1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * isl28022.c - driver for Renesas ISL28022 power monitor chip monitoring
4 *
5 * Copyright (c) 2023 Carsten Spieß <mail@carsten-spiess.de>
6 */
7
8 #include <linux/debugfs.h>
9 #include <linux/err.h>
10 #include <linux/hwmon.h>
11 #include <linux/i2c.h>
12 #include <linux/module.h>
13 #include <linux/regmap.h>
14
15 /* ISL28022 registers */
16 #define ISL28022_REG_CONFIG 0x00
17 #define ISL28022_REG_SHUNT 0x01
18 #define ISL28022_REG_BUS 0x02
19 #define ISL28022_REG_POWER 0x03
20 #define ISL28022_REG_CURRENT 0x04
21 #define ISL28022_REG_CALIB 0x05
22 #define ISL28022_REG_SHUNT_THR 0x06
23 #define ISL28022_REG_BUS_THR 0x07
24 #define ISL28022_REG_INT 0x08
25 #define ISL28022_REG_AUX 0x09
26 #define ISL28022_REG_MAX ISL28022_REG_AUX
27
28 /* ISL28022 config flags */
29 /* mode flags */
30 #define ISL28022_MODE_SHIFT 0
31 #define ISL28022_MODE_MASK 0x0007
32
33 #define ISL28022_MODE_PWR_DOWN 0x0
34 #define ISL28022_MODE_TRG_S 0x1
35 #define ISL28022_MODE_TRG_B 0x2
36 #define ISL28022_MODE_TRG_SB 0x3
37 #define ISL28022_MODE_ADC_OFF 0x4
38 #define ISL28022_MODE_CONT_S 0x5
39 #define ISL28022_MODE_CONT_B 0x6
40 #define ISL28022_MODE_CONT_SB 0x7
41
42 /* shunt ADC settings */
43 #define ISL28022_SADC_SHIFT 3
44 #define ISL28022_SADC_MASK 0x0078
45
46 #define ISL28022_BADC_SHIFT 7
47 #define ISL28022_BADC_MASK 0x0780
48
49 #define ISL28022_ADC_12 0x0 /* 12 bit ADC */
50 #define ISL28022_ADC_13 0x1 /* 13 bit ADC */
51 #define ISL28022_ADC_14 0x2 /* 14 bit ADC */
52 #define ISL28022_ADC_15 0x3 /* 15 bit ADC */
53 #define ISL28022_ADC_15_1 0x8 /* 15 bit ADC, 1 sample */
54 #define ISL28022_ADC_15_2 0x9 /* 15 bit ADC, 2 samples */
55 #define ISL28022_ADC_15_4 0xA /* 15 bit ADC, 4 samples */
56 #define ISL28022_ADC_15_8 0xB /* 15 bit ADC, 8 samples */
57 #define ISL28022_ADC_15_16 0xC /* 15 bit ADC, 16 samples */
58 #define ISL28022_ADC_15_32 0xD /* 15 bit ADC, 32 samples */
59 #define ISL28022_ADC_15_64 0xE /* 15 bit ADC, 64 samples */
60 #define ISL28022_ADC_15_128 0xF /* 15 bit ADC, 128 samples */
61
62 /* shunt voltage range */
63 #define ISL28022_PG_SHIFT 11
64 #define ISL28022_PG_MASK 0x1800
65
66 #define ISL28022_PG_40 0x0 /* +/-40 mV */
67 #define ISL28022_PG_80 0x1 /* +/-80 mV */
68 #define ISL28022_PG_160 0x2 /* +/-160 mV */
69 #define ISL28022_PG_320 0x3 /* +/-3200 mV */
70
71 /* bus voltage range */
72 #define ISL28022_BRNG_SHIFT 13
73 #define ISL28022_BRNG_MASK 0x6000
74
75 #define ISL28022_BRNG_16 0x0 /* 16 V */
76 #define ISL28022_BRNG_32 0x1 /* 32 V */
77 #define ISL28022_BRNG_60 0x3 /* 60 V */
78
79 /* reset */
80 #define ISL28022_RESET 0x8000
81
82 struct isl28022_data {
83 struct regmap *regmap;
84 u32 shunt;
85 u32 gain;
86 u32 average;
87 };
88
isl28022_read_in(struct device * dev,u32 attr,int channel,long * val)89 static int isl28022_read_in(struct device *dev, u32 attr, int channel, long *val)
90 {
91 struct isl28022_data *data = dev_get_drvdata(dev);
92 unsigned int regval;
93 int err;
94 u16 sign_bit;
95
96 switch (channel) {
97 case 0:
98 switch (attr) {
99 case hwmon_in_input:
100 err = regmap_read(data->regmap,
101 ISL28022_REG_BUS, ®val);
102 if (err < 0)
103 return err;
104 /* driver supports only 60V mode (BRNG 11) */
105 *val = (long)(((u16)regval) & 0xFFFC);
106 break;
107 default:
108 return -EOPNOTSUPP;
109 }
110 break;
111 case 1:
112 switch (attr) {
113 case hwmon_in_input:
114 err = regmap_read(data->regmap,
115 ISL28022_REG_SHUNT, ®val);
116 if (err < 0)
117 return err;
118 switch (data->gain) {
119 case 8:
120 sign_bit = (regval >> 15) & 0x01;
121 *val = (long)((((u16)regval) & 0x7FFF) -
122 (sign_bit * 32768)) / 100;
123 break;
124 case 4:
125 sign_bit = (regval >> 14) & 0x01;
126 *val = (long)((((u16)regval) & 0x3FFF) -
127 (sign_bit * 16384)) / 100;
128 break;
129 case 2:
130 sign_bit = (regval >> 13) & 0x01;
131 *val = (long)((((u16)regval) & 0x1FFF) -
132 (sign_bit * 8192)) / 100;
133 break;
134 case 1:
135 sign_bit = (regval >> 12) & 0x01;
136 *val = (long)((((u16)regval) & 0x0FFF) -
137 (sign_bit * 4096)) / 100;
138 break;
139 }
140 break;
141 default:
142 return -EOPNOTSUPP;
143 }
144 break;
145 default:
146 return -EOPNOTSUPP;
147 }
148
149 return 0;
150 }
151
isl28022_read_current(struct device * dev,u32 attr,long * val)152 static int isl28022_read_current(struct device *dev, u32 attr, long *val)
153 {
154 struct isl28022_data *data = dev_get_drvdata(dev);
155 unsigned int regval;
156 int err;
157
158 switch (attr) {
159 case hwmon_curr_input:
160 err = regmap_read(data->regmap,
161 ISL28022_REG_CURRENT, ®val);
162 if (err < 0)
163 return err;
164 *val = ((long)regval * 1250L * (long)data->gain) /
165 (long)data->shunt;
166 break;
167 default:
168 return -EOPNOTSUPP;
169 }
170
171 return 0;
172 }
173
isl28022_read_power(struct device * dev,u32 attr,long * val)174 static int isl28022_read_power(struct device *dev, u32 attr, long *val)
175 {
176 struct isl28022_data *data = dev_get_drvdata(dev);
177 unsigned int regval;
178 int err;
179
180 switch (attr) {
181 case hwmon_power_input:
182 err = regmap_read(data->regmap,
183 ISL28022_REG_POWER, ®val);
184 if (err < 0)
185 return err;
186 *val = ((51200000L * ((long)data->gain)) /
187 (long)data->shunt) * (long)regval;
188 break;
189 default:
190 return -EOPNOTSUPP;
191 }
192
193 return 0;
194 }
195
isl28022_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)196 static int isl28022_read(struct device *dev, enum hwmon_sensor_types type,
197 u32 attr, int channel, long *val)
198 {
199 switch (type) {
200 case hwmon_in:
201 return isl28022_read_in(dev, attr, channel, val);
202 case hwmon_curr:
203 return isl28022_read_current(dev, attr, val);
204 case hwmon_power:
205 return isl28022_read_power(dev, attr, val);
206 default:
207 return -EOPNOTSUPP;
208 }
209 return 0;
210 }
211
isl28022_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)212 static umode_t isl28022_is_visible(const void *data, enum hwmon_sensor_types type,
213 u32 attr, int channel)
214 {
215 switch (type) {
216 case hwmon_in:
217 switch (attr) {
218 case hwmon_in_input:
219 return 0444;
220 default:
221 break;
222 }
223 break;
224 case hwmon_curr:
225 switch (attr) {
226 case hwmon_curr_input:
227 return 0444;
228 default:
229 break;
230 }
231 break;
232 case hwmon_power:
233 switch (attr) {
234 case hwmon_power_input:
235 return 0444;
236 default:
237 break;
238 }
239 break;
240 default:
241 break;
242 }
243 return 0;
244 }
245
246 static const struct hwmon_channel_info *isl28022_info[] = {
247 HWMON_CHANNEL_INFO(in,
248 HWMON_I_INPUT, /* channel 0: bus voltage (mV) */
249 HWMON_I_INPUT), /* channel 1: shunt voltage (mV) */
250 HWMON_CHANNEL_INFO(curr,
251 HWMON_C_INPUT), /* channel 1: current (mA) */
252 HWMON_CHANNEL_INFO(power,
253 HWMON_P_INPUT), /* channel 1: power (µW) */
254 NULL
255 };
256
257 static const struct hwmon_ops isl28022_hwmon_ops = {
258 .is_visible = isl28022_is_visible,
259 .read = isl28022_read,
260 };
261
262 static const struct hwmon_chip_info isl28022_chip_info = {
263 .ops = &isl28022_hwmon_ops,
264 .info = isl28022_info,
265 };
266
isl28022_is_writeable_reg(struct device * dev,unsigned int reg)267 static bool isl28022_is_writeable_reg(struct device *dev, unsigned int reg)
268 {
269 switch (reg) {
270 case ISL28022_REG_CONFIG:
271 case ISL28022_REG_CALIB:
272 case ISL28022_REG_SHUNT_THR:
273 case ISL28022_REG_BUS_THR:
274 case ISL28022_REG_INT:
275 case ISL28022_REG_AUX:
276 return true;
277 }
278
279 return false;
280 }
281
isl28022_is_volatile_reg(struct device * dev,unsigned int reg)282 static bool isl28022_is_volatile_reg(struct device *dev, unsigned int reg)
283 {
284 switch (reg) {
285 case ISL28022_REG_CONFIG:
286 case ISL28022_REG_SHUNT:
287 case ISL28022_REG_BUS:
288 case ISL28022_REG_POWER:
289 case ISL28022_REG_CURRENT:
290 case ISL28022_REG_INT:
291 case ISL28022_REG_AUX:
292 return true;
293 }
294 return true;
295 }
296
297 static const struct regmap_config isl28022_regmap_config = {
298 .reg_bits = 8,
299 .val_bits = 16,
300 .max_register = ISL28022_REG_MAX,
301 .writeable_reg = isl28022_is_writeable_reg,
302 .volatile_reg = isl28022_is_volatile_reg,
303 .val_format_endian = REGMAP_ENDIAN_BIG,
304 .cache_type = REGCACHE_RBTREE,
305 .use_single_read = true,
306 .use_single_write = true,
307 };
308
shunt_voltage_show(struct seq_file * seqf,void * unused)309 static int shunt_voltage_show(struct seq_file *seqf, void *unused)
310 {
311 struct isl28022_data *data = seqf->private;
312 unsigned int regval;
313 int err;
314
315 err = regmap_read(data->regmap,
316 ISL28022_REG_SHUNT, ®val);
317 if (err)
318 return err;
319
320 /* print shunt voltage in micro volt */
321 seq_printf(seqf, "%d\n", regval * 10);
322
323 return 0;
324 }
325 DEFINE_SHOW_ATTRIBUTE(shunt_voltage);
326
327 /*
328 * read property values and make consistency checks.
329 *
330 * following values for shunt range and resistor are allowed:
331 * 40 mV -> gain 1, shunt min. 800 micro ohms
332 * 80 mV -> gain 2, shunt min. 1600 micro ohms
333 * 160 mV -> gain 4, shunt min. 3200 micro ohms
334 * 320 mV -> gain 8, shunt min. 6400 micro ohms
335 */
isl28022_read_properties(struct device * dev,struct isl28022_data * data)336 static int isl28022_read_properties(struct device *dev, struct isl28022_data *data)
337 {
338 u32 val;
339 int err;
340
341 err = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
342 if (err == -EINVAL)
343 val = 10000;
344 else if (err < 0)
345 return err;
346 data->shunt = val;
347
348 err = device_property_read_u32(dev, "renesas,shunt-range-microvolt", &val);
349 if (err == -EINVAL)
350 val = 320000;
351 else if (err < 0)
352 return err;
353
354 switch (val) {
355 case 40000:
356 data->gain = 1;
357 if (data->shunt < 800)
358 goto shunt_invalid;
359 break;
360 case 80000:
361 data->gain = 2;
362 if (data->shunt < 1600)
363 goto shunt_invalid;
364 break;
365 case 160000:
366 data->gain = 4;
367 if (data->shunt < 3200)
368 goto shunt_invalid;
369 break;
370 case 320000:
371 data->gain = 8;
372 if (data->shunt < 6400)
373 goto shunt_invalid;
374 break;
375 default:
376 return dev_err_probe(dev, -EINVAL,
377 "renesas,shunt-range-microvolt invalid value %d\n",
378 val);
379 }
380
381 err = device_property_read_u32(dev, "renesas,average-samples", &val);
382 if (err == -EINVAL)
383 val = 1;
384 else if (err < 0)
385 return err;
386 if (val > 128 || hweight32(val) != 1)
387 return dev_err_probe(dev, -EINVAL,
388 "renesas,average-samples invalid value %d\n",
389 val);
390
391 data->average = val;
392
393 return 0;
394
395 shunt_invalid:
396 return dev_err_probe(dev, -EINVAL,
397 "renesas,shunt-resistor-microvolt invalid value %d\n",
398 data->shunt);
399 }
400
401 /*
402 * write configuration and calibration registers
403 *
404 * The driver supports only shunt and bus continuous ADC mode at 15bit resolution
405 * with averaging from 1 to 128 samples (pow of 2) on both channels.
406 * Shunt voltage gain 1,2,4 or 8 is allowed.
407 * The bus voltage range is 60V fixed.
408 */
isl28022_config(struct isl28022_data * data)409 static int isl28022_config(struct isl28022_data *data)
410 {
411 int err;
412 u16 config;
413 u16 calib;
414
415 config = (ISL28022_MODE_CONT_SB << ISL28022_MODE_SHIFT) |
416 (ISL28022_BRNG_60 << ISL28022_BRNG_SHIFT) |
417 (__ffs(data->gain) << ISL28022_PG_SHIFT) |
418 ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_SADC_SHIFT) |
419 ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_BADC_SHIFT);
420
421 calib = data->shunt ? 0x8000 / data->gain : 0;
422
423 err = regmap_write(data->regmap, ISL28022_REG_CONFIG, config);
424 if (err < 0)
425 return err;
426
427 return regmap_write(data->regmap, ISL28022_REG_CALIB, calib);
428 }
429
isl28022_probe(struct i2c_client * client)430 static int isl28022_probe(struct i2c_client *client)
431 {
432 struct device *dev = &client->dev;
433 struct device *hwmon_dev;
434 struct isl28022_data *data;
435 int err;
436
437 if (!i2c_check_functionality(client->adapter,
438 I2C_FUNC_SMBUS_BYTE_DATA |
439 I2C_FUNC_SMBUS_WORD_DATA))
440 return -ENODEV;
441
442 data = devm_kzalloc(dev, sizeof(struct isl28022_data), GFP_KERNEL);
443 if (!data)
444 return -ENOMEM;
445
446 err = isl28022_read_properties(dev, data);
447 if (err)
448 return err;
449
450 data->regmap = devm_regmap_init_i2c(client, &isl28022_regmap_config);
451 if (IS_ERR(data->regmap))
452 return PTR_ERR(data->regmap);
453
454 err = isl28022_config(data);
455 if (err)
456 return err;
457
458 debugfs_create_file("shunt_voltage", 0444, client->debugfs, data, &shunt_voltage_fops);
459
460 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
461 data, &isl28022_chip_info, NULL);
462 if (IS_ERR(hwmon_dev))
463 return PTR_ERR(hwmon_dev);
464
465 return 0;
466 }
467
468 static const struct i2c_device_id isl28022_ids[] = {
469 { "isl28022" },
470 { /* LIST END */ }
471 };
472 MODULE_DEVICE_TABLE(i2c, isl28022_ids);
473
474 static const struct of_device_id __maybe_unused isl28022_of_match[] = {
475 { .compatible = "renesas,isl28022"},
476 { /* LIST END */ }
477 };
478 MODULE_DEVICE_TABLE(of, isl28022_of_match);
479
480 static struct i2c_driver isl28022_driver = {
481 .class = I2C_CLASS_HWMON,
482 .driver = {
483 .name = "isl28022",
484 },
485 .probe = isl28022_probe,
486 .id_table = isl28022_ids,
487 };
488 module_i2c_driver(isl28022_driver);
489
490 MODULE_AUTHOR("Carsten Spieß <mail@carsten-spiess.de>");
491 MODULE_DESCRIPTION("ISL28022 driver");
492 MODULE_LICENSE("GPL");
493