xref: /openbmc/linux/drivers/hwmon/lineage-pem.c (revision 9b93eb47)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Lineage Compact Power Line series of power entry modules.
4  *
5  * Copyright (C) 2010, 2011 Ericsson AB.
6  *
7  * Documentation:
8  *  http://www.lineagepower.com/oem/pdf/CPLI2C.pdf
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/i2c.h>
17 #include <linux/hwmon.h>
18 #include <linux/hwmon-sysfs.h>
19 #include <linux/jiffies.h>
20 
21 /*
22  * This driver supports various Lineage Compact Power Line DC/DC and AC/DC
23  * converters such as CP1800, CP2000AC, CP2000DC, CP2100DC, and others.
24  *
25  * The devices are nominally PMBus compliant. However, most standard PMBus
26  * commands are not supported. Specifically, all hardware monitoring and
27  * status reporting commands are non-standard. For this reason, a standard
28  * PMBus driver can not be used.
29  *
30  * All Lineage CPL devices have a built-in I2C bus master selector (PCA9541).
31  * To ensure device access, this driver should only be used as client driver
32  * to the pca9541 I2C master selector driver.
33  */
34 
35 /* Command codes */
36 #define PEM_OPERATION		0x01
37 #define PEM_CLEAR_INFO_FLAGS	0x03
38 #define PEM_VOUT_COMMAND	0x21
39 #define PEM_VOUT_OV_FAULT_LIMIT	0x40
40 #define PEM_READ_DATA_STRING	0xd0
41 #define PEM_READ_INPUT_STRING	0xdc
42 #define PEM_READ_FIRMWARE_REV	0xdd
43 #define PEM_READ_RUN_TIMER	0xde
44 #define PEM_FAN_HI_SPEED	0xdf
45 #define PEM_FAN_NORMAL_SPEED	0xe0
46 #define PEM_READ_FAN_SPEED	0xe1
47 
48 /* offsets in data string */
49 #define PEM_DATA_STATUS_2	0
50 #define PEM_DATA_STATUS_1	1
51 #define PEM_DATA_ALARM_2	2
52 #define PEM_DATA_ALARM_1	3
53 #define PEM_DATA_VOUT_LSB	4
54 #define PEM_DATA_VOUT_MSB	5
55 #define PEM_DATA_CURRENT	6
56 #define PEM_DATA_TEMP		7
57 
58 /* Virtual entries, to report constants */
59 #define PEM_DATA_TEMP_MAX	10
60 #define PEM_DATA_TEMP_CRIT	11
61 
62 /* offsets in input string */
63 #define PEM_INPUT_VOLTAGE	0
64 #define PEM_INPUT_POWER_LSB	1
65 #define PEM_INPUT_POWER_MSB	2
66 
67 /* offsets in fan data */
68 #define PEM_FAN_ADJUSTMENT	0
69 #define PEM_FAN_FAN1		1
70 #define PEM_FAN_FAN2		2
71 #define PEM_FAN_FAN3		3
72 
73 /* Status register bits */
74 #define STS1_OUTPUT_ON		(1 << 0)
75 #define STS1_LEDS_FLASHING	(1 << 1)
76 #define STS1_EXT_FAULT		(1 << 2)
77 #define STS1_SERVICE_LED_ON	(1 << 3)
78 #define STS1_SHUTDOWN_OCCURRED	(1 << 4)
79 #define STS1_INT_FAULT		(1 << 5)
80 #define STS1_ISOLATION_TEST_OK	(1 << 6)
81 
82 #define STS2_ENABLE_PIN_HI	(1 << 0)
83 #define STS2_DATA_OUT_RANGE	(1 << 1)
84 #define STS2_RESTARTED_OK	(1 << 1)
85 #define STS2_ISOLATION_TEST_FAIL (1 << 3)
86 #define STS2_HIGH_POWER_CAP	(1 << 4)
87 #define STS2_INVALID_INSTR	(1 << 5)
88 #define STS2_WILL_RESTART	(1 << 6)
89 #define STS2_PEC_ERR		(1 << 7)
90 
91 /* Alarm register bits */
92 #define ALRM1_VIN_OUT_LIMIT	(1 << 0)
93 #define ALRM1_VOUT_OUT_LIMIT	(1 << 1)
94 #define ALRM1_OV_VOLT_SHUTDOWN	(1 << 2)
95 #define ALRM1_VIN_OVERCURRENT	(1 << 3)
96 #define ALRM1_TEMP_WARNING	(1 << 4)
97 #define ALRM1_TEMP_SHUTDOWN	(1 << 5)
98 #define ALRM1_PRIMARY_FAULT	(1 << 6)
99 #define ALRM1_POWER_LIMIT	(1 << 7)
100 
101 #define ALRM2_5V_OUT_LIMIT	(1 << 1)
102 #define ALRM2_TEMP_FAULT	(1 << 2)
103 #define ALRM2_OV_LOW		(1 << 3)
104 #define ALRM2_DCDC_TEMP_HIGH	(1 << 4)
105 #define ALRM2_PRI_TEMP_HIGH	(1 << 5)
106 #define ALRM2_NO_PRIMARY	(1 << 6)
107 #define ALRM2_FAN_FAULT		(1 << 7)
108 
109 #define FIRMWARE_REV_LEN	4
110 #define DATA_STRING_LEN		9
111 #define INPUT_STRING_LEN	5	/* 4 for most devices	*/
112 #define FAN_SPEED_LEN		5
113 
114 struct pem_data {
115 	struct i2c_client *client;
116 	const struct attribute_group *groups[4];
117 
118 	struct mutex update_lock;
119 	bool valid;
120 	bool fans_supported;
121 	int input_length;
122 	unsigned long last_updated;	/* in jiffies */
123 
124 	u8 firmware_rev[FIRMWARE_REV_LEN];
125 	u8 data_string[DATA_STRING_LEN];
126 	u8 input_string[INPUT_STRING_LEN];
127 	u8 fan_speed[FAN_SPEED_LEN];
128 };
129 
130 static int pem_read_block(struct i2c_client *client, u8 command, u8 *data,
131 			  int data_len)
132 {
133 	u8 block_buffer[I2C_SMBUS_BLOCK_MAX];
134 	int result;
135 
136 	result = i2c_smbus_read_block_data(client, command, block_buffer);
137 	if (unlikely(result < 0))
138 		goto abort;
139 	if (unlikely(result == 0xff || result != data_len)) {
140 		result = -EIO;
141 		goto abort;
142 	}
143 	memcpy(data, block_buffer, data_len);
144 	result = 0;
145 abort:
146 	return result;
147 }
148 
149 static struct pem_data *pem_update_device(struct device *dev)
150 {
151 	struct pem_data *data = dev_get_drvdata(dev);
152 	struct i2c_client *client = data->client;
153 	struct pem_data *ret = data;
154 
155 	mutex_lock(&data->update_lock);
156 
157 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
158 		int result;
159 
160 		/* Read data string */
161 		result = pem_read_block(client, PEM_READ_DATA_STRING,
162 					data->data_string,
163 					sizeof(data->data_string));
164 		if (unlikely(result < 0)) {
165 			ret = ERR_PTR(result);
166 			goto abort;
167 		}
168 
169 		/* Read input string */
170 		if (data->input_length) {
171 			result = pem_read_block(client, PEM_READ_INPUT_STRING,
172 						data->input_string,
173 						data->input_length);
174 			if (unlikely(result < 0)) {
175 				ret = ERR_PTR(result);
176 				goto abort;
177 			}
178 		}
179 
180 		/* Read fan speeds */
181 		if (data->fans_supported) {
182 			result = pem_read_block(client, PEM_READ_FAN_SPEED,
183 						data->fan_speed,
184 						sizeof(data->fan_speed));
185 			if (unlikely(result < 0)) {
186 				ret = ERR_PTR(result);
187 				goto abort;
188 			}
189 		}
190 
191 		i2c_smbus_write_byte(client, PEM_CLEAR_INFO_FLAGS);
192 
193 		data->last_updated = jiffies;
194 		data->valid = 1;
195 	}
196 abort:
197 	mutex_unlock(&data->update_lock);
198 	return ret;
199 }
200 
201 static long pem_get_data(u8 *data, int len, int index)
202 {
203 	long val;
204 
205 	switch (index) {
206 	case PEM_DATA_VOUT_LSB:
207 		val = (data[index] + (data[index+1] << 8)) * 5 / 2;
208 		break;
209 	case PEM_DATA_CURRENT:
210 		val = data[index] * 200;
211 		break;
212 	case PEM_DATA_TEMP:
213 		val = data[index] * 1000;
214 		break;
215 	case PEM_DATA_TEMP_MAX:
216 		val = 97 * 1000;	/* 97 degrees C per datasheet */
217 		break;
218 	case PEM_DATA_TEMP_CRIT:
219 		val = 107 * 1000;	/* 107 degrees C per datasheet */
220 		break;
221 	default:
222 		WARN_ON_ONCE(1);
223 		val = 0;
224 	}
225 	return val;
226 }
227 
228 static long pem_get_input(u8 *data, int len, int index)
229 {
230 	long val;
231 
232 	switch (index) {
233 	case PEM_INPUT_VOLTAGE:
234 		if (len == INPUT_STRING_LEN)
235 			val = (data[index] + (data[index+1] << 8) - 75) * 1000;
236 		else
237 			val = (data[index] - 75) * 1000;
238 		break;
239 	case PEM_INPUT_POWER_LSB:
240 		if (len == INPUT_STRING_LEN)
241 			index++;
242 		val = (data[index] + (data[index+1] << 8)) * 1000000L;
243 		break;
244 	default:
245 		WARN_ON_ONCE(1);
246 		val = 0;
247 	}
248 	return val;
249 }
250 
251 static long pem_get_fan(u8 *data, int len, int index)
252 {
253 	long val;
254 
255 	switch (index) {
256 	case PEM_FAN_FAN1:
257 	case PEM_FAN_FAN2:
258 	case PEM_FAN_FAN3:
259 		val = data[index] * 100;
260 		break;
261 	default:
262 		WARN_ON_ONCE(1);
263 		val = 0;
264 	}
265 	return val;
266 }
267 
268 /*
269  * Show boolean, either a fault or an alarm.
270  * .nr points to the register, .index is the bit mask to check
271  */
272 static ssize_t pem_bool_show(struct device *dev, struct device_attribute *da,
273 			     char *buf)
274 {
275 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
276 	struct pem_data *data = pem_update_device(dev);
277 	u8 status;
278 
279 	if (IS_ERR(data))
280 		return PTR_ERR(data);
281 
282 	status = data->data_string[attr->nr] & attr->index;
283 	return snprintf(buf, PAGE_SIZE, "%d\n", !!status);
284 }
285 
286 static ssize_t pem_data_show(struct device *dev, struct device_attribute *da,
287 			     char *buf)
288 {
289 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
290 	struct pem_data *data = pem_update_device(dev);
291 	long value;
292 
293 	if (IS_ERR(data))
294 		return PTR_ERR(data);
295 
296 	value = pem_get_data(data->data_string, sizeof(data->data_string),
297 			     attr->index);
298 
299 	return snprintf(buf, PAGE_SIZE, "%ld\n", value);
300 }
301 
302 static ssize_t pem_input_show(struct device *dev, struct device_attribute *da,
303 			      char *buf)
304 {
305 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
306 	struct pem_data *data = pem_update_device(dev);
307 	long value;
308 
309 	if (IS_ERR(data))
310 		return PTR_ERR(data);
311 
312 	value = pem_get_input(data->input_string, sizeof(data->input_string),
313 			      attr->index);
314 
315 	return snprintf(buf, PAGE_SIZE, "%ld\n", value);
316 }
317 
318 static ssize_t pem_fan_show(struct device *dev, struct device_attribute *da,
319 			    char *buf)
320 {
321 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
322 	struct pem_data *data = pem_update_device(dev);
323 	long value;
324 
325 	if (IS_ERR(data))
326 		return PTR_ERR(data);
327 
328 	value = pem_get_fan(data->fan_speed, sizeof(data->fan_speed),
329 			    attr->index);
330 
331 	return snprintf(buf, PAGE_SIZE, "%ld\n", value);
332 }
333 
334 /* Voltages */
335 static SENSOR_DEVICE_ATTR_RO(in1_input, pem_data, PEM_DATA_VOUT_LSB);
336 static SENSOR_DEVICE_ATTR_2_RO(in1_alarm, pem_bool, PEM_DATA_ALARM_1,
337 			       ALRM1_VOUT_OUT_LIMIT);
338 static SENSOR_DEVICE_ATTR_2_RO(in1_crit_alarm, pem_bool, PEM_DATA_ALARM_1,
339 			       ALRM1_OV_VOLT_SHUTDOWN);
340 static SENSOR_DEVICE_ATTR_RO(in2_input, pem_input, PEM_INPUT_VOLTAGE);
341 static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, pem_bool, PEM_DATA_ALARM_1,
342 			       ALRM1_VIN_OUT_LIMIT | ALRM1_PRIMARY_FAULT);
343 
344 /* Currents */
345 static SENSOR_DEVICE_ATTR_RO(curr1_input, pem_data, PEM_DATA_CURRENT);
346 static SENSOR_DEVICE_ATTR_2_RO(curr1_alarm, pem_bool, PEM_DATA_ALARM_1,
347 			       ALRM1_VIN_OVERCURRENT);
348 
349 /* Power */
350 static SENSOR_DEVICE_ATTR_RO(power1_input, pem_input, PEM_INPUT_POWER_LSB);
351 static SENSOR_DEVICE_ATTR_2_RO(power1_alarm, pem_bool, PEM_DATA_ALARM_1,
352 			       ALRM1_POWER_LIMIT);
353 
354 /* Fans */
355 static SENSOR_DEVICE_ATTR_RO(fan1_input, pem_fan, PEM_FAN_FAN1);
356 static SENSOR_DEVICE_ATTR_RO(fan2_input, pem_fan, PEM_FAN_FAN2);
357 static SENSOR_DEVICE_ATTR_RO(fan3_input, pem_fan, PEM_FAN_FAN3);
358 static SENSOR_DEVICE_ATTR_2_RO(fan1_alarm, pem_bool, PEM_DATA_ALARM_2,
359 			       ALRM2_FAN_FAULT);
360 
361 /* Temperatures */
362 static SENSOR_DEVICE_ATTR_RO(temp1_input, pem_data, PEM_DATA_TEMP);
363 static SENSOR_DEVICE_ATTR_RO(temp1_max, pem_data, PEM_DATA_TEMP_MAX);
364 static SENSOR_DEVICE_ATTR_RO(temp1_crit, pem_data, PEM_DATA_TEMP_CRIT);
365 static SENSOR_DEVICE_ATTR_2_RO(temp1_alarm, pem_bool, PEM_DATA_ALARM_1,
366 			       ALRM1_TEMP_WARNING);
367 static SENSOR_DEVICE_ATTR_2_RO(temp1_crit_alarm, pem_bool, PEM_DATA_ALARM_1,
368 			       ALRM1_TEMP_SHUTDOWN);
369 static SENSOR_DEVICE_ATTR_2_RO(temp1_fault, pem_bool, PEM_DATA_ALARM_2,
370 			       ALRM2_TEMP_FAULT);
371 
372 static struct attribute *pem_attributes[] = {
373 	&sensor_dev_attr_in1_input.dev_attr.attr,
374 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
375 	&sensor_dev_attr_in1_crit_alarm.dev_attr.attr,
376 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
377 
378 	&sensor_dev_attr_curr1_alarm.dev_attr.attr,
379 
380 	&sensor_dev_attr_power1_alarm.dev_attr.attr,
381 
382 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
383 
384 	&sensor_dev_attr_temp1_input.dev_attr.attr,
385 	&sensor_dev_attr_temp1_max.dev_attr.attr,
386 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
387 	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
388 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
389 	&sensor_dev_attr_temp1_fault.dev_attr.attr,
390 
391 	NULL,
392 };
393 
394 static const struct attribute_group pem_group = {
395 	.attrs = pem_attributes,
396 };
397 
398 static struct attribute *pem_input_attributes[] = {
399 	&sensor_dev_attr_in2_input.dev_attr.attr,
400 	&sensor_dev_attr_curr1_input.dev_attr.attr,
401 	&sensor_dev_attr_power1_input.dev_attr.attr,
402 	NULL
403 };
404 
405 static const struct attribute_group pem_input_group = {
406 	.attrs = pem_input_attributes,
407 };
408 
409 static struct attribute *pem_fan_attributes[] = {
410 	&sensor_dev_attr_fan1_input.dev_attr.attr,
411 	&sensor_dev_attr_fan2_input.dev_attr.attr,
412 	&sensor_dev_attr_fan3_input.dev_attr.attr,
413 	NULL
414 };
415 
416 static const struct attribute_group pem_fan_group = {
417 	.attrs = pem_fan_attributes,
418 };
419 
420 static int pem_probe(struct i2c_client *client,
421 		     const struct i2c_device_id *id)
422 {
423 	struct i2c_adapter *adapter = client->adapter;
424 	struct device *dev = &client->dev;
425 	struct device *hwmon_dev;
426 	struct pem_data *data;
427 	int ret, idx = 0;
428 
429 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BLOCK_DATA
430 				     | I2C_FUNC_SMBUS_WRITE_BYTE))
431 		return -ENODEV;
432 
433 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
434 	if (!data)
435 		return -ENOMEM;
436 
437 	data->client = client;
438 	mutex_init(&data->update_lock);
439 
440 	/*
441 	 * We use the next two commands to determine if the device is really
442 	 * there.
443 	 */
444 	ret = pem_read_block(client, PEM_READ_FIRMWARE_REV,
445 			     data->firmware_rev, sizeof(data->firmware_rev));
446 	if (ret < 0)
447 		return ret;
448 
449 	ret = i2c_smbus_write_byte(client, PEM_CLEAR_INFO_FLAGS);
450 	if (ret < 0)
451 		return ret;
452 
453 	dev_info(dev, "Firmware revision %d.%d.%d\n",
454 		 data->firmware_rev[0], data->firmware_rev[1],
455 		 data->firmware_rev[2]);
456 
457 	/* sysfs hooks */
458 	data->groups[idx++] = &pem_group;
459 
460 	/*
461 	 * Check if input readings are supported.
462 	 * This is the case if we can read input data,
463 	 * and if the returned data is not all zeros.
464 	 * Note that input alarms are always supported.
465 	 */
466 	ret = pem_read_block(client, PEM_READ_INPUT_STRING,
467 			     data->input_string,
468 			     sizeof(data->input_string) - 1);
469 	if (!ret && (data->input_string[0] || data->input_string[1] ||
470 		     data->input_string[2]))
471 		data->input_length = sizeof(data->input_string) - 1;
472 	else if (ret < 0) {
473 		/* Input string is one byte longer for some devices */
474 		ret = pem_read_block(client, PEM_READ_INPUT_STRING,
475 				    data->input_string,
476 				    sizeof(data->input_string));
477 		if (!ret && (data->input_string[0] || data->input_string[1] ||
478 			    data->input_string[2] || data->input_string[3]))
479 			data->input_length = sizeof(data->input_string);
480 	}
481 
482 	if (data->input_length)
483 		data->groups[idx++] = &pem_input_group;
484 
485 	/*
486 	 * Check if fan speed readings are supported.
487 	 * This is the case if we can read fan speed data,
488 	 * and if the returned data is not all zeros.
489 	 * Note that the fan alarm is always supported.
490 	 */
491 	ret = pem_read_block(client, PEM_READ_FAN_SPEED,
492 			     data->fan_speed,
493 			     sizeof(data->fan_speed));
494 	if (!ret && (data->fan_speed[0] || data->fan_speed[1] ||
495 		     data->fan_speed[2] || data->fan_speed[3])) {
496 		data->fans_supported = true;
497 		data->groups[idx++] = &pem_fan_group;
498 	}
499 
500 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
501 							   data, data->groups);
502 	return PTR_ERR_OR_ZERO(hwmon_dev);
503 }
504 
505 static const struct i2c_device_id pem_id[] = {
506 	{"lineage_pem", 0},
507 	{}
508 };
509 MODULE_DEVICE_TABLE(i2c, pem_id);
510 
511 static struct i2c_driver pem_driver = {
512 	.driver = {
513 		   .name = "lineage_pem",
514 		   },
515 	.probe = pem_probe,
516 	.id_table = pem_id,
517 };
518 
519 module_i2c_driver(pem_driver);
520 
521 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
522 MODULE_DESCRIPTION("Lineage CPL PEM hardware monitoring driver");
523 MODULE_LICENSE("GPL");
524