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Diffstat (limited to 'drivers/hwmon/pmbus/ltc2978.c')
-rw-r--r--drivers/hwmon/pmbus/ltc2978.c408
1 files changed, 408 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
new file mode 100644
index 000000000000..820fff48910b
--- /dev/null
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -0,0 +1,408 @@
1/*
2 * Hardware monitoring driver for LTC2978 and LTC3880
3 *
4 * Copyright (c) 2011 Ericsson AB.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/i2c.h>
27#include "pmbus.h"
28
29enum chips { ltc2978, ltc3880 };
30
31/* LTC2978 and LTC3880 */
32#define LTC2978_MFR_VOUT_PEAK 0xdd
33#define LTC2978_MFR_VIN_PEAK 0xde
34#define LTC2978_MFR_TEMPERATURE_PEAK 0xdf
35#define LTC2978_MFR_SPECIAL_ID 0xe7
36
37/* LTC2978 only */
38#define LTC2978_MFR_VOUT_MIN 0xfb
39#define LTC2978_MFR_VIN_MIN 0xfc
40#define LTC2978_MFR_TEMPERATURE_MIN 0xfd
41
42/* LTC3880 only */
43#define LTC3880_MFR_IOUT_PEAK 0xd7
44#define LTC3880_MFR_CLEAR_PEAKS 0xe3
45#define LTC3880_MFR_TEMPERATURE2_PEAK 0xf4
46
47#define LTC2978_ID_REV1 0x0121
48#define LTC2978_ID_REV2 0x0122
49#define LTC3880_ID 0x4000
50#define LTC3880_ID_MASK 0xff00
51
52/*
53 * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
54 * happens pretty much each time chip data is updated. Raw peak data therefore
55 * does not provide much value. To be able to provide useful peak data, keep an
56 * internal cache of measured peak data, which is only cleared if an explicit
57 * "clear peak" command is executed for the sensor in question.
58 */
59struct ltc2978_data {
60 enum chips id;
61 int vin_min, vin_max;
62 int temp_min, temp_max;
63 int vout_min[8], vout_max[8];
64 int iout_max[2];
65 int temp2_max[2];
66 struct pmbus_driver_info info;
67};
68
69#define to_ltc2978_data(x) container_of(x, struct ltc2978_data, info)
70
71static inline int lin11_to_val(int data)
72{
73 s16 e = ((s16)data) >> 11;
74 s32 m = (((s16)(data << 5)) >> 5);
75
76 /*
77 * mantissa is 10 bit + sign, exponent adds up to 15 bit.
78 * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
79 */
80 e += 6;
81 return (e < 0 ? m >> -e : m << e);
82}
83
84static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
85 int reg)
86{
87 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
88 struct ltc2978_data *data = to_ltc2978_data(info);
89 int ret;
90
91 switch (reg) {
92 case PMBUS_VIRT_READ_VIN_MAX:
93 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_PEAK);
94 if (ret >= 0) {
95 if (lin11_to_val(ret) > lin11_to_val(data->vin_max))
96 data->vin_max = ret;
97 ret = data->vin_max;
98 }
99 break;
100 case PMBUS_VIRT_READ_VOUT_MAX:
101 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK);
102 if (ret >= 0) {
103 /*
104 * VOUT is 16 bit unsigned with fixed exponent,
105 * so we can compare it directly
106 */
107 if (ret > data->vout_max[page])
108 data->vout_max[page] = ret;
109 ret = data->vout_max[page];
110 }
111 break;
112 case PMBUS_VIRT_READ_TEMP_MAX:
113 ret = pmbus_read_word_data(client, page,
114 LTC2978_MFR_TEMPERATURE_PEAK);
115 if (ret >= 0) {
116 if (lin11_to_val(ret) > lin11_to_val(data->temp_max))
117 data->temp_max = ret;
118 ret = data->temp_max;
119 }
120 break;
121 case PMBUS_VIRT_RESET_VOUT_HISTORY:
122 case PMBUS_VIRT_RESET_VIN_HISTORY:
123 case PMBUS_VIRT_RESET_TEMP_HISTORY:
124 ret = 0;
125 break;
126 default:
127 ret = -ENODATA;
128 break;
129 }
130 return ret;
131}
132
133static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
134{
135 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
136 struct ltc2978_data *data = to_ltc2978_data(info);
137 int ret;
138
139 switch (reg) {
140 case PMBUS_VIRT_READ_VIN_MIN:
141 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN);
142 if (ret >= 0) {
143 if (lin11_to_val(ret) < lin11_to_val(data->vin_min))
144 data->vin_min = ret;
145 ret = data->vin_min;
146 }
147 break;
148 case PMBUS_VIRT_READ_VOUT_MIN:
149 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
150 if (ret >= 0) {
151 /*
152 * VOUT_MIN is known to not be supported on some lots
153 * of LTC2978 revision 1, and will return the maximum
154 * possible voltage if read. If VOUT_MAX is valid and
155 * lower than the reading of VOUT_MIN, use it instead.
156 */
157 if (data->vout_max[page] && ret > data->vout_max[page])
158 ret = data->vout_max[page];
159 if (ret < data->vout_min[page])
160 data->vout_min[page] = ret;
161 ret = data->vout_min[page];
162 }
163 break;
164 case PMBUS_VIRT_READ_TEMP_MIN:
165 ret = pmbus_read_word_data(client, page,
166 LTC2978_MFR_TEMPERATURE_MIN);
167 if (ret >= 0) {
168 if (lin11_to_val(ret)
169 < lin11_to_val(data->temp_min))
170 data->temp_min = ret;
171 ret = data->temp_min;
172 }
173 break;
174 case PMBUS_VIRT_READ_IOUT_MAX:
175 case PMBUS_VIRT_RESET_IOUT_HISTORY:
176 case PMBUS_VIRT_READ_TEMP2_MAX:
177 case PMBUS_VIRT_RESET_TEMP2_HISTORY:
178 ret = -ENXIO;
179 break;
180 default:
181 ret = ltc2978_read_word_data_common(client, page, reg);
182 break;
183 }
184 return ret;
185}
186
187static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
188{
189 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
190 struct ltc2978_data *data = to_ltc2978_data(info);
191 int ret;
192
193 switch (reg) {
194 case PMBUS_VIRT_READ_IOUT_MAX:
195 ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK);
196 if (ret >= 0) {
197 if (lin11_to_val(ret)
198 > lin11_to_val(data->iout_max[page]))
199 data->iout_max[page] = ret;
200 ret = data->iout_max[page];
201 }
202 break;
203 case PMBUS_VIRT_READ_TEMP2_MAX:
204 ret = pmbus_read_word_data(client, page,
205 LTC3880_MFR_TEMPERATURE2_PEAK);
206 if (ret >= 0) {
207 if (lin11_to_val(ret)
208 > lin11_to_val(data->temp2_max[page]))
209 data->temp2_max[page] = ret;
210 ret = data->temp2_max[page];
211 }
212 break;
213 case PMBUS_VIRT_READ_VIN_MIN:
214 case PMBUS_VIRT_READ_VOUT_MIN:
215 case PMBUS_VIRT_READ_TEMP_MIN:
216 ret = -ENXIO;
217 break;
218 case PMBUS_VIRT_RESET_IOUT_HISTORY:
219 case PMBUS_VIRT_RESET_TEMP2_HISTORY:
220 ret = 0;
221 break;
222 default:
223 ret = ltc2978_read_word_data_common(client, page, reg);
224 break;
225 }
226 return ret;
227}
228
229static int ltc2978_clear_peaks(struct i2c_client *client, int page,
230 enum chips id)
231{
232 int ret;
233
234 if (id == ltc2978)
235 ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
236 else
237 ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
238
239 return ret;
240}
241
242static int ltc2978_write_word_data(struct i2c_client *client, int page,
243 int reg, u16 word)
244{
245 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
246 struct ltc2978_data *data = to_ltc2978_data(info);
247 int ret;
248
249 switch (reg) {
250 case PMBUS_VIRT_RESET_IOUT_HISTORY:
251 data->iout_max[page] = 0x7fff;
252 ret = ltc2978_clear_peaks(client, page, data->id);
253 break;
254 case PMBUS_VIRT_RESET_TEMP2_HISTORY:
255 data->temp2_max[page] = 0x7fff;
256 ret = ltc2978_clear_peaks(client, page, data->id);
257 break;
258 case PMBUS_VIRT_RESET_VOUT_HISTORY:
259 data->vout_min[page] = 0xffff;
260 data->vout_max[page] = 0;
261 ret = ltc2978_clear_peaks(client, page, data->id);
262 break;
263 case PMBUS_VIRT_RESET_VIN_HISTORY:
264 data->vin_min = 0x7bff;
265 data->vin_max = 0;
266 ret = ltc2978_clear_peaks(client, page, data->id);
267 break;
268 case PMBUS_VIRT_RESET_TEMP_HISTORY:
269 data->temp_min = 0x7bff;
270 data->temp_max = 0x7fff;
271 ret = ltc2978_clear_peaks(client, page, data->id);
272 break;
273 default:
274 ret = -ENODATA;
275 break;
276 }
277 return ret;
278}
279
280static const struct i2c_device_id ltc2978_id[] = {
281 {"ltc2978", ltc2978},
282 {"ltc3880", ltc3880},
283 {}
284};
285MODULE_DEVICE_TABLE(i2c, ltc2978_id);
286
287static int ltc2978_probe(struct i2c_client *client,
288 const struct i2c_device_id *id)
289{
290 int chip_id, ret, i;
291 struct ltc2978_data *data;
292 struct pmbus_driver_info *info;
293
294 if (!i2c_check_functionality(client->adapter,
295 I2C_FUNC_SMBUS_READ_WORD_DATA))
296 return -ENODEV;
297
298 data = kzalloc(sizeof(struct ltc2978_data), GFP_KERNEL);
299 if (!data)
300 return -ENOMEM;
301
302 chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
303 if (chip_id < 0) {
304 ret = chip_id;
305 goto err_mem;
306 }
307
308 if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2) {
309 data->id = ltc2978;
310 } else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
311 data->id = ltc3880;
312 } else {
313 dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
314 ret = -ENODEV;
315 goto err_mem;
316 }
317 if (data->id != id->driver_data)
318 dev_warn(&client->dev,
319 "Device mismatch: Configured %s, detected %s\n",
320 id->name,
321 ltc2978_id[data->id].name);
322
323 info = &data->info;
324 info->write_word_data = ltc2978_write_word_data;
325
326 data->vout_min[0] = 0xffff;
327 data->vin_min = 0x7bff;
328 data->temp_min = 0x7bff;
329 data->temp_max = 0x7fff;
330
331 switch (id->driver_data) {
332 case ltc2978:
333 info->read_word_data = ltc2978_read_word_data;
334 info->pages = 8;
335 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
336 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
337 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
338 for (i = 1; i < 8; i++) {
339 info->func[i] = PMBUS_HAVE_VOUT
340 | PMBUS_HAVE_STATUS_VOUT;
341 data->vout_min[i] = 0xffff;
342 }
343 break;
344 case ltc3880:
345 info->read_word_data = ltc3880_read_word_data;
346 info->pages = 2;
347 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
348 | PMBUS_HAVE_STATUS_INPUT
349 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
350 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
351 | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
352 | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
353 info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
354 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
355 | PMBUS_HAVE_POUT
356 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
357 data->vout_min[1] = 0xffff;
358 break;
359 default:
360 ret = -ENODEV;
361 goto err_mem;
362 }
363
364 ret = pmbus_do_probe(client, id, info);
365 if (ret)
366 goto err_mem;
367 return 0;
368
369err_mem:
370 kfree(data);
371 return ret;
372}
373
374static int ltc2978_remove(struct i2c_client *client)
375{
376 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
377 const struct ltc2978_data *data = to_ltc2978_data(info);
378
379 pmbus_do_remove(client);
380 kfree(data);
381 return 0;
382}
383
384/* This is the driver that will be inserted */
385static struct i2c_driver ltc2978_driver = {
386 .driver = {
387 .name = "ltc2978",
388 },
389 .probe = ltc2978_probe,
390 .remove = ltc2978_remove,
391 .id_table = ltc2978_id,
392};
393
394static int __init ltc2978_init(void)
395{
396 return i2c_add_driver(&ltc2978_driver);
397}
398
399static void __exit ltc2978_exit(void)
400{
401 i2c_del_driver(&ltc2978_driver);
402}
403
404MODULE_AUTHOR("Guenter Roeck");
405MODULE_DESCRIPTION("PMBus driver for LTC2978 and LTC3880");
406MODULE_LICENSE("GPL");
407module_init(ltc2978_init);
408module_exit(ltc2978_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-08 23:49:21 -0500