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	     zl9101, zl9117 };
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 MFR_VMON_OV_FAULT_LIMIT		0xf5
38#define MFR_VMON_UV_FAULT_LIMIT		0xf6
39#define MFR_READ_VMON			0xf7
40
41#define VMON_UV_WARNING			BIT(5)
42#define VMON_OV_WARNING			BIT(4)
43#define VMON_UV_FAULT			BIT(1)
44#define VMON_OV_FAULT			BIT(0)
45
46#define ZL6100_WAIT_TIME		1000	/* uS	*/
47
48static ushort delay = ZL6100_WAIT_TIME;
49module_param(delay, ushort, 0644);
50MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
51
52/* Convert linear sensor value to milli-units */
53static long zl6100_l2d(s16 l)
54{
55	s16 exponent;
56	s32 mantissa;
57	long val;
58
59	exponent = l >> 11;
60	mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;
61
62	val = mantissa;
63
64	/* scale result to milli-units */
65	val = val * 1000L;
66
67	if (exponent >= 0)
68		val <<= exponent;
69	else
70		val >>= -exponent;
71
72	return val;
73}
74
75#define MAX_MANTISSA	(1023 * 1000)
76#define MIN_MANTISSA	(511 * 1000)
77
78static u16 zl6100_d2l(long val)
79{
80	s16 exponent = 0, mantissa;
81	bool negative = false;
82
83	/* simple case */
84	if (val == 0)
85		return 0;
86
87	if (val < 0) {
88		negative = true;
89		val = -val;
90	}
91
92	/* Reduce large mantissa until it fits into 10 bit */
93	while (val >= MAX_MANTISSA && exponent < 15) {
94		exponent++;
95		val >>= 1;
96	}
97	/* Increase small mantissa to improve precision */
98	while (val < MIN_MANTISSA && exponent > -15) {
99		exponent--;
100		val <<= 1;
101	}
102
103	/* Convert mantissa from milli-units to units */
104	mantissa = DIV_ROUND_CLOSEST(val, 1000);
105
106	/* Ensure that resulting number is within range */
107	if (mantissa > 0x3ff)
108		mantissa = 0x3ff;
109
110	/* restore sign */
111	if (negative)
112		mantissa = -mantissa;
113
114	/* Convert to 5 bit exponent, 11 bit mantissa */
115	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
116}
117
118/* Some chips need a delay between accesses */
119static inline void zl6100_wait(const struct zl6100_data *data)
120{
121	if (data->delay) {
122		s64 delta = ktime_us_delta(ktime_get(), data->access);
123		if (delta < data->delay)
124			udelay(data->delay - delta);
125	}
126}
127
128static int zl6100_read_word_data(struct i2c_client *client, int page,
129				 int phase, int reg)
130{
131	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
132	struct zl6100_data *data = to_zl6100_data(info);
133	int ret, vreg;
134
135	if (page > 0)
136		return -ENXIO;
137
138	if (data->id == zl2005) {
139		/*
140		 * Limit register detection is not reliable on ZL2005.
141		 * Make sure registers are not erroneously detected.
142		 */
143		switch (reg) {
144		case PMBUS_VOUT_OV_WARN_LIMIT:
145		case PMBUS_VOUT_UV_WARN_LIMIT:
146		case PMBUS_IOUT_OC_WARN_LIMIT:
147			return -ENXIO;
148		}
149	}
150
151	switch (reg) {
152	case PMBUS_VIRT_READ_VMON:
153		vreg = MFR_READ_VMON;
154		break;
155	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
156	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
157		vreg = MFR_VMON_OV_FAULT_LIMIT;
158		break;
159	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
160	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
161		vreg = MFR_VMON_UV_FAULT_LIMIT;
162		break;
163	default:
164		if (reg >= PMBUS_VIRT_BASE)
165			return -ENXIO;
166		vreg = reg;
167		break;
168	}
169
170	zl6100_wait(data);
171	ret = pmbus_read_word_data(client, page, phase, vreg);
172	data->access = ktime_get();
173	if (ret < 0)
174		return ret;
175
176	switch (reg) {
177	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
178		ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
179		break;
180	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
181		ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
182		break;
183	}
184
185	return ret;
186}
187
188static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
189{
190	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
191	struct zl6100_data *data = to_zl6100_data(info);
192	int ret, status;
193
194	if (page > 0)
195		return -ENXIO;
196
197	zl6100_wait(data);
198
199	switch (reg) {
200	case PMBUS_VIRT_STATUS_VMON:
201		ret = pmbus_read_byte_data(client, 0,
202					   PMBUS_STATUS_MFR_SPECIFIC);
203		if (ret < 0)
204			break;
205
206		status = 0;
207		if (ret & VMON_UV_WARNING)
208			status |= PB_VOLTAGE_UV_WARNING;
209		if (ret & VMON_OV_WARNING)
210			status |= PB_VOLTAGE_OV_WARNING;
211		if (ret & VMON_UV_FAULT)
212			status |= PB_VOLTAGE_UV_FAULT;
213		if (ret & VMON_OV_FAULT)
214			status |= PB_VOLTAGE_OV_FAULT;
215		ret = status;
216		break;
217	default:
218		ret = pmbus_read_byte_data(client, page, reg);
219		break;
220	}
221	data->access = ktime_get();
222
223	return ret;
224}
225
226static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
227				  u16 word)
228{
229	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
230	struct zl6100_data *data = to_zl6100_data(info);
231	int ret, vreg;
232
233	if (page > 0)
234		return -ENXIO;
235
236	switch (reg) {
237	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
238		word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
239		vreg = MFR_VMON_OV_FAULT_LIMIT;
240		pmbus_clear_cache(client);
241		break;
242	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
243		vreg = MFR_VMON_OV_FAULT_LIMIT;
244		pmbus_clear_cache(client);
245		break;
246	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
247		word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
248		vreg = MFR_VMON_UV_FAULT_LIMIT;
249		pmbus_clear_cache(client);
250		break;
251	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
252		vreg = MFR_VMON_UV_FAULT_LIMIT;
253		pmbus_clear_cache(client);
254		break;
255	default:
256		if (reg >= PMBUS_VIRT_BASE)
257			return -ENXIO;
258		vreg = reg;
259	}
260
261	zl6100_wait(data);
262	ret = pmbus_write_word_data(client, page, vreg, word);
263	data->access = ktime_get();
264
265	return ret;
266}
267
268static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
269{
270	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
271	struct zl6100_data *data = to_zl6100_data(info);
272	int ret;
273
274	if (page > 0)
275		return -ENXIO;
276
277	zl6100_wait(data);
278	ret = pmbus_write_byte(client, page, value);
279	data->access = ktime_get();
280
281	return ret;
282}
283
284static const struct i2c_device_id zl6100_id[] = {
285	{"bmr450", zl2005},
286	{"bmr451", zl2005},
287	{"bmr462", zl2008},
288	{"bmr463", zl2008},
289	{"bmr464", zl2008},
290	{"zl2004", zl2004},
291	{"zl2005", zl2005},
292	{"zl2006", zl2006},
293	{"zl2008", zl2008},
294	{"zl2105", zl2105},
295	{"zl2106", zl2106},
296	{"zl6100", zl6100},
297	{"zl6105", zl6105},
298	{"zl9101", zl9101},
299	{"zl9117", zl9117},
300	{ }
301};
302MODULE_DEVICE_TABLE(i2c, zl6100_id);
303
304static int zl6100_probe(struct i2c_client *client)
305{
306	int ret;
307	struct zl6100_data *data;
308	struct pmbus_driver_info *info;
309	u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
310	const struct i2c_device_id *mid;
311
312	if (!i2c_check_functionality(client->adapter,
313				     I2C_FUNC_SMBUS_READ_WORD_DATA
314				     | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
315		return -ENODEV;
316
317	ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
318					device_id);
319	if (ret < 0) {
320		dev_err(&client->dev, "Failed to read device ID\n");
321		return ret;
322	}
323	device_id[ret] = '\0';
324	dev_info(&client->dev, "Device ID %s\n", device_id);
325
326	mid = NULL;
327	for (mid = zl6100_id; mid->name[0]; mid++) {
328		if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
329			break;
330	}
331	if (!mid->name[0]) {
332		dev_err(&client->dev, "Unsupported device\n");
333		return -ENODEV;
334	}
335	if (strcmp(client->name, mid->name) != 0)
336		dev_notice(&client->dev,
337			   "Device mismatch: Configured %s, detected %s\n",
338			   client->name, mid->name);
339
340	data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
341			    GFP_KERNEL);
342	if (!data)
343		return -ENOMEM;
344
345	data->id = mid->driver_data;
346
347	/*
348	 * According to information from the chip vendor, all currently
349	 * supported chips are known to require a wait time between I2C
350	 * accesses.
351	 */
352	data->delay = delay;
353
354	/*
355	 * Since there was a direct I2C device access above, wait before
356	 * accessing the chip again.
357	 */
358	data->access = ktime_get();
359	zl6100_wait(data);
360
361	info = &data->info;
362
363	info->pages = 1;
364	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
365	  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
366	  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
367	  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
368
369	/*
370	 * ZL2004, ZL9101M, and ZL9117M support monitoring an extra voltage
371	 * (VMON for ZL2004, VDRV for ZL9101M and ZL9117M). Report it as vmon.
372	 */
373	if (data->id == zl2004 || data->id == zl9101 || data->id == zl9117)
374		info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;
375
376	ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
377	if (ret < 0)
378		return ret;
379
380	if (ret & ZL6100_MFR_XTEMP_ENABLE)
381		info->func[0] |= PMBUS_HAVE_TEMP2;
382
383	data->access = ktime_get();
384	zl6100_wait(data);
385
386	info->read_word_data = zl6100_read_word_data;
387	info->read_byte_data = zl6100_read_byte_data;
388	info->write_word_data = zl6100_write_word_data;
389	info->write_byte = zl6100_write_byte;
390
391	return pmbus_do_probe(client, info);
392}
393
394static struct i2c_driver zl6100_driver = {
395	.driver = {
396		   .name = "zl6100",
397		   },
398	.probe_new = zl6100_probe,
399	.remove = pmbus_do_remove,
400	.id_table = zl6100_id,
401};
402
403module_i2c_driver(zl6100_driver);
404
405MODULE_AUTHOR("Guenter Roeck");
406MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
407MODULE_LICENSE("GPL");
408