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 zl9101, zl9117 };
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 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
48 static ushort delay = ZL6100_WAIT_TIME;
49 module_param(delay, ushort, 0644);
50 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
51
52 /* Convert linear sensor value to milli-units */
zl6100_l2d(s16 l)53 static 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
zl6100_d2l(long val)78 static 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 */
zl6100_wait(const struct zl6100_data * data)119 static 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
zl6100_read_word_data(struct i2c_client * client,int page,int phase,int reg)128 static 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
zl6100_read_byte_data(struct i2c_client * client,int page,int reg)188 static 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
zl6100_write_word_data(struct i2c_client * client,int page,int reg,u16 word)226 static 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
zl6100_write_byte(struct i2c_client * client,int page,u8 value)268 static 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
284 static 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 };
302 MODULE_DEVICE_TABLE(i2c, zl6100_id);
303
zl6100_probe(struct i2c_client * client)304 static 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
394 static 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
403 module_i2c_driver(zl6100_driver);
404
405 MODULE_AUTHOR("Guenter Roeck");
406 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
407 MODULE_LICENSE("GPL");
408
