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 */
68 static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };
69 static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };
70
71 /* CM32181 Family */
72 static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };
73 static const int cm32181_als_it_values[] = {
74 25000, 50000, 100000, 200000, 400000, 800000
75 };
76
77 struct 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
91 static 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 */
cm32181_acpi_get_cpm(struct device * dev,char * obj_name,u64 * values,int count)105 static 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
cm32181_acpi_parse_cpm_tables(struct cm32181_chip * cm32181)140 static 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
cm32181_acpi_parse_cpm_tables(struct cm32181_chip * cm32181)172 static 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 */
cm32181_reg_init(struct cm32181_chip * cm32181)185 static 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 if (ACPI_HANDLE(cm32181->dev))
221 cm32181_acpi_parse_cpm_tables(cm32181);
222
223 /* Initialize registers*/
224 for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {
225 ret = i2c_smbus_write_word_data(client, i,
226 cm32181->conf_regs[i]);
227 if (ret < 0)
228 return ret;
229 }
230
231 return 0;
232 }
233
234 /**
235 * cm32181_read_als_it() - Get sensor integration time (ms)
236 * @cm32181: pointer of struct cm32181
237 * @val2: pointer of int to load the als_it value.
238 *
239 * Report the current integration time in milliseconds.
240 *
241 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
242 */
cm32181_read_als_it(struct cm32181_chip * cm32181,int * val2)243 static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
244 {
245 u16 als_it;
246 int i;
247
248 als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
249 als_it &= CM32181_CMD_ALS_IT_MASK;
250 als_it >>= CM32181_CMD_ALS_IT_SHIFT;
251 for (i = 0; i < cm32181->num_als_it; i++) {
252 if (als_it == cm32181->als_it_bits[i]) {
253 *val2 = cm32181->als_it_values[i];
254 return IIO_VAL_INT_PLUS_MICRO;
255 }
256 }
257
258 return -EINVAL;
259 }
260
261 /**
262 * cm32181_write_als_it() - Write sensor integration time
263 * @cm32181: pointer of struct cm32181.
264 * @val: integration time by millisecond.
265 *
266 * Convert integration time (ms) to sensor value.
267 *
268 * Return: i2c_smbus_write_word_data command return value.
269 */
cm32181_write_als_it(struct cm32181_chip * cm32181,int val)270 static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
271 {
272 struct i2c_client *client = cm32181->client;
273 u16 als_it;
274 int ret, i, n;
275
276 n = cm32181->num_als_it;
277 for (i = 0; i < n; i++)
278 if (val <= cm32181->als_it_values[i])
279 break;
280 if (i >= n)
281 i = n - 1;
282
283 als_it = cm32181->als_it_bits[i];
284 als_it <<= CM32181_CMD_ALS_IT_SHIFT;
285
286 mutex_lock(&cm32181->lock);
287 cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
288 ~CM32181_CMD_ALS_IT_MASK;
289 cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
290 als_it;
291 ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
292 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
293 mutex_unlock(&cm32181->lock);
294
295 return ret;
296 }
297
298 /**
299 * cm32181_get_lux() - report current lux value
300 * @cm32181: pointer of struct cm32181.
301 *
302 * Convert sensor raw data to lux. It depends on integration
303 * time and calibscale variable.
304 *
305 * Return: Positive value is lux, otherwise is error code.
306 */
cm32181_get_lux(struct cm32181_chip * cm32181)307 static int cm32181_get_lux(struct cm32181_chip *cm32181)
308 {
309 struct i2c_client *client = cm32181->client;
310 int ret;
311 int als_it;
312 u64 lux;
313
314 ret = cm32181_read_als_it(cm32181, &als_it);
315 if (ret < 0)
316 return -EINVAL;
317
318 lux = cm32181->lux_per_bit;
319 lux *= cm32181->lux_per_bit_base_it;
320 lux = div_u64(lux, als_it);
321
322 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
323 if (ret < 0)
324 return ret;
325
326 lux *= ret;
327 lux *= cm32181->calibscale;
328 lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);
329 lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);
330
331 if (lux > 0xFFFF)
332 lux = 0xFFFF;
333
334 return lux;
335 }
336
cm32181_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)337 static int cm32181_read_raw(struct iio_dev *indio_dev,
338 struct iio_chan_spec const *chan,
339 int *val, int *val2, long mask)
340 {
341 struct cm32181_chip *cm32181 = iio_priv(indio_dev);
342 int ret;
343
344 switch (mask) {
345 case IIO_CHAN_INFO_PROCESSED:
346 ret = cm32181_get_lux(cm32181);
347 if (ret < 0)
348 return ret;
349 *val = ret;
350 return IIO_VAL_INT;
351 case IIO_CHAN_INFO_CALIBSCALE:
352 *val = cm32181->calibscale;
353 return IIO_VAL_INT;
354 case IIO_CHAN_INFO_INT_TIME:
355 *val = 0;
356 ret = cm32181_read_als_it(cm32181, val2);
357 return ret;
358 }
359
360 return -EINVAL;
361 }
362
cm32181_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)363 static int cm32181_write_raw(struct iio_dev *indio_dev,
364 struct iio_chan_spec const *chan,
365 int val, int val2, long mask)
366 {
367 struct cm32181_chip *cm32181 = iio_priv(indio_dev);
368 int ret;
369
370 switch (mask) {
371 case IIO_CHAN_INFO_CALIBSCALE:
372 cm32181->calibscale = val;
373 return val;
374 case IIO_CHAN_INFO_INT_TIME:
375 ret = cm32181_write_als_it(cm32181, val2);
376 return ret;
377 }
378
379 return -EINVAL;
380 }
381
382 /**
383 * cm32181_get_it_available() - Get available ALS IT value
384 * @dev: pointer of struct device.
385 * @attr: pointer of struct device_attribute.
386 * @buf: pointer of return string buffer.
387 *
388 * Display the available integration time values by millisecond.
389 *
390 * Return: string length.
391 */
cm32181_get_it_available(struct device * dev,struct device_attribute * attr,char * buf)392 static ssize_t cm32181_get_it_available(struct device *dev,
393 struct device_attribute *attr, char *buf)
394 {
395 struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));
396 int i, n, len;
397
398 n = cm32181->num_als_it;
399 for (i = 0, len = 0; i < n; i++)
400 len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]);
401 return len + sprintf(buf + len, "\n");
402 }
403
404 static const struct iio_chan_spec cm32181_channels[] = {
405 {
406 .type = IIO_LIGHT,
407 .info_mask_separate =
408 BIT(IIO_CHAN_INFO_PROCESSED) |
409 BIT(IIO_CHAN_INFO_CALIBSCALE) |
410 BIT(IIO_CHAN_INFO_INT_TIME),
411 }
412 };
413
414 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
415 S_IRUGO, cm32181_get_it_available, NULL, 0);
416
417 static struct attribute *cm32181_attributes[] = {
418 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
419 NULL,
420 };
421
422 static const struct attribute_group cm32181_attribute_group = {
423 .attrs = cm32181_attributes
424 };
425
426 static const struct iio_info cm32181_info = {
427 .read_raw = &cm32181_read_raw,
428 .write_raw = &cm32181_write_raw,
429 .attrs = &cm32181_attribute_group,
430 };
431
cm32181_unregister_dummy_client(void * data)432 static void cm32181_unregister_dummy_client(void *data)
433 {
434 struct i2c_client *client = data;
435
436 /* Unregister the dummy client */
437 i2c_unregister_device(client);
438 }
439
cm32181_probe(struct i2c_client * client)440 static int cm32181_probe(struct i2c_client *client)
441 {
442 struct device *dev = &client->dev;
443 struct cm32181_chip *cm32181;
444 struct iio_dev *indio_dev;
445 int ret;
446
447 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));
448 if (!indio_dev)
449 return -ENOMEM;
450
451 i2c_set_clientdata(client, indio_dev);
452
453 /*
454 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
455 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
456 * Detect this and take the following step to deal with it:
457 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will
458 * not respond on its actual I2C address. Read a byte from the ARA
459 * to clear any pending Alerts.
460 * 2. Create a "dummy" client for the actual I2C address and
461 * use that client to communicate with the sensor.
462 */
463 if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
464 struct i2c_board_info board_info = { .type = "dummy" };
465
466 i2c_smbus_read_byte(client);
467
468 client = i2c_acpi_new_device(dev, 1, &board_info);
469 if (IS_ERR(client))
470 return PTR_ERR(client);
471
472 ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client);
473 if (ret)
474 return ret;
475 }
476
477 cm32181 = iio_priv(indio_dev);
478 cm32181->client = client;
479 cm32181->dev = dev;
480
481 mutex_init(&cm32181->lock);
482 indio_dev->channels = cm32181_channels;
483 indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
484 indio_dev->info = &cm32181_info;
485 indio_dev->name = dev_name(dev);
486 indio_dev->modes = INDIO_DIRECT_MODE;
487
488 ret = cm32181_reg_init(cm32181);
489 if (ret) {
490 dev_err(dev, "%s: register init failed\n", __func__);
491 return ret;
492 }
493
494 ret = devm_iio_device_register(dev, indio_dev);
495 if (ret) {
496 dev_err(dev, "%s: regist device failed\n", __func__);
497 return ret;
498 }
499
500 return 0;
501 }
502
cm32181_suspend(struct device * dev)503 static int cm32181_suspend(struct device *dev)
504 {
505 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
506 struct i2c_client *client = cm32181->client;
507
508 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
509 CM32181_CMD_ALS_DISABLE);
510 }
511
cm32181_resume(struct device * dev)512 static int cm32181_resume(struct device *dev)
513 {
514 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
515 struct i2c_client *client = cm32181->client;
516
517 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
518 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
519 }
520
521 static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);
522
523 static const struct of_device_id cm32181_of_match[] = {
524 { .compatible = "capella,cm3218" },
525 { .compatible = "capella,cm32181" },
526 { }
527 };
528 MODULE_DEVICE_TABLE(of, cm32181_of_match);
529
530 #ifdef CONFIG_ACPI
531 static const struct acpi_device_id cm32181_acpi_match[] = {
532 { "CPLM3218", 0 },
533 { }
534 };
535 MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);
536 #endif
537
538 static struct i2c_driver cm32181_driver = {
539 .driver = {
540 .name = "cm32181",
541 .acpi_match_table = ACPI_PTR(cm32181_acpi_match),
542 .of_match_table = cm32181_of_match,
543 .pm = pm_sleep_ptr(&cm32181_pm_ops),
544 },
545 .probe = cm32181_probe,
546 };
547
548 module_i2c_driver(cm32181_driver);
549
550 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
551 MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
552 MODULE_LICENSE("GPL");
553