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
tps23861_read_temp(struct tps23861_data * data,long * val)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, ®val);
132 if (err < 0)
133 return err;
134
135 *val = (regval * TEMPERATURE_LSB) - 20000;
136
137 return 0;
138 }
139
tps23861_read_voltage(struct tps23861_data * data,int channel,long * val)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 ®val, 2);
150 } else {
151 err = regmap_bulk_read(data->regmap,
152 INPUT_VOLTAGE_LSB,
153 ®val, 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
tps23861_read_current(struct tps23861_data * data,int channel,long * val)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 ®val, 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
tps23861_port_disable(struct tps23861_data * data,int channel)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
tps23861_port_enable(struct tps23861_data * data,int channel)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
tps23861_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)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
tps23861_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)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
tps23861_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)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
tps23861_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)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
tps23861_port_operating_mode(struct tps23861_data * data,int port)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, ®val);
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
tps23861_port_detect_status(struct tps23861_data * data,int port)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 ®val);
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
tps23861_port_class_status(struct tps23861_data * data,int port)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 ®val);
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
tps23861_port_poe_plus_status(struct tps23861_data * data,int port)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, ®val);
483
484 if (BIT(port + 3) & regval)
485 return "Yes";
486 else
487 return "No";
488 }
489
tps23861_port_resistance(struct tps23861_data * data,int port)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 ®val,
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
tps23861_port_status_show(struct seq_file * s,void * data)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
tps23861_init_debugfs(struct tps23861_data * data)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
tps23861_probe(struct i2c_client * client)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
tps23861_remove(struct i2c_client * client)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
