Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
82struct isl28022_data {
83 struct regmap *regmap;
84 u32 shunt;
85 u32 gain;
86 u32 average;
87};
88
89static 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
152static 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 u16 sign_bit;
158
159 switch (attr) {
160 case hwmon_curr_input:
161 err = regmap_read(data->regmap,
162 ISL28022_REG_CURRENT, ®val);
163 if (err < 0)
164 return err;
165 sign_bit = (regval >> 15) & 0x01;
166 *val = (((long)(((u16)regval) & 0x7FFF) - (sign_bit * 32768)) *
167 1250L * (long)data->gain) / (long)data->shunt;
168 break;
169 default:
170 return -EOPNOTSUPP;
171 }
172
173 return 0;
174}
175
176static int isl28022_read_power(struct device *dev, u32 attr, long *val)
177{
178 struct isl28022_data *data = dev_get_drvdata(dev);
179 unsigned int regval;
180 int err;
181
182 switch (attr) {
183 case hwmon_power_input:
184 err = regmap_read(data->regmap,
185 ISL28022_REG_POWER, ®val);
186 if (err < 0)
187 return err;
188 *val = ((51200000L * ((long)data->gain)) /
189 (long)data->shunt) * (long)regval;
190 break;
191 default:
192 return -EOPNOTSUPP;
193 }
194
195 return 0;
196}
197
198static int isl28022_read(struct device *dev, enum hwmon_sensor_types type,
199 u32 attr, int channel, long *val)
200{
201 switch (type) {
202 case hwmon_in:
203 return isl28022_read_in(dev, attr, channel, val);
204 case hwmon_curr:
205 return isl28022_read_current(dev, attr, val);
206 case hwmon_power:
207 return isl28022_read_power(dev, attr, val);
208 default:
209 return -EOPNOTSUPP;
210 }
211 return 0;
212}
213
214static umode_t isl28022_is_visible(const void *data, enum hwmon_sensor_types type,
215 u32 attr, int channel)
216{
217 switch (type) {
218 case hwmon_in:
219 switch (attr) {
220 case hwmon_in_input:
221 return 0444;
222 default:
223 break;
224 }
225 break;
226 case hwmon_curr:
227 switch (attr) {
228 case hwmon_curr_input:
229 return 0444;
230 default:
231 break;
232 }
233 break;
234 case hwmon_power:
235 switch (attr) {
236 case hwmon_power_input:
237 return 0444;
238 default:
239 break;
240 }
241 break;
242 default:
243 break;
244 }
245 return 0;
246}
247
248static const struct hwmon_channel_info *isl28022_info[] = {
249 HWMON_CHANNEL_INFO(in,
250 HWMON_I_INPUT, /* channel 0: bus voltage (mV) */
251 HWMON_I_INPUT), /* channel 1: shunt voltage (mV) */
252 HWMON_CHANNEL_INFO(curr,
253 HWMON_C_INPUT), /* channel 1: current (mA) */
254 HWMON_CHANNEL_INFO(power,
255 HWMON_P_INPUT), /* channel 1: power (µW) */
256 NULL
257};
258
259static const struct hwmon_ops isl28022_hwmon_ops = {
260 .is_visible = isl28022_is_visible,
261 .read = isl28022_read,
262};
263
264static const struct hwmon_chip_info isl28022_chip_info = {
265 .ops = &isl28022_hwmon_ops,
266 .info = isl28022_info,
267};
268
269static bool isl28022_is_writeable_reg(struct device *dev, unsigned int reg)
270{
271 switch (reg) {
272 case ISL28022_REG_CONFIG:
273 case ISL28022_REG_CALIB:
274 case ISL28022_REG_SHUNT_THR:
275 case ISL28022_REG_BUS_THR:
276 case ISL28022_REG_INT:
277 case ISL28022_REG_AUX:
278 return true;
279 }
280
281 return false;
282}
283
284static bool isl28022_is_volatile_reg(struct device *dev, unsigned int reg)
285{
286 switch (reg) {
287 case ISL28022_REG_CONFIG:
288 case ISL28022_REG_SHUNT:
289 case ISL28022_REG_BUS:
290 case ISL28022_REG_POWER:
291 case ISL28022_REG_CURRENT:
292 case ISL28022_REG_INT:
293 case ISL28022_REG_AUX:
294 return true;
295 }
296 return true;
297}
298
299static const struct regmap_config isl28022_regmap_config = {
300 .reg_bits = 8,
301 .val_bits = 16,
302 .max_register = ISL28022_REG_MAX,
303 .writeable_reg = isl28022_is_writeable_reg,
304 .volatile_reg = isl28022_is_volatile_reg,
305 .val_format_endian = REGMAP_ENDIAN_BIG,
306 .cache_type = REGCACHE_MAPLE,
307 .use_single_read = true,
308 .use_single_write = true,
309};
310
311static int shunt_voltage_show(struct seq_file *seqf, void *unused)
312{
313 struct isl28022_data *data = seqf->private;
314 unsigned int regval;
315 int err;
316
317 err = regmap_read(data->regmap,
318 ISL28022_REG_SHUNT, ®val);
319 if (err)
320 return err;
321
322 /* print shunt voltage in micro volt */
323 seq_printf(seqf, "%d\n", regval * 10);
324
325 return 0;
326}
327DEFINE_SHOW_ATTRIBUTE(shunt_voltage);
328
329/*
330 * read property values and make consistency checks.
331 *
332 * following values for shunt range and resistor are allowed:
333 * 40 mV -> gain 1, shunt min. 800 micro ohms
334 * 80 mV -> gain 2, shunt min. 1600 micro ohms
335 * 160 mV -> gain 4, shunt min. 3200 micro ohms
336 * 320 mV -> gain 8, shunt min. 6400 micro ohms
337 */
338static int isl28022_read_properties(struct device *dev, struct isl28022_data *data)
339{
340 u32 val;
341 int err;
342
343 err = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
344 if (err == -EINVAL)
345 val = 10000;
346 else if (err < 0)
347 return err;
348 data->shunt = val;
349
350 err = device_property_read_u32(dev, "renesas,shunt-range-microvolt", &val);
351 if (err == -EINVAL)
352 val = 320000;
353 else if (err < 0)
354 return err;
355
356 switch (val) {
357 case 40000:
358 data->gain = 1;
359 if (data->shunt < 800)
360 goto shunt_invalid;
361 break;
362 case 80000:
363 data->gain = 2;
364 if (data->shunt < 1600)
365 goto shunt_invalid;
366 break;
367 case 160000:
368 data->gain = 4;
369 if (data->shunt < 3200)
370 goto shunt_invalid;
371 break;
372 case 320000:
373 data->gain = 8;
374 if (data->shunt < 6400)
375 goto shunt_invalid;
376 break;
377 default:
378 return dev_err_probe(dev, -EINVAL,
379 "renesas,shunt-range-microvolt invalid value %d\n",
380 val);
381 }
382
383 err = device_property_read_u32(dev, "renesas,average-samples", &val);
384 if (err == -EINVAL)
385 val = 1;
386 else if (err < 0)
387 return err;
388 if (val > 128 || hweight32(val) != 1)
389 return dev_err_probe(dev, -EINVAL,
390 "renesas,average-samples invalid value %d\n",
391 val);
392
393 data->average = val;
394
395 return 0;
396
397shunt_invalid:
398 return dev_err_probe(dev, -EINVAL,
399 "renesas,shunt-resistor-microvolt invalid value %d\n",
400 data->shunt);
401}
402
403/*
404 * write configuration and calibration registers
405 *
406 * The driver supports only shunt and bus continuous ADC mode at 15bit resolution
407 * with averaging from 1 to 128 samples (pow of 2) on both channels.
408 * Shunt voltage gain 1,2,4 or 8 is allowed.
409 * The bus voltage range is 60V fixed.
410 */
411static int isl28022_config(struct isl28022_data *data)
412{
413 int err;
414 u16 config;
415 u16 calib;
416
417 config = (ISL28022_MODE_CONT_SB << ISL28022_MODE_SHIFT) |
418 (ISL28022_BRNG_60 << ISL28022_BRNG_SHIFT) |
419 (__ffs(data->gain) << ISL28022_PG_SHIFT) |
420 ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_SADC_SHIFT) |
421 ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_BADC_SHIFT);
422
423 calib = data->shunt ? 0x8000 / data->gain : 0;
424
425 err = regmap_write(data->regmap, ISL28022_REG_CONFIG, config);
426 if (err < 0)
427 return err;
428
429 return regmap_write(data->regmap, ISL28022_REG_CALIB, calib);
430}
431
432static int isl28022_probe(struct i2c_client *client)
433{
434 struct device *dev = &client->dev;
435 struct device *hwmon_dev;
436 struct isl28022_data *data;
437 int err;
438
439 if (!i2c_check_functionality(client->adapter,
440 I2C_FUNC_SMBUS_BYTE_DATA |
441 I2C_FUNC_SMBUS_WORD_DATA))
442 return -ENODEV;
443
444 data = devm_kzalloc(dev, sizeof(struct isl28022_data), GFP_KERNEL);
445 if (!data)
446 return -ENOMEM;
447
448 err = isl28022_read_properties(dev, data);
449 if (err)
450 return err;
451
452 data->regmap = devm_regmap_init_i2c(client, &isl28022_regmap_config);
453 if (IS_ERR(data->regmap))
454 return PTR_ERR(data->regmap);
455
456 err = isl28022_config(data);
457 if (err)
458 return err;
459
460 debugfs_create_file("shunt_voltage", 0444, client->debugfs, data, &shunt_voltage_fops);
461
462 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
463 data, &isl28022_chip_info, NULL);
464 if (IS_ERR(hwmon_dev))
465 return PTR_ERR(hwmon_dev);
466
467 return 0;
468}
469
470static const struct i2c_device_id isl28022_ids[] = {
471 { "isl28022" },
472 { /* LIST END */ }
473};
474MODULE_DEVICE_TABLE(i2c, isl28022_ids);
475
476static const struct of_device_id __maybe_unused isl28022_of_match[] = {
477 { .compatible = "renesas,isl28022"},
478 { /* LIST END */ }
479};
480MODULE_DEVICE_TABLE(of, isl28022_of_match);
481
482static struct i2c_driver isl28022_driver = {
483 .class = I2C_CLASS_HWMON,
484 .driver = {
485 .name = "isl28022",
486 },
487 .probe = isl28022_probe,
488 .id_table = isl28022_ids,
489};
490module_i2c_driver(isl28022_driver);
491
492MODULE_AUTHOR("Carsten Spieß <mail@carsten-spiess.de>");
493MODULE_DESCRIPTION("ISL28022 driver");
494MODULE_LICENSE("GPL");