1/*
2 * B53 register access through Switch Register Access Bridge Registers
3 *
4 * Copyright (C) 2013 Hauke Mehrtens <hauke@hauke-m.de>
5 *
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/delay.h>
22#include <linux/interrupt.h>
23#include <linux/platform_device.h>
24#include <linux/platform_data/b53.h>
25#include <linux/of.h>
26
27#include "b53_priv.h"
28#include "b53_serdes.h"
29
30/* command and status register of the SRAB */
31#define B53_SRAB_CMDSTAT 0x2c
32#define B53_SRAB_CMDSTAT_RST BIT(2)
33#define B53_SRAB_CMDSTAT_WRITE BIT(1)
34#define B53_SRAB_CMDSTAT_GORDYN BIT(0)
35#define B53_SRAB_CMDSTAT_PAGE 24
36#define B53_SRAB_CMDSTAT_REG 16
37
38/* high order word of write data to switch registe */
39#define B53_SRAB_WD_H 0x30
40
41/* low order word of write data to switch registe */
42#define B53_SRAB_WD_L 0x34
43
44/* high order word of read data from switch register */
45#define B53_SRAB_RD_H 0x38
46
47/* low order word of read data from switch register */
48#define B53_SRAB_RD_L 0x3c
49
50/* command and status register of the SRAB */
51#define B53_SRAB_CTRLS 0x40
52#define B53_SRAB_CTRLS_HOST_INTR BIT(1)
53#define B53_SRAB_CTRLS_RCAREQ BIT(3)
54#define B53_SRAB_CTRLS_RCAGNT BIT(4)
55#define B53_SRAB_CTRLS_SW_INIT_DONE BIT(6)
56
57/* the register captures interrupt pulses from the switch */
58#define B53_SRAB_INTR 0x44
59#define B53_SRAB_INTR_P(x) BIT(x)
60#define B53_SRAB_SWITCH_PHY BIT(8)
61#define B53_SRAB_1588_SYNC BIT(9)
62#define B53_SRAB_IMP1_SLEEP_TIMER BIT(10)
63#define B53_SRAB_P7_SLEEP_TIMER BIT(11)
64#define B53_SRAB_IMP0_SLEEP_TIMER BIT(12)
65
66/* Port mux configuration registers */
67#define B53_MUX_CONFIG_P5 0x00
68#define MUX_CONFIG_SGMII 0
69#define MUX_CONFIG_MII_LITE 1
70#define MUX_CONFIG_RGMII 2
71#define MUX_CONFIG_GMII 3
72#define MUX_CONFIG_GPHY 4
73#define MUX_CONFIG_INTERNAL 5
74#define MUX_CONFIG_MASK 0x7
75#define B53_MUX_CONFIG_P4 0x04
76
77struct b53_srab_port_priv {
78 int irq;
79 bool irq_enabled;
80 struct b53_device *dev;
81 unsigned int num;
82 phy_interface_t mode;
83};
84
85struct b53_srab_priv {
86 void __iomem *regs;
87 void __iomem *mux_config;
88 struct b53_srab_port_priv port_intrs[B53_N_PORTS];
89};
90
91static int b53_srab_request_grant(struct b53_device *dev)
92{
93 struct b53_srab_priv *priv = dev->priv;
94 u8 __iomem *regs = priv->regs;
95 u32 ctrls;
96 int i;
97
98 ctrls = readl(addr: regs + B53_SRAB_CTRLS);
99 ctrls |= B53_SRAB_CTRLS_RCAREQ;
100 writel(val: ctrls, addr: regs + B53_SRAB_CTRLS);
101
102 for (i = 0; i < 20; i++) {
103 ctrls = readl(addr: regs + B53_SRAB_CTRLS);
104 if (ctrls & B53_SRAB_CTRLS_RCAGNT)
105 break;
106 usleep_range(min: 10, max: 100);
107 }
108 if (WARN_ON(i == 5))
109 return -EIO;
110
111 return 0;
112}
113
114static void b53_srab_release_grant(struct b53_device *dev)
115{
116 struct b53_srab_priv *priv = dev->priv;
117 u8 __iomem *regs = priv->regs;
118 u32 ctrls;
119
120 ctrls = readl(addr: regs + B53_SRAB_CTRLS);
121 ctrls &= ~B53_SRAB_CTRLS_RCAREQ;
122 writel(val: ctrls, addr: regs + B53_SRAB_CTRLS);
123}
124
125static int b53_srab_op(struct b53_device *dev, u8 page, u8 reg, u32 op)
126{
127 struct b53_srab_priv *priv = dev->priv;
128 u8 __iomem *regs = priv->regs;
129 int i;
130 u32 cmdstat;
131
132 /* set register address */
133 cmdstat = (page << B53_SRAB_CMDSTAT_PAGE) |
134 (reg << B53_SRAB_CMDSTAT_REG) |
135 B53_SRAB_CMDSTAT_GORDYN |
136 op;
137 writel(val: cmdstat, addr: regs + B53_SRAB_CMDSTAT);
138
139 /* check if operation completed */
140 for (i = 0; i < 5; ++i) {
141 cmdstat = readl(addr: regs + B53_SRAB_CMDSTAT);
142 if (!(cmdstat & B53_SRAB_CMDSTAT_GORDYN))
143 break;
144 usleep_range(min: 10, max: 100);
145 }
146
147 if (WARN_ON(i == 5))
148 return -EIO;
149
150 return 0;
151}
152
153static int b53_srab_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
154{
155 struct b53_srab_priv *priv = dev->priv;
156 u8 __iomem *regs = priv->regs;
157 int ret = 0;
158
159 ret = b53_srab_request_grant(dev);
160 if (ret)
161 goto err;
162
163 ret = b53_srab_op(dev, page, reg, op: 0);
164 if (ret)
165 goto err;
166
167 *val = readl(addr: regs + B53_SRAB_RD_L) & 0xff;
168
169err:
170 b53_srab_release_grant(dev);
171
172 return ret;
173}
174
175static int b53_srab_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
176{
177 struct b53_srab_priv *priv = dev->priv;
178 u8 __iomem *regs = priv->regs;
179 int ret = 0;
180
181 ret = b53_srab_request_grant(dev);
182 if (ret)
183 goto err;
184
185 ret = b53_srab_op(dev, page, reg, op: 0);
186 if (ret)
187 goto err;
188
189 *val = readl(addr: regs + B53_SRAB_RD_L) & 0xffff;
190
191err:
192 b53_srab_release_grant(dev);
193
194 return ret;
195}
196
197static int b53_srab_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
198{
199 struct b53_srab_priv *priv = dev->priv;
200 u8 __iomem *regs = priv->regs;
201 int ret = 0;
202
203 ret = b53_srab_request_grant(dev);
204 if (ret)
205 goto err;
206
207 ret = b53_srab_op(dev, page, reg, op: 0);
208 if (ret)
209 goto err;
210
211 *val = readl(addr: regs + B53_SRAB_RD_L);
212
213err:
214 b53_srab_release_grant(dev);
215
216 return ret;
217}
218
219static int b53_srab_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
220{
221 struct b53_srab_priv *priv = dev->priv;
222 u8 __iomem *regs = priv->regs;
223 int ret = 0;
224
225 ret = b53_srab_request_grant(dev);
226 if (ret)
227 goto err;
228
229 ret = b53_srab_op(dev, page, reg, op: 0);
230 if (ret)
231 goto err;
232
233 *val = readl(addr: regs + B53_SRAB_RD_L);
234 *val += ((u64)readl(addr: regs + B53_SRAB_RD_H) & 0xffff) << 32;
235
236err:
237 b53_srab_release_grant(dev);
238
239 return ret;
240}
241
242static int b53_srab_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
243{
244 struct b53_srab_priv *priv = dev->priv;
245 u8 __iomem *regs = priv->regs;
246 int ret = 0;
247
248 ret = b53_srab_request_grant(dev);
249 if (ret)
250 goto err;
251
252 ret = b53_srab_op(dev, page, reg, op: 0);
253 if (ret)
254 goto err;
255
256 *val = readl(addr: regs + B53_SRAB_RD_L);
257 *val += (u64)readl(addr: regs + B53_SRAB_RD_H) << 32;
258
259err:
260 b53_srab_release_grant(dev);
261
262 return ret;
263}
264
265static int b53_srab_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
266{
267 struct b53_srab_priv *priv = dev->priv;
268 u8 __iomem *regs = priv->regs;
269 int ret = 0;
270
271 ret = b53_srab_request_grant(dev);
272 if (ret)
273 goto err;
274
275 writel(val: value, addr: regs + B53_SRAB_WD_L);
276
277 ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
278
279err:
280 b53_srab_release_grant(dev);
281
282 return ret;
283}
284
285static int b53_srab_write16(struct b53_device *dev, u8 page, u8 reg,
286 u16 value)
287{
288 struct b53_srab_priv *priv = dev->priv;
289 u8 __iomem *regs = priv->regs;
290 int ret = 0;
291
292 ret = b53_srab_request_grant(dev);
293 if (ret)
294 goto err;
295
296 writel(val: value, addr: regs + B53_SRAB_WD_L);
297
298 ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
299
300err:
301 b53_srab_release_grant(dev);
302
303 return ret;
304}
305
306static int b53_srab_write32(struct b53_device *dev, u8 page, u8 reg,
307 u32 value)
308{
309 struct b53_srab_priv *priv = dev->priv;
310 u8 __iomem *regs = priv->regs;
311 int ret = 0;
312
313 ret = b53_srab_request_grant(dev);
314 if (ret)
315 goto err;
316
317 writel(val: value, addr: regs + B53_SRAB_WD_L);
318
319 ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
320
321err:
322 b53_srab_release_grant(dev);
323
324 return ret;
325}
326
327static int b53_srab_write48(struct b53_device *dev, u8 page, u8 reg,
328 u64 value)
329{
330 struct b53_srab_priv *priv = dev->priv;
331 u8 __iomem *regs = priv->regs;
332 int ret = 0;
333
334 ret = b53_srab_request_grant(dev);
335 if (ret)
336 goto err;
337
338 writel(val: (u32)value, addr: regs + B53_SRAB_WD_L);
339 writel(val: (u16)(value >> 32), addr: regs + B53_SRAB_WD_H);
340
341 ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
342
343err:
344 b53_srab_release_grant(dev);
345
346 return ret;
347}
348
349static int b53_srab_write64(struct b53_device *dev, u8 page, u8 reg,
350 u64 value)
351{
352 struct b53_srab_priv *priv = dev->priv;
353 u8 __iomem *regs = priv->regs;
354 int ret = 0;
355
356 ret = b53_srab_request_grant(dev);
357 if (ret)
358 goto err;
359
360 writel(val: (u32)value, addr: regs + B53_SRAB_WD_L);
361 writel(val: (u32)(value >> 32), addr: regs + B53_SRAB_WD_H);
362
363 ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
364
365err:
366 b53_srab_release_grant(dev);
367
368 return ret;
369}
370
371static irqreturn_t b53_srab_port_thread(int irq, void *dev_id)
372{
373 struct b53_srab_port_priv *port = dev_id;
374 struct b53_device *dev = port->dev;
375
376 if (port->mode == PHY_INTERFACE_MODE_SGMII)
377 b53_port_event(ds: dev->ds, port: port->num);
378
379 return IRQ_HANDLED;
380}
381
382static irqreturn_t b53_srab_port_isr(int irq, void *dev_id)
383{
384 struct b53_srab_port_priv *port = dev_id;
385 struct b53_device *dev = port->dev;
386 struct b53_srab_priv *priv = dev->priv;
387
388 /* Acknowledge the interrupt */
389 writel(BIT(port->num), addr: priv->regs + B53_SRAB_INTR);
390
391 return IRQ_WAKE_THREAD;
392}
393
394#if IS_ENABLED(CONFIG_B53_SERDES)
395static u8 b53_srab_serdes_map_lane(struct b53_device *dev, int port)
396{
397 struct b53_srab_priv *priv = dev->priv;
398 struct b53_srab_port_priv *p = &priv->port_intrs[port];
399
400 if (p->mode != PHY_INTERFACE_MODE_SGMII)
401 return B53_INVALID_LANE;
402
403 switch (port) {
404 case 5:
405 return 0;
406 case 4:
407 return 1;
408 default:
409 return B53_INVALID_LANE;
410 }
411}
412#endif
413
414static int b53_srab_irq_enable(struct b53_device *dev, int port)
415{
416 struct b53_srab_priv *priv = dev->priv;
417 struct b53_srab_port_priv *p = &priv->port_intrs[port];
418 int ret = 0;
419
420 /* Interrupt is optional and was not specified, do not make
421 * this fatal
422 */
423 if (p->irq == -ENXIO)
424 return ret;
425
426 ret = request_threaded_irq(irq: p->irq, handler: b53_srab_port_isr,
427 thread_fn: b53_srab_port_thread, flags: 0,
428 name: dev_name(dev: dev->dev), dev: p);
429 if (!ret)
430 p->irq_enabled = true;
431
432 return ret;
433}
434
435static void b53_srab_irq_disable(struct b53_device *dev, int port)
436{
437 struct b53_srab_priv *priv = dev->priv;
438 struct b53_srab_port_priv *p = &priv->port_intrs[port];
439
440 if (p->irq_enabled) {
441 free_irq(p->irq, p);
442 p->irq_enabled = false;
443 }
444}
445
446static void b53_srab_phylink_get_caps(struct b53_device *dev, int port,
447 struct phylink_config *config)
448{
449 struct b53_srab_priv *priv = dev->priv;
450 struct b53_srab_port_priv *p = &priv->port_intrs[port];
451
452 switch (p->mode) {
453 case PHY_INTERFACE_MODE_SGMII:
454#if IS_ENABLED(CONFIG_B53_SERDES)
455 /* If p->mode indicates SGMII mode, that essentially means we
456 * are using a serdes. As the serdes for the capabilities.
457 */
458 b53_serdes_phylink_get_caps(dev, port, config);
459#endif
460 break;
461
462 case PHY_INTERFACE_MODE_NA:
463 break;
464
465 case PHY_INTERFACE_MODE_RGMII:
466 /* If we support RGMII, support all RGMII modes, since
467 * that dictates the PHY delay settings.
468 */
469 phy_interface_set_rgmii(intf: config->supported_interfaces);
470 break;
471
472 default:
473 /* Some other mode (e.g. MII, GMII etc) */
474 __set_bit(p->mode, config->supported_interfaces);
475 break;
476 }
477}
478
479static const struct b53_io_ops b53_srab_ops = {
480 .read8 = b53_srab_read8,
481 .read16 = b53_srab_read16,
482 .read32 = b53_srab_read32,
483 .read48 = b53_srab_read48,
484 .read64 = b53_srab_read64,
485 .write8 = b53_srab_write8,
486 .write16 = b53_srab_write16,
487 .write32 = b53_srab_write32,
488 .write48 = b53_srab_write48,
489 .write64 = b53_srab_write64,
490 .irq_enable = b53_srab_irq_enable,
491 .irq_disable = b53_srab_irq_disable,
492 .phylink_get_caps = b53_srab_phylink_get_caps,
493#if IS_ENABLED(CONFIG_B53_SERDES)
494 .phylink_mac_select_pcs = b53_serdes_phylink_mac_select_pcs,
495 .serdes_map_lane = b53_srab_serdes_map_lane,
496 .serdes_link_set = b53_serdes_link_set,
497#endif
498};
499
500static const struct of_device_id b53_srab_of_match[] = {
501 { .compatible = "brcm,bcm53010-srab" },
502 { .compatible = "brcm,bcm53011-srab" },
503 { .compatible = "brcm,bcm53012-srab" },
504 { .compatible = "brcm,bcm53018-srab" },
505 { .compatible = "brcm,bcm53019-srab" },
506 { .compatible = "brcm,bcm5301x-srab" },
507 { .compatible = "brcm,bcm11360-srab", .data = (void *)BCM583XX_DEVICE_ID },
508 { .compatible = "brcm,bcm58522-srab", .data = (void *)BCM58XX_DEVICE_ID },
509 { .compatible = "brcm,bcm58525-srab", .data = (void *)BCM58XX_DEVICE_ID },
510 { .compatible = "brcm,bcm58535-srab", .data = (void *)BCM58XX_DEVICE_ID },
511 { .compatible = "brcm,bcm58622-srab", .data = (void *)BCM58XX_DEVICE_ID },
512 { .compatible = "brcm,bcm58623-srab", .data = (void *)BCM58XX_DEVICE_ID },
513 { .compatible = "brcm,bcm58625-srab", .data = (void *)BCM58XX_DEVICE_ID },
514 { .compatible = "brcm,bcm88312-srab", .data = (void *)BCM58XX_DEVICE_ID },
515 { .compatible = "brcm,cygnus-srab", .data = (void *)BCM583XX_DEVICE_ID },
516 { .compatible = "brcm,nsp-srab", .data = (void *)BCM58XX_DEVICE_ID },
517 { .compatible = "brcm,omega-srab", .data = (void *)BCM583XX_DEVICE_ID },
518 { /* sentinel */ },
519};
520MODULE_DEVICE_TABLE(of, b53_srab_of_match);
521
522static void b53_srab_intr_set(struct b53_srab_priv *priv, bool set)
523{
524 u32 reg;
525
526 reg = readl(addr: priv->regs + B53_SRAB_CTRLS);
527 if (set)
528 reg |= B53_SRAB_CTRLS_HOST_INTR;
529 else
530 reg &= ~B53_SRAB_CTRLS_HOST_INTR;
531 writel(val: reg, addr: priv->regs + B53_SRAB_CTRLS);
532}
533
534static void b53_srab_prepare_irq(struct platform_device *pdev)
535{
536 struct b53_device *dev = platform_get_drvdata(pdev);
537 struct b53_srab_priv *priv = dev->priv;
538 struct b53_srab_port_priv *port;
539 unsigned int i;
540 char *name;
541
542 /* Clear all pending interrupts */
543 writel(val: 0xffffffff, addr: priv->regs + B53_SRAB_INTR);
544
545 for (i = 0; i < B53_N_PORTS; i++) {
546 port = &priv->port_intrs[i];
547
548 /* There is no port 6 */
549 if (i == 6)
550 continue;
551
552 name = kasprintf(GFP_KERNEL, fmt: "link_state_p%d", i);
553 if (!name)
554 return;
555
556 port->num = i;
557 port->dev = dev;
558 port->irq = platform_get_irq_byname_optional(dev: pdev, name);
559 kfree(objp: name);
560 }
561
562 b53_srab_intr_set(priv, set: true);
563}
564
565static void b53_srab_mux_init(struct platform_device *pdev)
566{
567 struct b53_device *dev = platform_get_drvdata(pdev);
568 struct b53_srab_priv *priv = dev->priv;
569 struct b53_srab_port_priv *p;
570 unsigned int port;
571 u32 reg, off = 0;
572 int ret;
573
574 if (dev->pdata && dev->pdata->chip_id != BCM58XX_DEVICE_ID)
575 return;
576
577 priv->mux_config = devm_platform_ioremap_resource(pdev, index: 1);
578 if (IS_ERR(ptr: priv->mux_config))
579 return;
580
581 /* Obtain the port mux configuration so we know which lanes
582 * actually map to SerDes lanes
583 */
584 for (port = 5; port > 3; port--, off += 4) {
585 p = &priv->port_intrs[port];
586
587 reg = readl(addr: priv->mux_config + B53_MUX_CONFIG_P5 + off);
588 switch (reg & MUX_CONFIG_MASK) {
589 case MUX_CONFIG_SGMII:
590 p->mode = PHY_INTERFACE_MODE_SGMII;
591 ret = b53_serdes_init(dev, port);
592 if (ret)
593 continue;
594 break;
595 case MUX_CONFIG_MII_LITE:
596 p->mode = PHY_INTERFACE_MODE_MII;
597 break;
598 case MUX_CONFIG_GMII:
599 p->mode = PHY_INTERFACE_MODE_GMII;
600 break;
601 case MUX_CONFIG_RGMII:
602 p->mode = PHY_INTERFACE_MODE_RGMII;
603 break;
604 case MUX_CONFIG_INTERNAL:
605 p->mode = PHY_INTERFACE_MODE_INTERNAL;
606 break;
607 default:
608 p->mode = PHY_INTERFACE_MODE_NA;
609 break;
610 }
611
612 if (p->mode != PHY_INTERFACE_MODE_NA)
613 dev_info(&pdev->dev, "Port %d mode: %s\n",
614 port, phy_modes(p->mode));
615 }
616}
617
618static int b53_srab_probe(struct platform_device *pdev)
619{
620 struct b53_platform_data *pdata = pdev->dev.platform_data;
621 struct device_node *dn = pdev->dev.of_node;
622 const struct of_device_id *of_id = NULL;
623 struct b53_srab_priv *priv;
624 struct b53_device *dev;
625
626 if (dn)
627 of_id = of_match_node(matches: b53_srab_of_match, node: dn);
628
629 if (of_id) {
630 pdata = devm_kzalloc(dev: &pdev->dev, size: sizeof(*pdata), GFP_KERNEL);
631 if (!pdata)
632 return -ENOMEM;
633
634 pdata->chip_id = (u32)(unsigned long)of_id->data;
635 }
636
637 priv = devm_kzalloc(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL);
638 if (!priv)
639 return -ENOMEM;
640
641 priv->regs = devm_platform_ioremap_resource(pdev, index: 0);
642 if (IS_ERR(ptr: priv->regs))
643 return PTR_ERR(ptr: priv->regs);
644
645 dev = b53_switch_alloc(base: &pdev->dev, ops: &b53_srab_ops, priv);
646 if (!dev)
647 return -ENOMEM;
648
649 if (pdata)
650 dev->pdata = pdata;
651
652 platform_set_drvdata(pdev, data: dev);
653
654 b53_srab_prepare_irq(pdev);
655 b53_srab_mux_init(pdev);
656
657 return b53_switch_register(dev);
658}
659
660static void b53_srab_remove(struct platform_device *pdev)
661{
662 struct b53_device *dev = platform_get_drvdata(pdev);
663
664 if (!dev)
665 return;
666
667 b53_srab_intr_set(priv: dev->priv, set: false);
668 b53_switch_remove(dev);
669}
670
671static void b53_srab_shutdown(struct platform_device *pdev)
672{
673 struct b53_device *dev = platform_get_drvdata(pdev);
674
675 if (!dev)
676 return;
677
678 b53_switch_shutdown(dev);
679
680 platform_set_drvdata(pdev, NULL);
681}
682
683static struct platform_driver b53_srab_driver = {
684 .probe = b53_srab_probe,
685 .remove_new = b53_srab_remove,
686 .shutdown = b53_srab_shutdown,
687 .driver = {
688 .name = "b53-srab-switch",
689 .of_match_table = b53_srab_of_match,
690 },
691};
692
693module_platform_driver(b53_srab_driver);
694MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
695MODULE_DESCRIPTION("B53 Switch Register Access Bridge Registers (SRAB) access driver");
696MODULE_LICENSE("Dual BSD/GPL");
697

source code of linux/drivers/net/dsa/b53/b53_srab.c