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 #include <linux/spinlock_types.h>
27 
28 #define MDIO_DRV_NAME "Hi-HNS_MDIO"
29 #define MDIO_BUS_NAME "Hisilicon MII Bus"
30 #define MDIO_DRV_VERSION "1.3.0"
31 #define MDIO_COPYRIGHT "Copyright(c) 2015 Huawei Corporation."
32 #define MDIO_DRV_STRING MDIO_BUS_NAME
33 #define MDIO_DEFAULT_DEVICE_DESCR MDIO_BUS_NAME
34 
35 #define MDIO_CTL_DEV_ADDR(x)	(x & 0x1f)
36 #define MDIO_CTL_PORT_ADDR(x)	((x & 0x1f) << 5)
37 
38 #define MDIO_TIMEOUT			1000000
39 
40 struct hns_mdio_sc_reg {
41 	u16 mdio_clk_en;
42 	u16 mdio_clk_dis;
43 	u16 mdio_reset_req;
44 	u16 mdio_reset_dreq;
45 	u16 mdio_clk_st;
46 	u16 mdio_reset_st;
47 };
48 
49 struct hns_mdio_device {
50 	void *vbase;		/* mdio reg base address */
51 	struct regmap *subctrl_vbase;
52 	struct hns_mdio_sc_reg sc_reg;
53 };
54 
55 /* mdio reg */
56 #define MDIO_COMMAND_REG		0x0
57 #define MDIO_ADDR_REG			0x4
58 #define MDIO_WDATA_REG			0x8
59 #define MDIO_RDATA_REG			0xc
60 #define MDIO_STA_REG			0x10
61 
62 /* cfg phy bit map */
63 #define MDIO_CMD_DEVAD_M	0x1f
64 #define MDIO_CMD_DEVAD_S	0
65 #define MDIO_CMD_PRTAD_M	0x1f
66 #define MDIO_CMD_PRTAD_S	5
67 #define MDIO_CMD_OP_M		0x3
68 #define MDIO_CMD_OP_S		10
69 #define MDIO_CMD_ST_M		0x3
70 #define MDIO_CMD_ST_S		12
71 #define MDIO_CMD_START_B	14
72 
73 #define MDIO_ADDR_DATA_M	0xffff
74 #define MDIO_ADDR_DATA_S	0
75 
76 #define MDIO_WDATA_DATA_M	0xffff
77 #define MDIO_WDATA_DATA_S	0
78 
79 #define MDIO_RDATA_DATA_M	0xffff
80 #define MDIO_RDATA_DATA_S	0
81 
82 #define MDIO_STATE_STA_B	0
83 
84 enum mdio_st_clause {
85 	MDIO_ST_CLAUSE_45 = 0,
86 	MDIO_ST_CLAUSE_22
87 };
88 
89 enum mdio_c22_op_seq {
90 	MDIO_C22_WRITE = 1,
91 	MDIO_C22_READ = 2
92 };
93 
94 enum mdio_c45_op_seq {
95 	MDIO_C45_WRITE_ADDR = 0,
96 	MDIO_C45_WRITE_DATA,
97 	MDIO_C45_READ_INCREMENT,
98 	MDIO_C45_READ
99 };
100 
101 /* peri subctrl reg */
102 #define MDIO_SC_CLK_EN		0x338
103 #define MDIO_SC_CLK_DIS		0x33C
104 #define MDIO_SC_RESET_REQ	0xA38
105 #define MDIO_SC_RESET_DREQ	0xA3C
106 #define MDIO_SC_CLK_ST		0x531C
107 #define MDIO_SC_RESET_ST	0x5A1C
108 
109 static void mdio_write_reg(void *base, u32 reg, u32 value)
110 {
111 	u8 __iomem *reg_addr = (u8 __iomem *)base;
112 
113 	writel_relaxed(value, reg_addr + reg);
114 }
115 
116 #define MDIO_WRITE_REG(a, reg, value) \
117 	mdio_write_reg((a)->vbase, (reg), (value))
118 
119 static u32 mdio_read_reg(void *base, u32 reg)
120 {
121 	u8 __iomem *reg_addr = (u8 __iomem *)base;
122 
123 	return readl_relaxed(reg_addr + reg);
124 }
125 
126 #define mdio_set_field(origin, mask, shift, val) \
127 	do { \
128 		(origin) &= (~((mask) << (shift))); \
129 		(origin) |= (((val) & (mask)) << (shift)); \
130 	} while (0)
131 
132 #define mdio_get_field(origin, mask, shift) (((origin) >> (shift)) & (mask))
133 
134 static void mdio_set_reg_field(void *base, u32 reg, u32 mask, u32 shift,
135 			       u32 val)
136 {
137 	u32 origin = mdio_read_reg(base, reg);
138 
139 	mdio_set_field(origin, mask, shift, val);
140 	mdio_write_reg(base, reg, origin);
141 }
142 
143 #define MDIO_SET_REG_FIELD(dev, reg, mask, shift, val) \
144 	mdio_set_reg_field((dev)->vbase, (reg), (mask), (shift), (val))
145 
146 static u32 mdio_get_reg_field(void *base, u32 reg, u32 mask, u32 shift)
147 {
148 	u32 origin;
149 
150 	origin = mdio_read_reg(base, reg);
151 	return mdio_get_field(origin, mask, shift);
152 }
153 
154 #define MDIO_GET_REG_FIELD(dev, reg, mask, shift) \
155 		mdio_get_reg_field((dev)->vbase, (reg), (mask), (shift))
156 
157 #define MDIO_GET_REG_BIT(dev, reg, bit) \
158 		mdio_get_reg_field((dev)->vbase, (reg), 0x1ull, (bit))
159 
160 #define MDIO_CHECK_SET_ST	1
161 #define MDIO_CHECK_CLR_ST	0
162 
163 static int mdio_sc_cfg_reg_write(struct hns_mdio_device *mdio_dev,
164 				 u32 cfg_reg, u32 set_val,
165 				 u32 st_reg, u32 st_msk, u8 check_st)
166 {
167 	u32 time_cnt;
168 	u32 reg_value;
169 
170 	regmap_write(mdio_dev->subctrl_vbase, cfg_reg, set_val);
171 
172 	for (time_cnt = MDIO_TIMEOUT; time_cnt; time_cnt--) {
173 		regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
174 		reg_value &= st_msk;
175 		if ((!!check_st) == (!!reg_value))
176 			break;
177 	}
178 
179 	if ((!!check_st) != (!!reg_value))
180 		return -EBUSY;
181 
182 	return 0;
183 }
184 
185 static int hns_mdio_wait_ready(struct mii_bus *bus)
186 {
187 	struct hns_mdio_device *mdio_dev = bus->priv;
188 	int i;
189 	u32 cmd_reg_value = 1;
190 
191 	/* waitting for MDIO_COMMAND_REG 's mdio_start==0 */
192 	/* after that can do read or write*/
193 	for (i = 0; cmd_reg_value; i++) {
194 		cmd_reg_value = MDIO_GET_REG_BIT(mdio_dev,
195 						 MDIO_COMMAND_REG,
196 						 MDIO_CMD_START_B);
197 		if (i == MDIO_TIMEOUT)
198 			return -ETIMEDOUT;
199 	}
200 
201 	return 0;
202 }
203 
204 static void hns_mdio_cmd_write(struct hns_mdio_device *mdio_dev,
205 			       u8 is_c45, u8 op, u8 phy_id, u16 cmd)
206 {
207 	u32 cmd_reg_value;
208 	u8 st = is_c45 ? MDIO_ST_CLAUSE_45 : MDIO_ST_CLAUSE_22;
209 
210 	cmd_reg_value = st << MDIO_CMD_ST_S;
211 	cmd_reg_value |= op << MDIO_CMD_OP_S;
212 	cmd_reg_value |=
213 		(phy_id & MDIO_CMD_PRTAD_M) << MDIO_CMD_PRTAD_S;
214 	cmd_reg_value |= (cmd & MDIO_CMD_DEVAD_M) << MDIO_CMD_DEVAD_S;
215 	cmd_reg_value |= 1 << MDIO_CMD_START_B;
216 
217 	MDIO_WRITE_REG(mdio_dev, MDIO_COMMAND_REG, cmd_reg_value);
218 }
219 
220 /**
221  * hns_mdio_write - access phy register
222  * @bus: mdio bus
223  * @phy_id: phy id
224  * @regnum: register num
225  * @value: register value
226  *
227  * Return 0 on success, negative on failure
228  */
229 static int hns_mdio_write(struct mii_bus *bus,
230 			  int phy_id, int regnum, u16 data)
231 {
232 	int ret;
233 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
234 	u8 devad = ((regnum >> 16) & 0x1f);
235 	u8 is_c45 = !!(regnum & MII_ADDR_C45);
236 	u16 reg = (u16)(regnum & 0xffff);
237 	u8 op;
238 	u16 cmd_reg_cfg;
239 
240 	dev_dbg(&bus->dev, "mdio write %s,base is %p\n",
241 		bus->id, mdio_dev->vbase);
242 	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x, write data=%d\n",
243 		phy_id, is_c45, devad, reg, data);
244 
245 	/* wait for ready */
246 	ret = hns_mdio_wait_ready(bus);
247 	if (ret) {
248 		dev_err(&bus->dev, "MDIO bus is busy\n");
249 		return ret;
250 	}
251 
252 	if (!is_c45) {
253 		cmd_reg_cfg = reg;
254 		op = MDIO_C22_WRITE;
255 	} else {
256 		/* config the cmd-reg to write addr*/
257 		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
258 				   MDIO_ADDR_DATA_S, reg);
259 
260 		hns_mdio_cmd_write(mdio_dev, is_c45,
261 				   MDIO_C45_WRITE_ADDR, phy_id, devad);
262 
263 		/* check for read or write opt is finished */
264 		ret = hns_mdio_wait_ready(bus);
265 		if (ret) {
266 			dev_err(&bus->dev, "MDIO bus is busy\n");
267 			return ret;
268 		}
269 
270 		/* config the data needed writing */
271 		cmd_reg_cfg = devad;
272 		op = MDIO_C45_WRITE_ADDR;
273 	}
274 
275 	MDIO_SET_REG_FIELD(mdio_dev, MDIO_WDATA_REG, MDIO_WDATA_DATA_M,
276 			   MDIO_WDATA_DATA_S, data);
277 
278 	hns_mdio_cmd_write(mdio_dev, is_c45, op, phy_id, cmd_reg_cfg);
279 
280 	return 0;
281 }
282 
283 /**
284  * hns_mdio_read - access phy register
285  * @bus: mdio bus
286  * @phy_id: phy id
287  * @regnum: register num
288  * @value: register value
289  *
290  * Return phy register value
291  */
292 static int hns_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
293 {
294 	int ret;
295 	u16 reg_val = 0;
296 	u8 devad = ((regnum >> 16) & 0x1f);
297 	u8 is_c45 = !!(regnum & MII_ADDR_C45);
298 	u16 reg = (u16)(regnum & 0xffff);
299 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
300 
301 	dev_dbg(&bus->dev, "mdio read %s,base is %p\n",
302 		bus->id, mdio_dev->vbase);
303 	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x!\n",
304 		phy_id, is_c45, devad, reg);
305 
306 	/* Step 1: wait for ready */
307 	ret = hns_mdio_wait_ready(bus);
308 	if (ret) {
309 		dev_err(&bus->dev, "MDIO bus is busy\n");
310 		return ret;
311 	}
312 
313 	if (!is_c45) {
314 		hns_mdio_cmd_write(mdio_dev, is_c45,
315 				   MDIO_C22_READ, phy_id, reg);
316 	} else {
317 		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
318 				   MDIO_ADDR_DATA_S, reg);
319 
320 		/* Step 2; config the cmd-reg to write addr*/
321 		hns_mdio_cmd_write(mdio_dev, is_c45,
322 				   MDIO_C45_WRITE_ADDR, phy_id, devad);
323 
324 		/* Step 3: 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 		hns_mdio_cmd_write(mdio_dev, is_c45,
332 				   MDIO_C45_WRITE_ADDR, phy_id, devad);
333 	}
334 
335 	/* Step 5: waitting for MDIO_COMMAND_REG 's mdio_start==0,*/
336 	/* check for read or write opt is finished */
337 	ret = hns_mdio_wait_ready(bus);
338 	if (ret) {
339 		dev_err(&bus->dev, "MDIO bus is busy\n");
340 		return ret;
341 	}
342 
343 	reg_val = MDIO_GET_REG_BIT(mdio_dev, MDIO_STA_REG, MDIO_STATE_STA_B);
344 	if (reg_val) {
345 		dev_err(&bus->dev, " ERROR! MDIO Read failed!\n");
346 		return -EBUSY;
347 	}
348 
349 	/* Step 6; get out data*/
350 	reg_val = (u16)MDIO_GET_REG_FIELD(mdio_dev, MDIO_RDATA_REG,
351 					  MDIO_RDATA_DATA_M, MDIO_RDATA_DATA_S);
352 
353 	return reg_val;
354 }
355 
356 /**
357  * hns_mdio_reset - reset mdio bus
358  * @bus: mdio bus
359  *
360  * Return 0 on success, negative on failure
361  */
362 static int hns_mdio_reset(struct mii_bus *bus)
363 {
364 	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
365 	const struct hns_mdio_sc_reg *sc_reg;
366 	int ret;
367 
368 	if (dev_of_node(bus->parent)) {
369 		if (!mdio_dev->subctrl_vbase) {
370 			dev_err(&bus->dev, "mdio sys ctl reg has not maped\n");
371 			return -ENODEV;
372 		}
373 
374 		sc_reg = &mdio_dev->sc_reg;
375 		/* 1. reset req, and read reset st check */
376 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_reset_req,
377 					    0x1, sc_reg->mdio_reset_st, 0x1,
378 					    MDIO_CHECK_SET_ST);
379 		if (ret) {
380 			dev_err(&bus->dev, "MDIO reset fail\n");
381 			return ret;
382 		}
383 
384 		/* 2. dis clk, and read clk st check */
385 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_clk_dis,
386 					    0x1, sc_reg->mdio_clk_st, 0x1,
387 					    MDIO_CHECK_CLR_ST);
388 		if (ret) {
389 			dev_err(&bus->dev, "MDIO dis clk fail\n");
390 			return ret;
391 		}
392 
393 		/* 3. reset dreq, and read reset st check */
394 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_reset_dreq,
395 					    0x1, sc_reg->mdio_reset_st, 0x1,
396 					    MDIO_CHECK_CLR_ST);
397 		if (ret) {
398 			dev_err(&bus->dev, "MDIO dis clk fail\n");
399 			return ret;
400 		}
401 
402 		/* 4. en clk, and read clk st check */
403 		ret = mdio_sc_cfg_reg_write(mdio_dev, sc_reg->mdio_clk_en,
404 					    0x1, sc_reg->mdio_clk_st, 0x1,
405 					    MDIO_CHECK_SET_ST);
406 		if (ret)
407 			dev_err(&bus->dev, "MDIO en clk fail\n");
408 	} else if (is_acpi_node(bus->parent->fwnode)) {
409 		acpi_status s;
410 
411 		s = acpi_evaluate_object(ACPI_HANDLE(bus->parent),
412 					 "_RST", NULL, NULL);
413 		if (ACPI_FAILURE(s)) {
414 			dev_err(&bus->dev, "Reset failed, return:%#x\n", s);
415 			ret = -EBUSY;
416 		} else {
417 			ret = 0;
418 		}
419 	} else {
420 		dev_err(&bus->dev, "Can not get cfg data from DT or ACPI\n");
421 		ret = -ENXIO;
422 	}
423 	return ret;
424 }
425 
426 /**
427  * hns_mdio_probe - probe mdio device
428  * @pdev: mdio platform device
429  *
430  * Return 0 on success, negative on failure
431  */
432 static int hns_mdio_probe(struct platform_device *pdev)
433 {
434 	struct hns_mdio_device *mdio_dev;
435 	struct mii_bus *new_bus;
436 	struct resource *res;
437 	int ret = -ENODEV;
438 
439 	if (!pdev) {
440 		dev_err(NULL, "pdev is NULL!\r\n");
441 		return -ENODEV;
442 	}
443 
444 	mdio_dev = devm_kzalloc(&pdev->dev, sizeof(*mdio_dev), GFP_KERNEL);
445 	if (!mdio_dev)
446 		return -ENOMEM;
447 
448 	new_bus = devm_mdiobus_alloc(&pdev->dev);
449 	if (!new_bus) {
450 		dev_err(&pdev->dev, "mdiobus_alloc fail!\n");
451 		return -ENOMEM;
452 	}
453 
454 	new_bus->name = MDIO_BUS_NAME;
455 	new_bus->read = hns_mdio_read;
456 	new_bus->write = hns_mdio_write;
457 	new_bus->reset = hns_mdio_reset;
458 	new_bus->priv = mdio_dev;
459 	new_bus->parent = &pdev->dev;
460 
461 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
462 	mdio_dev->vbase = devm_ioremap_resource(&pdev->dev, res);
463 	if (IS_ERR(mdio_dev->vbase)) {
464 		ret = PTR_ERR(mdio_dev->vbase);
465 		return ret;
466 	}
467 
468 	platform_set_drvdata(pdev, new_bus);
469 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%s", "Mii",
470 		 dev_name(&pdev->dev));
471 	if (dev_of_node(&pdev->dev)) {
472 		struct of_phandle_args reg_args;
473 
474 		ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
475 						       "subctrl-vbase",
476 						       4,
477 						       0,
478 						       &reg_args);
479 		if (!ret) {
480 			mdio_dev->subctrl_vbase =
481 				syscon_node_to_regmap(reg_args.np);
482 			if (IS_ERR(mdio_dev->subctrl_vbase)) {
483 				dev_warn(&pdev->dev, "syscon_node_to_regmap error\n");
484 				mdio_dev->subctrl_vbase = NULL;
485 			} else {
486 				if (reg_args.args_count == 4) {
487 					mdio_dev->sc_reg.mdio_clk_en =
488 						(u16)reg_args.args[0];
489 					mdio_dev->sc_reg.mdio_clk_dis =
490 						(u16)reg_args.args[0] + 4;
491 					mdio_dev->sc_reg.mdio_reset_req =
492 						(u16)reg_args.args[1];
493 					mdio_dev->sc_reg.mdio_reset_dreq =
494 						(u16)reg_args.args[1] + 4;
495 					mdio_dev->sc_reg.mdio_clk_st =
496 						(u16)reg_args.args[2];
497 					mdio_dev->sc_reg.mdio_reset_st =
498 						(u16)reg_args.args[3];
499 				} else {
500 					/* for compatible */
501 					mdio_dev->sc_reg.mdio_clk_en =
502 						MDIO_SC_CLK_EN;
503 					mdio_dev->sc_reg.mdio_clk_dis =
504 						MDIO_SC_CLK_DIS;
505 					mdio_dev->sc_reg.mdio_reset_req =
506 						MDIO_SC_RESET_REQ;
507 					mdio_dev->sc_reg.mdio_reset_dreq =
508 						MDIO_SC_RESET_DREQ;
509 					mdio_dev->sc_reg.mdio_clk_st =
510 						MDIO_SC_CLK_ST;
511 					mdio_dev->sc_reg.mdio_reset_st =
512 						MDIO_SC_RESET_ST;
513 				}
514 			}
515 		} else {
516 			dev_warn(&pdev->dev, "find syscon ret = %#x\n", ret);
517 			mdio_dev->subctrl_vbase = NULL;
518 		}
519 
520 		ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
521 	} else if (is_acpi_node(pdev->dev.fwnode)) {
522 		/* Clear all the IRQ properties */
523 		memset(new_bus->irq, PHY_POLL, 4 * PHY_MAX_ADDR);
524 
525 		/* Mask out all PHYs from auto probing. */
526 		new_bus->phy_mask = ~0;
527 
528 		/* Register the MDIO bus */
529 		ret = mdiobus_register(new_bus);
530 	} else {
531 		dev_err(&pdev->dev, "Can not get cfg data from DT or ACPI\n");
532 		ret = -ENXIO;
533 	}
534 
535 	if (ret) {
536 		dev_err(&pdev->dev, "Cannot register as MDIO bus!\n");
537 		platform_set_drvdata(pdev, NULL);
538 		return ret;
539 	}
540 
541 	return 0;
542 }
543 
544 /**
545  * hns_mdio_remove - remove mdio device
546  * @pdev: mdio platform device
547  *
548  * Return 0 on success, negative on failure
549  */
550 static int hns_mdio_remove(struct platform_device *pdev)
551 {
552 	struct mii_bus *bus;
553 
554 	bus = platform_get_drvdata(pdev);
555 
556 	mdiobus_unregister(bus);
557 	platform_set_drvdata(pdev, NULL);
558 	return 0;
559 }
560 
561 static const struct of_device_id hns_mdio_match[] = {
562 	{.compatible = "hisilicon,mdio"},
563 	{.compatible = "hisilicon,hns-mdio"},
564 	{}
565 };
566 MODULE_DEVICE_TABLE(of, hns_mdio_match);
567 
568 static const struct acpi_device_id hns_mdio_acpi_match[] = {
569 	{ "HISI0141", 0 },
570 	{ },
571 };
572 MODULE_DEVICE_TABLE(acpi, hns_mdio_acpi_match);
573 
574 static struct platform_driver hns_mdio_driver = {
575 	.probe = hns_mdio_probe,
576 	.remove = hns_mdio_remove,
577 	.driver = {
578 		   .name = MDIO_DRV_NAME,
579 		   .of_match_table = hns_mdio_match,
580 		   .acpi_match_table = ACPI_PTR(hns_mdio_acpi_match),
581 		   },
582 };
583 
584 module_platform_driver(hns_mdio_driver);
585 
586 MODULE_LICENSE("GPL");
587 MODULE_AUTHOR("Huawei Tech. Co., Ltd.");
588 MODULE_DESCRIPTION("Hisilicon HNS MDIO driver");
589 MODULE_ALIAS("platform:" MDIO_DRV_NAME);
590