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.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
113struct tps23861_data {
114 struct regmap *regmap;
115 u32 shunt_resistor;
116 struct i2c_client *client;
117 struct dentry *debugfs_dir;
118};
119
120static struct regmap_config tps23861_regmap_config = {
121 .reg_bits = 8,
122 .val_bits = 8,
123 .max_register = 0x6f,
124};
125
126static int tps23861_read_temp(struct tps23861_data *data, long *val)
127{
128 unsigned int regval;
129 int err;
130
131 err = regmap_read(map: data->regmap, TEMPERATURE, val: &regval);
132 if (err < 0)
133 return err;
134
135 *val = (regval * TEMPERATURE_LSB) - 20000;
136
137 return 0;
138}
139
140static int tps23861_read_voltage(struct tps23861_data *data, int channel,
141 long *val)
142{
143 __le16 regval;
144 long raw_val;
145 int err;
146
147 if (channel < TPS23861_NUM_PORTS) {
148 err = regmap_bulk_read(map: data->regmap,
149 PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
150 val: &regval, val_count: 2);
151 } else {
152 err = regmap_bulk_read(map: data->regmap,
153 INPUT_VOLTAGE_LSB,
154 val: &regval, val_count: 2);
155 }
156 if (err < 0)
157 return err;
158
159 raw_val = le16_to_cpu(regval);
160 *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000;
161
162 return 0;
163}
164
165static int tps23861_read_current(struct tps23861_data *data, int channel,
166 long *val)
167{
168 long raw_val, current_lsb;
169 __le16 regval;
170
171 int err;
172
173 if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
174 current_lsb = CURRENT_LSB_255;
175 else
176 current_lsb = CURRENT_LSB_250;
177
178 err = regmap_bulk_read(map: data->regmap,
179 PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
180 val: &regval, val_count: 2);
181 if (err < 0)
182 return err;
183
184 raw_val = le16_to_cpu(regval);
185 *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000;
186
187 return 0;
188}
189
190static int tps23861_port_disable(struct tps23861_data *data, int channel)
191{
192 unsigned int regval = 0;
193 int err;
194
195 regval |= BIT(channel + 4);
196 err = regmap_write(map: data->regmap, POWER_ENABLE, val: regval);
197
198 return err;
199}
200
201static int tps23861_port_enable(struct tps23861_data *data, int channel)
202{
203 unsigned int regval = 0;
204 int err;
205
206 regval |= BIT(channel);
207 regval |= BIT(channel + 4);
208 err = regmap_write(map: data->regmap, DETECT_CLASS_RESTART, val: regval);
209
210 return err;
211}
212
213static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
214 u32 attr, int channel)
215{
216 switch (type) {
217 case hwmon_temp:
218 switch (attr) {
219 case hwmon_temp_input:
220 case hwmon_temp_label:
221 return 0444;
222 default:
223 return 0;
224 }
225 case hwmon_in:
226 switch (attr) {
227 case hwmon_in_input:
228 case hwmon_in_label:
229 return 0444;
230 case hwmon_in_enable:
231 return 0200;
232 default:
233 return 0;
234 }
235 case hwmon_curr:
236 switch (attr) {
237 case hwmon_curr_input:
238 case hwmon_curr_label:
239 return 0444;
240 default:
241 return 0;
242 }
243 default:
244 return 0;
245 }
246}
247
248static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
249 u32 attr, int channel, long val)
250{
251 struct tps23861_data *data = dev_get_drvdata(dev);
252 int err;
253
254 switch (type) {
255 case hwmon_in:
256 switch (attr) {
257 case hwmon_in_enable:
258 if (val == 0)
259 err = tps23861_port_disable(data, channel);
260 else if (val == 1)
261 err = tps23861_port_enable(data, channel);
262 else
263 err = -EINVAL;
264 break;
265 default:
266 return -EOPNOTSUPP;
267 }
268 break;
269 default:
270 return -EOPNOTSUPP;
271 }
272
273 return err;
274}
275
276static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
277 u32 attr, int channel, long *val)
278{
279 struct tps23861_data *data = dev_get_drvdata(dev);
280 int err;
281
282 switch (type) {
283 case hwmon_temp:
284 switch (attr) {
285 case hwmon_temp_input:
286 err = tps23861_read_temp(data, val);
287 break;
288 default:
289 return -EOPNOTSUPP;
290 }
291 break;
292 case hwmon_in:
293 switch (attr) {
294 case hwmon_in_input:
295 err = tps23861_read_voltage(data, channel, val);
296 break;
297 default:
298 return -EOPNOTSUPP;
299 }
300 break;
301 case hwmon_curr:
302 switch (attr) {
303 case hwmon_curr_input:
304 err = tps23861_read_current(data, channel, val);
305 break;
306 default:
307 return -EOPNOTSUPP;
308 }
309 break;
310 default:
311 return -EOPNOTSUPP;
312 }
313
314 return err;
315}
316
317static const char * const tps23861_port_label[] = {
318 "Port1",
319 "Port2",
320 "Port3",
321 "Port4",
322 "Input",
323};
324
325static int tps23861_read_string(struct device *dev,
326 enum hwmon_sensor_types type,
327 u32 attr, int channel, const char **str)
328{
329 switch (type) {
330 case hwmon_in:
331 case hwmon_curr:
332 *str = tps23861_port_label[channel];
333 break;
334 case hwmon_temp:
335 *str = "Die";
336 break;
337 default:
338 return -EOPNOTSUPP;
339 }
340
341 return 0;
342}
343
344static const struct hwmon_channel_info * const tps23861_info[] = {
345 HWMON_CHANNEL_INFO(chip,
346 HWMON_C_REGISTER_TZ),
347 HWMON_CHANNEL_INFO(temp,
348 HWMON_T_INPUT | HWMON_T_LABEL),
349 HWMON_CHANNEL_INFO(in,
350 HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
351 HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
352 HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
353 HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
354 HWMON_I_INPUT | HWMON_I_LABEL),
355 HWMON_CHANNEL_INFO(curr,
356 HWMON_C_INPUT | HWMON_C_LABEL,
357 HWMON_C_INPUT | HWMON_C_LABEL,
358 HWMON_C_INPUT | HWMON_C_LABEL,
359 HWMON_C_INPUT | HWMON_C_LABEL),
360 NULL
361};
362
363static const struct hwmon_ops tps23861_hwmon_ops = {
364 .is_visible = tps23861_is_visible,
365 .write = tps23861_write,
366 .read = tps23861_read,
367 .read_string = tps23861_read_string,
368};
369
370static const struct hwmon_chip_info tps23861_chip_info = {
371 .ops = &tps23861_hwmon_ops,
372 .info = tps23861_info,
373};
374
375static char *port_operating_mode_string(uint8_t mode_reg, unsigned int port)
376{
377 unsigned int mode = ~0;
378
379 if (port < TPS23861_NUM_PORTS)
380 mode = (mode_reg >> (2 * port)) & OPERATING_MODE_PORT_1_MASK;
381
382 switch (mode) {
383 case OPERATING_MODE_OFF:
384 return "Off";
385 case OPERATING_MODE_MANUAL:
386 return "Manual";
387 case OPERATING_MODE_SEMI:
388 return "Semi-Auto";
389 case OPERATING_MODE_AUTO:
390 return "Auto";
391 default:
392 return "Invalid";
393 }
394}
395
396static char *port_detect_status_string(uint8_t status_reg)
397{
398 switch (FIELD_GET(PORT_STATUS_DETECT_MASK, status_reg)) {
399 case PORT_DETECT_UNKNOWN:
400 return "Unknown device";
401 case PORT_DETECT_SHORT:
402 return "Short circuit";
403 case PORT_DETECT_RESISTANCE_LOW:
404 return "Too low resistance";
405 case PORT_DETECT_RESISTANCE_OK:
406 return "Valid resistance";
407 case PORT_DETECT_RESISTANCE_HIGH:
408 return "Too high resistance";
409 case PORT_DETECT_OPEN_CIRCUIT:
410 return "Open circuit";
411 case PORT_DETECT_MOSFET_FAULT:
412 return "MOSFET fault";
413 case PORT_DETECT_LEGACY:
414 return "Legacy device";
415 case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
416 return "Invalid capacitance, beyond clamp voltage";
417 case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
418 return "Invalid capacitance, insufficient voltage delta";
419 case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
420 return "Valid capacitance, outside of legacy range";
421 case PORT_DETECT_RESERVED:
422 case PORT_DETECT_RESERVED_2:
423 default:
424 return "Invalid";
425 }
426}
427
428static char *port_class_status_string(uint8_t status_reg)
429{
430 switch (FIELD_GET(PORT_STATUS_CLASS_MASK, status_reg)) {
431 case PORT_CLASS_UNKNOWN:
432 return "Unknown";
433 case PORT_CLASS_RESERVED:
434 case PORT_CLASS_0:
435 return "0";
436 case PORT_CLASS_1:
437 return "1";
438 case PORT_CLASS_2:
439 return "2";
440 case PORT_CLASS_3:
441 return "3";
442 case PORT_CLASS_4:
443 return "4";
444 case PORT_CLASS_OVERCURRENT:
445 return "Overcurrent";
446 case PORT_CLASS_MISMATCH:
447 return "Mismatch";
448 default:
449 return "Invalid";
450 }
451}
452
453static char *port_poe_plus_status_string(uint8_t poe_plus, unsigned int port)
454{
455 return (BIT(port + 4) & poe_plus) ? "Yes" : "No";
456}
457
458static int tps23861_port_resistance(struct tps23861_data *data, int port)
459{
460 unsigned int raw_val;
461 __le16 regval;
462
463 regmap_bulk_read(map: data->regmap,
464 PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * port,
465 val: &regval,
466 val_count: 2);
467
468 raw_val = le16_to_cpu(regval);
469 switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, raw_val)) {
470 case PORT_RESISTANCE_RSN_OTHER:
471 return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB) / 10000;
472 case PORT_RESISTANCE_RSN_LOW:
473 return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB_LOW) / 10000;
474 case PORT_RESISTANCE_RSN_SHORT:
475 case PORT_RESISTANCE_RSN_OPEN:
476 default:
477 return 0;
478 }
479}
480
481static int tps23861_port_status_show(struct seq_file *s, void *data)
482{
483 struct tps23861_data *priv = s->private;
484 unsigned int i, mode, poe_plus, status;
485
486 regmap_read(map: priv->regmap, OPERATING_MODE, val: &mode);
487 regmap_read(map: priv->regmap, POE_PLUS, val: &poe_plus);
488
489 for (i = 0; i < TPS23861_NUM_PORTS; i++) {
490 regmap_read(map: priv->regmap, PORT_1_STATUS + i, val: &status);
491
492 seq_printf(m: s, fmt: "Port: \t\t%d\n", i + 1);
493 seq_printf(m: s, fmt: "Operating mode: %s\n", port_operating_mode_string(mode_reg: mode, port: i));
494 seq_printf(m: s, fmt: "Detected: \t%s\n", port_detect_status_string(status_reg: status));
495 seq_printf(m: s, fmt: "Class: \t\t%s\n", port_class_status_string(status_reg: status));
496 seq_printf(m: s, fmt: "PoE Plus: \t%s\n", port_poe_plus_status_string(poe_plus, port: i));
497 seq_printf(m: s, fmt: "Resistance: \t%d\n", tps23861_port_resistance(data: priv, port: i));
498 seq_putc(m: s, c: '\n');
499 }
500
501 return 0;
502}
503
504DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);
505
506static void tps23861_init_debugfs(struct tps23861_data *data,
507 struct device *hwmon_dev)
508{
509 const char *debugfs_name;
510
511 debugfs_name = devm_kasprintf(dev: &data->client->dev, GFP_KERNEL, fmt: "%s-%s",
512 data->client->name, dev_name(dev: hwmon_dev));
513 if (!debugfs_name)
514 return;
515
516 data->debugfs_dir = debugfs_create_dir(name: debugfs_name, NULL);
517
518 debugfs_create_file(name: "port_status",
519 mode: 0400,
520 parent: data->debugfs_dir,
521 data,
522 fops: &tps23861_port_status_fops);
523}
524
525static int tps23861_probe(struct i2c_client *client)
526{
527 struct device *dev = &client->dev;
528 struct tps23861_data *data;
529 struct device *hwmon_dev;
530 u32 shunt_resistor;
531
532 data = devm_kzalloc(dev, size: sizeof(*data), GFP_KERNEL);
533 if (!data)
534 return -ENOMEM;
535
536 data->client = client;
537 i2c_set_clientdata(client, data);
538
539 data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
540 if (IS_ERR(ptr: data->regmap)) {
541 dev_err(dev, "failed to allocate register map\n");
542 return PTR_ERR(ptr: data->regmap);
543 }
544
545 if (!of_property_read_u32(np: dev->of_node, propname: "shunt-resistor-micro-ohms", out_value: &shunt_resistor))
546 data->shunt_resistor = shunt_resistor;
547 else
548 data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
549
550 if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
551 regmap_clear_bits(map: data->regmap,
552 TPS23861_GENERAL_MASK_1,
553 TPS23861_CURRENT_SHUNT_MASK);
554 else
555 regmap_set_bits(map: data->regmap,
556 TPS23861_GENERAL_MASK_1,
557 TPS23861_CURRENT_SHUNT_MASK);
558
559 hwmon_dev = devm_hwmon_device_register_with_info(dev, name: client->name,
560 drvdata: data, info: &tps23861_chip_info,
561 NULL);
562 if (IS_ERR(ptr: hwmon_dev))
563 return PTR_ERR(ptr: hwmon_dev);
564
565 tps23861_init_debugfs(data, hwmon_dev);
566
567 return 0;
568}
569
570static void tps23861_remove(struct i2c_client *client)
571{
572 struct tps23861_data *data = i2c_get_clientdata(client);
573
574 debugfs_remove_recursive(dentry: data->debugfs_dir);
575}
576
577static const struct of_device_id __maybe_unused tps23861_of_match[] = {
578 { .compatible = "ti,tps23861", },
579 { },
580};
581MODULE_DEVICE_TABLE(of, tps23861_of_match);
582
583static struct i2c_driver tps23861_driver = {
584 .probe = tps23861_probe,
585 .remove = tps23861_remove,
586 .driver = {
587 .name = "tps23861",
588 .of_match_table = of_match_ptr(tps23861_of_match),
589 },
590};
591module_i2c_driver(tps23861_driver);
592
593MODULE_LICENSE("GPL");
594MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
595MODULE_DESCRIPTION("TI TPS23861 PoE PSE");
596

source code of linux/drivers/hwmon/tps23861.c