arch/mips/cavium-octeon/executive/cvmx-helper-sgmii.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 SGMII initialization, configuration,
  30  * and monitoring.
  31  */
  32
  33 #include <asm/octeon/octeon.h>
  34
  35 #include <asm/octeon/cvmx-config.h>
  36
  37 #include <asm/octeon/cvmx-mdio.h>
  38 #include <asm/octeon/cvmx-helper.h>
  39 #include <asm/octeon/cvmx-helper-board.h>
  40
  41 #include <asm/octeon/cvmx-gmxx-defs.h>
  42 #include <asm/octeon/cvmx-pcsx-defs.h>
  43
  44 void __cvmx_interrupt_gmxx_enable(int interface);
  45 void __cvmx_interrupt_pcsx_intx_en_reg_enable(int index, int block);
  46 void __cvmx_interrupt_pcsxx_int_en_reg_enable(int index);
  47
  48 /**
  49  * Perform initialization required only once for an SGMII port.
  50  *
  51  * @interface: Interface to init
  52  * @index:     Index of prot on the interface
  53  *
  54  * Returns Zero on success, negative on failure
  55  */
  56 static int __cvmx_helper_sgmii_hardware_init_one_time(int interface, int index)
  57 {
  58         const uint64_t clock_mhz = cvmx_sysinfo_get()->cpu_clock_hz / 1000000;
  59         union cvmx_pcsx_miscx_ctl_reg pcs_misc_ctl_reg;
  60         union cvmx_pcsx_linkx_timer_count_reg pcsx_linkx_timer_count_reg;
  61         union cvmx_gmxx_prtx_cfg gmxx_prtx_cfg;
  62
  63         /* Disable GMX */
  64         gmxx_prtx_cfg.u64 = cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
  65         gmxx_prtx_cfg.s.en = 0;
  66         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmxx_prtx_cfg.u64);
  67
  68         /*
  69          * Write PCS*_LINK*_TIMER_COUNT_REG[COUNT] with the
  70          * appropriate value. 1000BASE-X specifies a 10ms
  71          * interval. SGMII specifies a 1.6ms interval.
  72          */
  73         pcs_misc_ctl_reg.u64 =
  74             cvmx_read_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface));
  75         pcsx_linkx_timer_count_reg.u64 =
  76             cvmx_read_csr(CVMX_PCSX_LINKX_TIMER_COUNT_REG(index, interface));
  77         if (pcs_misc_ctl_reg.s.mode) {
  78                 /* 1000BASE-X */
  79                 pcsx_linkx_timer_count_reg.s.count =
  80                     (10000ull * clock_mhz) >> 10;
  81         } else {
  82                 /* SGMII */
  83                 pcsx_linkx_timer_count_reg.s.count =
  84                     (1600ull * clock_mhz) >> 10;
  85         }
  86         cvmx_write_csr(CVMX_PCSX_LINKX_TIMER_COUNT_REG(index, interface),
  87                        pcsx_linkx_timer_count_reg.u64);
  88
  89         /*
  90          * Write the advertisement register to be used as the
  91          * tx_Config_Reg<D15:D0> of the autonegotiation.  In
  92          * 1000BASE-X mode, tx_Config_Reg<D15:D0> is PCS*_AN*_ADV_REG.
  93          * In SGMII PHY mode, tx_Config_Reg<D15:D0> is
  94          * PCS*_SGM*_AN_ADV_REG.  In SGMII MAC mode,
  95          * tx_Config_Reg<D15:D0> is the fixed value 0x4001, so this
  96          * step can be skipped.
  97          */
  98         if (pcs_misc_ctl_reg.s.mode) {
  99                 /* 1000BASE-X */
 100                 union cvmx_pcsx_anx_adv_reg pcsx_anx_adv_reg;
 101                 pcsx_anx_adv_reg.u64 =
 102                     cvmx_read_csr(CVMX_PCSX_ANX_ADV_REG(index, interface));
 103                 pcsx_anx_adv_reg.s.rem_flt = 0;
 104                 pcsx_anx_adv_reg.s.pause = 3;
 105                 pcsx_anx_adv_reg.s.hfd = 1;
 106                 pcsx_anx_adv_reg.s.fd = 1;
 107                 cvmx_write_csr(CVMX_PCSX_ANX_ADV_REG(index, interface),
 108                                pcsx_anx_adv_reg.u64);
 109         } else {
 110                 union cvmx_pcsx_miscx_ctl_reg pcsx_miscx_ctl_reg;
 111                 pcsx_miscx_ctl_reg.u64 =
 112                     cvmx_read_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface));
 113                 if (pcsx_miscx_ctl_reg.s.mac_phy) {
 114                         /* PHY Mode */
 115                         union cvmx_pcsx_sgmx_an_adv_reg pcsx_sgmx_an_adv_reg;
 116                         pcsx_sgmx_an_adv_reg.u64 =
 117                             cvmx_read_csr(CVMX_PCSX_SGMX_AN_ADV_REG
 118                                           (index, interface));
 119                         pcsx_sgmx_an_adv_reg.s.link = 1;
 120                         pcsx_sgmx_an_adv_reg.s.dup = 1;
 121                         pcsx_sgmx_an_adv_reg.s.speed = 2;
 122                         cvmx_write_csr(CVMX_PCSX_SGMX_AN_ADV_REG
 123                                        (index, interface),
 124                                        pcsx_sgmx_an_adv_reg.u64);
 125                 } else {
 126                         /* MAC Mode - Nothing to do */
 127                 }
 128         }
 129         return 0;
 130 }
 131
 132 /**
 133  * Initialize the SERTES link for the first time or after a loss
 134  * of link.
 135  *
 136  * @interface: Interface to init
 137  * @index:     Index of prot on the interface
 138  *
 139  * Returns Zero on success, negative on failure
 140  */
 141 static int __cvmx_helper_sgmii_hardware_init_link(int interface, int index)
 142 {
 143         union cvmx_pcsx_mrx_control_reg control_reg;
 144
 145         /*
 146          * Take PCS through a reset sequence.
 147          * PCS*_MR*_CONTROL_REG[PWR_DN] should be cleared to zero.
 148          * Write PCS*_MR*_CONTROL_REG[RESET]=1 (while not changing the
 149          * value of the other PCS*_MR*_CONTROL_REG bits).  Read
 150          * PCS*_MR*_CONTROL_REG[RESET] until it changes value to
 151          * zero.
 152          */
 153         control_reg.u64 =
 154             cvmx_read_csr(CVMX_PCSX_MRX_CONTROL_REG(index, interface));
 155         if (cvmx_sysinfo_get()->board_type != CVMX_BOARD_TYPE_SIM) {
 156                 control_reg.s.reset = 1;
 157                 cvmx_write_csr(CVMX_PCSX_MRX_CONTROL_REG(index, interface),
 158                                control_reg.u64);
 159                 if (CVMX_WAIT_FOR_FIELD64
 160                     (CVMX_PCSX_MRX_CONTROL_REG(index, interface),
 161                      union cvmx_pcsx_mrx_control_reg, reset, ==, 0, 10000)) {
 162                         cvmx_dprintf("SGMII%d: Timeout waiting for port %d "
 163                                      "to finish reset\n",
 164                              interface, index);
 165                         return -1;
 166                 }
 167         }
 168
 169         /*
 170          * Write PCS*_MR*_CONTROL_REG[RST_AN]=1 to ensure a fresh
 171          * sgmii negotiation starts.
 172          */
 173         control_reg.s.rst_an = 1;
 174         control_reg.s.an_en = 1;
 175         control_reg.s.pwr_dn = 0;
 176         cvmx_write_csr(CVMX_PCSX_MRX_CONTROL_REG(index, interface),
 177                        control_reg.u64);
 178
 179         /*
 180          * Wait for PCS*_MR*_STATUS_REG[AN_CPT] to be set, indicating
 181          * that sgmii autonegotiation is complete. In MAC mode this
 182          * isn't an ethernet link, but a link between Octeon and the
 183          * PHY.
 184          */
 185         if ((cvmx_sysinfo_get()->board_type != CVMX_BOARD_TYPE_SIM) &&
 186             CVMX_WAIT_FOR_FIELD64(CVMX_PCSX_MRX_STATUS_REG(index, interface),
 187                                   union cvmx_pcsx_mrx_status_reg, an_cpt, ==, 1,
 188                                   10000)) {
 189                 /* cvmx_dprintf("SGMII%d: Port %d link timeout\n", interface, index); */
 190                 return -1;
 191         }
 192         return 0;
 193 }
 194
 195 /**
 196  * Configure an SGMII link to the specified speed after the SERTES
 197  * link is up.
 198  *
 199  * @interface: Interface to init
 200  * @index:     Index of prot on the interface
 201  * @link_info: Link state to configure
 202  *
 203  * Returns Zero on success, negative on failure
 204  */
 205 static int __cvmx_helper_sgmii_hardware_init_link_speed(int interface,
 206                                                         int index,
 207                                                         cvmx_helper_link_info_t
 208                                                         link_info)
 209 {
 210         int is_enabled;
 211         union cvmx_gmxx_prtx_cfg gmxx_prtx_cfg;
 212         union cvmx_pcsx_miscx_ctl_reg pcsx_miscx_ctl_reg;
 213
 214         /* Disable GMX before we make any changes. Remember the enable state */
 215         gmxx_prtx_cfg.u64 = cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 216         is_enabled = gmxx_prtx_cfg.s.en;
 217         gmxx_prtx_cfg.s.en = 0;
 218         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmxx_prtx_cfg.u64);
 219
 220         /* Wait for GMX to be idle */
 221         if (CVMX_WAIT_FOR_FIELD64
 222             (CVMX_GMXX_PRTX_CFG(index, interface), union cvmx_gmxx_prtx_cfg,
 223              rx_idle, ==, 1, 10000)
 224             || CVMX_WAIT_FOR_FIELD64(CVMX_GMXX_PRTX_CFG(index, interface),
 225                                      union cvmx_gmxx_prtx_cfg, tx_idle, ==, 1,
 226                                      10000)) {
 227                 cvmx_dprintf
 228                     ("SGMII%d: Timeout waiting for port %d to be idle\n",
 229                      interface, index);
 230                 return -1;
 231         }
 232
 233         /* Read GMX CFG again to make sure the disable completed */
 234         gmxx_prtx_cfg.u64 = cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 235
 236         /*
 237          * Get the misc control for PCS. We will need to set the
 238          * duplication amount.
 239          */
 240         pcsx_miscx_ctl_reg.u64 =
 241             cvmx_read_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface));
 242
 243         /*
 244          * Use GMXENO to force the link down if the status we get says
 245          * it should be down.
 246          */
 247         pcsx_miscx_ctl_reg.s.gmxeno = !link_info.s.link_up;
 248
 249         /* Only change the duplex setting if the link is up */
 250         if (link_info.s.link_up)
 251                 gmxx_prtx_cfg.s.duplex = link_info.s.full_duplex;
 252
 253         /* Do speed based setting for GMX */
 254         switch (link_info.s.speed) {
 255         case 10:
 256                 gmxx_prtx_cfg.s.speed = 0;
 257                 gmxx_prtx_cfg.s.speed_msb = 1;
 258                 gmxx_prtx_cfg.s.slottime = 0;
 259                 /* Setting from GMX-603 */
 260                 pcsx_miscx_ctl_reg.s.samp_pt = 25;
 261                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 64);
 262                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0);
 263                 break;
 264         case 100:
 265                 gmxx_prtx_cfg.s.speed = 0;
 266                 gmxx_prtx_cfg.s.speed_msb = 0;
 267                 gmxx_prtx_cfg.s.slottime = 0;
 268                 pcsx_miscx_ctl_reg.s.samp_pt = 0x5;
 269                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 64);
 270                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 0);
 271                 break;
 272         case 1000:
 273                 gmxx_prtx_cfg.s.speed = 1;
 274                 gmxx_prtx_cfg.s.speed_msb = 0;
 275                 gmxx_prtx_cfg.s.slottime = 1;
 276                 pcsx_miscx_ctl_reg.s.samp_pt = 1;
 277                 cvmx_write_csr(CVMX_GMXX_TXX_SLOT(index, interface), 512);
 278                 cvmx_write_csr(CVMX_GMXX_TXX_BURST(index, interface), 8192);
 279                 break;
 280         default:
 281                 break;
 282         }
 283
 284         /* Write the new misc control for PCS */
 285         cvmx_write_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface),
 286                        pcsx_miscx_ctl_reg.u64);
 287
 288         /* Write the new GMX settings with the port still disabled */
 289         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmxx_prtx_cfg.u64);
 290
 291         /* Read GMX CFG again to make sure the config completed */
 292         gmxx_prtx_cfg.u64 = cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 293
 294         /* Restore the enabled / disabled state */
 295         gmxx_prtx_cfg.s.en = is_enabled;
 296         cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface), gmxx_prtx_cfg.u64);
 297
 298         return 0;
 299 }
 300
 301 /**
 302  * Bring up the SGMII interface to be ready for packet I/O but
 303  * leave I/O disabled using the GMX override. This function
 304  * follows the bringup documented in 10.6.3 of the manual.
 305  *
 306  * @interface: Interface to bringup
 307  * @num_ports: Number of ports on the interface
 308  *
 309  * Returns Zero on success, negative on failure
 310  */
 311 static int __cvmx_helper_sgmii_hardware_init(int interface, int num_ports)
 312 {
 313         int index;
 314
 315         __cvmx_helper_setup_gmx(interface, num_ports);
 316
 317         for (index = 0; index < num_ports; index++) {
 318                 int ipd_port = cvmx_helper_get_ipd_port(interface, index);
 319                 __cvmx_helper_sgmii_hardware_init_one_time(interface, index);
 320                 __cvmx_helper_sgmii_link_set(ipd_port,
 321                                              __cvmx_helper_sgmii_link_get
 322                                              (ipd_port));
 323
 324         }
 325
 326         return 0;
 327 }
 328
 329 int __cvmx_helper_sgmii_enumerate(int interface)
 330 {
 331         return 4;
 332 }
 333 /**
 334  * Probe a SGMII interface and determine the number of ports
 335  * connected to it. The SGMII interface should still be down after
 336  * this call.
 337  *
 338  * @interface: Interface to probe
 339  *
 340  * Returns Number of ports on the interface. Zero to disable.
 341  */
 342 int __cvmx_helper_sgmii_probe(int interface)
 343 {
 344         union cvmx_gmxx_inf_mode mode;
 345
 346         /*
 347          * Due to errata GMX-700 on CN56XXp1.x and CN52XXp1.x, the
 348          * interface needs to be enabled before IPD otherwise per port
 349          * backpressure may not work properly
 350          */
 351         mode.u64 = cvmx_read_csr(CVMX_GMXX_INF_MODE(interface));
 352         mode.s.en = 1;
 353         cvmx_write_csr(CVMX_GMXX_INF_MODE(interface), mode.u64);
 354         return __cvmx_helper_sgmii_enumerate(interface);
 355 }
 356
 357 /**
 358  * Bringup and enable a SGMII interface. After this call packet
 359  * I/O should be fully functional. This is called with IPD
 360  * enabled but PKO disabled.
 361  *
 362  * @interface: Interface to bring up
 363  *
 364  * Returns Zero on success, negative on failure
 365  */
 366 int __cvmx_helper_sgmii_enable(int interface)
 367 {
 368         int num_ports = cvmx_helper_ports_on_interface(interface);
 369         int index;
 370
 371         __cvmx_helper_sgmii_hardware_init(interface, num_ports);
 372
 373         for (index = 0; index < num_ports; index++) {
 374                 union cvmx_gmxx_prtx_cfg gmxx_prtx_cfg;
 375                 gmxx_prtx_cfg.u64 =
 376                     cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 377                 gmxx_prtx_cfg.s.en = 1;
 378                 cvmx_write_csr(CVMX_GMXX_PRTX_CFG(index, interface),
 379                                gmxx_prtx_cfg.u64);
 380                 __cvmx_interrupt_pcsx_intx_en_reg_enable(index, interface);
 381         }
 382         __cvmx_interrupt_pcsxx_int_en_reg_enable(interface);
 383         __cvmx_interrupt_gmxx_enable(interface);
 384         return 0;
 385 }
 386
 387 /**
 388  * Return the link state of an IPD/PKO port as returned by
 389  * auto negotiation. The result of this function may not match
 390  * Octeon's link config if auto negotiation has changed since
 391  * the last call to cvmx_helper_link_set().
 392  *
 393  * @ipd_port: IPD/PKO port to query
 394  *
 395  * Returns Link state
 396  */
 397 cvmx_helper_link_info_t __cvmx_helper_sgmii_link_get(int ipd_port)
 398 {
 399         cvmx_helper_link_info_t result;
 400         union cvmx_pcsx_miscx_ctl_reg pcs_misc_ctl_reg;
 401         int interface = cvmx_helper_get_interface_num(ipd_port);
 402         int index = cvmx_helper_get_interface_index_num(ipd_port);
 403         union cvmx_pcsx_mrx_control_reg pcsx_mrx_control_reg;
 404
 405         result.u64 = 0;
 406
 407         if (cvmx_sysinfo_get()->board_type == CVMX_BOARD_TYPE_SIM) {
 408                 /* The simulator gives you a simulated 1Gbps full duplex link */
 409                 result.s.link_up = 1;
 410                 result.s.full_duplex = 1;
 411                 result.s.speed = 1000;
 412                 return result;
 413         }
 414
 415         pcsx_mrx_control_reg.u64 =
 416             cvmx_read_csr(CVMX_PCSX_MRX_CONTROL_REG(index, interface));
 417         if (pcsx_mrx_control_reg.s.loopbck1) {
 418                 /* Force 1Gbps full duplex link for internal loopback */
 419                 result.s.link_up = 1;
 420                 result.s.full_duplex = 1;
 421                 result.s.speed = 1000;
 422                 return result;
 423         }
 424
 425         pcs_misc_ctl_reg.u64 =
 426             cvmx_read_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface));
 427         if (pcs_misc_ctl_reg.s.mode) {
 428                 /* 1000BASE-X */
 429                 /* FIXME */
 430         } else {
 431                 union cvmx_pcsx_miscx_ctl_reg pcsx_miscx_ctl_reg;
 432                 pcsx_miscx_ctl_reg.u64 =
 433                     cvmx_read_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface));
 434                 if (pcsx_miscx_ctl_reg.s.mac_phy) {
 435                         /* PHY Mode */
 436                         union cvmx_pcsx_mrx_status_reg pcsx_mrx_status_reg;
 437                         union cvmx_pcsx_anx_results_reg pcsx_anx_results_reg;
 438
 439                         /*
 440                          * Don't bother continuing if the SERTES low
 441                          * level link is down
 442                          */
 443                         pcsx_mrx_status_reg.u64 =
 444                             cvmx_read_csr(CVMX_PCSX_MRX_STATUS_REG
 445                                           (index, interface));
 446                         if (pcsx_mrx_status_reg.s.lnk_st == 0) {
 447                                 if (__cvmx_helper_sgmii_hardware_init_link
 448                                     (interface, index) != 0)
 449                                         return result;
 450                         }
 451
 452                         /* Read the autoneg results */
 453                         pcsx_anx_results_reg.u64 =
 454                             cvmx_read_csr(CVMX_PCSX_ANX_RESULTS_REG
 455                                           (index, interface));
 456                         if (pcsx_anx_results_reg.s.an_cpt) {
 457                                 /*
 458                                  * Auto negotiation is complete. Set
 459                                  * status accordingly.
 460                                  */
 461                                 result.s.full_duplex =
 462                                     pcsx_anx_results_reg.s.dup;
 463                                 result.s.link_up =
 464                                     pcsx_anx_results_reg.s.link_ok;
 465                                 switch (pcsx_anx_results_reg.s.spd) {
 466                                 case 0:
 467                                         result.s.speed = 10;
 468                                         break;
 469                                 case 1:
 470                                         result.s.speed = 100;
 471                                         break;
 472                                 case 2:
 473                                         result.s.speed = 1000;
 474                                         break;
 475                                 default:
 476                                         result.s.speed = 0;
 477                                         result.s.link_up = 0;
 478                                         break;
 479                                 }
 480                         } else {
 481                                 /*
 482                                  * Auto negotiation isn't
 483                                  * complete. Return link down.
 484                                  */
 485                                 result.s.speed = 0;
 486                                 result.s.link_up = 0;
 487                         }
 488                 } else {        /* MAC Mode */
 489
 490                         result = __cvmx_helper_board_link_get(ipd_port);
 491                 }
 492         }
 493         return result;
 494 }
 495
 496 /**
 497  * Configure an IPD/PKO port for the specified link state. This
 498  * function does not influence auto negotiation at the PHY level.
 499  * The passed link state must always match the link state returned
 500  * by cvmx_helper_link_get(). It is normally best to use
 501  * cvmx_helper_link_autoconf() instead.
 502  *
 503  * @ipd_port:  IPD/PKO port to configure
 504  * @link_info: The new link state
 505  *
 506  * Returns Zero on success, negative on failure
 507  */
 508 int __cvmx_helper_sgmii_link_set(int ipd_port,
 509                                  cvmx_helper_link_info_t link_info)
 510 {
 511         int interface = cvmx_helper_get_interface_num(ipd_port);
 512         int index = cvmx_helper_get_interface_index_num(ipd_port);
 513         __cvmx_helper_sgmii_hardware_init_link(interface, index);
 514         return __cvmx_helper_sgmii_hardware_init_link_speed(interface, index,
 515                                                             link_info);
 516 }
 517
 518 /**
 519  * Configure a port for internal and/or external loopback. Internal
 520  * loopback causes packets sent by the port to be received by
 521  * Octeon. External loopback causes packets received from the wire to
 522  * sent out again.
 523  *
 524  * @ipd_port: IPD/PKO port to loopback.
 525  * @enable_internal:
 526  *                 Non zero if you want internal loopback
 527  * @enable_external:
 528  *                 Non zero if you want external loopback
 529  *
 530  * Returns Zero on success, negative on failure.
 531  */
 532 int __cvmx_helper_sgmii_configure_loopback(int ipd_port, int enable_internal,
 533                                            int enable_external)
 534 {
 535         int interface = cvmx_helper_get_interface_num(ipd_port);
 536         int index = cvmx_helper_get_interface_index_num(ipd_port);
 537         union cvmx_pcsx_mrx_control_reg pcsx_mrx_control_reg;
 538         union cvmx_pcsx_miscx_ctl_reg pcsx_miscx_ctl_reg;
 539
 540         pcsx_mrx_control_reg.u64 =
 541             cvmx_read_csr(CVMX_PCSX_MRX_CONTROL_REG(index, interface));
 542         pcsx_mrx_control_reg.s.loopbck1 = enable_internal;
 543         cvmx_write_csr(CVMX_PCSX_MRX_CONTROL_REG(index, interface),
 544                        pcsx_mrx_control_reg.u64);
 545
 546         pcsx_miscx_ctl_reg.u64 =
 547             cvmx_read_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface));
 548         pcsx_miscx_ctl_reg.s.loopbck2 = enable_external;
 549         cvmx_write_csr(CVMX_PCSX_MISCX_CTL_REG(index, interface),
 550                        pcsx_miscx_ctl_reg.u64);
 551
 552         __cvmx_helper_sgmii_hardware_init_link(interface, index);
 553         return 0;
 554 }