1 /*
2  * Copyright (c) 2014-2015 Hisilicon Limited.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 
10 #include <linux/acpi.h>
11 #include <linux/errno.h>
12 #include <linux/etherdevice.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/netdevice.h>
19 #include <linux/of_address.h>
20 #include <linux/of.h>
21 #include <linux/of_mdio.h>
22 #include <linux/of_platform.h>
23 #include <linux/phy.h>
24 #include <linux/platform_device.h>
25 #include <linux/regmap.h>
26 
27 #define MDIO_DRV_NAME "Hi-HNS_MDIO"
28 #define MDIO_BUS_NAME "Hisilicon MII Bus"
29 
30 #define MDIO_TIMEOUT			1000000
31 
32 struct hns_mdio_sc_reg {
33 	u16 mdio_clk_en;
34 	u16 mdio_clk_dis;
35 	u16 mdio_reset_req;
36 	u16 mdio_reset_dreq;
37 	u16 mdio_clk_st;
38 	u16 mdio_reset_st;
39 };
40 
41 struct hns_mdio_device {
42 	u8 __iomem *vbase;		/* mdio reg base address */
43 	struct regmap *subctrl_vbase;
44 	struct hns_mdio_sc_reg sc_reg;
45 };
46 
47 /* mdio reg */
48 #define MDIO_COMMAND_REG		0x0
49 #define MDIO_ADDR_REG			0x4
50 #define MDIO_WDATA_REG			0x8
51 #define MDIO_RDATA_REG			0xc
52 #define MDIO_STA_REG			0x10
53 
54 /* cfg phy bit map */
55 #define MDIO_CMD_DEVAD_M	0x1f
56 #define MDIO_CMD_DEVAD_S	0
57 #define MDIO_CMD_PRTAD_M	0x1f
58 #define MDIO_CMD_PRTAD_S	5
59 #define MDIO_CMD_OP_S		10
60 #define MDIO_CMD_ST_S		12
61 #define MDIO_CMD_START_B	14
62 
63 #define MDIO_ADDR_DATA_M	0xffff
64 #define MDIO_ADDR_DATA_S	0
65 
66 #define MDIO_WDATA_DATA_M	0xffff
67 #define MDIO_WDATA_DATA_S	0
68 
69 #define MDIO_RDATA_DATA_M	0xffff
70 #define MDIO_RDATA_DATA_S	0
71 
72 #define MDIO_STATE_STA_B	0
73 
74 enum mdio_st_clause {
75 	MDIO_ST_CLAUSE_45 = 0,
76 	MDIO_ST_CLAUSE_22
77 };
78 
79 enum mdio_c22_op_seq {
80 	MDIO_C22_WRITE = 1,
81 	MDIO_C22_READ = 2
82 };
83 
84 enum mdio_c45_op_seq {
85 	MDIO_C45_WRITE_ADDR = 0,
86 	MDIO_C45_WRITE_DATA,
87 	MDIO_C45_READ_INCREMENT,
88 	MDIO_C45_READ
89 };
90 
91 /* peri subctrl reg */
92 #define MDIO_SC_CLK_EN		0x338
93 #define MDIO_SC_CLK_DIS		0x33C
94 #define MDIO_SC_RESET_REQ	0xA38
95 #define MDIO_SC_RESET_DREQ	0xA3C
96 #define MDIO_SC_CLK_ST		0x531C
97 #define MDIO_SC_RESET_ST	0x5A1C
98 
99 static void mdio_write_reg(u8 __iomem *base, u32 reg, u32 value)
100 {
101 	writel_relaxed(value, base + reg);
102 }
103 
104 #define MDIO_WRITE_REG(a, reg, value) \
105 	mdio_write_reg((a)->vbase, (reg), (value))
106 
107 static u32 mdio_read_reg(u8 __iomem *base, u32 reg)
108 {
109 	return readl_relaxed(base + reg);
110 }
111 
112 #define mdio_set_field(origin, mask, shift, val) \
113 	do { \
114 		(origin) &= (~((mask) << (shift))); \
115 		(origin) |= (((val) & (mask)) << (shift)); \
116 	} while (0)
117 
118 #define mdio_get_field(origin, mask, shift) (((origin) >> (shift)) & (mask))
119 
120 static void mdio_set_reg_field(u8 __iomem *base, u32 reg, u32 mask, u32 shift,
121 			       u32 val)
122 {
123 	u32 origin = mdio_read_reg(base, reg);
124 
125 	mdio_set_field(origin, mask, shift, val);
126 	mdio_write_reg(base, reg, origin);
127 }
128 
129 #define MDIO_SET_REG_FIELD(dev, reg, mask, shift, val) \
130 	mdio_set_reg_field((dev)->vbase, (reg), (mask), (shift), (val))
131 
132 static u32 mdio_get_reg_field(u8 __iomem *base, u32 reg, u32 mask, u32 shift)
133 {
134 	u32 origin;
135 
136 	origin = mdio_read_reg(base, reg);
137 	return mdio_get_field(origin, mask, shift);
138 }
139 
140 #define MDIO_GET_REG_FIELD(dev, reg, mask, shift) \
141 		mdio_get_reg_field((dev)->vbase, (reg), (mask), (shift))
142 
143 #define MDIO_GET_REG_BIT(dev, reg, bit) \
144 		mdio_get_reg_field((dev)->vbase, (reg), 0x1ull, (bit))
145 
146 #define MDIO_CHECK_SET_ST	1
147 #define MDIO_CHECK_CLR_ST	0
148 
149 static int mdio_sc_cfg_reg_write(struct hns_mdio_device *mdio_dev,
150 				 u32 cfg_reg, u32 set_val,
151 				 u32 st_reg, u32 st_msk, u8 check_st)
152 {
153 	u32 time_cnt;
154 	u32 reg_value;
155 
156 	regmap_write(mdio_dev->subctrl_vbase, cfg_reg, set_val);
157 
158 	for (time_cnt = MDIO_TIMEOUT; time_cnt; time_cnt--) {
159 		regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
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 	/* waitting 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  * @value: 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  * @value: register value
277  *
278  * Return phy register value
279  */
280 static int hns_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
281 {
282 	int ret;
283 	u16 reg_val = 0;
284 	u8 devad = ((regnum >> 16) & 0x1f);
285 	u8 is_c45 = !!(regnum & MII_ADDR_C45);
286 	u16 reg = (u16)(regnum & 0xffff);
287 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
288 
289 	dev_dbg(&bus->dev, "mdio read %s,base is %p\n",
290 		bus->id, mdio_dev->vbase);
291 	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x!\n",
292 		phy_id, is_c45, devad, reg);
293 
294 	/* Step 1: wait for ready */
295 	ret = hns_mdio_wait_ready(bus);
296 	if (ret) {
297 		dev_err(&bus->dev, "MDIO bus is busy\n");
298 		return ret;
299 	}
300 
301 	if (!is_c45) {
302 		hns_mdio_cmd_write(mdio_dev, is_c45,
303 				   MDIO_C22_READ, phy_id, reg);
304 	} else {
305 		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
306 				   MDIO_ADDR_DATA_S, reg);
307 
308 		/* Step 2; config the cmd-reg to write addr*/
309 		hns_mdio_cmd_write(mdio_dev, is_c45,
310 				   MDIO_C45_WRITE_ADDR, phy_id, devad);
311 
312 		/* Step 3: check for read or write opt is finished */
313 		ret = hns_mdio_wait_ready(bus);
314 		if (ret) {
315 			dev_err(&bus->dev, "MDIO bus is busy\n");
316 			return ret;
317 		}
318 
319 		hns_mdio_cmd_write(mdio_dev, is_c45,
320 				   MDIO_C45_READ, phy_id, devad);
321 	}
322 
323 	/* Step 5: waitting for MDIO_COMMAND_REG 's mdio_start==0,*/
324 	/* check for read or write opt is finished */
325 	ret = hns_mdio_wait_ready(bus);
326 	if (ret) {
327 		dev_err(&bus->dev, "MDIO bus is busy\n");
328 		return ret;
329 	}
330 
331 	reg_val = MDIO_GET_REG_BIT(mdio_dev, MDIO_STA_REG, MDIO_STATE_STA_B);
332 	if (reg_val) {
333 		dev_err(&bus->dev, " ERROR! MDIO Read failed!\n");
334 		return -EBUSY;
335 	}
336 
337 	/* Step 6; get out data*/
338 	reg_val = (u16)MDIO_GET_REG_FIELD(mdio_dev, MDIO_RDATA_REG,
339 					  MDIO_RDATA_DATA_M, MDIO_RDATA_DATA_S);
340 
341 	return reg_val;
342 }
343 
344 /**
345  * hns_mdio_reset - reset mdio bus
346  * @bus: mdio bus
347  *
348  * Return 0 on success, negative on failure
349  */
350 static int hns_mdio_reset(struct mii_bus *bus)
351 {
352 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
353 	const struct hns_mdio_sc_reg *sc_reg;
354 	int ret;
355 
356 	if (dev_of_node(bus->parent)) {
357 		if (!mdio_dev->subctrl_vbase) {
358 			dev_err(&bus->dev, "mdio sys ctl reg has not maped\n");
359 			return -ENODEV;
360 		}
361 
362 		sc_reg = &mdio_dev->sc_reg;
363 		/* 1. reset req, and read reset st check */
364 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_reset_req,
365 					    0x1, sc_reg->mdio_reset_st, 0x1,
366 					    MDIO_CHECK_SET_ST);
367 		if (ret) {
368 			dev_err(&bus->dev, "MDIO reset fail\n");
369 			return ret;
370 		}
371 
372 		/* 2. dis clk, and read clk st check */
373 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_clk_dis,
374 					    0x1, sc_reg->mdio_clk_st, 0x1,
375 					    MDIO_CHECK_CLR_ST);
376 		if (ret) {
377 			dev_err(&bus->dev, "MDIO dis clk fail\n");
378 			return ret;
379 		}
380 
381 		/* 3. reset dreq, and read reset st check */
382 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_reset_dreq,
383 					    0x1, sc_reg->mdio_reset_st, 0x1,
384 					    MDIO_CHECK_CLR_ST);
385 		if (ret) {
386 			dev_err(&bus->dev, "MDIO dis clk fail\n");
387 			return ret;
388 		}
389 
390 		/* 4. en clk, and read clk st check */
391 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_clk_en,
392 					    0x1, sc_reg->mdio_clk_st, 0x1,
393 					    MDIO_CHECK_SET_ST);
394 		if (ret)
395 			dev_err(&bus->dev, "MDIO en clk fail\n");
396 	} else if (is_acpi_node(bus->parent->fwnode)) {
397 		acpi_status s;
398 
399 		s = acpi_evaluate_object(ACPI_HANDLE(bus->parent),
400 					 "_RST", NULL, NULL);
401 		if (ACPI_FAILURE(s)) {
402 			dev_err(&bus->dev, "Reset failed, return:%#x\n", s);
403 			ret = -EBUSY;
404 		} else {
405 			ret = 0;
406 		}
407 	} else {
408 		dev_err(&bus->dev, "Can not get cfg data from DT or ACPI\n");
409 		ret = -ENXIO;
410 	}
411 	return ret;
412 }
413 
414 /**
415  * hns_mdio_probe - probe mdio device
416  * @pdev: mdio platform device
417  *
418  * Return 0 on success, negative on failure
419  */
420 static int hns_mdio_probe(struct platform_device *pdev)
421 {
422 	struct hns_mdio_device *mdio_dev;
423 	struct mii_bus *new_bus;
424 	struct resource *res;
425 	int ret = -ENODEV;
426 
427 	if (!pdev) {
428 		dev_err(NULL, "pdev is NULL!\r\n");
429 		return -ENODEV;
430 	}
431 
432 	mdio_dev = devm_kzalloc(&pdev->dev, sizeof(*mdio_dev), GFP_KERNEL);
433 	if (!mdio_dev)
434 		return -ENOMEM;
435 
436 	new_bus = devm_mdiobus_alloc(&pdev->dev);
437 	if (!new_bus) {
438 		dev_err(&pdev->dev, "mdiobus_alloc fail!\n");
439 		return -ENOMEM;
440 	}
441 
442 	new_bus->name = MDIO_BUS_NAME;
443 	new_bus->read = hns_mdio_read;
444 	new_bus->write = hns_mdio_write;
445 	new_bus->reset = hns_mdio_reset;
446 	new_bus->priv = mdio_dev;
447 	new_bus->parent = &pdev->dev;
448 
449 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
450 	mdio_dev->vbase = devm_ioremap_resource(&pdev->dev, res);
451 	if (IS_ERR(mdio_dev->vbase)) {
452 		ret = PTR_ERR(mdio_dev->vbase);
453 		return ret;
454 	}
455 
456 	platform_set_drvdata(pdev, new_bus);
457 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%s", "Mii",
458 		 dev_name(&pdev->dev));
459 	if (dev_of_node(&pdev->dev)) {
460 		struct of_phandle_args reg_args;
461 
462 		ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
463 						       "subctrl-vbase",
464 						       4,
465 						       0,
466 						       &reg_args);
467 		if (!ret) {
468 			mdio_dev->subctrl_vbase =
469 				syscon_node_to_regmap(reg_args.np);
470 			if (IS_ERR(mdio_dev->subctrl_vbase)) {
471 				dev_warn(&pdev->dev, "syscon_node_to_regmap error\n");
472 				mdio_dev->subctrl_vbase = NULL;
473 			} else {
474 				if (reg_args.args_count == 4) {
475 					mdio_dev->sc_reg.mdio_clk_en =
476 						(u16)reg_args.args[0];
477 					mdio_dev->sc_reg.mdio_clk_dis =
478 						(u16)reg_args.args[0] + 4;
479 					mdio_dev->sc_reg.mdio_reset_req =
480 						(u16)reg_args.args[1];
481 					mdio_dev->sc_reg.mdio_reset_dreq =
482 						(u16)reg_args.args[1] + 4;
483 					mdio_dev->sc_reg.mdio_clk_st =
484 						(u16)reg_args.args[2];
485 					mdio_dev->sc_reg.mdio_reset_st =
486 						(u16)reg_args.args[3];
487 				} else {
488 					/* for compatible */
489 					mdio_dev->sc_reg.mdio_clk_en =
490 						MDIO_SC_CLK_EN;
491 					mdio_dev->sc_reg.mdio_clk_dis =
492 						MDIO_SC_CLK_DIS;
493 					mdio_dev->sc_reg.mdio_reset_req =
494 						MDIO_SC_RESET_REQ;
495 					mdio_dev->sc_reg.mdio_reset_dreq =
496 						MDIO_SC_RESET_DREQ;
497 					mdio_dev->sc_reg.mdio_clk_st =
498 						MDIO_SC_CLK_ST;
499 					mdio_dev->sc_reg.mdio_reset_st =
500 						MDIO_SC_RESET_ST;
501 				}
502 			}
503 		} else {
504 			dev_warn(&pdev->dev, "find syscon ret = %#x\n", ret);
505 			mdio_dev->subctrl_vbase = NULL;
506 		}
507 
508 		ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
509 	} else if (is_acpi_node(pdev->dev.fwnode)) {
510 		/* Clear all the IRQ properties */
511 		memset(new_bus->irq, PHY_POLL, 4 * PHY_MAX_ADDR);
512 
513 		/* Mask out all PHYs from auto probing. */
514 		new_bus->phy_mask = ~0;
515 
516 		/* Register the MDIO bus */
517 		ret = mdiobus_register(new_bus);
518 	} else {
519 		dev_err(&pdev->dev, "Can not get cfg data from DT or ACPI\n");
520 		ret = -ENXIO;
521 	}
522 
523 	if (ret) {
524 		dev_err(&pdev->dev, "Cannot register as MDIO bus!\n");
525 		platform_set_drvdata(pdev, NULL);
526 		return ret;
527 	}
528 
529 	return 0;
530 }
531 
532 /**
533  * hns_mdio_remove - remove mdio device
534  * @pdev: mdio platform device
535  *
536  * Return 0 on success, negative on failure
537  */
538 static int hns_mdio_remove(struct platform_device *pdev)
539 {
540 	struct mii_bus *bus;
541 
542 	bus = platform_get_drvdata(pdev);
543 
544 	mdiobus_unregister(bus);
545 	platform_set_drvdata(pdev, NULL);
546 	return 0;
547 }
548 
549 static const struct of_device_id hns_mdio_match[] = {
550 	{.compatible = "hisilicon,mdio"},
551 	{.compatible = "hisilicon,hns-mdio"},
552 	{}
553 };
554 MODULE_DEVICE_TABLE(of, hns_mdio_match);
555 
556 static const struct acpi_device_id hns_mdio_acpi_match[] = {
557 	{ "HISI0141", 0 },
558 	{ },
559 };
560 MODULE_DEVICE_TABLE(acpi, hns_mdio_acpi_match);
561 
562 static struct platform_driver hns_mdio_driver = {
563 	.probe = hns_mdio_probe,
564 	.remove = hns_mdio_remove,
565 	.driver = {
566 		   .name = MDIO_DRV_NAME,
567 		   .of_match_table = hns_mdio_match,
568 		   .acpi_match_table = ACPI_PTR(hns_mdio_acpi_match),
569 		   },
570 };
571 
572 module_platform_driver(hns_mdio_driver);
573 
574 MODULE_LICENSE("GPL");
575 MODULE_AUTHOR("Huawei Tech. Co., Ltd.");
576 MODULE_DESCRIPTION("Hisilicon HNS MDIO driver");
577 MODULE_ALIAS("platform:" MDIO_DRV_NAME);
578