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  */
__cvmx_helper_sgmii_hardware_init_one_time(int interface,int index)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  */
__cvmx_helper_sgmii_hardware_init_link(int interface,int index)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  */
__cvmx_helper_sgmii_hardware_init_link_speed(int interface,int index,cvmx_helper_link_info_t link_info)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  */
__cvmx_helper_sgmii_hardware_init(int interface,int num_ports)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 
__cvmx_helper_sgmii_enumerate(int interface)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  */
__cvmx_helper_sgmii_probe(int interface)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  */
__cvmx_helper_sgmii_enable(int interface)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  */
__cvmx_helper_sgmii_link_get(int ipd_port)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  */
__cvmx_helper_sgmii_link_set(int ipd_port,cvmx_helper_link_info_t link_info)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  */
__cvmx_helper_sgmii_configure_loopback(int ipd_port,int enable_internal,int enable_external)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 }
555