1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Marvell 88E6xxx Switch Global (1) Registers support
4  *
5  * Copyright (c) 2008 Marvell Semiconductor
6  *
7  * Copyright (c) 2016-2017 Savoir-faire Linux Inc.
8  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
9  */
10 
11 #include <linux/bitfield.h>
12 
13 #include "chip.h"
14 #include "global1.h"
15 
mv88e6xxx_g1_read(struct mv88e6xxx_chip * chip,int reg,u16 * val)16 int mv88e6xxx_g1_read(struct mv88e6xxx_chip *chip, int reg, u16 *val)
17 {
18 	int addr = chip->info->global1_addr;
19 
20 	return mv88e6xxx_read(chip, addr, reg, val);
21 }
22 
mv88e6xxx_g1_write(struct mv88e6xxx_chip * chip,int reg,u16 val)23 int mv88e6xxx_g1_write(struct mv88e6xxx_chip *chip, int reg, u16 val)
24 {
25 	int addr = chip->info->global1_addr;
26 
27 	return mv88e6xxx_write(chip, addr, reg, val);
28 }
29 
mv88e6xxx_g1_wait_bit(struct mv88e6xxx_chip * chip,int reg,int bit,int val)30 int mv88e6xxx_g1_wait_bit(struct mv88e6xxx_chip *chip, int reg, int
31 			  bit, int val)
32 {
33 	return mv88e6xxx_wait_bit(chip, chip->info->global1_addr, reg,
34 				  bit, val);
35 }
36 
mv88e6xxx_g1_wait_mask(struct mv88e6xxx_chip * chip,int reg,u16 mask,u16 val)37 int mv88e6xxx_g1_wait_mask(struct mv88e6xxx_chip *chip, int reg,
38 			   u16 mask, u16 val)
39 {
40 	return mv88e6xxx_wait_mask(chip, chip->info->global1_addr, reg,
41 				   mask, val);
42 }
43 
44 /* Offset 0x00: Switch Global Status Register */
45 
mv88e6185_g1_wait_ppu_disabled(struct mv88e6xxx_chip * chip)46 static int mv88e6185_g1_wait_ppu_disabled(struct mv88e6xxx_chip *chip)
47 {
48 	return mv88e6xxx_g1_wait_mask(chip, MV88E6XXX_G1_STS,
49 				      MV88E6185_G1_STS_PPU_STATE_MASK,
50 				      MV88E6185_G1_STS_PPU_STATE_DISABLED);
51 }
52 
mv88e6185_g1_wait_ppu_polling(struct mv88e6xxx_chip * chip)53 static int mv88e6185_g1_wait_ppu_polling(struct mv88e6xxx_chip *chip)
54 {
55 	return mv88e6xxx_g1_wait_mask(chip, MV88E6XXX_G1_STS,
56 				      MV88E6185_G1_STS_PPU_STATE_MASK,
57 				      MV88E6185_G1_STS_PPU_STATE_POLLING);
58 }
59 
mv88e6352_g1_wait_ppu_polling(struct mv88e6xxx_chip * chip)60 static int mv88e6352_g1_wait_ppu_polling(struct mv88e6xxx_chip *chip)
61 {
62 	int bit = __bf_shf(MV88E6352_G1_STS_PPU_STATE);
63 
64 	return mv88e6xxx_g1_wait_bit(chip, MV88E6XXX_G1_STS, bit, 1);
65 }
66 
mv88e6xxx_g1_wait_init_ready(struct mv88e6xxx_chip * chip)67 static int mv88e6xxx_g1_wait_init_ready(struct mv88e6xxx_chip *chip)
68 {
69 	int bit = __bf_shf(MV88E6XXX_G1_STS_INIT_READY);
70 
71 	/* Wait up to 1 second for the switch to be ready. The InitReady bit 11
72 	 * is set to a one when all units inside the device (ATU, VTU, etc.)
73 	 * have finished their initialization and are ready to accept frames.
74 	 */
75 	return mv88e6xxx_g1_wait_bit(chip, MV88E6XXX_G1_STS, bit, 1);
76 }
77 
78 /* Offset 0x01: Switch MAC Address Register Bytes 0 & 1
79  * Offset 0x02: Switch MAC Address Register Bytes 2 & 3
80  * Offset 0x03: Switch MAC Address Register Bytes 4 & 5
81  */
mv88e6xxx_g1_set_switch_mac(struct mv88e6xxx_chip * chip,u8 * addr)82 int mv88e6xxx_g1_set_switch_mac(struct mv88e6xxx_chip *chip, u8 *addr)
83 {
84 	u16 reg;
85 	int err;
86 
87 	reg = (addr[0] << 8) | addr[1];
88 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_MAC_01, reg);
89 	if (err)
90 		return err;
91 
92 	reg = (addr[2] << 8) | addr[3];
93 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_MAC_23, reg);
94 	if (err)
95 		return err;
96 
97 	reg = (addr[4] << 8) | addr[5];
98 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_MAC_45, reg);
99 	if (err)
100 		return err;
101 
102 	return 0;
103 }
104 
105 /* Offset 0x04: Switch Global Control Register */
106 
mv88e6185_g1_reset(struct mv88e6xxx_chip * chip)107 int mv88e6185_g1_reset(struct mv88e6xxx_chip *chip)
108 {
109 	u16 val;
110 	int err;
111 
112 	/* Set the SWReset bit 15 along with the PPUEn bit 14, to also restart
113 	 * the PPU, including re-doing PHY detection and initialization
114 	 */
115 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL1, &val);
116 	if (err)
117 		return err;
118 
119 	val |= MV88E6XXX_G1_CTL1_SW_RESET;
120 	val |= MV88E6XXX_G1_CTL1_PPU_ENABLE;
121 
122 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_CTL1, val);
123 	if (err)
124 		return err;
125 
126 	err = mv88e6xxx_g1_wait_init_ready(chip);
127 	if (err)
128 		return err;
129 
130 	return mv88e6185_g1_wait_ppu_polling(chip);
131 }
132 
mv88e6250_g1_reset(struct mv88e6xxx_chip * chip)133 int mv88e6250_g1_reset(struct mv88e6xxx_chip *chip)
134 {
135 	u16 val;
136 	int err;
137 
138 	/* Set the SWReset bit 15 */
139 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL1, &val);
140 	if (err)
141 		return err;
142 
143 	val |= MV88E6XXX_G1_CTL1_SW_RESET;
144 
145 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_CTL1, val);
146 	if (err)
147 		return err;
148 
149 	return mv88e6xxx_g1_wait_init_ready(chip);
150 }
151 
mv88e6352_g1_reset(struct mv88e6xxx_chip * chip)152 int mv88e6352_g1_reset(struct mv88e6xxx_chip *chip)
153 {
154 	int err;
155 
156 	err = mv88e6250_g1_reset(chip);
157 	if (err)
158 		return err;
159 
160 	return mv88e6352_g1_wait_ppu_polling(chip);
161 }
162 
mv88e6185_g1_ppu_enable(struct mv88e6xxx_chip * chip)163 int mv88e6185_g1_ppu_enable(struct mv88e6xxx_chip *chip)
164 {
165 	u16 val;
166 	int err;
167 
168 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL1, &val);
169 	if (err)
170 		return err;
171 
172 	val |= MV88E6XXX_G1_CTL1_PPU_ENABLE;
173 
174 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_CTL1, val);
175 	if (err)
176 		return err;
177 
178 	return mv88e6185_g1_wait_ppu_polling(chip);
179 }
180 
mv88e6185_g1_ppu_disable(struct mv88e6xxx_chip * chip)181 int mv88e6185_g1_ppu_disable(struct mv88e6xxx_chip *chip)
182 {
183 	u16 val;
184 	int err;
185 
186 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL1, &val);
187 	if (err)
188 		return err;
189 
190 	val &= ~MV88E6XXX_G1_CTL1_PPU_ENABLE;
191 
192 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_CTL1, val);
193 	if (err)
194 		return err;
195 
196 	return mv88e6185_g1_wait_ppu_disabled(chip);
197 }
198 
199 /* Offset 0x10: IP-PRI Mapping Register 0
200  * Offset 0x11: IP-PRI Mapping Register 1
201  * Offset 0x12: IP-PRI Mapping Register 2
202  * Offset 0x13: IP-PRI Mapping Register 3
203  * Offset 0x14: IP-PRI Mapping Register 4
204  * Offset 0x15: IP-PRI Mapping Register 5
205  * Offset 0x16: IP-PRI Mapping Register 6
206  * Offset 0x17: IP-PRI Mapping Register 7
207  */
208 
mv88e6085_g1_ip_pri_map(struct mv88e6xxx_chip * chip)209 int mv88e6085_g1_ip_pri_map(struct mv88e6xxx_chip *chip)
210 {
211 	int err;
212 
213 	/* Reset the IP TOS/DiffServ/Traffic priorities to defaults */
214 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_0, 0x0000);
215 	if (err)
216 		return err;
217 
218 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_1, 0x0000);
219 	if (err)
220 		return err;
221 
222 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_2, 0x5555);
223 	if (err)
224 		return err;
225 
226 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_3, 0x5555);
227 	if (err)
228 		return err;
229 
230 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_4, 0xaaaa);
231 	if (err)
232 		return err;
233 
234 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_5, 0xaaaa);
235 	if (err)
236 		return err;
237 
238 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_6, 0xffff);
239 	if (err)
240 		return err;
241 
242 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IP_PRI_7, 0xffff);
243 	if (err)
244 		return err;
245 
246 	return 0;
247 }
248 
249 /* Offset 0x18: IEEE-PRI Register */
250 
mv88e6085_g1_ieee_pri_map(struct mv88e6xxx_chip * chip)251 int mv88e6085_g1_ieee_pri_map(struct mv88e6xxx_chip *chip)
252 {
253 	/* Reset the IEEE Tag priorities to defaults */
254 	return mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IEEE_PRI, 0xfa41);
255 }
256 
mv88e6250_g1_ieee_pri_map(struct mv88e6xxx_chip * chip)257 int mv88e6250_g1_ieee_pri_map(struct mv88e6xxx_chip *chip)
258 {
259 	/* Reset the IEEE Tag priorities to defaults */
260 	return mv88e6xxx_g1_write(chip, MV88E6XXX_G1_IEEE_PRI, 0xfa50);
261 }
262 
263 /* Offset 0x1a: Monitor Control */
264 /* Offset 0x1a: Monitor & MGMT Control on some devices */
265 
mv88e6095_g1_set_egress_port(struct mv88e6xxx_chip * chip,int port)266 int mv88e6095_g1_set_egress_port(struct mv88e6xxx_chip *chip, int port)
267 {
268 	u16 reg;
269 	int err;
270 
271 	err = mv88e6xxx_g1_read(chip, MV88E6185_G1_MONITOR_CTL, &reg);
272 	if (err)
273 		return err;
274 
275 	reg &= ~(MV88E6185_G1_MONITOR_CTL_INGRESS_DEST_MASK |
276 		 MV88E6185_G1_MONITOR_CTL_EGRESS_DEST_MASK);
277 
278 	reg |= port << __bf_shf(MV88E6185_G1_MONITOR_CTL_INGRESS_DEST_MASK) |
279 		port << __bf_shf(MV88E6185_G1_MONITOR_CTL_EGRESS_DEST_MASK);
280 
281 	return mv88e6xxx_g1_write(chip, MV88E6185_G1_MONITOR_CTL, reg);
282 }
283 
284 /* Older generations also call this the ARP destination. It has been
285  * generalized in more modern devices such that more than ARP can
286  * egress it
287  */
mv88e6095_g1_set_cpu_port(struct mv88e6xxx_chip * chip,int port)288 int mv88e6095_g1_set_cpu_port(struct mv88e6xxx_chip *chip, int port)
289 {
290 	u16 reg;
291 	int err;
292 
293 	err = mv88e6xxx_g1_read(chip, MV88E6185_G1_MONITOR_CTL, &reg);
294 	if (err)
295 		return err;
296 
297 	reg &= ~MV88E6185_G1_MONITOR_CTL_ARP_DEST_MASK;
298 	reg |= port << __bf_shf(MV88E6185_G1_MONITOR_CTL_ARP_DEST_MASK);
299 
300 	return mv88e6xxx_g1_write(chip, MV88E6185_G1_MONITOR_CTL, reg);
301 }
302 
mv88e6390_g1_monitor_write(struct mv88e6xxx_chip * chip,u16 pointer,u8 data)303 static int mv88e6390_g1_monitor_write(struct mv88e6xxx_chip *chip,
304 				      u16 pointer, u8 data)
305 {
306 	u16 reg;
307 
308 	reg = MV88E6390_G1_MONITOR_MGMT_CTL_UPDATE | pointer | data;
309 
310 	return mv88e6xxx_g1_write(chip, MV88E6390_G1_MONITOR_MGMT_CTL, reg);
311 }
312 
mv88e6390_g1_set_egress_port(struct mv88e6xxx_chip * chip,int port)313 int mv88e6390_g1_set_egress_port(struct mv88e6xxx_chip *chip, int port)
314 {
315 	u16 ptr;
316 	int err;
317 
318 	ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_INGRESS_DEST;
319 	err = mv88e6390_g1_monitor_write(chip, ptr, port);
320 	if (err)
321 		return err;
322 
323 	ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_EGRESS_DEST;
324 	err = mv88e6390_g1_monitor_write(chip, ptr, port);
325 	if (err)
326 		return err;
327 
328 	return 0;
329 }
330 
mv88e6390_g1_set_cpu_port(struct mv88e6xxx_chip * chip,int port)331 int mv88e6390_g1_set_cpu_port(struct mv88e6xxx_chip *chip, int port)
332 {
333 	u16 ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_CPU_DEST;
334 
335 	return mv88e6390_g1_monitor_write(chip, ptr, port);
336 }
337 
mv88e6390_g1_mgmt_rsvd2cpu(struct mv88e6xxx_chip * chip)338 int mv88e6390_g1_mgmt_rsvd2cpu(struct mv88e6xxx_chip *chip)
339 {
340 	u16 ptr;
341 	int err;
342 
343 	/* 01:80:c2:00:00:00-01:80:c2:00:00:07 are Management */
344 	ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_0180C200000XLO;
345 	err = mv88e6390_g1_monitor_write(chip, ptr, 0xff);
346 	if (err)
347 		return err;
348 
349 	/* 01:80:c2:00:00:08-01:80:c2:00:00:0f are Management */
350 	ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_0180C200000XHI;
351 	err = mv88e6390_g1_monitor_write(chip, ptr, 0xff);
352 	if (err)
353 		return err;
354 
355 	/* 01:80:c2:00:00:20-01:80:c2:00:00:27 are Management */
356 	ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_0180C200002XLO;
357 	err = mv88e6390_g1_monitor_write(chip, ptr, 0xff);
358 	if (err)
359 		return err;
360 
361 	/* 01:80:c2:00:00:28-01:80:c2:00:00:2f are Management */
362 	ptr = MV88E6390_G1_MONITOR_MGMT_CTL_PTR_0180C200002XHI;
363 	err = mv88e6390_g1_monitor_write(chip, ptr, 0xff);
364 	if (err)
365 		return err;
366 
367 	return 0;
368 }
369 
370 /* Offset 0x1c: Global Control 2 */
371 
mv88e6xxx_g1_ctl2_mask(struct mv88e6xxx_chip * chip,u16 mask,u16 val)372 static int mv88e6xxx_g1_ctl2_mask(struct mv88e6xxx_chip *chip, u16 mask,
373 				  u16 val)
374 {
375 	u16 reg;
376 	int err;
377 
378 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL2, &reg);
379 	if (err)
380 		return err;
381 
382 	reg &= ~mask;
383 	reg |= val & mask;
384 
385 	return mv88e6xxx_g1_write(chip, MV88E6XXX_G1_CTL2, reg);
386 }
387 
mv88e6185_g1_set_cascade_port(struct mv88e6xxx_chip * chip,int port)388 int mv88e6185_g1_set_cascade_port(struct mv88e6xxx_chip *chip, int port)
389 {
390 	const u16 mask = MV88E6185_G1_CTL2_CASCADE_PORT_MASK;
391 
392 	return mv88e6xxx_g1_ctl2_mask(chip, mask, port << __bf_shf(mask));
393 }
394 
mv88e6085_g1_rmu_disable(struct mv88e6xxx_chip * chip)395 int mv88e6085_g1_rmu_disable(struct mv88e6xxx_chip *chip)
396 {
397 	return mv88e6xxx_g1_ctl2_mask(chip, MV88E6085_G1_CTL2_P10RM |
398 				      MV88E6085_G1_CTL2_RM_ENABLE, 0);
399 }
400 
mv88e6352_g1_rmu_disable(struct mv88e6xxx_chip * chip)401 int mv88e6352_g1_rmu_disable(struct mv88e6xxx_chip *chip)
402 {
403 	return mv88e6xxx_g1_ctl2_mask(chip, MV88E6352_G1_CTL2_RMU_MODE_MASK,
404 				      MV88E6352_G1_CTL2_RMU_MODE_DISABLED);
405 }
406 
mv88e6390_g1_rmu_disable(struct mv88e6xxx_chip * chip)407 int mv88e6390_g1_rmu_disable(struct mv88e6xxx_chip *chip)
408 {
409 	return mv88e6xxx_g1_ctl2_mask(chip, MV88E6390_G1_CTL2_RMU_MODE_MASK,
410 				      MV88E6390_G1_CTL2_RMU_MODE_DISABLED);
411 }
412 
mv88e6390_g1_stats_set_histogram(struct mv88e6xxx_chip * chip)413 int mv88e6390_g1_stats_set_histogram(struct mv88e6xxx_chip *chip)
414 {
415 	return mv88e6xxx_g1_ctl2_mask(chip, MV88E6390_G1_CTL2_HIST_MODE_MASK,
416 				      MV88E6390_G1_CTL2_HIST_MODE_RX |
417 				      MV88E6390_G1_CTL2_HIST_MODE_TX);
418 }
419 
mv88e6xxx_g1_set_device_number(struct mv88e6xxx_chip * chip,int index)420 int mv88e6xxx_g1_set_device_number(struct mv88e6xxx_chip *chip, int index)
421 {
422 	return mv88e6xxx_g1_ctl2_mask(chip,
423 				      MV88E6XXX_G1_CTL2_DEVICE_NUMBER_MASK,
424 				      index);
425 }
426 
427 /* Offset 0x1d: Statistics Operation 2 */
428 
mv88e6xxx_g1_stats_wait(struct mv88e6xxx_chip * chip)429 static int mv88e6xxx_g1_stats_wait(struct mv88e6xxx_chip *chip)
430 {
431 	int bit = __bf_shf(MV88E6XXX_G1_STATS_OP_BUSY);
432 
433 	return mv88e6xxx_g1_wait_bit(chip, MV88E6XXX_G1_STATS_OP, bit, 0);
434 }
435 
mv88e6095_g1_stats_set_histogram(struct mv88e6xxx_chip * chip)436 int mv88e6095_g1_stats_set_histogram(struct mv88e6xxx_chip *chip)
437 {
438 	u16 val;
439 	int err;
440 
441 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_STATS_OP, &val);
442 	if (err)
443 		return err;
444 
445 	val |= MV88E6XXX_G1_STATS_OP_HIST_RX_TX;
446 
447 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_STATS_OP, val);
448 
449 	return err;
450 }
451 
mv88e6xxx_g1_stats_snapshot(struct mv88e6xxx_chip * chip,int port)452 int mv88e6xxx_g1_stats_snapshot(struct mv88e6xxx_chip *chip, int port)
453 {
454 	int err;
455 
456 	/* Snapshot the hardware statistics counters for this port. */
457 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_STATS_OP,
458 				 MV88E6XXX_G1_STATS_OP_BUSY |
459 				 MV88E6XXX_G1_STATS_OP_CAPTURE_PORT |
460 				 MV88E6XXX_G1_STATS_OP_HIST_RX_TX | port);
461 	if (err)
462 		return err;
463 
464 	/* Wait for the snapshotting to complete. */
465 	return mv88e6xxx_g1_stats_wait(chip);
466 }
467 
mv88e6320_g1_stats_snapshot(struct mv88e6xxx_chip * chip,int port)468 int mv88e6320_g1_stats_snapshot(struct mv88e6xxx_chip *chip, int port)
469 {
470 	port = (port + 1) << 5;
471 
472 	return mv88e6xxx_g1_stats_snapshot(chip, port);
473 }
474 
mv88e6390_g1_stats_snapshot(struct mv88e6xxx_chip * chip,int port)475 int mv88e6390_g1_stats_snapshot(struct mv88e6xxx_chip *chip, int port)
476 {
477 	int err;
478 
479 	port = (port + 1) << 5;
480 
481 	/* Snapshot the hardware statistics counters for this port. */
482 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_STATS_OP,
483 				 MV88E6XXX_G1_STATS_OP_BUSY |
484 				 MV88E6XXX_G1_STATS_OP_CAPTURE_PORT | port);
485 	if (err)
486 		return err;
487 
488 	/* Wait for the snapshotting to complete. */
489 	return mv88e6xxx_g1_stats_wait(chip);
490 }
491 
mv88e6xxx_g1_stats_read(struct mv88e6xxx_chip * chip,int stat,u32 * val)492 void mv88e6xxx_g1_stats_read(struct mv88e6xxx_chip *chip, int stat, u32 *val)
493 {
494 	u32 value;
495 	u16 reg;
496 	int err;
497 
498 	*val = 0;
499 
500 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_STATS_OP,
501 				 MV88E6XXX_G1_STATS_OP_BUSY |
502 				 MV88E6XXX_G1_STATS_OP_READ_CAPTURED | stat);
503 	if (err)
504 		return;
505 
506 	err = mv88e6xxx_g1_stats_wait(chip);
507 	if (err)
508 		return;
509 
510 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_STATS_COUNTER_32, &reg);
511 	if (err)
512 		return;
513 
514 	value = reg << 16;
515 
516 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_STATS_COUNTER_01, &reg);
517 	if (err)
518 		return;
519 
520 	*val = value | reg;
521 }
522 
mv88e6xxx_g1_stats_clear(struct mv88e6xxx_chip * chip)523 int mv88e6xxx_g1_stats_clear(struct mv88e6xxx_chip *chip)
524 {
525 	int err;
526 	u16 val;
527 
528 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_STATS_OP, &val);
529 	if (err)
530 		return err;
531 
532 	/* Keep the histogram mode bits */
533 	val &= MV88E6XXX_G1_STATS_OP_HIST_RX_TX;
534 	val |= MV88E6XXX_G1_STATS_OP_BUSY | MV88E6XXX_G1_STATS_OP_FLUSH_ALL;
535 
536 	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_STATS_OP, val);
537 	if (err)
538 		return err;
539 
540 	/* Wait for the flush to complete. */
541 	return mv88e6xxx_g1_stats_wait(chip);
542 }
543