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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 Capella Microsystems Inc.
4 * Author: Kevin Tsai <ktsai@capellamicro.com>
5 */
6
7#include <linux/acpi.h>
8#include <linux/delay.h>
9#include <linux/err.h>
10#include <linux/i2c.h>
11#include <linux/mutex.h>
12#include <linux/module.h>
13#include <linux/mod_devicetable.h>
14#include <linux/interrupt.h>
15#include <linux/regulator/consumer.h>
16#include <linux/iio/iio.h>
17#include <linux/iio/sysfs.h>
18#include <linux/iio/events.h>
19#include <linux/init.h>
20
21/* Registers Address */
22#define CM32181_REG_ADDR_CMD 0x00
23#define CM32181_REG_ADDR_WH 0x01
24#define CM32181_REG_ADDR_WL 0x02
25#define CM32181_REG_ADDR_TEST 0x03
26#define CM32181_REG_ADDR_ALS 0x04
27#define CM32181_REG_ADDR_STATUS 0x06
28#define CM32181_REG_ADDR_ID 0x07
29
30/* Number of Configurable Registers */
31#define CM32181_CONF_REG_NUM 4
32
33/* CMD register */
34#define CM32181_CMD_ALS_DISABLE BIT(0)
35#define CM32181_CMD_ALS_INT_EN BIT(1)
36#define CM32181_CMD_ALS_THRES_WINDOW BIT(2)
37
38#define CM32181_CMD_ALS_PERS_SHIFT 4
39#define CM32181_CMD_ALS_PERS_MASK (0x03 << CM32181_CMD_ALS_PERS_SHIFT)
40#define CM32181_CMD_ALS_PERS_DEFAULT (0x01 << CM32181_CMD_ALS_PERS_SHIFT)
41
42#define CM32181_CMD_ALS_IT_SHIFT 6
43#define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT)
44#define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT)
45
46#define CM32181_CMD_ALS_SM_SHIFT 11
47#define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT)
48#define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT)
49
50#define CM32181_LUX_PER_BIT 500 /* ALS_SM=01 IT=800ms */
51#define CM32181_LUX_PER_BIT_RESOLUTION 100000
52#define CM32181_LUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */
53#define CM32181_CALIBSCALE_DEFAULT 100000
54#define CM32181_CALIBSCALE_RESOLUTION 100000
55
56#define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c
57
58/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */
59#define CPM0_REGS_BITMAP 2
60#define CPM0_HEADER_SIZE 3
61
62/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */
63#define CPM1_LUX_PER_BIT 0
64#define CPM1_CALIBSCALE 1
65#define CPM1_SIZE 3
66
67/* CM3218 Family */
68static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };
69static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };
70
71/* CM32181 Family */
72static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };
73static const int cm32181_als_it_values[] = {
74 25000, 50000, 100000, 200000, 400000, 800000
75};
76
77struct cm32181_chip {
78 struct i2c_client *client;
79 struct device *dev;
80 struct mutex lock;
81 u16 conf_regs[CM32181_CONF_REG_NUM];
82 unsigned long init_regs_bitmap;
83 int calibscale;
84 int lux_per_bit;
85 int lux_per_bit_base_it;
86 int num_als_it;
87 const int *als_it_bits;
88 const int *als_it_values;
89};
90
91static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2);
92
93#ifdef CONFIG_ACPI
94/**
95 * cm32181_acpi_get_cpm() - Get CPM object from ACPI
96 * @dev: pointer of struct device.
97 * @obj_name: pointer of ACPI object name.
98 * @values: pointer of array for return elements.
99 * @count: maximum size of return array.
100 *
101 * Convert ACPI CPM table to array.
102 *
103 * Return: -ENODEV for fail. Otherwise is number of elements.
104 */
105static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name,
106 u64 *values, int count)
107{
108 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
109 union acpi_object *cpm, *elem;
110 acpi_handle handle;
111 acpi_status status;
112 int i;
113
114 handle = ACPI_HANDLE(dev);
115 if (!handle)
116 return -ENODEV;
117
118 status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
119 if (ACPI_FAILURE(status)) {
120 dev_err(dev, "object %s not found\n", obj_name);
121 return -ENODEV;
122 }
123
124 cpm = buffer.pointer;
125 if (cpm->package.count > count)
126 dev_warn(dev, "%s table contains %u values, only using first %d values\n",
127 obj_name, cpm->package.count, count);
128
129 count = min_t(int, cpm->package.count, count);
130 for (i = 0; i < count; i++) {
131 elem = &(cpm->package.elements[i]);
132 values[i] = elem->integer.value;
133 }
134
135 kfree(buffer.pointer);
136
137 return count;
138}
139
140static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
141{
142 u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM];
143 struct device *dev = cm32181->dev;
144 int i, count;
145
146 count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals));
147 if (count <= CPM0_HEADER_SIZE)
148 return;
149
150 count -= CPM0_HEADER_SIZE;
151
152 cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP];
153 cm32181->init_regs_bitmap &= GENMASK(count - 1, 0);
154 for_each_set_bit(i, &cm32181->init_regs_bitmap, count)
155 cm32181->conf_regs[i] = vals[CPM0_HEADER_SIZE + i];
156
157 count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals));
158 if (count != CPM1_SIZE)
159 return;
160
161 cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT];
162
163 /* Check for uncalibrated devices */
164 if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT)
165 return;
166
167 cm32181->calibscale = vals[CPM1_CALIBSCALE];
168 /* CPM1 lux_per_bit is for the current it value */
169 cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it);
170}
171#else
172static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
173{
174}
175#endif /* CONFIG_ACPI */
176
177/**
178 * cm32181_reg_init() - Initialize CM32181 registers
179 * @cm32181: pointer of struct cm32181.
180 *
181 * Initialize CM32181 ambient light sensor register to default values.
182 *
183 * Return: 0 for success; otherwise for error code.
184 */
185static int cm32181_reg_init(struct cm32181_chip *cm32181)
186{
187 struct i2c_client *client = cm32181->client;
188 int i;
189 s32 ret;
190
191 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
192 if (ret < 0)
193 return ret;
194
195 /* check device ID */
196 switch (ret & 0xFF) {
197 case 0x18: /* CM3218 */
198 cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits);
199 cm32181->als_it_bits = cm3218_als_it_bits;
200 cm32181->als_it_values = cm3218_als_it_values;
201 break;
202 case 0x81: /* CM32181 */
203 case 0x82: /* CM32182, fully compat. with CM32181 */
204 cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits);
205 cm32181->als_it_bits = cm32181_als_it_bits;
206 cm32181->als_it_values = cm32181_als_it_values;
207 break;
208 default:
209 return -ENODEV;
210 }
211
212 /* Default Values */
213 cm32181->conf_regs[CM32181_REG_ADDR_CMD] =
214 CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
215 cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD);
216 cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
217 cm32181->lux_per_bit = CM32181_LUX_PER_BIT;
218 cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT;
219
220 cm32181_acpi_parse_cpm_tables(cm32181);
221
222 /* Initialize registers*/
223 for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {
224 ret = i2c_smbus_write_word_data(client, i,
225 cm32181->conf_regs[i]);
226 if (ret < 0)
227 return ret;
228 }
229
230 return 0;
231}
232
233/**
234 * cm32181_read_als_it() - Get sensor integration time (ms)
235 * @cm32181: pointer of struct cm32181
236 * @val2: pointer of int to load the als_it value.
237 *
238 * Report the current integration time in milliseconds.
239 *
240 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
241 */
242static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
243{
244 u16 als_it;
245 int i;
246
247 als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
248 als_it &= CM32181_CMD_ALS_IT_MASK;
249 als_it >>= CM32181_CMD_ALS_IT_SHIFT;
250 for (i = 0; i < cm32181->num_als_it; i++) {
251 if (als_it == cm32181->als_it_bits[i]) {
252 *val2 = cm32181->als_it_values[i];
253 return IIO_VAL_INT_PLUS_MICRO;
254 }
255 }
256
257 return -EINVAL;
258}
259
260/**
261 * cm32181_write_als_it() - Write sensor integration time
262 * @cm32181: pointer of struct cm32181.
263 * @val: integration time by millisecond.
264 *
265 * Convert integration time (ms) to sensor value.
266 *
267 * Return: i2c_smbus_write_word_data command return value.
268 */
269static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
270{
271 struct i2c_client *client = cm32181->client;
272 u16 als_it;
273 int ret, i, n;
274
275 n = cm32181->num_als_it;
276 for (i = 0; i < n; i++)
277 if (val <= cm32181->als_it_values[i])
278 break;
279 if (i >= n)
280 i = n - 1;
281
282 als_it = cm32181->als_it_bits[i];
283 als_it <<= CM32181_CMD_ALS_IT_SHIFT;
284
285 mutex_lock(&cm32181->lock);
286 cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
287 ~CM32181_CMD_ALS_IT_MASK;
288 cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
289 als_it;
290 ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
291 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
292 mutex_unlock(&cm32181->lock);
293
294 return ret;
295}
296
297/**
298 * cm32181_get_lux() - report current lux value
299 * @cm32181: pointer of struct cm32181.
300 *
301 * Convert sensor raw data to lux. It depends on integration
302 * time and calibscale variable.
303 *
304 * Return: Positive value is lux, otherwise is error code.
305 */
306static int cm32181_get_lux(struct cm32181_chip *cm32181)
307{
308 struct i2c_client *client = cm32181->client;
309 int ret;
310 int als_it;
311 u64 lux;
312
313 ret = cm32181_read_als_it(cm32181, &als_it);
314 if (ret < 0)
315 return -EINVAL;
316
317 lux = cm32181->lux_per_bit;
318 lux *= cm32181->lux_per_bit_base_it;
319 lux = div_u64(lux, als_it);
320
321 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
322 if (ret < 0)
323 return ret;
324
325 lux *= ret;
326 lux *= cm32181->calibscale;
327 lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);
328 lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);
329
330 if (lux > 0xFFFF)
331 lux = 0xFFFF;
332
333 return lux;
334}
335
336static int cm32181_read_raw(struct iio_dev *indio_dev,
337 struct iio_chan_spec const *chan,
338 int *val, int *val2, long mask)
339{
340 struct cm32181_chip *cm32181 = iio_priv(indio_dev);
341 int ret;
342
343 switch (mask) {
344 case IIO_CHAN_INFO_PROCESSED:
345 ret = cm32181_get_lux(cm32181);
346 if (ret < 0)
347 return ret;
348 *val = ret;
349 return IIO_VAL_INT;
350 case IIO_CHAN_INFO_CALIBSCALE:
351 *val = cm32181->calibscale;
352 return IIO_VAL_INT;
353 case IIO_CHAN_INFO_INT_TIME:
354 *val = 0;
355 ret = cm32181_read_als_it(cm32181, val2);
356 return ret;
357 }
358
359 return -EINVAL;
360}
361
362static int cm32181_write_raw(struct iio_dev *indio_dev,
363 struct iio_chan_spec const *chan,
364 int val, int val2, long mask)
365{
366 struct cm32181_chip *cm32181 = iio_priv(indio_dev);
367 int ret;
368
369 switch (mask) {
370 case IIO_CHAN_INFO_CALIBSCALE:
371 cm32181->calibscale = val;
372 return val;
373 case IIO_CHAN_INFO_INT_TIME:
374 ret = cm32181_write_als_it(cm32181, val2);
375 return ret;
376 }
377
378 return -EINVAL;
379}
380
381/**
382 * cm32181_get_it_available() - Get available ALS IT value
383 * @dev: pointer of struct device.
384 * @attr: pointer of struct device_attribute.
385 * @buf: pointer of return string buffer.
386 *
387 * Display the available integration time values by millisecond.
388 *
389 * Return: string length.
390 */
391static ssize_t cm32181_get_it_available(struct device *dev,
392 struct device_attribute *attr, char *buf)
393{
394 struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));
395 int i, n, len;
396
397 n = cm32181->num_als_it;
398 for (i = 0, len = 0; i < n; i++)
399 len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]);
400 return len + sprintf(buf + len, "\n");
401}
402
403static const struct iio_chan_spec cm32181_channels[] = {
404 {
405 .type = IIO_LIGHT,
406 .info_mask_separate =
407 BIT(IIO_CHAN_INFO_PROCESSED) |
408 BIT(IIO_CHAN_INFO_CALIBSCALE) |
409 BIT(IIO_CHAN_INFO_INT_TIME),
410 }
411};
412
413static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
414 S_IRUGO, cm32181_get_it_available, NULL, 0);
415
416static struct attribute *cm32181_attributes[] = {
417 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
418 NULL,
419};
420
421static const struct attribute_group cm32181_attribute_group = {
422 .attrs = cm32181_attributes
423};
424
425static const struct iio_info cm32181_info = {
426 .read_raw = &cm32181_read_raw,
427 .write_raw = &cm32181_write_raw,
428 .attrs = &cm32181_attribute_group,
429};
430
431static void cm32181_unregister_dummy_client(void *data)
432{
433 struct i2c_client *client = data;
434
435 /* Unregister the dummy client */
436 i2c_unregister_device(client);
437}
438
439static int cm32181_probe(struct i2c_client *client)
440{
441 struct device *dev = &client->dev;
442 struct cm32181_chip *cm32181;
443 struct iio_dev *indio_dev;
444 int ret;
445
446 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));
447 if (!indio_dev)
448 return -ENOMEM;
449
450 i2c_set_clientdata(client, indio_dev);
451
452 /*
453 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
454 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
455 * Detect this and take the following step to deal with it:
456 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will
457 * not respond on its actual I2C address. Read a byte from the ARA
458 * to clear any pending Alerts.
459 * 2. Create a "dummy" client for the actual I2C address and
460 * use that client to communicate with the sensor.
461 */
462 if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
463 struct i2c_board_info board_info = { .type = "dummy" };
464
465 i2c_smbus_read_byte(client);
466
467 client = i2c_acpi_new_device(dev, 1, &board_info);
468 if (IS_ERR(client))
469 return PTR_ERR(client);
470
471 ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client);
472 if (ret)
473 return ret;
474 }
475
476 cm32181 = iio_priv(indio_dev);
477 cm32181->client = client;
478 cm32181->dev = dev;
479
480 mutex_init(&cm32181->lock);
481 indio_dev->channels = cm32181_channels;
482 indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
483 indio_dev->info = &cm32181_info;
484 indio_dev->name = dev_name(dev);
485 indio_dev->modes = INDIO_DIRECT_MODE;
486
487 ret = cm32181_reg_init(cm32181);
488 if (ret) {
489 dev_err(dev, "%s: register init failed\n", __func__);
490 return ret;
491 }
492
493 ret = devm_iio_device_register(dev, indio_dev);
494 if (ret) {
495 dev_err(dev, "%s: regist device failed\n", __func__);
496 return ret;
497 }
498
499 return 0;
500}
501
502static int cm32181_suspend(struct device *dev)
503{
504 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
505 struct i2c_client *client = cm32181->client;
506
507 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
508 CM32181_CMD_ALS_DISABLE);
509}
510
511static int cm32181_resume(struct device *dev)
512{
513 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
514 struct i2c_client *client = cm32181->client;
515
516 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
517 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
518}
519
520static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);
521
522static const struct of_device_id cm32181_of_match[] = {
523 { .compatible = "capella,cm3218" },
524 { .compatible = "capella,cm32181" },
525 { }
526};
527MODULE_DEVICE_TABLE(of, cm32181_of_match);
528
529#ifdef CONFIG_ACPI
530static const struct acpi_device_id cm32181_acpi_match[] = {
531 { "CPLM3218", 0 },
532 { }
533};
534MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);
535#endif
536
537static struct i2c_driver cm32181_driver = {
538 .driver = {
539 .name = "cm32181",
540 .acpi_match_table = ACPI_PTR(cm32181_acpi_match),
541 .of_match_table = cm32181_of_match,
542 .pm = pm_sleep_ptr(&cm32181_pm_ops),
543 },
544 .probe = cm32181_probe,
545};
546
547module_i2c_driver(cm32181_driver);
548
549MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
550MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
551MODULE_LICENSE("GPL");