xref: /openbmc/linux/drivers/hwmon/pmbus/ibm-cffps.c (revision 08283d30)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2017 IBM Corp.
4  */
5 
6 #include <linux/bitops.h>
7 #include <linux/debugfs.h>
8 #include <linux/device.h>
9 #include <linux/fs.h>
10 #include <linux/i2c.h>
11 #include <linux/jiffies.h>
12 #include <linux/leds.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/of_device.h>
16 #include <linux/pmbus.h>
17 
18 #include "pmbus.h"
19 
20 #define CFFPS_FRU_CMD				0x9A
21 #define CFFPS_PN_CMD				0x9B
22 #define CFFPS_SN_CMD				0x9E
23 #define CFFPS_CCIN_CMD				0xBD
24 #define CFFPS_FW_CMD				0xFA
25 #define CFFPS1_FW_NUM_BYTES			4
26 #define CFFPS2_FW_NUM_WORDS			3
27 #define CFFPS_SYS_CONFIG_CMD			0xDA
28 
29 #define CFFPS_INPUT_HISTORY_CMD			0xD6
30 #define CFFPS_INPUT_HISTORY_SIZE		100
31 
32 /* STATUS_MFR_SPECIFIC bits */
33 #define CFFPS_MFR_FAN_FAULT			BIT(0)
34 #define CFFPS_MFR_THERMAL_FAULT			BIT(1)
35 #define CFFPS_MFR_OV_FAULT			BIT(2)
36 #define CFFPS_MFR_UV_FAULT			BIT(3)
37 #define CFFPS_MFR_PS_KILL			BIT(4)
38 #define CFFPS_MFR_OC_FAULT			BIT(5)
39 #define CFFPS_MFR_VAUX_FAULT			BIT(6)
40 #define CFFPS_MFR_CURRENT_SHARE_WARNING		BIT(7)
41 
42 #define CFFPS_LED_BLINK				BIT(0)
43 #define CFFPS_LED_ON				BIT(1)
44 #define CFFPS_LED_OFF				BIT(2)
45 #define CFFPS_BLINK_RATE_MS			250
46 
47 enum {
48 	CFFPS_DEBUGFS_INPUT_HISTORY = 0,
49 	CFFPS_DEBUGFS_FRU,
50 	CFFPS_DEBUGFS_PN,
51 	CFFPS_DEBUGFS_SN,
52 	CFFPS_DEBUGFS_CCIN,
53 	CFFPS_DEBUGFS_FW,
54 	CFFPS_DEBUGFS_NUM_ENTRIES
55 };
56 
57 enum versions { cffps1, cffps2 };
58 
59 struct ibm_cffps_input_history {
60 	struct mutex update_lock;
61 	unsigned long last_update;
62 
63 	u8 byte_count;
64 	u8 data[CFFPS_INPUT_HISTORY_SIZE];
65 };
66 
67 struct ibm_cffps {
68 	enum versions version;
69 	struct i2c_client *client;
70 
71 	struct ibm_cffps_input_history input_history;
72 
73 	int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];
74 
75 	char led_name[32];
76 	u8 led_state;
77 	struct led_classdev led;
78 };
79 
80 #define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)])
81 
82 static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
83 					    char __user *buf, size_t count,
84 					    loff_t *ppos)
85 {
86 	int rc;
87 	u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD };
88 	u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 };
89 	struct i2c_msg msg[2] = {
90 		{
91 			.addr = psu->client->addr,
92 			.flags = psu->client->flags,
93 			.len = 1,
94 			.buf = msgbuf0,
95 		}, {
96 			.addr = psu->client->addr,
97 			.flags = psu->client->flags | I2C_M_RD,
98 			.len = CFFPS_INPUT_HISTORY_SIZE + 1,
99 			.buf = msgbuf1,
100 		},
101 	};
102 
103 	if (!*ppos) {
104 		mutex_lock(&psu->input_history.update_lock);
105 		if (time_after(jiffies, psu->input_history.last_update + HZ)) {
106 			/*
107 			 * Use a raw i2c transfer, since we need more bytes
108 			 * than Linux I2C supports through smbus xfr (only 32).
109 			 */
110 			rc = i2c_transfer(psu->client->adapter, msg, 2);
111 			if (rc < 0) {
112 				mutex_unlock(&psu->input_history.update_lock);
113 				return rc;
114 			}
115 
116 			psu->input_history.byte_count = msgbuf1[0];
117 			memcpy(psu->input_history.data, &msgbuf1[1],
118 			       CFFPS_INPUT_HISTORY_SIZE);
119 			psu->input_history.last_update = jiffies;
120 		}
121 
122 		mutex_unlock(&psu->input_history.update_lock);
123 	}
124 
125 	return simple_read_from_buffer(buf, count, ppos,
126 				       psu->input_history.data,
127 				       psu->input_history.byte_count);
128 }
129 
130 static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
131 				    size_t count, loff_t *ppos)
132 {
133 	u8 cmd;
134 	int i, rc;
135 	int *idxp = file->private_data;
136 	int idx = *idxp;
137 	struct ibm_cffps *psu = to_psu(idxp, idx);
138 	char data[I2C_SMBUS_BLOCK_MAX] = { 0 };
139 
140 	pmbus_set_page(psu->client, 0);
141 
142 	switch (idx) {
143 	case CFFPS_DEBUGFS_INPUT_HISTORY:
144 		return ibm_cffps_read_input_history(psu, buf, count, ppos);
145 	case CFFPS_DEBUGFS_FRU:
146 		cmd = CFFPS_FRU_CMD;
147 		break;
148 	case CFFPS_DEBUGFS_PN:
149 		cmd = CFFPS_PN_CMD;
150 		break;
151 	case CFFPS_DEBUGFS_SN:
152 		cmd = CFFPS_SN_CMD;
153 		break;
154 	case CFFPS_DEBUGFS_CCIN:
155 		rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
156 		if (rc < 0)
157 			return rc;
158 
159 		rc = snprintf(data, 5, "%04X", rc);
160 		goto done;
161 	case CFFPS_DEBUGFS_FW:
162 		switch (psu->version) {
163 		case cffps1:
164 			for (i = 0; i < CFFPS1_FW_NUM_BYTES; ++i) {
165 				rc = i2c_smbus_read_byte_data(psu->client,
166 							      CFFPS_FW_CMD +
167 								i);
168 				if (rc < 0)
169 					return rc;
170 
171 				snprintf(&data[i * 2], 3, "%02X", rc);
172 			}
173 
174 			rc = i * 2;
175 			break;
176 		case cffps2:
177 			for (i = 0; i < CFFPS2_FW_NUM_WORDS; ++i) {
178 				rc = i2c_smbus_read_word_data(psu->client,
179 							      CFFPS_FW_CMD +
180 								i);
181 				if (rc < 0)
182 					return rc;
183 
184 				snprintf(&data[i * 4], 5, "%04X", rc);
185 			}
186 
187 			rc = i * 4;
188 			break;
189 		default:
190 			return -EOPNOTSUPP;
191 		}
192 		goto done;
193 	default:
194 		return -EINVAL;
195 	}
196 
197 	rc = i2c_smbus_read_block_data(psu->client, cmd, data);
198 	if (rc < 0)
199 		return rc;
200 
201 done:
202 	data[rc] = '\n';
203 	rc += 2;
204 
205 	return simple_read_from_buffer(buf, count, ppos, data, rc);
206 }
207 
208 static const struct file_operations ibm_cffps_fops = {
209 	.llseek = noop_llseek,
210 	.read = ibm_cffps_debugfs_op,
211 	.open = simple_open,
212 };
213 
214 static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
215 				    int reg)
216 {
217 	int rc, mfr;
218 
219 	switch (reg) {
220 	case PMBUS_STATUS_VOUT:
221 	case PMBUS_STATUS_IOUT:
222 	case PMBUS_STATUS_TEMPERATURE:
223 	case PMBUS_STATUS_FAN_12:
224 		rc = pmbus_read_byte_data(client, page, reg);
225 		if (rc < 0)
226 			return rc;
227 
228 		mfr = pmbus_read_byte_data(client, page,
229 					   PMBUS_STATUS_MFR_SPECIFIC);
230 		if (mfr < 0)
231 			/*
232 			 * Return the status register instead of an error,
233 			 * since we successfully read status.
234 			 */
235 			return rc;
236 
237 		/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
238 		if (reg == PMBUS_STATUS_FAN_12) {
239 			if (mfr & CFFPS_MFR_FAN_FAULT)
240 				rc |= PB_FAN_FAN1_FAULT;
241 		} else if (reg == PMBUS_STATUS_TEMPERATURE) {
242 			if (mfr & CFFPS_MFR_THERMAL_FAULT)
243 				rc |= PB_TEMP_OT_FAULT;
244 		} else if (reg == PMBUS_STATUS_VOUT) {
245 			if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
246 				rc |= PB_VOLTAGE_OV_FAULT;
247 			if (mfr & CFFPS_MFR_UV_FAULT)
248 				rc |= PB_VOLTAGE_UV_FAULT;
249 		} else if (reg == PMBUS_STATUS_IOUT) {
250 			if (mfr & CFFPS_MFR_OC_FAULT)
251 				rc |= PB_IOUT_OC_FAULT;
252 			if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
253 				rc |= PB_CURRENT_SHARE_FAULT;
254 		}
255 		break;
256 	default:
257 		rc = -ENODATA;
258 		break;
259 	}
260 
261 	return rc;
262 }
263 
264 static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
265 				    int reg)
266 {
267 	int rc, mfr;
268 
269 	switch (reg) {
270 	case PMBUS_STATUS_WORD:
271 		rc = pmbus_read_word_data(client, page, reg);
272 		if (rc < 0)
273 			return rc;
274 
275 		mfr = pmbus_read_byte_data(client, page,
276 					   PMBUS_STATUS_MFR_SPECIFIC);
277 		if (mfr < 0)
278 			/*
279 			 * Return the status register instead of an error,
280 			 * since we successfully read status.
281 			 */
282 			return rc;
283 
284 		if (mfr & CFFPS_MFR_PS_KILL)
285 			rc |= PB_STATUS_OFF;
286 		break;
287 	default:
288 		rc = -ENODATA;
289 		break;
290 	}
291 
292 	return rc;
293 }
294 
295 static void ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
296 					 enum led_brightness brightness)
297 {
298 	int rc;
299 	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
300 
301 	if (brightness == LED_OFF) {
302 		psu->led_state = CFFPS_LED_OFF;
303 	} else {
304 		brightness = LED_FULL;
305 		if (psu->led_state != CFFPS_LED_BLINK)
306 			psu->led_state = CFFPS_LED_ON;
307 	}
308 
309 	pmbus_set_page(psu->client, 0);
310 
311 	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
312 				       psu->led_state);
313 	if (rc < 0)
314 		return;
315 
316 	led_cdev->brightness = brightness;
317 }
318 
319 static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
320 				   unsigned long *delay_on,
321 				   unsigned long *delay_off)
322 {
323 	int rc;
324 	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
325 
326 	psu->led_state = CFFPS_LED_BLINK;
327 
328 	if (led_cdev->brightness == LED_OFF)
329 		return 0;
330 
331 	pmbus_set_page(psu->client, 0);
332 
333 	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
334 				       CFFPS_LED_BLINK);
335 	if (rc < 0)
336 		return rc;
337 
338 	*delay_on = CFFPS_BLINK_RATE_MS;
339 	*delay_off = CFFPS_BLINK_RATE_MS;
340 
341 	return 0;
342 }
343 
344 static void ibm_cffps_create_led_class(struct ibm_cffps *psu)
345 {
346 	int rc;
347 	struct i2c_client *client = psu->client;
348 	struct device *dev = &client->dev;
349 
350 	snprintf(psu->led_name, sizeof(psu->led_name), "%s-%02x", client->name,
351 		 client->addr);
352 	psu->led.name = psu->led_name;
353 	psu->led.max_brightness = LED_FULL;
354 	psu->led.brightness_set = ibm_cffps_led_brightness_set;
355 	psu->led.blink_set = ibm_cffps_led_blink_set;
356 
357 	rc = devm_led_classdev_register(dev, &psu->led);
358 	if (rc)
359 		dev_warn(dev, "failed to register led class: %d\n", rc);
360 }
361 
362 static struct pmbus_driver_info ibm_cffps_info[] = {
363 	[cffps1] = {
364 		.pages = 1,
365 		.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
366 			PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
367 			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
368 			PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
369 			PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
370 			PMBUS_HAVE_STATUS_FAN12,
371 		.read_byte_data = ibm_cffps_read_byte_data,
372 		.read_word_data = ibm_cffps_read_word_data,
373 	},
374 	[cffps2] = {
375 		.pages = 2,
376 		.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
377 			PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
378 			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
379 			PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
380 			PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
381 			PMBUS_HAVE_STATUS_FAN12,
382 		.func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
383 			PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
384 			PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT,
385 		.read_byte_data = ibm_cffps_read_byte_data,
386 		.read_word_data = ibm_cffps_read_word_data,
387 	},
388 };
389 
390 static struct pmbus_platform_data ibm_cffps_pdata = {
391 	.flags = PMBUS_SKIP_STATUS_CHECK,
392 };
393 
394 static int ibm_cffps_probe(struct i2c_client *client,
395 			   const struct i2c_device_id *id)
396 {
397 	int i, rc;
398 	enum versions vs;
399 	struct dentry *debugfs;
400 	struct dentry *ibm_cffps_dir;
401 	struct ibm_cffps *psu;
402 	const void *md = of_device_get_match_data(&client->dev);
403 
404 	if (md)
405 		vs = (enum versions)md;
406 	else if (id)
407 		vs = (enum versions)id->driver_data;
408 	else
409 		vs = cffps1;
410 
411 	client->dev.platform_data = &ibm_cffps_pdata;
412 	rc = pmbus_do_probe(client, id, &ibm_cffps_info[vs]);
413 	if (rc)
414 		return rc;
415 
416 	/*
417 	 * Don't fail the probe if there isn't enough memory for leds and
418 	 * debugfs.
419 	 */
420 	psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
421 	if (!psu)
422 		return 0;
423 
424 	psu->version = vs;
425 	psu->client = client;
426 	mutex_init(&psu->input_history.update_lock);
427 	psu->input_history.last_update = jiffies - HZ;
428 
429 	ibm_cffps_create_led_class(psu);
430 
431 	/* Don't fail the probe if we can't create debugfs */
432 	debugfs = pmbus_get_debugfs_dir(client);
433 	if (!debugfs)
434 		return 0;
435 
436 	ibm_cffps_dir = debugfs_create_dir(client->name, debugfs);
437 	if (!ibm_cffps_dir)
438 		return 0;
439 
440 	for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
441 		psu->debugfs_entries[i] = i;
442 
443 	debugfs_create_file("input_history", 0444, ibm_cffps_dir,
444 			    &psu->debugfs_entries[CFFPS_DEBUGFS_INPUT_HISTORY],
445 			    &ibm_cffps_fops);
446 	debugfs_create_file("fru", 0444, ibm_cffps_dir,
447 			    &psu->debugfs_entries[CFFPS_DEBUGFS_FRU],
448 			    &ibm_cffps_fops);
449 	debugfs_create_file("part_number", 0444, ibm_cffps_dir,
450 			    &psu->debugfs_entries[CFFPS_DEBUGFS_PN],
451 			    &ibm_cffps_fops);
452 	debugfs_create_file("serial_number", 0444, ibm_cffps_dir,
453 			    &psu->debugfs_entries[CFFPS_DEBUGFS_SN],
454 			    &ibm_cffps_fops);
455 	debugfs_create_file("ccin", 0444, ibm_cffps_dir,
456 			    &psu->debugfs_entries[CFFPS_DEBUGFS_CCIN],
457 			    &ibm_cffps_fops);
458 	debugfs_create_file("fw_version", 0444, ibm_cffps_dir,
459 			    &psu->debugfs_entries[CFFPS_DEBUGFS_FW],
460 			    &ibm_cffps_fops);
461 
462 	return 0;
463 }
464 
465 static const struct i2c_device_id ibm_cffps_id[] = {
466 	{ "ibm_cffps1", cffps1 },
467 	{ "ibm_cffps2", cffps2 },
468 	{}
469 };
470 MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
471 
472 static const struct of_device_id ibm_cffps_of_match[] = {
473 	{
474 		.compatible = "ibm,cffps1",
475 		.data = (void *)cffps1
476 	},
477 	{
478 		.compatible = "ibm,cffps2",
479 		.data = (void *)cffps2
480 	},
481 	{}
482 };
483 MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
484 
485 static struct i2c_driver ibm_cffps_driver = {
486 	.driver = {
487 		.name = "ibm-cffps",
488 		.of_match_table = ibm_cffps_of_match,
489 	},
490 	.probe = ibm_cffps_probe,
491 	.remove = pmbus_do_remove,
492 	.id_table = ibm_cffps_id,
493 };
494 
495 module_i2c_driver(ibm_cffps_driver);
496 
497 MODULE_AUTHOR("Eddie James");
498 MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
499 MODULE_LICENSE("GPL");
500