xref: /openbmc/linux/drivers/hwmon/pmbus/zl6100.c (revision 99a15348)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Hardware monitoring driver for ZL6100 and compatibles
4  *
5  * Copyright (c) 2011 Ericsson AB.
6  * Copyright (c) 2012 Guenter Roeck
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/err.h>
14 #include <linux/slab.h>
15 #include <linux/i2c.h>
16 #include <linux/ktime.h>
17 #include <linux/delay.h>
18 #include "pmbus.h"
19 
20 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
21 	     zl8802, zl9101, zl9117, zls1003, zls4009 };
22 
23 struct zl6100_data {
24 	int id;
25 	ktime_t access;		/* chip access time */
26 	int delay;		/* Delay between chip accesses in uS */
27 	struct pmbus_driver_info info;
28 };
29 
30 #define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)
31 
32 #define ZL6100_MFR_CONFIG		0xd0
33 #define ZL6100_DEVICE_ID		0xe4
34 
35 #define ZL6100_MFR_XTEMP_ENABLE		BIT(7)
36 
37 #define ZL8802_MFR_USER_GLOBAL_CONFIG	0xe9
38 #define ZL8802_MFR_TMON_ENABLE		BIT(12)
39 #define ZL8802_MFR_USER_CONFIG		0xd1
40 #define ZL8802_MFR_XTEMP_ENABLE_2	BIT(1)
41 #define ZL8802_MFR_DDC_CONFIG		0xd3
42 #define ZL8802_MFR_PHASES_MASK		0x0007
43 
44 #define MFR_VMON_OV_FAULT_LIMIT		0xf5
45 #define MFR_VMON_UV_FAULT_LIMIT		0xf6
46 #define MFR_READ_VMON			0xf7
47 
48 #define VMON_UV_WARNING			BIT(5)
49 #define VMON_OV_WARNING			BIT(4)
50 #define VMON_UV_FAULT			BIT(1)
51 #define VMON_OV_FAULT			BIT(0)
52 
53 #define ZL6100_WAIT_TIME		1000	/* uS	*/
54 
55 static ushort delay = ZL6100_WAIT_TIME;
56 module_param(delay, ushort, 0644);
57 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
58 
59 /* Convert linear sensor value to milli-units */
60 static long zl6100_l2d(s16 l)
61 {
62 	s16 exponent;
63 	s32 mantissa;
64 	long val;
65 
66 	exponent = l >> 11;
67 	mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;
68 
69 	val = mantissa;
70 
71 	/* scale result to milli-units */
72 	val = val * 1000L;
73 
74 	if (exponent >= 0)
75 		val <<= exponent;
76 	else
77 		val >>= -exponent;
78 
79 	return val;
80 }
81 
82 #define MAX_MANTISSA	(1023 * 1000)
83 #define MIN_MANTISSA	(511 * 1000)
84 
85 static u16 zl6100_d2l(long val)
86 {
87 	s16 exponent = 0, mantissa;
88 	bool negative = false;
89 
90 	/* simple case */
91 	if (val == 0)
92 		return 0;
93 
94 	if (val < 0) {
95 		negative = true;
96 		val = -val;
97 	}
98 
99 	/* Reduce large mantissa until it fits into 10 bit */
100 	while (val >= MAX_MANTISSA && exponent < 15) {
101 		exponent++;
102 		val >>= 1;
103 	}
104 	/* Increase small mantissa to improve precision */
105 	while (val < MIN_MANTISSA && exponent > -15) {
106 		exponent--;
107 		val <<= 1;
108 	}
109 
110 	/* Convert mantissa from milli-units to units */
111 	mantissa = DIV_ROUND_CLOSEST(val, 1000);
112 
113 	/* Ensure that resulting number is within range */
114 	if (mantissa > 0x3ff)
115 		mantissa = 0x3ff;
116 
117 	/* restore sign */
118 	if (negative)
119 		mantissa = -mantissa;
120 
121 	/* Convert to 5 bit exponent, 11 bit mantissa */
122 	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
123 }
124 
125 /* Some chips need a delay between accesses */
126 static inline void zl6100_wait(const struct zl6100_data *data)
127 {
128 	if (data->delay) {
129 		s64 delta = ktime_us_delta(ktime_get(), data->access);
130 		if (delta < data->delay)
131 			udelay(data->delay - delta);
132 	}
133 }
134 
135 static int zl6100_read_word_data(struct i2c_client *client, int page,
136 				 int phase, int reg)
137 {
138 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
139 	struct zl6100_data *data = to_zl6100_data(info);
140 	int ret, vreg;
141 
142 	if (page >= info->pages)
143 		return -ENXIO;
144 
145 	if (data->id == zl2005) {
146 		/*
147 		 * Limit register detection is not reliable on ZL2005.
148 		 * Make sure registers are not erroneously detected.
149 		 */
150 		switch (reg) {
151 		case PMBUS_VOUT_OV_WARN_LIMIT:
152 		case PMBUS_VOUT_UV_WARN_LIMIT:
153 		case PMBUS_IOUT_OC_WARN_LIMIT:
154 			return -ENXIO;
155 		}
156 	}
157 
158 	switch (reg) {
159 	case PMBUS_VIRT_READ_VMON:
160 		vreg = MFR_READ_VMON;
161 		break;
162 	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
163 	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
164 		vreg = MFR_VMON_OV_FAULT_LIMIT;
165 		break;
166 	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
167 	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
168 		vreg = MFR_VMON_UV_FAULT_LIMIT;
169 		break;
170 	default:
171 		if (reg >= PMBUS_VIRT_BASE)
172 			return -ENXIO;
173 		vreg = reg;
174 		break;
175 	}
176 
177 	zl6100_wait(data);
178 	ret = pmbus_read_word_data(client, page, phase, vreg);
179 	data->access = ktime_get();
180 	if (ret < 0)
181 		return ret;
182 
183 	switch (reg) {
184 	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
185 		ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
186 		break;
187 	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
188 		ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
189 		break;
190 	}
191 
192 	return ret;
193 }
194 
195 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
196 {
197 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
198 	struct zl6100_data *data = to_zl6100_data(info);
199 	int ret, status;
200 
201 	if (page >= info->pages)
202 		return -ENXIO;
203 
204 	zl6100_wait(data);
205 
206 	switch (reg) {
207 	case PMBUS_VIRT_STATUS_VMON:
208 		ret = pmbus_read_byte_data(client, 0,
209 					   PMBUS_STATUS_MFR_SPECIFIC);
210 		if (ret < 0)
211 			break;
212 
213 		status = 0;
214 		if (ret & VMON_UV_WARNING)
215 			status |= PB_VOLTAGE_UV_WARNING;
216 		if (ret & VMON_OV_WARNING)
217 			status |= PB_VOLTAGE_OV_WARNING;
218 		if (ret & VMON_UV_FAULT)
219 			status |= PB_VOLTAGE_UV_FAULT;
220 		if (ret & VMON_OV_FAULT)
221 			status |= PB_VOLTAGE_OV_FAULT;
222 		ret = status;
223 		break;
224 	default:
225 		ret = pmbus_read_byte_data(client, page, reg);
226 		break;
227 	}
228 	data->access = ktime_get();
229 
230 	return ret;
231 }
232 
233 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
234 				  u16 word)
235 {
236 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
237 	struct zl6100_data *data = to_zl6100_data(info);
238 	int ret, vreg;
239 
240 	if (page >= info->pages)
241 		return -ENXIO;
242 
243 	switch (reg) {
244 	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
245 		word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
246 		vreg = MFR_VMON_OV_FAULT_LIMIT;
247 		pmbus_clear_cache(client);
248 		break;
249 	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
250 		vreg = MFR_VMON_OV_FAULT_LIMIT;
251 		pmbus_clear_cache(client);
252 		break;
253 	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
254 		word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
255 		vreg = MFR_VMON_UV_FAULT_LIMIT;
256 		pmbus_clear_cache(client);
257 		break;
258 	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
259 		vreg = MFR_VMON_UV_FAULT_LIMIT;
260 		pmbus_clear_cache(client);
261 		break;
262 	default:
263 		if (reg >= PMBUS_VIRT_BASE)
264 			return -ENXIO;
265 		vreg = reg;
266 	}
267 
268 	zl6100_wait(data);
269 	ret = pmbus_write_word_data(client, page, vreg, word);
270 	data->access = ktime_get();
271 
272 	return ret;
273 }
274 
275 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
276 {
277 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
278 	struct zl6100_data *data = to_zl6100_data(info);
279 	int ret;
280 
281 	if (page >= info->pages)
282 		return -ENXIO;
283 
284 	zl6100_wait(data);
285 	ret = pmbus_write_byte(client, page, value);
286 	data->access = ktime_get();
287 
288 	return ret;
289 }
290 
291 static const struct i2c_device_id zl6100_id[] = {
292 	{"bmr450", zl2005},
293 	{"bmr451", zl2005},
294 	{"bmr462", zl2008},
295 	{"bmr463", zl2008},
296 	{"bmr464", zl2008},
297 	{"bmr465", zls4009},
298 	{"bmr466", zls1003},
299 	{"bmr467", zls4009},
300 	{"bmr469", zl8802},
301 	{"zl2004", zl2004},
302 	{"zl2005", zl2005},
303 	{"zl2006", zl2006},
304 	{"zl2008", zl2008},
305 	{"zl2105", zl2105},
306 	{"zl2106", zl2106},
307 	{"zl6100", zl6100},
308 	{"zl6105", zl6105},
309 	{"zl8802", zl8802},
310 	{"zl9101", zl9101},
311 	{"zl9117", zl9117},
312 	{"zls1003", zls1003},
313 	{"zls4009", zls4009},
314 	{ }
315 };
316 MODULE_DEVICE_TABLE(i2c, zl6100_id);
317 
318 static int zl6100_probe(struct i2c_client *client)
319 {
320 	int ret, i;
321 	struct zl6100_data *data;
322 	struct pmbus_driver_info *info;
323 	u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
324 	const struct i2c_device_id *mid;
325 
326 	if (!i2c_check_functionality(client->adapter,
327 				     I2C_FUNC_SMBUS_READ_WORD_DATA
328 				     | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
329 		return -ENODEV;
330 
331 	ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
332 					device_id);
333 	if (ret < 0) {
334 		dev_err(&client->dev, "Failed to read device ID\n");
335 		return ret;
336 	}
337 	device_id[ret] = '\0';
338 	dev_info(&client->dev, "Device ID %s\n", device_id);
339 
340 	mid = NULL;
341 	for (mid = zl6100_id; mid->name[0]; mid++) {
342 		if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
343 			break;
344 	}
345 	if (!mid->name[0]) {
346 		dev_err(&client->dev, "Unsupported device\n");
347 		return -ENODEV;
348 	}
349 	if (strcmp(client->name, mid->name) != 0)
350 		dev_notice(&client->dev,
351 			   "Device mismatch: Configured %s, detected %s\n",
352 			   client->name, mid->name);
353 
354 	data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
355 			    GFP_KERNEL);
356 	if (!data)
357 		return -ENOMEM;
358 
359 	data->id = mid->driver_data;
360 
361 	/*
362 	 * According to information from the chip vendor, all currently
363 	 * supported chips are known to require a wait time between I2C
364 	 * accesses.
365 	 */
366 	data->delay = delay;
367 
368 	/*
369 	 * Since there was a direct I2C device access above, wait before
370 	 * accessing the chip again.
371 	 */
372 	data->access = ktime_get();
373 	zl6100_wait(data);
374 
375 	info = &data->info;
376 
377 	info->pages = 1;
378 	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
379 	  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
380 	  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
381 	  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
382 
383 	/*
384 	 * ZL2004, ZL8802, ZL9101M, ZL9117M and ZLS4009 support monitoring
385 	 * an extra voltage (VMON for ZL2004, ZL8802 and ZLS4009,
386 	 * VDRV for ZL9101M and ZL9117M). Report it as vmon.
387 	 */
388 	if (data->id == zl2004 || data->id == zl8802 || data->id == zl9101 ||
389 	    data->id == zl9117 || data->id == zls4009)
390 		info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;
391 
392 	/*
393 	 * ZL8802 has two outputs that can be used either independently or in
394 	 * a current sharing configuration. The driver uses the DDC_CONFIG
395 	 * register to check if the module is running with independent or
396 	 * shared outputs. If the module is in shared output mode, only one
397 	 * output voltage will be reported.
398 	 */
399 	if (data->id == zl8802) {
400 		info->pages = 2;
401 		info->func[0] |= PMBUS_HAVE_IIN;
402 
403 		ret = i2c_smbus_read_word_data(client, ZL8802_MFR_DDC_CONFIG);
404 		if (ret < 0)
405 			return ret;
406 
407 		data->access = ktime_get();
408 		zl6100_wait(data);
409 
410 		if (ret & ZL8802_MFR_PHASES_MASK)
411 			info->func[1] |= PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
412 		else
413 			info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
414 				| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
415 
416 		for (i = 0; i < 2; i++) {
417 			ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
418 			if (ret < 0)
419 				return ret;
420 
421 			data->access = ktime_get();
422 			zl6100_wait(data);
423 
424 			ret = i2c_smbus_read_word_data(client, ZL8802_MFR_USER_CONFIG);
425 			if (ret < 0)
426 				return ret;
427 
428 			if (ret & ZL8802_MFR_XTEMP_ENABLE_2)
429 				info->func[i] |= PMBUS_HAVE_TEMP2;
430 
431 			data->access = ktime_get();
432 			zl6100_wait(data);
433 		}
434 		ret = i2c_smbus_read_word_data(client, ZL8802_MFR_USER_GLOBAL_CONFIG);
435 		if (ret < 0)
436 			return ret;
437 
438 		if (ret & ZL8802_MFR_TMON_ENABLE)
439 			info->func[0] |= PMBUS_HAVE_TEMP3;
440 	} else {
441 		ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
442 		if (ret < 0)
443 			return ret;
444 
445 		if (ret & ZL6100_MFR_XTEMP_ENABLE)
446 			info->func[0] |= PMBUS_HAVE_TEMP2;
447 	}
448 
449 	data->access = ktime_get();
450 	zl6100_wait(data);
451 
452 	info->read_word_data = zl6100_read_word_data;
453 	info->read_byte_data = zl6100_read_byte_data;
454 	info->write_word_data = zl6100_write_word_data;
455 	info->write_byte = zl6100_write_byte;
456 
457 	return pmbus_do_probe(client, info);
458 }
459 
460 static struct i2c_driver zl6100_driver = {
461 	.driver = {
462 		   .name = "zl6100",
463 		   },
464 	.probe_new = zl6100_probe,
465 	.id_table = zl6100_id,
466 };
467 
468 module_i2c_driver(zl6100_driver);
469 
470 MODULE_AUTHOR("Guenter Roeck");
471 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
472 MODULE_LICENSE("GPL");
473 MODULE_IMPORT_NS(PMBUS);
474