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