 136          * Discovery and enumeration of the SLD instances within a design
 137          * requires interrogation of the sld_hub to determine the dimensions
 138          * of the USER1 DR (m and n) and associating each SLD instance, specifically
 139          * the Virtual JTAG megafunction instances, with an address value
 140          * contained within the ADDR bits of the USER1 DR.
 141          *
 142          * The SLD hub contains the HUB IP Configuration Register and SLD_NODE_INFO
 143          * register for each SLD node in the design. The HUB IP configuration register provides
 144          * information needed to determine the dimensions of the USER1 DR chain. The
 145          * SLD_NODE_INFO register is used to determine the address mapping for Virtual
 146          * JTAG instance in your design. This register set is shifted out by issuing the
 147          * HUB_INFO instruction. Both the ADDR bits for the SLD hub and the HUB_INFO
 148          * instruction is 0 × 0.
 149          * Because m and n are unknown at this point, the DR register
 150          * (ADDR bits + VIR_VALUE) must be filled with zeros. Shifting a sequence of 64 zeroes
 151          * into the USER1 DR is sufficient to cover the most conservative case for m and n.
 152          */
 153
 154         uint8_t t[4];
 155         struct scan_field field;
 156         struct jtag_tap *tap = jtag_info->tap;
 157
 158         /* Select VIR */
 159         buf_set_u32(t, 0, tap->ir_length, ALTERA_CYCLONE_CMD_USER1);
 160         field.num_bits = tap->ir_length;
 161         field.out_value = t;
 162         field.in_value = NULL;
 163         jtag_add_ir_scan(tap, &field, TAP_IDLE);
 164
 165         /* Select the SLD Hub */
 166         field.num_bits = 64;
 167         field.out_value = NULL;
 168         field.in_value = NULL;
 169         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
 170
 171         /* HUB IP Configuration Register
 172          *
 173          * When the USER1 and HUB_INFO instruction sequence is issued, the
 174          * USER0 instruction must be applied to enable the target register
 175          * of the HUB_INFO instruction. The HUB IP configuration register
 176          * is shifted out using eight four-bit nibble scans of the DR register.
 177          * Each four-bit scan must pass through the UPDATE_DR state before
 178          * the next four-bit scan. The 8 scans are assembled into a 32-bit
 179          * value with the definitions shown in the table below.
 180          *
 181          * --------------------------------------------------------------------------------
 182          *  NIBBLE7 | NIBBLE6 | NIBBLE5 | NIBBLE4 | NIBBLE3 | NIBBLE2 | NIBBLE1 | NIBBLE0
 183          * ----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+-----
 184          *     |    |    |    |    |    |    |    |    |    |    |    |    |    |    |
 185          * ----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+-----
 186          * HUB IP version|         N         | ALTERA_MFG_ID (0x06E)  |     SUM (m, n)
 187          * --------------+-------------------+------------------------+--------------------
 188          */
 189
 190         /* Select VDR */
 191         buf_set_u32(t, 0, tap->ir_length, ALTERA_CYCLONE_CMD_USER0);
 192         field.num_bits = tap->ir_length;
 193         field.out_value = t;
 194         field.in_value = NULL;
 195         jtag_add_ir_scan(tap, &field, TAP_IDLE);
 196
 197         int retval = jtag_execute_queue();
 198         if (retval != ERROR_OK)
 199                 return retval;
 200
 201         uint8_t nibble;
 202         uint32_t hub_info = 0;
 203
 204         for (int i = 0; i < 8; i++) {
 205                 field.num_bits = 4;
 206                 field.out_value = NULL;
 207                 field.in_value = &nibble;
 208                 jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
 209                 retval = jtag_execute_queue();
 210                 if (retval != ERROR_OK)
 211                         return retval;
 212                 hub_info = ((hub_info >> 4) | ((nibble & 0xf) << 28));
 213         }
 214
 215         int nb_nodes = NB_NODES(hub_info);
 216         int m_width = M_WIDTH(hub_info);
 217
 218         LOG_DEBUG("SLD HUB Configuration register");
 219         LOG_DEBUG("------------------------------");
 220         LOG_DEBUG("m_width         = %d", m_width);
 221         LOG_DEBUG("manufacturer_id = 0x%02x", MANUF(hub_info));
 222         LOG_DEBUG("nb_of_node      = %d", nb_nodes);
 223         LOG_DEBUG("version         = %d", VER(hub_info));
 224         LOG_DEBUG("VIR length      = %d", guess_addr_width(nb_nodes) + m_width);
 225
 226         /* Because the number of SLD nodes is now known, the Nodes on the hub can be
 227          * enumerated by repeating the 8 four-bit nibble scans, once for each Node,
 228          * to yield the SLD_NODE_INFO register of each Node. The DR nibble shifts
 229          * are a continuation of the HUB_INFO DR shift used to shift out the Hub IP
 230          * Configuration register.
 231          *
 232          * The order of the Nodes as they are shifted out determines the ADDR
 233          * values for the Nodes, beginning with, for the first Node SLD_NODE_INFO
 234          * shifted out, up to and including, for the last node on the hub. The
 235          * tables below show the SLD_NODE_INFO register and a their functional descriptions.
 236          *
 237          *  --------------+-----------+---------------+----------------
 238          *   31        27 | 26     19 | 18          8 | 7            0
 239          *  --------------+-----------+---------------+----------------
 240          *   Node Version |  NODE ID  |  NODE MFG_ID  |  NODE INST ID
 241          *
 242          */
 243
 244         int vjtag_node_address = -1;
 245         int node_index;
 246         uint32_t node_info = 0;
 247         for (node_index = 0; node_index < nb_nodes; node_index++) {
 248
 249                 for (int i = 0; i < 8; i++) {
 250                         field.num_bits = 4;
 251                         field.out_value = NULL;
 252                         field.in_value = &nibble;
 253                         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
 254                         retval = jtag_execute_queue();
 255                         if (retval != ERROR_OK)
 256                                 return retval;
 257                         node_info = ((node_info >> 4) | ((nibble & 0xf) << 28));
 258                 }
 259
 260                 LOG_DEBUG("Node info register");
 261                 LOG_DEBUG("--------------------");
 262                 LOG_DEBUG("instance_id     = %d", ID(node_info));
 263                 LOG_DEBUG("manufacturer_id = 0x%02x", MANUF(node_info));
 264                 LOG_DEBUG("node_id         = %d (%s)", ID(node_info),
 265                                                        id_to_string(ID(node_info)));
 266                 LOG_DEBUG("version         = %d", VER(node_info));
 267
 268                 if (ID(node_info) == VJTAG_NODE_ID)
 269                         vjtag_node_address = node_index + 1;
 270         }
 271
 272         if (vjtag_node_address < 0) {
 273                 LOG_ERROR("No VJTAG TAP instance found !");
 274                 return ERROR_FAIL;
 275         }
 276
 277         /* Select VIR */
 278         t[0] = ALTERA_CYCLONE_CMD_USER1;
 279         field.num_bits = tap->ir_length;
 280         field.out_value = t;
 281         field.in_value = NULL;
 282         jtag_add_ir_scan(tap, &field, TAP_IDLE);
 283
 284         /* Send the DEBUG command to the VJTAG IR */
 285         buf_set_u32(t, 0, field.num_bits, (vjtag_node_address << m_width) | ALT_VJTAG_CMD_DEBUG);
 286         field.num_bits = guess_addr_width(nb_nodes) + m_width;
 287         field.out_value = t;
 288         field.in_value = NULL;
 289         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
 290
 291         /* Select the VJTAG DR */
 292         t[0] = ALTERA_CYCLONE_CMD_USER0;
 293         field.num_bits = tap->ir_length;
 294         field.out_value = t;
 295         field.in_value = NULL;
 296         jtag_add_ir_scan(tap, &field, TAP_IDLE);
 297
 298         return jtag_execute_queue();
 299 }
 300
 301 static struct or1k_tap_ip vjtag_tap = {
 302         .name = "vjtag",
 303         .init = or1k_tap_vjtag_init,
 304 };
 305
 306 int or1k_tap_vjtag_register(void)
 307 {
 308         list_add_tail(&vjtag_tap.list, &tap_list);
 309         return 0;
 310 }