1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2014-2015 Hisilicon Limited.
4  */
5 
6 #include <linux/acpi.h>
7 #include <linux/errno.h>
8 #include <linux/etherdevice.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/netdevice.h>
15 #include <linux/of_address.h>
16 #include <linux/of.h>
17 #include <linux/of_mdio.h>
18 #include <linux/of_platform.h>
19 #include <linux/phy.h>
20 #include <linux/platform_device.h>
21 #include <linux/regmap.h>
22 
23 #define MDIO_DRV_NAME "Hi-HNS_MDIO"
24 #define MDIO_BUS_NAME "Hisilicon MII Bus"
25 
26 #define MDIO_TIMEOUT			1000000
27 
28 struct hns_mdio_sc_reg {
29 	u16 mdio_clk_en;
30 	u16 mdio_clk_dis;
31 	u16 mdio_reset_req;
32 	u16 mdio_reset_dreq;
33 	u16 mdio_clk_st;
34 	u16 mdio_reset_st;
35 };
36 
37 struct hns_mdio_device {
38 	u8 __iomem *vbase;		/* mdio reg base address */
39 	struct regmap *subctrl_vbase;
40 	struct hns_mdio_sc_reg sc_reg;
41 };
42 
43 /* mdio reg */
44 #define MDIO_COMMAND_REG		0x0
45 #define MDIO_ADDR_REG			0x4
46 #define MDIO_WDATA_REG			0x8
47 #define MDIO_RDATA_REG			0xc
48 #define MDIO_STA_REG			0x10
49 
50 /* cfg phy bit map */
51 #define MDIO_CMD_DEVAD_M	0x1f
52 #define MDIO_CMD_DEVAD_S	0
53 #define MDIO_CMD_PRTAD_M	0x1f
54 #define MDIO_CMD_PRTAD_S	5
55 #define MDIO_CMD_OP_S		10
56 #define MDIO_CMD_ST_S		12
57 #define MDIO_CMD_START_B	14
58 
59 #define MDIO_ADDR_DATA_M	0xffff
60 #define MDIO_ADDR_DATA_S	0
61 
62 #define MDIO_WDATA_DATA_M	0xffff
63 #define MDIO_WDATA_DATA_S	0
64 
65 #define MDIO_RDATA_DATA_M	0xffff
66 #define MDIO_RDATA_DATA_S	0
67 
68 #define MDIO_STATE_STA_B	0
69 
70 enum mdio_st_clause {
71 	MDIO_ST_CLAUSE_45 = 0,
72 	MDIO_ST_CLAUSE_22
73 };
74 
75 enum mdio_c22_op_seq {
76 	MDIO_C22_WRITE = 1,
77 	MDIO_C22_READ = 2
78 };
79 
80 enum mdio_c45_op_seq {
81 	MDIO_C45_WRITE_ADDR = 0,
82 	MDIO_C45_WRITE_DATA,
83 	MDIO_C45_READ_INCREMENT,
84 	MDIO_C45_READ
85 };
86 
87 /* peri subctrl reg */
88 #define MDIO_SC_CLK_EN		0x338
89 #define MDIO_SC_CLK_DIS		0x33C
90 #define MDIO_SC_RESET_REQ	0xA38
91 #define MDIO_SC_RESET_DREQ	0xA3C
92 #define MDIO_SC_CLK_ST		0x531C
93 #define MDIO_SC_RESET_ST	0x5A1C
94 
95 static void mdio_write_reg(u8 __iomem *base, u32 reg, u32 value)
96 {
97 	writel_relaxed(value, base + reg);
98 }
99 
100 #define MDIO_WRITE_REG(a, reg, value) \
101 	mdio_write_reg((a)->vbase, (reg), (value))
102 
103 static u32 mdio_read_reg(u8 __iomem *base, u32 reg)
104 {
105 	return readl_relaxed(base + reg);
106 }
107 
108 #define mdio_set_field(origin, mask, shift, val) \
109 	do { \
110 		(origin) &= (~((mask) << (shift))); \
111 		(origin) |= (((val) & (mask)) << (shift)); \
112 	} while (0)
113 
114 #define mdio_get_field(origin, mask, shift) (((origin) >> (shift)) & (mask))
115 
116 static void mdio_set_reg_field(u8 __iomem *base, u32 reg, u32 mask, u32 shift,
117 			       u32 val)
118 {
119 	u32 origin = mdio_read_reg(base, reg);
120 
121 	mdio_set_field(origin, mask, shift, val);
122 	mdio_write_reg(base, reg, origin);
123 }
124 
125 #define MDIO_SET_REG_FIELD(dev, reg, mask, shift, val) \
126 	mdio_set_reg_field((dev)->vbase, (reg), (mask), (shift), (val))
127 
128 static u32 mdio_get_reg_field(u8 __iomem *base, u32 reg, u32 mask, u32 shift)
129 {
130 	u32 origin;
131 
132 	origin = mdio_read_reg(base, reg);
133 	return mdio_get_field(origin, mask, shift);
134 }
135 
136 #define MDIO_GET_REG_FIELD(dev, reg, mask, shift) \
137 		mdio_get_reg_field((dev)->vbase, (reg), (mask), (shift))
138 
139 #define MDIO_GET_REG_BIT(dev, reg, bit) \
140 		mdio_get_reg_field((dev)->vbase, (reg), 0x1ull, (bit))
141 
142 #define MDIO_CHECK_SET_ST	1
143 #define MDIO_CHECK_CLR_ST	0
144 
145 static int mdio_sc_cfg_reg_write(struct hns_mdio_device *mdio_dev,
146 				 u32 cfg_reg, u32 set_val,
147 				 u32 st_reg, u32 st_msk, u8 check_st)
148 {
149 	u32 time_cnt;
150 	u32 reg_value;
151 	int ret;
152 
153 	regmap_write(mdio_dev->subctrl_vbase, cfg_reg, set_val);
154 
155 	for (time_cnt = MDIO_TIMEOUT; time_cnt; time_cnt--) {
156 		ret = regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
157 		if (ret)
158 			return ret;
159 
160 		reg_value &= st_msk;
161 		if ((!!check_st) == (!!reg_value))
162 			break;
163 	}
164 
165 	if ((!!check_st) != (!!reg_value))
166 		return -EBUSY;
167 
168 	return 0;
169 }
170 
171 static int hns_mdio_wait_ready(struct mii_bus *bus)
172 {
173 	struct hns_mdio_device *mdio_dev = bus->priv;
174 	u32 cmd_reg_value;
175 	int i;
176 
177 	/* waiting for MDIO_COMMAND_REG's mdio_start==0 */
178 	/* after that can do read or write*/
179 	for (i = 0; i < MDIO_TIMEOUT; i++) {
180 		cmd_reg_value = MDIO_GET_REG_BIT(mdio_dev,
181 						 MDIO_COMMAND_REG,
182 						 MDIO_CMD_START_B);
183 		if (!cmd_reg_value)
184 			break;
185 	}
186 	if ((i == MDIO_TIMEOUT) && cmd_reg_value)
187 		return -ETIMEDOUT;
188 
189 	return 0;
190 }
191 
192 static void hns_mdio_cmd_write(struct hns_mdio_device *mdio_dev,
193 			       u8 is_c45, u8 op, u8 phy_id, u16 cmd)
194 {
195 	u32 cmd_reg_value;
196 	u8 st = is_c45 ? MDIO_ST_CLAUSE_45 : MDIO_ST_CLAUSE_22;
197 
198 	cmd_reg_value = st << MDIO_CMD_ST_S;
199 	cmd_reg_value |= op << MDIO_CMD_OP_S;
200 	cmd_reg_value |=
201 		(phy_id & MDIO_CMD_PRTAD_M) << MDIO_CMD_PRTAD_S;
202 	cmd_reg_value |= (cmd & MDIO_CMD_DEVAD_M) << MDIO_CMD_DEVAD_S;
203 	cmd_reg_value |= 1 << MDIO_CMD_START_B;
204 
205 	MDIO_WRITE_REG(mdio_dev, MDIO_COMMAND_REG, cmd_reg_value);
206 }
207 
208 /**
209  * hns_mdio_write - access phy register
210  * @bus: mdio bus
211  * @phy_id: phy id
212  * @regnum: register num
213  * @data: register value
214  *
215  * Return 0 on success, negative on failure
216  */
217 static int hns_mdio_write(struct mii_bus *bus,
218 			  int phy_id, int regnum, u16 data)
219 {
220 	int ret;
221 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
222 	u8 devad = ((regnum >> 16) & 0x1f);
223 	u8 is_c45 = !!(regnum & MII_ADDR_C45);
224 	u16 reg = (u16)(regnum & 0xffff);
225 	u8 op;
226 	u16 cmd_reg_cfg;
227 
228 	dev_dbg(&bus->dev, "mdio write %s,base is %p\n",
229 		bus->id, mdio_dev->vbase);
230 	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x, write data=%d\n",
231 		phy_id, is_c45, devad, reg, data);
232 
233 	/* wait for ready */
234 	ret = hns_mdio_wait_ready(bus);
235 	if (ret) {
236 		dev_err(&bus->dev, "MDIO bus is busy\n");
237 		return ret;
238 	}
239 
240 	if (!is_c45) {
241 		cmd_reg_cfg = reg;
242 		op = MDIO_C22_WRITE;
243 	} else {
244 		/* config the cmd-reg to write addr*/
245 		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
246 				   MDIO_ADDR_DATA_S, reg);
247 
248 		hns_mdio_cmd_write(mdio_dev, is_c45,
249 				   MDIO_C45_WRITE_ADDR, phy_id, devad);
250 
251 		/* check for read or write opt is finished */
252 		ret = hns_mdio_wait_ready(bus);
253 		if (ret) {
254 			dev_err(&bus->dev, "MDIO bus is busy\n");
255 			return ret;
256 		}
257 
258 		/* config the data needed writing */
259 		cmd_reg_cfg = devad;
260 		op = MDIO_C45_WRITE_DATA;
261 	}
262 
263 	MDIO_SET_REG_FIELD(mdio_dev, MDIO_WDATA_REG, MDIO_WDATA_DATA_M,
264 			   MDIO_WDATA_DATA_S, data);
265 
266 	hns_mdio_cmd_write(mdio_dev, is_c45, op, phy_id, cmd_reg_cfg);
267 
268 	return 0;
269 }
270 
271 /**
272  * hns_mdio_read - access phy register
273  * @bus: mdio bus
274  * @phy_id: phy id
275  * @regnum: register num
276  *
277  * Return phy register value
278  */
279 static int hns_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
280 {
281 	int ret;
282 	u16 reg_val;
283 	u8 devad = ((regnum >> 16) & 0x1f);
284 	u8 is_c45 = !!(regnum & MII_ADDR_C45);
285 	u16 reg = (u16)(regnum & 0xffff);
286 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
287 
288 	dev_dbg(&bus->dev, "mdio read %s,base is %p\n",
289 		bus->id, mdio_dev->vbase);
290 	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x!\n",
291 		phy_id, is_c45, devad, reg);
292 
293 	/* Step 1: wait for ready */
294 	ret = hns_mdio_wait_ready(bus);
295 	if (ret) {
296 		dev_err(&bus->dev, "MDIO bus is busy\n");
297 		return ret;
298 	}
299 
300 	if (!is_c45) {
301 		hns_mdio_cmd_write(mdio_dev, is_c45,
302 				   MDIO_C22_READ, phy_id, reg);
303 	} else {
304 		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
305 				   MDIO_ADDR_DATA_S, reg);
306 
307 		/* Step 2; config the cmd-reg to write addr*/
308 		hns_mdio_cmd_write(mdio_dev, is_c45,
309 				   MDIO_C45_WRITE_ADDR, phy_id, devad);
310 
311 		/* Step 3: check for read or write opt is finished */
312 		ret = hns_mdio_wait_ready(bus);
313 		if (ret) {
314 			dev_err(&bus->dev, "MDIO bus is busy\n");
315 			return ret;
316 		}
317 
318 		hns_mdio_cmd_write(mdio_dev, is_c45,
319 				   MDIO_C45_READ, phy_id, devad);
320 	}
321 
322 	/* Step 5: waiting for MDIO_COMMAND_REG's mdio_start==0,*/
323 	/* check for read or write opt is finished */
324 	ret = hns_mdio_wait_ready(bus);
325 	if (ret) {
326 		dev_err(&bus->dev, "MDIO bus is busy\n");
327 		return ret;
328 	}
329 
330 	reg_val = MDIO_GET_REG_BIT(mdio_dev, MDIO_STA_REG, MDIO_STATE_STA_B);
331 	if (reg_val) {
332 		dev_err(&bus->dev, " ERROR! MDIO Read failed!\n");
333 		return -EBUSY;
334 	}
335 
336 	/* Step 6; get out data*/
337 	reg_val = (u16)MDIO_GET_REG_FIELD(mdio_dev, MDIO_RDATA_REG,
338 					  MDIO_RDATA_DATA_M, MDIO_RDATA_DATA_S);
339 
340 	return reg_val;
341 }
342 
343 /**
344  * hns_mdio_reset - reset mdio bus
345  * @bus: mdio bus
346  *
347  * Return 0 on success, negative on failure
348  */
349 static int hns_mdio_reset(struct mii_bus *bus)
350 {
351 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
352 	const struct hns_mdio_sc_reg *sc_reg;
353 	int ret;
354 
355 	if (dev_of_node(bus->parent)) {
356 		if (!mdio_dev->subctrl_vbase) {
357 			dev_err(&bus->dev, "mdio sys ctl reg has not mapped\n");
358 			return -ENODEV;
359 		}
360 
361 		sc_reg = &mdio_dev->sc_reg;
362 		/* 1. reset req, and read reset st check */
363 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_reset_req,
364 					    0x1, sc_reg->mdio_reset_st, 0x1,
365 					    MDIO_CHECK_SET_ST);
366 		if (ret) {
367 			dev_err(&bus->dev, "MDIO reset fail\n");
368 			return ret;
369 		}
370 
371 		/* 2. dis clk, and read clk st check */
372 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_clk_dis,
373 					    0x1, sc_reg->mdio_clk_st, 0x1,
374 					    MDIO_CHECK_CLR_ST);
375 		if (ret) {
376 			dev_err(&bus->dev, "MDIO dis clk fail\n");
377 			return ret;
378 		}
379 
380 		/* 3. reset dreq, and read reset st check */
381 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_reset_dreq,
382 					    0x1, sc_reg->mdio_reset_st, 0x1,
383 					    MDIO_CHECK_CLR_ST);
384 		if (ret) {
385 			dev_err(&bus->dev, "MDIO dis clk fail\n");
386 			return ret;
387 		}
388 
389 		/* 4. en clk, and read clk st check */
390 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_clk_en,
391 					    0x1, sc_reg->mdio_clk_st, 0x1,
392 					    MDIO_CHECK_SET_ST);
393 		if (ret)
394 			dev_err(&bus->dev, "MDIO en clk fail\n");
395 	} else if (is_acpi_node(bus->parent->fwnode)) {
396 		acpi_status s;
397 
398 		s = acpi_evaluate_object(ACPI_HANDLE(bus->parent),
399 					 "_RST", NULL, NULL);
400 		if (ACPI_FAILURE(s)) {
401 			dev_err(&bus->dev, "Reset failed, return:%#x\n", s);
402 			ret = -EBUSY;
403 		} else {
404 			ret = 0;
405 		}
406 	} else {
407 		dev_err(&bus->dev, "Can not get cfg data from DT or ACPI\n");
408 		ret = -ENXIO;
409 	}
410 	return ret;
411 }
412 
413 /**
414  * hns_mdio_probe - probe mdio device
415  * @pdev: mdio platform device
416  *
417  * Return 0 on success, negative on failure
418  */
419 static int hns_mdio_probe(struct platform_device *pdev)
420 {
421 	struct hns_mdio_device *mdio_dev;
422 	struct mii_bus *new_bus;
423 	int ret;
424 
425 	if (!pdev) {
426 		dev_err(NULL, "pdev is NULL!\r\n");
427 		return -ENODEV;
428 	}
429 
430 	mdio_dev = devm_kzalloc(&pdev->dev, sizeof(*mdio_dev), GFP_KERNEL);
431 	if (!mdio_dev)
432 		return -ENOMEM;
433 
434 	new_bus = devm_mdiobus_alloc(&pdev->dev);
435 	if (!new_bus) {
436 		dev_err(&pdev->dev, "mdiobus_alloc fail!\n");
437 		return -ENOMEM;
438 	}
439 
440 	new_bus->name = MDIO_BUS_NAME;
441 	new_bus->read = hns_mdio_read;
442 	new_bus->write = hns_mdio_write;
443 	new_bus->reset = hns_mdio_reset;
444 	new_bus->priv = mdio_dev;
445 	new_bus->parent = &pdev->dev;
446 
447 	mdio_dev->vbase = devm_platform_ioremap_resource(pdev, 0);
448 	if (IS_ERR(mdio_dev->vbase)) {
449 		ret = PTR_ERR(mdio_dev->vbase);
450 		return ret;
451 	}
452 
453 	platform_set_drvdata(pdev, new_bus);
454 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%s", "Mii",
455 		 dev_name(&pdev->dev));
456 	if (dev_of_node(&pdev->dev)) {
457 		struct of_phandle_args reg_args;
458 
459 		ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
460 						       "subctrl-vbase",
461 						       4,
462 						       0,
463 						       &reg_args);
464 		if (!ret) {
465 			mdio_dev->subctrl_vbase =
466 				syscon_node_to_regmap(reg_args.np);
467 			if (IS_ERR(mdio_dev->subctrl_vbase)) {
468 				dev_warn(&pdev->dev, "syscon_node_to_regmap error\n");
469 				mdio_dev->subctrl_vbase = NULL;
470 			} else {
471 				if (reg_args.args_count == 4) {
472 					mdio_dev->sc_reg.mdio_clk_en =
473 						(u16)reg_args.args[0];
474 					mdio_dev->sc_reg.mdio_clk_dis =
475 						(u16)reg_args.args[0] + 4;
476 					mdio_dev->sc_reg.mdio_reset_req =
477 						(u16)reg_args.args[1];
478 					mdio_dev->sc_reg.mdio_reset_dreq =
479 						(u16)reg_args.args[1] + 4;
480 					mdio_dev->sc_reg.mdio_clk_st =
481 						(u16)reg_args.args[2];
482 					mdio_dev->sc_reg.mdio_reset_st =
483 						(u16)reg_args.args[3];
484 				} else {
485 					/* for compatible */
486 					mdio_dev->sc_reg.mdio_clk_en =
487 						MDIO_SC_CLK_EN;
488 					mdio_dev->sc_reg.mdio_clk_dis =
489 						MDIO_SC_CLK_DIS;
490 					mdio_dev->sc_reg.mdio_reset_req =
491 						MDIO_SC_RESET_REQ;
492 					mdio_dev->sc_reg.mdio_reset_dreq =
493 						MDIO_SC_RESET_DREQ;
494 					mdio_dev->sc_reg.mdio_clk_st =
495 						MDIO_SC_CLK_ST;
496 					mdio_dev->sc_reg.mdio_reset_st =
497 						MDIO_SC_RESET_ST;
498 				}
499 			}
500 		} else {
501 			dev_warn(&pdev->dev, "find syscon ret = %#x\n", ret);
502 			mdio_dev->subctrl_vbase = NULL;
503 		}
504 
505 		ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
506 	} else if (is_acpi_node(pdev->dev.fwnode)) {
507 		/* Clear all the IRQ properties */
508 		memset(new_bus->irq, PHY_POLL, 4 * PHY_MAX_ADDR);
509 
510 		/* Mask out all PHYs from auto probing. */
511 		new_bus->phy_mask = ~0;
512 
513 		/* Register the MDIO bus */
514 		ret = mdiobus_register(new_bus);
515 	} else {
516 		dev_err(&pdev->dev, "Can not get cfg data from DT or ACPI\n");
517 		ret = -ENXIO;
518 	}
519 
520 	if (ret) {
521 		dev_err(&pdev->dev, "Cannot register as MDIO bus!\n");
522 		platform_set_drvdata(pdev, NULL);
523 		return ret;
524 	}
525 
526 	return 0;
527 }
528 
529 /**
530  * hns_mdio_remove - remove mdio device
531  * @pdev: mdio platform device
532  *
533  * Return 0 on success, negative on failure
534  */
535 static int hns_mdio_remove(struct platform_device *pdev)
536 {
537 	struct mii_bus *bus;
538 
539 	bus = platform_get_drvdata(pdev);
540 
541 	mdiobus_unregister(bus);
542 	platform_set_drvdata(pdev, NULL);
543 	return 0;
544 }
545 
546 static const struct of_device_id hns_mdio_match[] = {
547 	{.compatible = "hisilicon,mdio"},
548 	{.compatible = "hisilicon,hns-mdio"},
549 	{}
550 };
551 MODULE_DEVICE_TABLE(of, hns_mdio_match);
552 
553 static const struct acpi_device_id hns_mdio_acpi_match[] = {
554 	{ "HISI0141", 0 },
555 	{ },
556 };
557 MODULE_DEVICE_TABLE(acpi, hns_mdio_acpi_match);
558 
559 static struct platform_driver hns_mdio_driver = {
560 	.probe = hns_mdio_probe,
561 	.remove = hns_mdio_remove,
562 	.driver = {
563 		   .name = MDIO_DRV_NAME,
564 		   .of_match_table = hns_mdio_match,
565 		   .acpi_match_table = ACPI_PTR(hns_mdio_acpi_match),
566 		   },
567 };
568 
569 module_platform_driver(hns_mdio_driver);
570 
571 MODULE_LICENSE("GPL");
572 MODULE_AUTHOR("Huawei Tech. Co., Ltd.");
573 MODULE_DESCRIPTION("Hisilicon HNS MDIO driver");
574 MODULE_ALIAS("platform:" MDIO_DRV_NAME);
575