xref: /openbmc/linux/drivers/hwmon/tps23861.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2020 Sartura Ltd.
4  *
5  * Driver for the TI TPS23861 PoE PSE.
6  *
7  * Author: Robert Marko <robert.marko@sartura.hr>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/debugfs.h>
12 #include <linux/delay.h>
13 #include <linux/hwmon-sysfs.h>
14 #include <linux/hwmon.h>
15 #include <linux/i2c.h>
16 #include <linux/module.h>
17 #include <linux/of_device.h>
18 #include <linux/regmap.h>
19 
20 #define TEMPERATURE			0x2c
21 #define INPUT_VOLTAGE_LSB		0x2e
22 #define INPUT_VOLTAGE_MSB		0x2f
23 #define PORT_1_CURRENT_LSB		0x30
24 #define PORT_1_CURRENT_MSB		0x31
25 #define PORT_1_VOLTAGE_LSB		0x32
26 #define PORT_1_VOLTAGE_MSB		0x33
27 #define PORT_2_CURRENT_LSB		0x34
28 #define PORT_2_CURRENT_MSB		0x35
29 #define PORT_2_VOLTAGE_LSB		0x36
30 #define PORT_2_VOLTAGE_MSB		0x37
31 #define PORT_3_CURRENT_LSB		0x38
32 #define PORT_3_CURRENT_MSB		0x39
33 #define PORT_3_VOLTAGE_LSB		0x3a
34 #define PORT_3_VOLTAGE_MSB		0x3b
35 #define PORT_4_CURRENT_LSB		0x3c
36 #define PORT_4_CURRENT_MSB		0x3d
37 #define PORT_4_VOLTAGE_LSB		0x3e
38 #define PORT_4_VOLTAGE_MSB		0x3f
39 #define PORT_N_CURRENT_LSB_OFFSET	0x04
40 #define PORT_N_VOLTAGE_LSB_OFFSET	0x04
41 #define VOLTAGE_CURRENT_MASK		GENMASK(13, 0)
42 #define PORT_1_RESISTANCE_LSB		0x60
43 #define PORT_1_RESISTANCE_MSB		0x61
44 #define PORT_2_RESISTANCE_LSB		0x62
45 #define PORT_2_RESISTANCE_MSB		0x63
46 #define PORT_3_RESISTANCE_LSB		0x64
47 #define PORT_3_RESISTANCE_MSB		0x65
48 #define PORT_4_RESISTANCE_LSB		0x66
49 #define PORT_4_RESISTANCE_MSB		0x67
50 #define PORT_N_RESISTANCE_LSB_OFFSET	0x02
51 #define PORT_RESISTANCE_MASK		GENMASK(13, 0)
52 #define PORT_RESISTANCE_RSN_MASK	GENMASK(15, 14)
53 #define PORT_RESISTANCE_RSN_OTHER	0
54 #define PORT_RESISTANCE_RSN_LOW		1
55 #define PORT_RESISTANCE_RSN_OPEN	2
56 #define PORT_RESISTANCE_RSN_SHORT	3
57 #define PORT_1_STATUS			0x0c
58 #define PORT_2_STATUS			0x0d
59 #define PORT_3_STATUS			0x0e
60 #define PORT_4_STATUS			0x0f
61 #define PORT_STATUS_CLASS_MASK		GENMASK(7, 4)
62 #define PORT_STATUS_DETECT_MASK		GENMASK(3, 0)
63 #define PORT_CLASS_UNKNOWN		0
64 #define PORT_CLASS_1			1
65 #define PORT_CLASS_2			2
66 #define PORT_CLASS_3			3
67 #define PORT_CLASS_4			4
68 #define PORT_CLASS_RESERVED		5
69 #define PORT_CLASS_0			6
70 #define PORT_CLASS_OVERCURRENT		7
71 #define PORT_CLASS_MISMATCH		8
72 #define PORT_DETECT_UNKNOWN		0
73 #define PORT_DETECT_SHORT		1
74 #define PORT_DETECT_RESERVED		2
75 #define PORT_DETECT_RESISTANCE_LOW	3
76 #define PORT_DETECT_RESISTANCE_OK	4
77 #define PORT_DETECT_RESISTANCE_HIGH	5
78 #define PORT_DETECT_OPEN_CIRCUIT	6
79 #define PORT_DETECT_RESERVED_2		7
80 #define PORT_DETECT_MOSFET_FAULT	8
81 #define PORT_DETECT_LEGACY		9
82 /* Measurment beyond clamp voltage */
83 #define PORT_DETECT_CAPACITANCE_INVALID_BEYOND	10
84 /* Insufficient voltage delta */
85 #define PORT_DETECT_CAPACITANCE_INVALID_DELTA	11
86 #define PORT_DETECT_CAPACITANCE_OUT_OF_RANGE	12
87 #define POE_PLUS			0x40
88 #define OPERATING_MODE			0x12
89 #define OPERATING_MODE_OFF		0
90 #define OPERATING_MODE_MANUAL		1
91 #define OPERATING_MODE_SEMI		2
92 #define OPERATING_MODE_AUTO		3
93 #define OPERATING_MODE_PORT_1_MASK	GENMASK(1, 0)
94 #define OPERATING_MODE_PORT_2_MASK	GENMASK(3, 2)
95 #define OPERATING_MODE_PORT_3_MASK	GENMASK(5, 4)
96 #define OPERATING_MODE_PORT_4_MASK	GENMASK(7, 6)
97 
98 #define DETECT_CLASS_RESTART		0x18
99 #define POWER_ENABLE			0x19
100 #define TPS23861_NUM_PORTS		4
101 
102 #define TPS23861_GENERAL_MASK_1		0x17
103 #define TPS23861_CURRENT_SHUNT_MASK	BIT(0)
104 
105 #define TEMPERATURE_LSB			652 /* 0.652 degrees Celsius */
106 #define VOLTAGE_LSB			3662 /* 3.662 mV */
107 #define SHUNT_RESISTOR_DEFAULT		255000 /* 255 mOhm */
108 #define CURRENT_LSB_250			62260 /* 62.260 uA */
109 #define CURRENT_LSB_255			61039 /* 61.039 uA */
110 #define RESISTANCE_LSB			110966 /* 11.0966 Ohm*/
111 #define RESISTANCE_LSB_LOW		157216 /* 15.7216 Ohm*/
112 
113 struct tps23861_data {
114 	struct regmap *regmap;
115 	u32 shunt_resistor;
116 	struct i2c_client *client;
117 	struct dentry *debugfs_dir;
118 };
119 
120 static struct regmap_config tps23861_regmap_config = {
121 	.reg_bits = 8,
122 	.val_bits = 8,
123 	.max_register = 0x6f,
124 };
125 
126 static int tps23861_read_temp(struct tps23861_data *data, long *val)
127 {
128 	unsigned int regval;
129 	int err;
130 
131 	err = regmap_read(data->regmap, TEMPERATURE, &regval);
132 	if (err < 0)
133 		return err;
134 
135 	*val = (regval * TEMPERATURE_LSB) - 20000;
136 
137 	return 0;
138 }
139 
140 static int tps23861_read_voltage(struct tps23861_data *data, int channel,
141 				 long *val)
142 {
143 	unsigned int regval;
144 	int err;
145 
146 	if (channel < TPS23861_NUM_PORTS) {
147 		err = regmap_bulk_read(data->regmap,
148 				       PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
149 				       &regval, 2);
150 	} else {
151 		err = regmap_bulk_read(data->regmap,
152 				       INPUT_VOLTAGE_LSB,
153 				       &regval, 2);
154 	}
155 	if (err < 0)
156 		return err;
157 
158 	*val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
159 
160 	return 0;
161 }
162 
163 static int tps23861_read_current(struct tps23861_data *data, int channel,
164 				 long *val)
165 {
166 	unsigned int current_lsb;
167 	unsigned int regval;
168 	int err;
169 
170 	if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
171 		current_lsb = CURRENT_LSB_255;
172 	else
173 		current_lsb = CURRENT_LSB_250;
174 
175 	err = regmap_bulk_read(data->regmap,
176 			       PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
177 			       &regval, 2);
178 	if (err < 0)
179 		return err;
180 
181 	*val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
182 
183 	return 0;
184 }
185 
186 static int tps23861_port_disable(struct tps23861_data *data, int channel)
187 {
188 	unsigned int regval = 0;
189 	int err;
190 
191 	regval |= BIT(channel + 4);
192 	err = regmap_write(data->regmap, POWER_ENABLE, regval);
193 
194 	return err;
195 }
196 
197 static int tps23861_port_enable(struct tps23861_data *data, int channel)
198 {
199 	unsigned int regval = 0;
200 	int err;
201 
202 	regval |= BIT(channel);
203 	regval |= BIT(channel + 4);
204 	err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);
205 
206 	return err;
207 }
208 
209 static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
210 				   u32 attr, int channel)
211 {
212 	switch (type) {
213 	case hwmon_temp:
214 		switch (attr) {
215 		case hwmon_temp_input:
216 		case hwmon_temp_label:
217 			return 0444;
218 		default:
219 			return 0;
220 		}
221 	case hwmon_in:
222 		switch (attr) {
223 		case hwmon_in_input:
224 		case hwmon_in_label:
225 			return 0444;
226 		case hwmon_in_enable:
227 			return 0200;
228 		default:
229 			return 0;
230 		}
231 	case hwmon_curr:
232 		switch (attr) {
233 		case hwmon_curr_input:
234 		case hwmon_curr_label:
235 			return 0444;
236 		default:
237 			return 0;
238 		}
239 	default:
240 		return 0;
241 	}
242 }
243 
244 static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
245 			  u32 attr, int channel, long val)
246 {
247 	struct tps23861_data *data = dev_get_drvdata(dev);
248 	int err;
249 
250 	switch (type) {
251 	case hwmon_in:
252 		switch (attr) {
253 		case hwmon_in_enable:
254 			if (val == 0)
255 				err = tps23861_port_disable(data, channel);
256 			else if (val == 1)
257 				err = tps23861_port_enable(data, channel);
258 			else
259 				err = -EINVAL;
260 			break;
261 		default:
262 			return -EOPNOTSUPP;
263 		}
264 		break;
265 	default:
266 		return -EOPNOTSUPP;
267 	}
268 
269 	return err;
270 }
271 
272 static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
273 			 u32 attr, int channel, long *val)
274 {
275 	struct tps23861_data *data = dev_get_drvdata(dev);
276 	int err;
277 
278 	switch (type) {
279 	case hwmon_temp:
280 		switch (attr) {
281 		case hwmon_temp_input:
282 			err = tps23861_read_temp(data, val);
283 			break;
284 		default:
285 			return -EOPNOTSUPP;
286 		}
287 		break;
288 	case hwmon_in:
289 		switch (attr) {
290 		case hwmon_in_input:
291 			err = tps23861_read_voltage(data, channel, val);
292 			break;
293 		default:
294 			return -EOPNOTSUPP;
295 		}
296 		break;
297 	case hwmon_curr:
298 		switch (attr) {
299 		case hwmon_curr_input:
300 			err = tps23861_read_current(data, channel, val);
301 			break;
302 		default:
303 			return -EOPNOTSUPP;
304 		}
305 		break;
306 	default:
307 		return -EOPNOTSUPP;
308 	}
309 
310 	return err;
311 }
312 
313 static const char * const tps23861_port_label[] = {
314 	"Port1",
315 	"Port2",
316 	"Port3",
317 	"Port4",
318 	"Input",
319 };
320 
321 static int tps23861_read_string(struct device *dev,
322 				enum hwmon_sensor_types type,
323 				u32 attr, int channel, const char **str)
324 {
325 	switch (type) {
326 	case hwmon_in:
327 	case hwmon_curr:
328 		*str = tps23861_port_label[channel];
329 		break;
330 	case hwmon_temp:
331 		*str = "Die";
332 		break;
333 	default:
334 		return -EOPNOTSUPP;
335 	}
336 
337 	return 0;
338 }
339 
340 static const struct hwmon_channel_info *tps23861_info[] = {
341 	HWMON_CHANNEL_INFO(chip,
342 			   HWMON_C_REGISTER_TZ),
343 	HWMON_CHANNEL_INFO(temp,
344 			   HWMON_T_INPUT | HWMON_T_LABEL),
345 	HWMON_CHANNEL_INFO(in,
346 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
347 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
348 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
349 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
350 			   HWMON_I_INPUT | HWMON_I_LABEL),
351 	HWMON_CHANNEL_INFO(curr,
352 			   HWMON_C_INPUT | HWMON_C_LABEL,
353 			   HWMON_C_INPUT | HWMON_C_LABEL,
354 			   HWMON_C_INPUT | HWMON_C_LABEL,
355 			   HWMON_C_INPUT | HWMON_C_LABEL),
356 	NULL
357 };
358 
359 static const struct hwmon_ops tps23861_hwmon_ops = {
360 	.is_visible = tps23861_is_visible,
361 	.write = tps23861_write,
362 	.read = tps23861_read,
363 	.read_string = tps23861_read_string,
364 };
365 
366 static const struct hwmon_chip_info tps23861_chip_info = {
367 	.ops = &tps23861_hwmon_ops,
368 	.info = tps23861_info,
369 };
370 
371 static char *tps23861_port_operating_mode(struct tps23861_data *data, int port)
372 {
373 	unsigned int regval;
374 	int mode;
375 
376 	regmap_read(data->regmap, OPERATING_MODE, &regval);
377 
378 	switch (port) {
379 	case 1:
380 		mode = FIELD_GET(OPERATING_MODE_PORT_1_MASK, regval);
381 		break;
382 	case 2:
383 		mode = FIELD_GET(OPERATING_MODE_PORT_2_MASK, regval);
384 		break;
385 	case 3:
386 		mode = FIELD_GET(OPERATING_MODE_PORT_3_MASK, regval);
387 		break;
388 	case 4:
389 		mode = FIELD_GET(OPERATING_MODE_PORT_4_MASK, regval);
390 		break;
391 	default:
392 		mode = -EINVAL;
393 	}
394 
395 	switch (mode) {
396 	case OPERATING_MODE_OFF:
397 		return "Off";
398 	case OPERATING_MODE_MANUAL:
399 		return "Manual";
400 	case OPERATING_MODE_SEMI:
401 		return "Semi-Auto";
402 	case OPERATING_MODE_AUTO:
403 		return "Auto";
404 	default:
405 		return "Invalid";
406 	}
407 }
408 
409 static char *tps23861_port_detect_status(struct tps23861_data *data, int port)
410 {
411 	unsigned int regval;
412 
413 	regmap_read(data->regmap,
414 		    PORT_1_STATUS + (port - 1),
415 		    &regval);
416 
417 	switch (FIELD_GET(PORT_STATUS_DETECT_MASK, regval)) {
418 	case PORT_DETECT_UNKNOWN:
419 		return "Unknown device";
420 	case PORT_DETECT_SHORT:
421 		return "Short circuit";
422 	case PORT_DETECT_RESISTANCE_LOW:
423 		return "Too low resistance";
424 	case PORT_DETECT_RESISTANCE_OK:
425 		return "Valid resistance";
426 	case PORT_DETECT_RESISTANCE_HIGH:
427 		return "Too high resistance";
428 	case PORT_DETECT_OPEN_CIRCUIT:
429 		return "Open circuit";
430 	case PORT_DETECT_MOSFET_FAULT:
431 		return "MOSFET fault";
432 	case PORT_DETECT_LEGACY:
433 		return "Legacy device";
434 	case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
435 		return "Invalid capacitance, beyond clamp voltage";
436 	case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
437 		return "Invalid capacitance, insufficient voltage delta";
438 	case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
439 		return "Valid capacitance, outside of legacy range";
440 	case PORT_DETECT_RESERVED:
441 	case PORT_DETECT_RESERVED_2:
442 	default:
443 		return "Invalid";
444 	}
445 }
446 
447 static char *tps23861_port_class_status(struct tps23861_data *data, int port)
448 {
449 	unsigned int regval;
450 
451 	regmap_read(data->regmap,
452 		    PORT_1_STATUS + (port - 1),
453 		    &regval);
454 
455 	switch (FIELD_GET(PORT_STATUS_CLASS_MASK, regval)) {
456 	case PORT_CLASS_UNKNOWN:
457 		return "Unknown";
458 	case PORT_CLASS_RESERVED:
459 	case PORT_CLASS_0:
460 		return "0";
461 	case PORT_CLASS_1:
462 		return "1";
463 	case PORT_CLASS_2:
464 		return "2";
465 	case PORT_CLASS_3:
466 		return "3";
467 	case PORT_CLASS_4:
468 		return "4";
469 	case PORT_CLASS_OVERCURRENT:
470 		return "Overcurrent";
471 	case PORT_CLASS_MISMATCH:
472 		return "Mismatch";
473 	default:
474 		return "Invalid";
475 	}
476 }
477 
478 static char *tps23861_port_poe_plus_status(struct tps23861_data *data, int port)
479 {
480 	unsigned int regval;
481 
482 	regmap_read(data->regmap, POE_PLUS, &regval);
483 
484 	if (BIT(port + 3) & regval)
485 		return "Yes";
486 	else
487 		return "No";
488 }
489 
490 static int tps23861_port_resistance(struct tps23861_data *data, int port)
491 {
492 	u16 regval;
493 
494 	regmap_bulk_read(data->regmap,
495 			 PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * (port - 1),
496 			 &regval,
497 			 2);
498 
499 	switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, regval)) {
500 	case PORT_RESISTANCE_RSN_OTHER:
501 		return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB) / 10000;
502 	case PORT_RESISTANCE_RSN_LOW:
503 		return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB_LOW) / 10000;
504 	case PORT_RESISTANCE_RSN_SHORT:
505 	case PORT_RESISTANCE_RSN_OPEN:
506 	default:
507 		return 0;
508 	}
509 }
510 
511 static int tps23861_port_status_show(struct seq_file *s, void *data)
512 {
513 	struct tps23861_data *priv = s->private;
514 	int i;
515 
516 	for (i = 1; i < TPS23861_NUM_PORTS + 1; i++) {
517 		seq_printf(s, "Port: \t\t%d\n", i);
518 		seq_printf(s, "Operating mode: %s\n", tps23861_port_operating_mode(priv, i));
519 		seq_printf(s, "Detected: \t%s\n", tps23861_port_detect_status(priv, i));
520 		seq_printf(s, "Class: \t\t%s\n", tps23861_port_class_status(priv, i));
521 		seq_printf(s, "PoE Plus: \t%s\n", tps23861_port_poe_plus_status(priv, i));
522 		seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
523 		seq_putc(s, '\n');
524 	}
525 
526 	return 0;
527 }
528 
529 DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);
530 
531 static void tps23861_init_debugfs(struct tps23861_data *data)
532 {
533 	data->debugfs_dir = debugfs_create_dir(data->client->name, NULL);
534 
535 	debugfs_create_file("port_status",
536 			    0400,
537 			    data->debugfs_dir,
538 			    data,
539 			    &tps23861_port_status_fops);
540 }
541 
542 static int tps23861_probe(struct i2c_client *client)
543 {
544 	struct device *dev = &client->dev;
545 	struct tps23861_data *data;
546 	struct device *hwmon_dev;
547 	u32 shunt_resistor;
548 
549 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
550 	if (!data)
551 		return -ENOMEM;
552 
553 	data->client = client;
554 	i2c_set_clientdata(client, data);
555 
556 	data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
557 	if (IS_ERR(data->regmap)) {
558 		dev_err(dev, "failed to allocate register map\n");
559 		return PTR_ERR(data->regmap);
560 	}
561 
562 	if (!of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor))
563 		data->shunt_resistor = shunt_resistor;
564 	else
565 		data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
566 
567 	if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
568 		regmap_clear_bits(data->regmap,
569 				  TPS23861_GENERAL_MASK_1,
570 				  TPS23861_CURRENT_SHUNT_MASK);
571 	else
572 		regmap_set_bits(data->regmap,
573 				TPS23861_GENERAL_MASK_1,
574 				TPS23861_CURRENT_SHUNT_MASK);
575 
576 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
577 							 data, &tps23861_chip_info,
578 							 NULL);
579 	if (IS_ERR(hwmon_dev))
580 		return PTR_ERR(hwmon_dev);
581 
582 	tps23861_init_debugfs(data);
583 
584 	return 0;
585 }
586 
587 static int tps23861_remove(struct i2c_client *client)
588 {
589 	struct tps23861_data *data = i2c_get_clientdata(client);
590 
591 	debugfs_remove_recursive(data->debugfs_dir);
592 
593 	return 0;
594 }
595 
596 static const struct of_device_id __maybe_unused tps23861_of_match[] = {
597 	{ .compatible = "ti,tps23861", },
598 	{ },
599 };
600 MODULE_DEVICE_TABLE(of, tps23861_of_match);
601 
602 static struct i2c_driver tps23861_driver = {
603 	.probe_new		= tps23861_probe,
604 	.remove			= tps23861_remove,
605 	.driver = {
606 		.name		= "tps23861",
607 		.of_match_table	= of_match_ptr(tps23861_of_match),
608 	},
609 };
610 module_i2c_driver(tps23861_driver);
611 
612 MODULE_LICENSE("GPL");
613 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
614 MODULE_DESCRIPTION("TI TPS23861 PoE PSE");
615