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
20enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
21	     zl8802, zl9101, zl9117, zls1003, zls4009 };
22
23struct 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
55static ushort delay = ZL6100_WAIT_TIME;
56module_param(delay, ushort, 0644);
57MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
58
59/* Convert linear sensor value to milli-units */
60static 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
85static 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 */
126static 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
135static 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
195static 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
233static 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
275static 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
291static 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};
316MODULE_DEVICE_TABLE(i2c, zl6100_id);
317
318static 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
460static struct i2c_driver zl6100_driver = {
461	.driver = {
462		   .name = "zl6100",
463		   },
464	.probe = zl6100_probe,
465	.id_table = zl6100_id,
466};
467
468module_i2c_driver(zl6100_driver);
469
470MODULE_AUTHOR("Guenter Roeck");
471MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
472MODULE_LICENSE("GPL");
473MODULE_IMPORT_NS(PMBUS);
474