drivers/staging/octeon/cvmx-helper-rgmii.c

   1 /***********************license start***************
   2  * Author: Cavium Networks
   3  *
   4  * Contact: support@caviumnetworks.com
   5  * This file is part of the OCTEON SDK
   6  *
   7  * Copyright (c) 2003-2008 Cavium Networks
   8  *
   9  * This file is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License, Version 2, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This file is distributed in the hope that it will be useful, but
  14  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
  15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  16  * NONINFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this file; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  22  * or visit http://www.gnu.org/licenses/.
  23  *
  24  * This file may also be available under a different license from Cavium.
  25  * Contact Cavium Networks for more information
  26  ***********************license end**************************************/
  27
  28 /*
  29  * Functions for RGMII/GMII/MII initialization, configuration,
  30  * and monitoring.
  31  */
  32 #include <asm/octeon/octeon.h>
  33
  34 #include "cvmx-config.h"
  35
  36
  37 #include "cvmx-mdio.h"
  38 #include "cvmx-pko.h"
  39 #include "cvmx-helper.h"
  40 #include "cvmx-helper-board.h"
  41
  42 #include <asm/octeon/cvmx-npi-defs.h>
  43 #include "cvmx-gmxx-defs.h"
  44 #include "cvmx-asxx-defs.h"
  45 #include "cvmx-dbg-defs.h"
  46
  47 void __cvmx_interrupt_gmxx_enable(int interface);
  48 void __cvmx_interrupt_asxx_enable(int block);
  49
  50 /**
  51  * Probe RGMII ports and determine the number present
  52  *
  53  * @interface: Interface to probe
  54  *
  55  * Returns Number of RGMII/GMII/MII ports (0-4).
  56  */
  57 int __cvmx_helper_rgmii_probe(int interface)
  58 {
  59         int num_ports = 0;
  60         union cvmx_gmxx_inf_mode mode;
  61         mode.u64 = cvmx_read_csr(CVMX_GMXX_INF_MODE(interface));
  62
  63         if (mode.s.type) {
  64                 if (OCTEON_IS_MODEL(OCTEON_CN38XX)
  65                     || OCTEON_IS_MODEL(OCTEON_CN58XX)) {
  66                         cvmx_dprintf("ERROR: RGMII initialize called in "
  67                                      "SPI interface\n");
  68                 } else if (OCTEON_IS_MODEL(OCTEON_CN31XX)
  69                            || OCTEON_IS_MODEL(OCTEON_CN30XX)
  70                            || OCTEON_IS_MODEL(OCTEON_CN50XX)) {
  71                         /*
  72                          * On these chips "type" says we're in
  73                          * GMII/MII mode. This limits us to 2 ports
  74                          */
  75                         num_ports = 2;
  76                 } else {
  77                         cvmx_dprintf("ERROR: Unsupported Octeon model in %s\n",
  78                                      __func__);
  79                 }
  80         } else {
  81                 if (OCTEON_IS_MODEL(OCTEON_CN38XX)
  82                     || OCTEON_IS_MODEL(OCTEON_CN58XX)) {
  83                         num_ports = 4;
  84                 } else if (OCTEON_IS_MODEL(OCTEON_CN31XX)
  85                            || OCTEON_IS_MODEL(OCTEON_CN30XX)
  86                            || OCTEON_IS_MODEL(OCTEON_CN50XX)) {
  87                         num_ports = 3;
  88                 } else {
  89                         cvmx_dprintf("ERROR: Unsupported Octeon model in %s\n",
  90                                      __func__);
  91                 }
  92         }
  93         return num_ports;
  94 }
  95
  96 /**
  97  * Put an RGMII interface in loopback mode. Internal packets sent
  98  * out will be received back again on the same port. Externally
  99  * received packets will echo back out.
 100  *
 101  * @port:   IPD port number to loop.
 102  */
 103 void cvmx_helper_rgmii_internal_loopback(int port)
 104 {
 105         int interface = (port >> 4) & 1;
 106         int index = port & 0xf;
 107         uint64_t tmp;
 108
 109         union cvmx_gmxx_prtx_cfg gmx_cfg;
 110         gmx_cfg.u64 = 0;
 111         gmx_cfg.s.duplex = 1;
 112         gmx_cfg.s.slottime = 1;
 113         gmx_cfg.s.speed = 1;
 114         cvmx_write_csr(CVMX_GMXX_TXX_CLK(index, interface), 1);
 115         cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 0x200);
 116         cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0x2000);
 117         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmx_cfg.u64);
 118         tmp = cvmx_read_csr(CVMX_ASXX_PRT_LOOP(interface));
 119         cvmx_write_csr(CVMX_ASXX_PRT_LOOP(interface), (1 << index) | tmp);
 120         tmp = cvmx_read_csr(CVMX_ASXX_TX_PRT_EN(interface));
 121         cvmx_write_csr(CVMX_ASXX_TX_PRT_EN(interface), (1 << index) | tmp);
 122         tmp = cvmx_read_csr(CVMX_ASXX_RX_PRT_EN(interface));
 123         cvmx_write_csr(CVMX_ASXX_RX_PRT_EN(interface), (1 << index) | tmp);
 124         gmx_cfg.s.en = 1;
 125         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmx_cfg.u64);
 126 }
 127
 128 /**
 129  * Workaround ASX setup errata with CN38XX pass1
 130  *
 131  * @interface: Interface to setup
 132  * @port:      Port to setup (0..3)
 133  * @cpu_clock_hz:
 134  *                  Chip frequency in Hertz
 135  *
 136  * Returns Zero on success, negative on failure
 137  */
 138 static int __cvmx_helper_errata_asx_pass1(int interface, int port,
 139                                           int cpu_clock_hz)
 140 {
 141         /* Set hi water mark as per errata GMX-4 */
 142         if (cpu_clock_hz >= 325000000 && cpu_clock_hz < 375000000)
 143                 cvmx_write_csr(CVMX_ASXX_TX_HI_WATERX(port, interface), 12);
 144         else if (cpu_clock_hz >= 375000000 && cpu_clock_hz < 437000000)
 145                 cvmx_write_csr(CVMX_ASXX_TX_HI_WATERX(port, interface), 11);
 146         else if (cpu_clock_hz >= 437000000 && cpu_clock_hz < 550000000)
 147                 cvmx_write_csr(CVMX_ASXX_TX_HI_WATERX(port, interface), 10);
 148         else if (cpu_clock_hz >= 550000000 && cpu_clock_hz < 687000000)
 149                 cvmx_write_csr(CVMX_ASXX_TX_HI_WATERX(port, interface), 9);
 150         else
 151                 cvmx_dprintf("Illegal clock frequency (%d). "
 152                         "CVMX_ASXX_TX_HI_WATERX not set\n", cpu_clock_hz);
 153         return 0;
 154 }
 155
 156 /**
 157  * Configure all of the ASX, GMX, and PKO regsiters required
 158  * to get RGMII to function on the supplied interface.
 159  *
 160  * @interface: PKO Interface to configure (0 or 1)
 161  *
 162  * Returns Zero on success
 163  */
 164 int __cvmx_helper_rgmii_enable(int interface)
 165 {
 166         int num_ports = cvmx_helper_ports_on_interface(interface);
 167         int port;
 168         struct cvmx_sysinfo *sys_info_ptr = cvmx_sysinfo_get();
 169         union cvmx_gmxx_inf_mode mode;
 170         union cvmx_asxx_tx_prt_en asx_tx;
 171         union cvmx_asxx_rx_prt_en asx_rx;
 172
 173         mode.u64 = cvmx_read_csr(CVMX_GMXX_INF_MODE(interface));
 174
 175         if (mode.s.en == 0)
 176                 return -1;
 177         if ((OCTEON_IS_MODEL(OCTEON_CN38XX) ||
 178              OCTEON_IS_MODEL(OCTEON_CN58XX)) && mode.s.type == 1)
 179                 /* Ignore SPI interfaces */
 180                 return -1;
 181
 182         /* Configure the ASX registers needed to use the RGMII ports */
 183         asx_tx.u64 = 0;
 184         asx_tx.s.prt_en = cvmx_build_mask(num_ports);
 185         cvmx_write_csr(CVMX_ASXX_TX_PRT_EN(interface), asx_tx.u64);
 186
 187         asx_rx.u64 = 0;
 188         asx_rx.s.prt_en = cvmx_build_mask(num_ports);
 189         cvmx_write_csr(CVMX_ASXX_RX_PRT_EN(interface), asx_rx.u64);
 190
 191         /* Configure the GMX registers needed to use the RGMII ports */
 192         for (port = 0; port < num_ports; port++) {
 193                 /* Setting of CVMX_GMXX_TXX_THRESH has been moved to
 194                    __cvmx_helper_setup_gmx() */
 195
 196                 if (cvmx_octeon_is_pass1())
 197                         __cvmx_helper_errata_asx_pass1(interface, port,
 198                                                        sys_info_ptr->
 199                                                        cpu_clock_hz);
 200                 else {
 201                         /*
 202                          * Configure more flexible RGMII preamble
 203                          * checking. Pass 1 doesn't support this
 204                          * feature.
 205                          */
 206                         union cvmx_gmxx_rxx_frm_ctl frm_ctl;
 207                         frm_ctl.u64 =
 208                             cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL
 209                                           (port, interface));
 210                         /* New field, so must be compile time */
 211                         frm_ctl.s.pre_free = 1;
 212                         cvmx_write_csr(CVMX_GMXX_RXX_FRM_CTL(port, interface),
 213                                        frm_ctl.u64);
 214                 }
 215
 216                 /*
 217                  * Each pause frame transmitted will ask for about 10M
 218                  * bit times before resume.  If buffer space comes
 219                  * available before that time has expired, an XON
 220                  * pause frame (0 time) will be transmitted to restart
 221                  * the flow.
 222                  */
 223                 cvmx_write_csr(CVMX_GMXX_TXX_PAUSE_PKT_TIME(port, interface),
 224                                20000);
 225                 cvmx_write_csr(CVMX_GMXX_TXX_PAUSE_PKT_INTERVAL
 226                                (port, interface), 19000);
 227
 228                 if (OCTEON_IS_MODEL(OCTEON_CN50XX)) {
 229                         cvmx_write_csr(CVMX_ASXX_TX_CLK_SETX(port, interface),
 230                                        16);
 231                         cvmx_write_csr(CVMX_ASXX_RX_CLK_SETX(port, interface),
 232                                        16);
 233                 } else {
 234                         cvmx_write_csr(CVMX_ASXX_TX_CLK_SETX(port, interface),
 235                                        24);
 236                         cvmx_write_csr(CVMX_ASXX_RX_CLK_SETX(port, interface),
 237                                        24);
 238                 }
 239         }
 240
 241         __cvmx_helper_setup_gmx(interface, num_ports);
 242
 243         /* enable the ports now */
 244         for (port = 0; port < num_ports; port++) {
 245                 union cvmx_gmxx_prtx_cfg gmx_cfg;
 246                 cvmx_helper_link_autoconf(cvmx_helper_get_ipd_port
 247                                           (interface, port));
 248                 gmx_cfg.u64 =
 249                     cvmx_read_csr(CVMX_GMXX_PRTX_CFG(port, interface));
 250                 gmx_cfg.s.en = 1;
 251                 cvmx_write_csr(CVMX_GMXX_PRTX_CFG(port, interface),
 252                                gmx_cfg.u64);
 253         }
 254         __cvmx_interrupt_asxx_enable(interface);
 255         __cvmx_interrupt_gmxx_enable(interface);
 256
 257         return 0;
 258 }
 259
 260 /**
 261  * Return the link state of an IPD/PKO port as returned by
 262  * auto negotiation. The result of this function may not match
 263  * Octeon's link config if auto negotiation has changed since
 264  * the last call to cvmx_helper_link_set().
 265  *
 266  * @ipd_port: IPD/PKO port to query
 267  *
 268  * Returns Link state
 269  */
 270 cvmx_helper_link_info_t __cvmx_helper_rgmii_link_get(int ipd_port)
 271 {
 272         int interface = cvmx_helper_get_interface_num(ipd_port);
 273         int index = cvmx_helper_get_interface_index_num(ipd_port);
 274         union cvmx_asxx_prt_loop asxx_prt_loop;
 275
 276         asxx_prt_loop.u64 = cvmx_read_csr(CVMX_ASXX_PRT_LOOP(interface));
 277         if (asxx_prt_loop.s.int_loop & (1 << index)) {
 278                 /* Force 1Gbps full duplex on internal loopback */
 279                 cvmx_helper_link_info_t result;
 280                 result.u64 = 0;
 281                 result.s.full_duplex = 1;
 282                 result.s.link_up = 1;
 283                 result.s.speed = 1000;
 284                 return result;
 285         } else
 286                 return __cvmx_helper_board_link_get(ipd_port);
 287 }
 288
 289 /**
 290  * Configure an IPD/PKO port for the specified link state. This
 291  * function does not influence auto negotiation at the PHY level.
 292  * The passed link state must always match the link state returned
 293  * by cvmx_helper_link_get(). It is normally best to use
 294  * cvmx_helper_link_autoconf() instead.
 295  *
 296  * @ipd_port:  IPD/PKO port to configure
 297  * @link_info: The new link state
 298  *
 299  * Returns Zero on success, negative on failure
 300  */
 301 int __cvmx_helper_rgmii_link_set(int ipd_port,
 302                                  cvmx_helper_link_info_t link_info)
 303 {
 304         int result = 0;
 305         int interface = cvmx_helper_get_interface_num(ipd_port);
 306         int index = cvmx_helper_get_interface_index_num(ipd_port);
 307         union cvmx_gmxx_prtx_cfg original_gmx_cfg;
 308         union cvmx_gmxx_prtx_cfg new_gmx_cfg;
 309         union cvmx_pko_mem_queue_qos pko_mem_queue_qos;
 310         union cvmx_pko_mem_queue_qos pko_mem_queue_qos_save[16];
 311         union cvmx_gmxx_tx_ovr_bp gmx_tx_ovr_bp;
 312         union cvmx_gmxx_tx_ovr_bp gmx_tx_ovr_bp_save;
 313         int i;
 314
 315         /* Ignore speed sets in the simulator */
 316         if (cvmx_sysinfo_get()->board_type == CVMX_BOARD_TYPE_SIM)
 317                 return 0;
 318
 319         /* Read the current settings so we know the current enable state */
 320         original_gmx_cfg.u64 =
 321             cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 322         new_gmx_cfg = original_gmx_cfg;
 323
 324         /* Disable the lowest level RX */
 325         cvmx_write_csr(CVMX_ASXX_RX_PRT_EN(interface),
 326                        cvmx_read_csr(CVMX_ASXX_RX_PRT_EN(interface)) &
 327                                      ~(1 << index));
 328
 329         /* Disable all queues so that TX should become idle */
 330         for (i = 0; i < cvmx_pko_get_num_queues(ipd_port); i++) {
 331                 int queue = cvmx_pko_get_base_queue(ipd_port) + i;
 332                 cvmx_write_csr(CVMX_PKO_REG_READ_IDX, queue);
 333                 pko_mem_queue_qos.u64 = cvmx_read_csr(CVMX_PKO_MEM_QUEUE_QOS);
 334                 pko_mem_queue_qos.s.pid = ipd_port;
 335                 pko_mem_queue_qos.s.qid = queue;
 336                 pko_mem_queue_qos_save[i] = pko_mem_queue_qos;
 337                 pko_mem_queue_qos.s.qos_mask = 0;
 338                 cvmx_write_csr(CVMX_PKO_MEM_QUEUE_QOS, pko_mem_queue_qos.u64);
 339         }
 340
 341         /* Disable backpressure */
 342         gmx_tx_ovr_bp.u64 = cvmx_read_csr(CVMX_GMXX_TX_OVR_BP(interface));
 343         gmx_tx_ovr_bp_save = gmx_tx_ovr_bp;
 344         gmx_tx_ovr_bp.s.bp &= ~(1 << index);
 345         gmx_tx_ovr_bp.s.en |= 1 << index;
 346         cvmx_write_csr(CVMX_GMXX_TX_OVR_BP(interface), gmx_tx_ovr_bp.u64);
 347         cvmx_read_csr(CVMX_GMXX_TX_OVR_BP(interface));
 348
 349         /*
 350          * Poll the GMX state machine waiting for it to become
 351          * idle. Preferably we should only change speed when it is
 352          * idle. If it doesn't become idle we will still do the speed
 353          * change, but there is a slight chance that GMX will
 354          * lockup.
 355          */
 356         cvmx_write_csr(CVMX_NPI_DBG_SELECT,
 357                        interface * 0x800 + index * 0x100 + 0x880);
 358         CVMX_WAIT_FOR_FIELD64(CVMX_DBG_DATA, union cvmx_dbg_data, data & 7,
 359                         ==, 0, 10000);
 360         CVMX_WAIT_FOR_FIELD64(CVMX_DBG_DATA, union cvmx_dbg_data, data & 0xf,
 361                         ==, 0, 10000);
 362
 363         /* Disable the port before we make any changes */
 364         new_gmx_cfg.s.en = 0;
 365         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), new_gmx_cfg.u64);
 366         cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 367
 368         /* Set full/half duplex */
 369         if (cvmx_octeon_is_pass1())
 370                 /* Half duplex is broken for 38XX Pass 1 */
 371                 new_gmx_cfg.s.duplex = 1;
 372         else if (!link_info.s.link_up)
 373                 /* Force full duplex on down links */
 374                 new_gmx_cfg.s.duplex = 1;
 375         else
 376                 new_gmx_cfg.s.duplex = link_info.s.full_duplex;
 377
 378         /* Set the link speed. Anything unknown is set to 1Gbps */
 379         if (link_info.s.speed == 10) {
 380                 new_gmx_cfg.s.slottime = 0;
 381                 new_gmx_cfg.s.speed = 0;
 382         } else if (link_info.s.speed == 100) {
 383                 new_gmx_cfg.s.slottime = 0;
 384                 new_gmx_cfg.s.speed = 0;
 385         } else {
 386                 new_gmx_cfg.s.slottime = 1;
 387                 new_gmx_cfg.s.speed = 1;
 388         }
 389
 390         /* Adjust the clocks */
 391         if (link_info.s.speed == 10) {
 392                 cvmx_write_csr(CVMX_GMXX_TXX_CLK(index, interface), 50);
 393                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 0x40);
 394                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0);
 395         } else if (link_info.s.speed == 100) {
 396                 cvmx_write_csr(CVMX_GMXX_TXX_CLK(index, interface), 5);
 397                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 0x40);
 398                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0);
 399         } else {
 400                 cvmx_write_csr(CVMX_GMXX_TXX_CLK(index, interface), 1);
 401                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 0x200);
 402                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0x2000);
 403         }
 404
 405         if (OCTEON_IS_MODEL(OCTEON_CN30XX) || OCTEON_IS_MODEL(OCTEON_CN50XX)) {
 406                 if ((link_info.s.speed == 10) || (link_info.s.speed == 100)) {
 407                         union cvmx_gmxx_inf_mode mode;
 408                         mode.u64 = cvmx_read_csr(CVMX_GMXX_INF_MODE(interface));
 409
 410         /*
 411          * Port  .en  .type  .p0mii  Configuration
 412          * ----  ---  -----  ------  -----------------------------------------
 413          *  X      0     X      X    All links are disabled.
 414          *  0      1     X      0    Port 0 is RGMII
 415          *  0      1     X      1    Port 0 is MII
 416          *  1      1     0      X    Ports 1 and 2 are configured as RGMII ports.
 417          *  1      1     1      X    Port 1: GMII/MII; Port 2: disabled. GMII or
 418          *                           MII port is selected by GMX_PRT1_CFG[SPEED].
 419          */
 420
 421                         /* In MII mode, CLK_CNT = 1. */
 422                         if (((index == 0) && (mode.s.p0mii == 1))
 423                             || ((index != 0) && (mode.s.type == 1))) {
 424                                 cvmx_write_csr(CVMX_GMXX_TXX_CLK
 425                                                (index, interface), 1);
 426                         }
 427                 }
 428         }
 429
 430         /* Do a read to make sure all setup stuff is complete */
 431         cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 432
 433         /* Save the new GMX setting without enabling the port */
 434         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), new_gmx_cfg.u64);
 435
 436         /* Enable the lowest level RX */
 437         cvmx_write_csr(CVMX_ASXX_RX_PRT_EN(interface),
 438                        cvmx_read_csr(CVMX_ASXX_RX_PRT_EN(interface)) | (1 <<
 439                                                                         index));
 440
 441         /* Re-enable the TX path */
 442         for (i = 0; i < cvmx_pko_get_num_queues(ipd_port); i++) {
 443                 int queue = cvmx_pko_get_base_queue(ipd_port) + i;
 444                 cvmx_write_csr(CVMX_PKO_REG_READ_IDX, queue);
 445                 cvmx_write_csr(CVMX_PKO_MEM_QUEUE_QOS,
 446                                pko_mem_queue_qos_save[i].u64);
 447         }
 448
 449         /* Restore backpressure */
 450         cvmx_write_csr(CVMX_GMXX_TX_OVR_BP(interface), gmx_tx_ovr_bp_save.u64);
 451
 452         /* Restore the GMX enable state. Port config is complete */
 453         new_gmx_cfg.s.en = original_gmx_cfg.s.en;
 454         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), new_gmx_cfg.u64);
 455
 456         return result;
 457 }
 458
 459 /**
 460  * Configure a port for internal and/or external loopback. Internal loopback
 461  * causes packets sent by the port to be received by Octeon. External loopback
 462  * causes packets received from the wire to sent out again.
 463  *
 464  * @ipd_port: IPD/PKO port to loopback.
 465  * @enable_internal:
 466  *                 Non zero if you want internal loopback
 467  * @enable_external:
 468  *                 Non zero if you want external loopback
 469  *
 470  * Returns Zero on success, negative on failure.
 471  */
 472 int __cvmx_helper_rgmii_configure_loopback(int ipd_port, int enable_internal,
 473                                            int enable_external)
 474 {
 475         int interface = cvmx_helper_get_interface_num(ipd_port);
 476         int index = cvmx_helper_get_interface_index_num(ipd_port);
 477         int original_enable;
 478         union cvmx_gmxx_prtx_cfg gmx_cfg;
 479         union cvmx_asxx_prt_loop asxx_prt_loop;
 480
 481         /* Read the current enable state and save it */
 482         gmx_cfg.u64 = cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 483         original_enable = gmx_cfg.s.en;
 484         /* Force port to be disabled */
 485         gmx_cfg.s.en = 0;
 486         if (enable_internal) {
 487                 /* Force speed if we're doing internal loopback */
 488                 gmx_cfg.s.duplex = 1;
 489                 gmx_cfg.s.slottime = 1;
 490                 gmx_cfg.s.speed = 1;
 491                 cvmx_write_csr(CVMX_GMXX_TXX_CLK(index, interface), 1);
 492                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 0x200);
 493                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0x2000);
 494         }
 495         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmx_cfg.u64);
 496
 497         /* Set the loopback bits */
 498         asxx_prt_loop.u64 = cvmx_read_csr(CVMX_ASXX_PRT_LOOP(interface));
 499         if (enable_internal)
 500                 asxx_prt_loop.s.int_loop |= 1 << index;
 501         else
 502                 asxx_prt_loop.s.int_loop &= ~(1 << index);
 503         if (enable_external)
 504                 asxx_prt_loop.s.ext_loop |= 1 << index;
 505         else
 506                 asxx_prt_loop.s.ext_loop &= ~(1 << index);
 507         cvmx_write_csr(CVMX_ASXX_PRT_LOOP(interface), asxx_prt_loop.u64);
 508
 509         /* Force enables in internal loopback */
 510         if (enable_internal) {
 511                 uint64_t tmp;
 512                 tmp = cvmx_read_csr(CVMX_ASXX_TX_PRT_EN(interface));
 513                 cvmx_write_csr(CVMX_ASXX_TX_PRT_EN(interface),
 514                                (1 << index) | tmp);
 515                 tmp = cvmx_read_csr(CVMX_ASXX_RX_PRT_EN(interface));
 516                 cvmx_write_csr(CVMX_ASXX_RX_PRT_EN(interface),
 517                                (1 << index) | tmp);
 518                 original_enable = 1;
 519         }
 520
 521         /* Restore the enable state */
 522         gmx_cfg.s.en = original_enable;
 523         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmx_cfg.u64);
 524         return 0;
 525 }