1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Hardware monitoring driver for Maxim MAX16508, MAX16600, MAX16601,
4 * and MAX16602.
5 *
6 * Implementation notes:
7 *
8 * This chip series supports two rails, VCORE and VSA. Telemetry information
9 * for the two rails is reported in two subsequent I2C addresses. The driver
10 * instantiates a dummy I2C client at the second I2C address to report
11 * information for the VSA rail in a single instance of the driver.
12 * Telemetry for the VSA rail is reported to the PMBus core in PMBus page 2.
13 *
14 * The chip reports input current using two separate methods. The input current
15 * reported with the standard READ_IIN command is derived from the output
16 * current. The first method is reported to the PMBus core with PMBus page 0,
17 * the second method is reported with PMBus page 1.
18 *
19 * The chip supports reading per-phase temperatures and per-phase input/output
20 * currents for VCORE. Telemetry is reported in vendor specific registers.
21 * The driver translates the vendor specific register values to PMBus standard
22 * register values and reports per-phase information in PMBus page 0.
23 *
24 * Copyright 2019, 2020 Google LLC.
25 */
26
27 #include <linux/bits.h>
28 #include <linux/i2c.h>
29 #include <linux/init.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32
33 #include "pmbus.h"
34
35 enum chips { max16508, max16600, max16601, max16602 };
36
37 #define REG_DEFAULT_NUM_POP 0xc4
38 #define REG_SETPT_DVID 0xd1
39 #define DAC_10MV_MODE BIT(4)
40 #define REG_IOUT_AVG_PK 0xee
41 #define REG_IIN_SENSOR 0xf1
42 #define REG_TOTAL_INPUT_POWER 0xf2
43 #define REG_PHASE_ID 0xf3
44 #define CORE_RAIL_INDICATOR BIT(7)
45 #define REG_PHASE_REPORTING 0xf4
46
47 #define MAX16601_NUM_PHASES 8
48
49 struct max16601_data {
50 enum chips id;
51 struct pmbus_driver_info info;
52 struct i2c_client *vsa;
53 int iout_avg_pkg;
54 };
55
56 #define to_max16601_data(x) container_of(x, struct max16601_data, info)
57
max16601_read_byte(struct i2c_client * client,int page,int reg)58 static int max16601_read_byte(struct i2c_client *client, int page, int reg)
59 {
60 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
61 struct max16601_data *data = to_max16601_data(info);
62
63 if (page > 0) {
64 if (page == 2) /* VSA */
65 return i2c_smbus_read_byte_data(data->vsa, reg);
66 return -EOPNOTSUPP;
67 }
68 return -ENODATA;
69 }
70
max16601_read_word(struct i2c_client * client,int page,int phase,int reg)71 static int max16601_read_word(struct i2c_client *client, int page, int phase,
72 int reg)
73 {
74 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
75 struct max16601_data *data = to_max16601_data(info);
76 u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
77 int ret;
78
79 switch (page) {
80 case 0: /* VCORE */
81 if (phase == 0xff)
82 return -ENODATA;
83 switch (reg) {
84 case PMBUS_READ_IIN:
85 case PMBUS_READ_IOUT:
86 case PMBUS_READ_TEMPERATURE_1:
87 ret = i2c_smbus_write_byte_data(client, REG_PHASE_ID,
88 phase);
89 if (ret)
90 return ret;
91 ret = i2c_smbus_read_block_data(client,
92 REG_PHASE_REPORTING,
93 buf);
94 if (ret < 0)
95 return ret;
96 if (ret < 6)
97 return -EIO;
98 switch (reg) {
99 case PMBUS_READ_TEMPERATURE_1:
100 return buf[1] << 8 | buf[0];
101 case PMBUS_READ_IOUT:
102 return buf[3] << 8 | buf[2];
103 case PMBUS_READ_IIN:
104 return buf[5] << 8 | buf[4];
105 default:
106 break;
107 }
108 }
109 return -EOPNOTSUPP;
110 case 1: /* VCORE, read IIN/PIN from sensor element */
111 switch (reg) {
112 case PMBUS_READ_IIN:
113 return i2c_smbus_read_word_data(client, REG_IIN_SENSOR);
114 case PMBUS_READ_PIN:
115 return i2c_smbus_read_word_data(client,
116 REG_TOTAL_INPUT_POWER);
117 default:
118 break;
119 }
120 return -EOPNOTSUPP;
121 case 2: /* VSA */
122 switch (reg) {
123 case PMBUS_VIRT_READ_IOUT_MAX:
124 ret = i2c_smbus_read_word_data(data->vsa,
125 REG_IOUT_AVG_PK);
126 if (ret < 0)
127 return ret;
128 if (sign_extend32(ret, 10) >
129 sign_extend32(data->iout_avg_pkg, 10))
130 data->iout_avg_pkg = ret;
131 return data->iout_avg_pkg;
132 case PMBUS_VIRT_RESET_IOUT_HISTORY:
133 return 0;
134 case PMBUS_IOUT_OC_FAULT_LIMIT:
135 case PMBUS_IOUT_OC_WARN_LIMIT:
136 case PMBUS_OT_FAULT_LIMIT:
137 case PMBUS_OT_WARN_LIMIT:
138 case PMBUS_READ_IIN:
139 case PMBUS_READ_IOUT:
140 case PMBUS_READ_TEMPERATURE_1:
141 case PMBUS_STATUS_WORD:
142 return i2c_smbus_read_word_data(data->vsa, reg);
143 default:
144 return -EOPNOTSUPP;
145 }
146 default:
147 return -EOPNOTSUPP;
148 }
149 }
150
max16601_write_byte(struct i2c_client * client,int page,u8 reg)151 static int max16601_write_byte(struct i2c_client *client, int page, u8 reg)
152 {
153 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
154 struct max16601_data *data = to_max16601_data(info);
155
156 if (page == 2) {
157 if (reg == PMBUS_CLEAR_FAULTS)
158 return i2c_smbus_write_byte(data->vsa, reg);
159 return -EOPNOTSUPP;
160 }
161 return -ENODATA;
162 }
163
max16601_write_word(struct i2c_client * client,int page,int reg,u16 value)164 static int max16601_write_word(struct i2c_client *client, int page, int reg,
165 u16 value)
166 {
167 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
168 struct max16601_data *data = to_max16601_data(info);
169
170 switch (page) {
171 case 0: /* VCORE */
172 return -ENODATA;
173 case 1: /* VCORE IIN/PIN from sensor element */
174 default:
175 return -EOPNOTSUPP;
176 case 2: /* VSA */
177 switch (reg) {
178 case PMBUS_VIRT_RESET_IOUT_HISTORY:
179 data->iout_avg_pkg = 0xfc00;
180 return 0;
181 case PMBUS_IOUT_OC_FAULT_LIMIT:
182 case PMBUS_IOUT_OC_WARN_LIMIT:
183 case PMBUS_OT_FAULT_LIMIT:
184 case PMBUS_OT_WARN_LIMIT:
185 return i2c_smbus_write_word_data(data->vsa, reg, value);
186 default:
187 return -EOPNOTSUPP;
188 }
189 }
190 }
191
max16601_identify(struct i2c_client * client,struct pmbus_driver_info * info)192 static int max16601_identify(struct i2c_client *client,
193 struct pmbus_driver_info *info)
194 {
195 struct max16601_data *data = to_max16601_data(info);
196 int reg;
197
198 reg = i2c_smbus_read_byte_data(client, REG_SETPT_DVID);
199 if (reg < 0)
200 return reg;
201 if (reg & DAC_10MV_MODE)
202 info->vrm_version[0] = vr13;
203 else
204 info->vrm_version[0] = vr12;
205
206 if (data->id != max16600 && data->id != max16601 && data->id != max16602)
207 return 0;
208
209 reg = i2c_smbus_read_byte_data(client, REG_DEFAULT_NUM_POP);
210 if (reg < 0)
211 return reg;
212
213 /*
214 * If REG_DEFAULT_NUM_POP returns 0, we don't know how many phases
215 * are populated. Stick with the default in that case.
216 */
217 reg &= 0x0f;
218 if (reg && reg <= MAX16601_NUM_PHASES)
219 info->phases[0] = reg;
220
221 return 0;
222 }
223
224 static struct pmbus_driver_info max16601_info = {
225 .pages = 3,
226 .format[PSC_VOLTAGE_IN] = linear,
227 .format[PSC_VOLTAGE_OUT] = vid,
228 .format[PSC_CURRENT_IN] = linear,
229 .format[PSC_CURRENT_OUT] = linear,
230 .format[PSC_TEMPERATURE] = linear,
231 .format[PSC_POWER] = linear,
232 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
233 PMBUS_HAVE_STATUS_INPUT |
234 PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
235 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
236 PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
237 PMBUS_HAVE_POUT | PMBUS_PAGE_VIRTUAL | PMBUS_PHASE_VIRTUAL,
238 .func[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_PAGE_VIRTUAL,
239 .func[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT |
240 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
241 PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_PAGE_VIRTUAL,
242 .phases[0] = MAX16601_NUM_PHASES,
243 .pfunc[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
244 .pfunc[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
245 .pfunc[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
246 .pfunc[3] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
247 .pfunc[4] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
248 .pfunc[5] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
249 .pfunc[6] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
250 .pfunc[7] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
251 .identify = max16601_identify,
252 .read_byte_data = max16601_read_byte,
253 .read_word_data = max16601_read_word,
254 .write_byte = max16601_write_byte,
255 .write_word_data = max16601_write_word,
256 };
257
max16601_remove(void * _data)258 static void max16601_remove(void *_data)
259 {
260 struct max16601_data *data = _data;
261
262 i2c_unregister_device(data->vsa);
263 }
264
265 static const struct i2c_device_id max16601_id[] = {
266 {"max16508", max16508},
267 {"max16600", max16600},
268 {"max16601", max16601},
269 {"max16602", max16602},
270 {}
271 };
272 MODULE_DEVICE_TABLE(i2c, max16601_id);
273
max16601_get_id(struct i2c_client * client)274 static int max16601_get_id(struct i2c_client *client)
275 {
276 struct device *dev = &client->dev;
277 u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
278 enum chips id;
279 int ret;
280
281 ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
282 if (ret < 0 || ret < 11)
283 return -ENODEV;
284
285 /*
286 * PMBUS_IC_DEVICE_ID is expected to return MAX1660[012]y.xx",
287 * "MAX16500y.xx".cdxxcccccccccc, or "MAX16508y.xx".
288 */
289 if (!strncmp(buf, "MAX16500", 8) || !strncmp(buf, "MAX16508", 8)) {
290 id = max16508;
291 } else if (!strncmp(buf, "MAX16600", 8)) {
292 id = max16600;
293 } else if (!strncmp(buf, "MAX16601", 8)) {
294 id = max16601;
295 } else if (!strncmp(buf, "MAX16602", 8)) {
296 id = max16602;
297 } else {
298 buf[ret] = '\0';
299 dev_err(dev, "Unsupported chip '%s'\n", buf);
300 return -ENODEV;
301 }
302 return id;
303 }
304
max16601_probe(struct i2c_client * client)305 static int max16601_probe(struct i2c_client *client)
306 {
307 struct device *dev = &client->dev;
308 const struct i2c_device_id *id;
309 struct max16601_data *data;
310 int ret, chip_id;
311
312 if (!i2c_check_functionality(client->adapter,
313 I2C_FUNC_SMBUS_READ_BYTE_DATA |
314 I2C_FUNC_SMBUS_READ_BLOCK_DATA))
315 return -ENODEV;
316
317 chip_id = max16601_get_id(client);
318 if (chip_id < 0)
319 return chip_id;
320
321 id = i2c_match_id(max16601_id, client);
322 if (chip_id != id->driver_data)
323 dev_warn(&client->dev,
324 "Device mismatch: Configured %s (%d), detected %d\n",
325 id->name, (int) id->driver_data, chip_id);
326
327 ret = i2c_smbus_read_byte_data(client, REG_PHASE_ID);
328 if (ret < 0)
329 return ret;
330 if (!(ret & CORE_RAIL_INDICATOR)) {
331 dev_err(dev,
332 "Driver must be instantiated on CORE rail I2C address\n");
333 return -ENODEV;
334 }
335
336 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
337 if (!data)
338 return -ENOMEM;
339
340 data->id = chip_id;
341 data->iout_avg_pkg = 0xfc00;
342 data->vsa = i2c_new_dummy_device(client->adapter, client->addr + 1);
343 if (IS_ERR(data->vsa)) {
344 dev_err(dev, "Failed to register VSA client\n");
345 return PTR_ERR(data->vsa);
346 }
347 ret = devm_add_action_or_reset(dev, max16601_remove, data);
348 if (ret)
349 return ret;
350
351 data->info = max16601_info;
352
353 return pmbus_do_probe(client, &data->info);
354 }
355
356 static struct i2c_driver max16601_driver = {
357 .driver = {
358 .name = "max16601",
359 },
360 .probe = max16601_probe,
361 .id_table = max16601_id,
362 };
363
364 module_i2c_driver(max16601_driver);
365
366 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
367 MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601");
368 MODULE_LICENSE("GPL v2");
369 MODULE_IMPORT_NS("PMBUS");
370