1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/debugfs.h>
4 #include <linux/delay.h>
5 #include <linux/err.h>
6 #include <linux/i2c.h>
7 #include <linux/init.h>
8 #include <linux/hwmon.h>
9 #include <linux/module.h>
10 #include <linux/mutex.h>
11 
12 /* Aries current average temp ADC code CSR */
13 #define ARIES_CURRENT_AVG_TEMP_ADC_CSR	0x42c
14 
15 /* Device Load check register */
16 #define ARIES_CODE_LOAD_REG	0x605
17 /* Value indicating FW was loaded properly, [3:1] = 3'b111 */
18 #define ARIES_LOAD_CODE	0xe
19 
20 /* Main Micro Heartbeat register */
21 #define ARIES_MM_HEARTBEAT_ADDR	0x923
22 
23 /* Reg offset to specify Address for MM assisted accesses */
24 #define ARIES_MM_ASSIST_REG_ADDR_OFFSET	0xd99
25 /* Reg offset to specify Command for MM assisted accesses */
26 #define ARIES_MM_ASSIST_CMD_OFFSET	0xd9d
27 /* Reg offset to MM SPARE 0 used specify Address[7:0] */
28 #define ARIES_MM_ASSIST_SPARE_0_OFFSET	0xd9f
29 /* Reg offset to MM SPARE 3 used specify Data Byte 0 */
30 #define ARIES_MM_ASSIST_SPARE_3_OFFSET	0xda2
31 /* Wide register reads */
32 #define ARIES_MM_RD_WIDE_REG_2B	0x1d
33 #define ARIES_MM_RD_WIDE_REG_3B	0x1e
34 #define ARIES_MM_RD_WIDE_REG_4B	0x1f
35 #define ARIES_MM_RD_WIDE_REG_5B	0x20
36 
37 /* Time delay between checking MM status of EEPROM write (microseconds) */
38 #define ARIES_MM_STATUS_TIME	5000
39 
40 /* AL Main SRAM DMEM offset (A0) */
41 #define AL_MAIN_SRAM_DMEM_OFFSET	(64 * 1024)
42 /* SRAM read command */
43 #define AL_TG_RD_LOC_IND_SRAM	0x16
44 
45 /* Offset for main micro FW info */
46 #define ARIES_MAIN_MICRO_FW_INFO	(96 * 1024 - 128)
47 /* FW Info (Major) offset location in struct */
48 #define ARIES_MM_FW_VERSION_MAJOR	0
49 /* FW Info (Minor) offset location in struct */
50 #define ARIES_MM_FW_VERSION_MINOR	1
51 /* FW Info (Build no.) offset location in struct */
52 #define ARIES_MM_FW_VERSION_BUILD	2
53 
54 #define ARIES_TEMP_CAL_CODE_DEFAULT	84
55 
56 /* Struct defining FW version loaded on an Aries device */
57 struct pt5161l_fw_ver {
58 	u8 major;
59 	u8 minor;
60 	u16 build;
61 };
62 
63 /* Each client has this additional data */
64 struct pt5161l_data {
65 	struct i2c_client *client;
66 	struct pt5161l_fw_ver fw_ver;
67 	struct mutex lock; /* for atomic I2C transactions */
68 	bool init_done;
69 	bool code_load_okay; /* indicate if code load reg value is expected */
70 	bool mm_heartbeat_okay; /* indicate if Main Micro heartbeat is good */
71 	bool mm_wide_reg_access; /* MM assisted wide register access */
72 };
73 
74 /*
75  * Write multiple data bytes to Aries over I2C
76  */
77 static int pt5161l_write_block_data(struct pt5161l_data *data, u32 address,
78 				    u8 len, u8 *val)
79 {
80 	struct i2c_client *client = data->client;
81 	int ret;
82 	u8 remain_len = len;
83 	u8 xfer_len, curr_len;
84 	u8 buf[16];
85 	u8 cmd = 0x0F; /* [7]:pec_en, [4:2]:func, [1]:start, [0]:end */
86 	u8 config = 0x40; /* [6]:cfg_type, [4:1]:burst_len, [0]:address bit16 */
87 
88 	while (remain_len > 0) {
89 		if (remain_len > 4) {
90 			curr_len = 4;
91 			remain_len -= 4;
92 		} else {
93 			curr_len = remain_len;
94 			remain_len = 0;
95 		}
96 
97 		buf[0] = config | (curr_len - 1) << 1 | ((address >> 16) & 0x1);
98 		buf[1] = (address >> 8) & 0xff;
99 		buf[2] = address & 0xff;
100 		memcpy(&buf[3], val, curr_len);
101 
102 		xfer_len = 3 + curr_len;
103 		ret = i2c_smbus_write_block_data(client, cmd, xfer_len, buf);
104 		if (ret)
105 			return ret;
106 
107 		val += curr_len;
108 		address += curr_len;
109 	}
110 
111 	return 0;
112 }
113 
114 /*
115  * Read multiple data bytes from Aries over I2C
116  */
117 static int pt5161l_read_block_data(struct pt5161l_data *data, u32 address,
118 				   u8 len, u8 *val)
119 {
120 	struct i2c_client *client = data->client;
121 	int ret, tries;
122 	u8 remain_len = len;
123 	u8 curr_len;
124 	u8 wbuf[16], rbuf[24];
125 	u8 cmd = 0x08; /* [7]:pec_en, [4:2]:func, [1]:start, [0]:end */
126 	u8 config = 0x00; /* [6]:cfg_type, [4:1]:burst_len, [0]:address bit16 */
127 
128 	while (remain_len > 0) {
129 		if (remain_len > 16) {
130 			curr_len = 16;
131 			remain_len -= 16;
132 		} else {
133 			curr_len = remain_len;
134 			remain_len = 0;
135 		}
136 
137 		wbuf[0] = config | (curr_len - 1) << 1 |
138 			  ((address >> 16) & 0x1);
139 		wbuf[1] = (address >> 8) & 0xff;
140 		wbuf[2] = address & 0xff;
141 
142 		for (tries = 0; tries < 3; tries++) {
143 			ret = i2c_smbus_write_block_data(client, (cmd | 0x2), 3,
144 							 wbuf);
145 			if (ret)
146 				return ret;
147 
148 			ret = i2c_smbus_read_block_data(client, (cmd | 0x1),
149 							rbuf);
150 			if (ret == curr_len)
151 				break;
152 		}
153 		if (tries >= 3)
154 			return ret;
155 
156 		memcpy(val, rbuf, curr_len);
157 		val += curr_len;
158 		address += curr_len;
159 	}
160 
161 	return 0;
162 }
163 
164 static int pt5161l_read_wide_reg(struct pt5161l_data *data, u32 address,
165 				 u8 width, u8 *val)
166 {
167 	int ret, tries;
168 	u8 buf[8];
169 	u8 status;
170 
171 	/*
172 	 * Safely access wide registers using mailbox method to prevent
173 	 * risking conflict with Aries firmware; otherwise fallback to
174 	 * legacy, less secure method.
175 	 */
176 	if (data->mm_wide_reg_access) {
177 		buf[0] = address & 0xff;
178 		buf[1] = (address >> 8) & 0xff;
179 		buf[2] = (address >> 16) & 0x1;
180 		ret = pt5161l_write_block_data(data,
181 					       ARIES_MM_ASSIST_SPARE_0_OFFSET,
182 					       3, buf);
183 		if (ret)
184 			return ret;
185 
186 		/* Set command based on width */
187 		switch (width) {
188 		case 2:
189 			buf[0] = ARIES_MM_RD_WIDE_REG_2B;
190 			break;
191 		case 3:
192 			buf[0] = ARIES_MM_RD_WIDE_REG_3B;
193 			break;
194 		case 4:
195 			buf[0] = ARIES_MM_RD_WIDE_REG_4B;
196 			break;
197 		case 5:
198 			buf[0] = ARIES_MM_RD_WIDE_REG_5B;
199 			break;
200 		default:
201 			return -EINVAL;
202 		}
203 		ret = pt5161l_write_block_data(data, ARIES_MM_ASSIST_CMD_OFFSET,
204 					       1, buf);
205 		if (ret)
206 			return ret;
207 
208 		status = 0xff;
209 		for (tries = 0; tries < 100; tries++) {
210 			ret = pt5161l_read_block_data(data,
211 						      ARIES_MM_ASSIST_CMD_OFFSET,
212 						      1, &status);
213 			if (ret)
214 				return ret;
215 
216 			if (status == 0)
217 				break;
218 
219 			usleep_range(ARIES_MM_STATUS_TIME,
220 				     ARIES_MM_STATUS_TIME + 1000);
221 		}
222 		if (status != 0)
223 			return -ETIMEDOUT;
224 
225 		ret = pt5161l_read_block_data(data,
226 					      ARIES_MM_ASSIST_SPARE_3_OFFSET,
227 					      width, val);
228 		if (ret)
229 			return ret;
230 	} else {
231 		return pt5161l_read_block_data(data, address, width, val);
232 	}
233 
234 	return 0;
235 }
236 
237 /*
238  * Read multiple (up to eight) data bytes from micro SRAM over I2C
239  */
240 static int
241 pt5161l_read_block_data_main_micro_indirect(struct pt5161l_data *data,
242 					    u32 address, u8 len, u8 *val)
243 {
244 	int ret, tries;
245 	u8 buf[8];
246 	u8 i, status;
247 	u32 uind_offs = ARIES_MM_ASSIST_REG_ADDR_OFFSET;
248 	u32 eeprom_base, eeprom_addr;
249 
250 	/* No multi-byte indirect support here. Hence read a byte at a time */
251 	eeprom_base = address - AL_MAIN_SRAM_DMEM_OFFSET;
252 	for (i = 0; i < len; i++) {
253 		eeprom_addr = eeprom_base + i;
254 		buf[0] = eeprom_addr & 0xff;
255 		buf[1] = (eeprom_addr >> 8) & 0xff;
256 		buf[2] = (eeprom_addr >> 16) & 0xff;
257 		ret = pt5161l_write_block_data(data, uind_offs, 3, buf);
258 		if (ret)
259 			return ret;
260 
261 		buf[0] = AL_TG_RD_LOC_IND_SRAM;
262 		ret = pt5161l_write_block_data(data, uind_offs + 4, 1, buf);
263 		if (ret)
264 			return ret;
265 
266 		status = 0xff;
267 		for (tries = 0; tries < 255; tries++) {
268 			ret = pt5161l_read_block_data(data, uind_offs + 4, 1,
269 						      &status);
270 			if (ret)
271 				return ret;
272 
273 			if (status == 0)
274 				break;
275 		}
276 		if (status != 0)
277 			return -ETIMEDOUT;
278 
279 		ret = pt5161l_read_block_data(data, uind_offs + 3, 1, buf);
280 		if (ret)
281 			return ret;
282 
283 		val[i] = buf[0];
284 	}
285 
286 	return 0;
287 }
288 
289 /*
290  * Check firmware load status
291  */
292 static int pt5161l_fw_load_check(struct pt5161l_data *data)
293 {
294 	int ret;
295 	u8 buf[8];
296 
297 	ret = pt5161l_read_block_data(data, ARIES_CODE_LOAD_REG, 1, buf);
298 	if (ret)
299 		return ret;
300 
301 	if (buf[0] < ARIES_LOAD_CODE) {
302 		dev_dbg(&data->client->dev,
303 			"Code Load reg unexpected. Not all modules are loaded %x\n",
304 			buf[0]);
305 		data->code_load_okay = false;
306 	} else {
307 		data->code_load_okay = true;
308 	}
309 
310 	return 0;
311 }
312 
313 /*
314  * Check main micro heartbeat
315  */
316 static int pt5161l_heartbeat_check(struct pt5161l_data *data)
317 {
318 	int ret, tries;
319 	u8 buf[8];
320 	u8 heartbeat;
321 	bool hb_changed = false;
322 
323 	ret = pt5161l_read_block_data(data, ARIES_MM_HEARTBEAT_ADDR, 1, buf);
324 	if (ret)
325 		return ret;
326 
327 	heartbeat = buf[0];
328 	for (tries = 0; tries < 100; tries++) {
329 		ret = pt5161l_read_block_data(data, ARIES_MM_HEARTBEAT_ADDR, 1,
330 					      buf);
331 		if (ret)
332 			return ret;
333 
334 		if (buf[0] != heartbeat) {
335 			hb_changed = true;
336 			break;
337 		}
338 	}
339 	data->mm_heartbeat_okay = hb_changed;
340 
341 	return 0;
342 }
343 
344 /*
345  * Check the status of firmware
346  */
347 static int pt5161l_fwsts_check(struct pt5161l_data *data)
348 {
349 	int ret;
350 	u8 buf[8];
351 	u8 major = 0, minor = 0;
352 	u16 build = 0;
353 
354 	ret = pt5161l_fw_load_check(data);
355 	if (ret)
356 		return ret;
357 
358 	ret = pt5161l_heartbeat_check(data);
359 	if (ret)
360 		return ret;
361 
362 	if (data->code_load_okay && data->mm_heartbeat_okay) {
363 		ret = pt5161l_read_block_data_main_micro_indirect(data, ARIES_MAIN_MICRO_FW_INFO +
364 								  ARIES_MM_FW_VERSION_MAJOR,
365 								  1, &major);
366 		if (ret)
367 			return ret;
368 
369 		ret = pt5161l_read_block_data_main_micro_indirect(data, ARIES_MAIN_MICRO_FW_INFO +
370 								  ARIES_MM_FW_VERSION_MINOR,
371 								  1, &minor);
372 		if (ret)
373 			return ret;
374 
375 		ret = pt5161l_read_block_data_main_micro_indirect(data, ARIES_MAIN_MICRO_FW_INFO +
376 								  ARIES_MM_FW_VERSION_BUILD,
377 								  2, buf);
378 		if (ret)
379 			return ret;
380 		build = buf[1] << 8 | buf[0];
381 	}
382 	data->fw_ver.major = major;
383 	data->fw_ver.minor = minor;
384 	data->fw_ver.build = build;
385 
386 	return 0;
387 }
388 
389 static int pt5161l_fw_is_at_least(struct pt5161l_data *data, u8 major, u8 minor,
390 				  u16 build)
391 {
392 	u32 ver = major << 24 | minor << 16 | build;
393 	u32 curr_ver = data->fw_ver.major << 24 | data->fw_ver.minor << 16 |
394 		       data->fw_ver.build;
395 
396 	if (curr_ver >= ver)
397 		return true;
398 
399 	return false;
400 }
401 
402 static int pt5161l_init_dev(struct pt5161l_data *data)
403 {
404 	int ret;
405 
406 	mutex_lock(&data->lock);
407 	ret = pt5161l_fwsts_check(data);
408 	mutex_unlock(&data->lock);
409 	if (ret)
410 		return ret;
411 
412 	/* Firmware 2.2.0 enables safe access to wide registers */
413 	if (pt5161l_fw_is_at_least(data, 2, 2, 0))
414 		data->mm_wide_reg_access = true;
415 
416 	data->init_done = true;
417 
418 	return 0;
419 }
420 
421 static int pt5161l_read(struct device *dev, enum hwmon_sensor_types type,
422 			u32 attr, int channel, long *val)
423 {
424 	struct pt5161l_data *data = dev_get_drvdata(dev);
425 	int ret;
426 	u8 buf[8];
427 	u32 adc_code;
428 
429 	switch (attr) {
430 	case hwmon_temp_input:
431 		if (!data->init_done) {
432 			ret = pt5161l_init_dev(data);
433 			if (ret)
434 				return ret;
435 		}
436 
437 		mutex_lock(&data->lock);
438 		ret = pt5161l_read_wide_reg(data,
439 					    ARIES_CURRENT_AVG_TEMP_ADC_CSR, 4,
440 					    buf);
441 		mutex_unlock(&data->lock);
442 		if (ret) {
443 			dev_dbg(dev, "Read adc_code failed %d\n", ret);
444 			return ret;
445 		}
446 
447 		adc_code = buf[3] << 24 | buf[2] << 16 | buf[1] << 8 | buf[0];
448 		if (adc_code == 0 || adc_code >= 0x3ff) {
449 			dev_dbg(dev, "Invalid adc_code %x\n", adc_code);
450 			return -EIO;
451 		}
452 
453 		*val = 110000 +
454 		       ((adc_code - (ARIES_TEMP_CAL_CODE_DEFAULT + 250)) *
455 			-320);
456 		break;
457 	default:
458 		return -EOPNOTSUPP;
459 	}
460 
461 	return 0;
462 }
463 
464 static umode_t pt5161l_is_visible(const void *data,
465 				  enum hwmon_sensor_types type, u32 attr,
466 				  int channel)
467 {
468 	switch (attr) {
469 	case hwmon_temp_input:
470 		return 0444;
471 	default:
472 		break;
473 	}
474 
475 	return 0;
476 }
477 
478 static const struct hwmon_channel_info *pt5161l_info[] = {
479 	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
480 	NULL
481 };
482 
483 static const struct hwmon_ops pt5161l_hwmon_ops = {
484 	.is_visible = pt5161l_is_visible,
485 	.read = pt5161l_read,
486 };
487 
488 static const struct hwmon_chip_info pt5161l_chip_info = {
489 	.ops = &pt5161l_hwmon_ops,
490 	.info = pt5161l_info,
491 };
492 
493 static ssize_t pt5161l_debugfs_read_fw_ver(struct file *file, char __user *buf,
494 					   size_t count, loff_t *ppos)
495 {
496 	struct pt5161l_data *data = file->private_data;
497 	int ret;
498 	char ver[32];
499 
500 	mutex_lock(&data->lock);
501 	ret = pt5161l_fwsts_check(data);
502 	mutex_unlock(&data->lock);
503 	if (ret)
504 		return ret;
505 
506 	ret = snprintf(ver, sizeof(ver), "%u.%u.%u\n", data->fw_ver.major,
507 		       data->fw_ver.minor, data->fw_ver.build);
508 
509 	return simple_read_from_buffer(buf, count, ppos, ver, ret);
510 }
511 
512 static const struct file_operations pt5161l_debugfs_ops_fw_ver = {
513 	.read = pt5161l_debugfs_read_fw_ver,
514 	.open = simple_open,
515 };
516 
517 static ssize_t pt5161l_debugfs_read_fw_load_sts(struct file *file,
518 						char __user *buf, size_t count,
519 						loff_t *ppos)
520 {
521 	struct pt5161l_data *data = file->private_data;
522 	int ret;
523 	bool status = false;
524 	char health[16];
525 
526 	mutex_lock(&data->lock);
527 	ret = pt5161l_fw_load_check(data);
528 	mutex_unlock(&data->lock);
529 	if (ret == 0)
530 		status = data->code_load_okay;
531 
532 	ret = snprintf(health, sizeof(health), "%s\n",
533 		       status ? "normal" : "abnormal");
534 
535 	return simple_read_from_buffer(buf, count, ppos, health, ret);
536 }
537 
538 static const struct file_operations pt5161l_debugfs_ops_fw_load_sts = {
539 	.read = pt5161l_debugfs_read_fw_load_sts,
540 	.open = simple_open,
541 };
542 
543 static ssize_t pt5161l_debugfs_read_hb_sts(struct file *file, char __user *buf,
544 					   size_t count, loff_t *ppos)
545 {
546 	struct pt5161l_data *data = file->private_data;
547 	int ret;
548 	bool status = false;
549 	char health[16];
550 
551 	mutex_lock(&data->lock);
552 	ret = pt5161l_heartbeat_check(data);
553 	mutex_unlock(&data->lock);
554 	if (ret == 0)
555 		status = data->mm_heartbeat_okay;
556 
557 	ret = snprintf(health, sizeof(health), "%s\n",
558 		       status ? "normal" : "abnormal");
559 
560 	return simple_read_from_buffer(buf, count, ppos, health, ret);
561 }
562 
563 static const struct file_operations pt5161l_debugfs_ops_hb_sts = {
564 	.read = pt5161l_debugfs_read_hb_sts,
565 	.open = simple_open,
566 };
567 
568 static void pt5161l_init_debugfs(struct i2c_client *client, struct pt5161l_data *data)
569 {
570 	debugfs_create_file("fw_ver", 0444, client->debugfs, data,
571 			    &pt5161l_debugfs_ops_fw_ver);
572 
573 	debugfs_create_file("fw_load_status", 0444, client->debugfs, data,
574 			    &pt5161l_debugfs_ops_fw_load_sts);
575 
576 	debugfs_create_file("heartbeat_status", 0444, client->debugfs, data,
577 			    &pt5161l_debugfs_ops_hb_sts);
578 }
579 
580 static int pt5161l_probe(struct i2c_client *client)
581 {
582 	struct device *dev = &client->dev;
583 	struct device *hwmon_dev;
584 	struct pt5161l_data *data;
585 
586 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
587 	if (!data)
588 		return -ENOMEM;
589 
590 	data->client = client;
591 	mutex_init(&data->lock);
592 	pt5161l_init_dev(data);
593 	dev_set_drvdata(dev, data);
594 
595 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
596 							 data,
597 							 &pt5161l_chip_info,
598 							 NULL);
599 	if (IS_ERR(hwmon_dev))
600 		return PTR_ERR(hwmon_dev);
601 
602 	pt5161l_init_debugfs(client, data);
603 
604 	return 0;
605 }
606 
607 static const struct of_device_id __maybe_unused pt5161l_of_match[] = {
608 	{ .compatible = "asteralabs,pt5161l" },
609 	{},
610 };
611 MODULE_DEVICE_TABLE(of, pt5161l_of_match);
612 
613 static const struct acpi_device_id __maybe_unused pt5161l_acpi_match[] = {
614 	{ "PT5161L", 0 },
615 	{},
616 };
617 MODULE_DEVICE_TABLE(acpi, pt5161l_acpi_match);
618 
619 static const struct i2c_device_id pt5161l_id[] = {
620 	{ "pt5161l" },
621 	{}
622 };
623 MODULE_DEVICE_TABLE(i2c, pt5161l_id);
624 
625 static struct i2c_driver pt5161l_driver = {
626 	.class = I2C_CLASS_HWMON,
627 	.driver = {
628 		.name = "pt5161l",
629 		.of_match_table = of_match_ptr(pt5161l_of_match),
630 		.acpi_match_table = ACPI_PTR(pt5161l_acpi_match),
631 	},
632 	.probe = pt5161l_probe,
633 	.id_table = pt5161l_id,
634 };
635 module_i2c_driver(pt5161l_driver);
636 
637 MODULE_AUTHOR("Cosmo Chou <cosmo.chou@quantatw.com>");
638 MODULE_DESCRIPTION("Hwmon driver for Astera Labs Aries PCIe retimer");
639 MODULE_LICENSE("GPL");
640