1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * CM3232 Ambient Light Sensor
4 *
5 * Copyright (C) 2014-2015 Capella Microsystems Inc.
6 * Author: Kevin Tsai <ktsai@capellamicro.com>
7 *
8 * IIO driver for CM3232 (7-bit I2C slave address 0x10).
9 */
10
11 #include <linux/i2c.h>
12 #include <linux/module.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 #include <linux/init.h>
17
18 /* Registers Address */
19 #define CM3232_REG_ADDR_CMD 0x00
20 #define CM3232_REG_ADDR_ALS 0x50
21 #define CM3232_REG_ADDR_ID 0x53
22
23 #define CM3232_CMD_ALS_DISABLE BIT(0)
24
25 #define CM3232_CMD_ALS_IT_SHIFT 2
26 #define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4))
27 #define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)
28
29 #define CM3232_CMD_ALS_RESET BIT(6)
30
31 #define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT
32
33 #define CM3232_HW_ID 0x32
34 #define CM3232_CALIBSCALE_DEFAULT 100000
35 #define CM3232_CALIBSCALE_RESOLUTION 100000
36 #define CM3232_MLUX_PER_LUX 1000
37
38 #define CM3232_MLUX_PER_BIT_DEFAULT 64
39 #define CM3232_MLUX_PER_BIT_BASE_IT 100000
40
41 static const struct {
42 int val;
43 int val2;
44 u8 it;
45 } cm3232_als_it_scales[] = {
46 {0, 100000, 0}, /* 0.100000 */
47 {0, 200000, 1}, /* 0.200000 */
48 {0, 400000, 2}, /* 0.400000 */
49 {0, 800000, 3}, /* 0.800000 */
50 {1, 600000, 4}, /* 1.600000 */
51 {3, 200000, 5}, /* 3.200000 */
52 };
53
54 struct cm3232_als_info {
55 u8 regs_cmd_default;
56 u8 hw_id;
57 int calibscale;
58 int mlux_per_bit;
59 int mlux_per_bit_base_it;
60 };
61
62 static struct cm3232_als_info cm3232_als_info_default = {
63 .regs_cmd_default = CM3232_CMD_DEFAULT,
64 .hw_id = CM3232_HW_ID,
65 .calibscale = CM3232_CALIBSCALE_DEFAULT,
66 .mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
67 .mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
68 };
69
70 struct cm3232_chip {
71 struct i2c_client *client;
72 struct cm3232_als_info *als_info;
73 u8 regs_cmd;
74 u16 regs_als;
75 };
76
77 /**
78 * cm3232_reg_init() - Initialize CM3232
79 * @chip: pointer of struct cm3232_chip.
80 *
81 * Check and initialize CM3232 ambient light sensor.
82 *
83 * Return: 0 for success; otherwise for error code.
84 */
cm3232_reg_init(struct cm3232_chip * chip)85 static int cm3232_reg_init(struct cm3232_chip *chip)
86 {
87 struct i2c_client *client = chip->client;
88 s32 ret;
89
90 chip->als_info = &cm3232_als_info_default;
91
92 /* Identify device */
93 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
94 if (ret < 0) {
95 dev_err(&chip->client->dev, "Error reading addr_id\n");
96 return ret;
97 }
98
99 if ((ret & 0xFF) != chip->als_info->hw_id)
100 return -ENODEV;
101
102 /* Disable and reset device */
103 chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
104 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
105 chip->regs_cmd);
106 if (ret < 0) {
107 dev_err(&chip->client->dev, "Error writing reg_cmd\n");
108 return ret;
109 }
110
111 /* Register default value */
112 chip->regs_cmd = chip->als_info->regs_cmd_default;
113
114 /* Configure register */
115 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
116 chip->regs_cmd);
117 if (ret < 0)
118 dev_err(&chip->client->dev, "Error writing reg_cmd\n");
119
120 return ret;
121 }
122
123 /**
124 * cm3232_read_als_it() - Get sensor integration time
125 * @chip: pointer of struct cm3232_chip
126 * @val: pointer of int to load the integration (sec).
127 * @val2: pointer of int to load the integration time (microsecond).
128 *
129 * Report the current integration time.
130 *
131 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
132 */
cm3232_read_als_it(struct cm3232_chip * chip,int * val,int * val2)133 static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)
134 {
135 u16 als_it;
136 int i;
137
138 als_it = chip->regs_cmd;
139 als_it &= CM3232_CMD_ALS_IT_MASK;
140 als_it >>= CM3232_CMD_ALS_IT_SHIFT;
141 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
142 if (als_it == cm3232_als_it_scales[i].it) {
143 *val = cm3232_als_it_scales[i].val;
144 *val2 = cm3232_als_it_scales[i].val2;
145 return IIO_VAL_INT_PLUS_MICRO;
146 }
147 }
148
149 return -EINVAL;
150 }
151
152 /**
153 * cm3232_write_als_it() - Write sensor integration time
154 * @chip: pointer of struct cm3232_chip.
155 * @val: integration time in second.
156 * @val2: integration time in microsecond.
157 *
158 * Convert integration time to sensor value.
159 *
160 * Return: i2c_smbus_write_byte_data command return value.
161 */
cm3232_write_als_it(struct cm3232_chip * chip,int val,int val2)162 static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
163 {
164 struct i2c_client *client = chip->client;
165 u16 als_it, cmd;
166 int i;
167 s32 ret;
168
169 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
170 if (val == cm3232_als_it_scales[i].val &&
171 val2 == cm3232_als_it_scales[i].val2) {
172
173 als_it = cm3232_als_it_scales[i].it;
174 als_it <<= CM3232_CMD_ALS_IT_SHIFT;
175
176 cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
177 cmd |= als_it;
178 ret = i2c_smbus_write_byte_data(client,
179 CM3232_REG_ADDR_CMD,
180 cmd);
181 if (ret < 0)
182 return ret;
183 chip->regs_cmd = cmd;
184 return 0;
185 }
186 }
187 return -EINVAL;
188 }
189
190 /**
191 * cm3232_get_lux() - report current lux value
192 * @chip: pointer of struct cm3232_chip.
193 *
194 * Convert sensor data to lux. It depends on integration
195 * time and calibscale variable.
196 *
197 * Return: Zero or positive value is lux, otherwise error code.
198 */
cm3232_get_lux(struct cm3232_chip * chip)199 static int cm3232_get_lux(struct cm3232_chip *chip)
200 {
201 struct i2c_client *client = chip->client;
202 struct cm3232_als_info *als_info = chip->als_info;
203 int ret;
204 int val, val2;
205 int als_it;
206 u64 lux;
207
208 /* Calculate mlux per bit based on als_it */
209 ret = cm3232_read_als_it(chip, &val, &val2);
210 if (ret < 0)
211 return -EINVAL;
212 als_it = val * 1000000 + val2;
213 lux = (__force u64)als_info->mlux_per_bit;
214 lux *= als_info->mlux_per_bit_base_it;
215 lux = div_u64(lux, als_it);
216
217 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
218 if (ret < 0) {
219 dev_err(&client->dev, "Error reading reg_addr_als\n");
220 return ret;
221 }
222
223 chip->regs_als = (u16)ret;
224 lux *= chip->regs_als;
225 lux *= als_info->calibscale;
226 lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
227 lux = div_u64(lux, CM3232_MLUX_PER_LUX);
228
229 if (lux > 0xFFFF)
230 lux = 0xFFFF;
231
232 return (int)lux;
233 }
234
cm3232_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)235 static int cm3232_read_raw(struct iio_dev *indio_dev,
236 struct iio_chan_spec const *chan,
237 int *val, int *val2, long mask)
238 {
239 struct cm3232_chip *chip = iio_priv(indio_dev);
240 struct cm3232_als_info *als_info = chip->als_info;
241 int ret;
242
243 switch (mask) {
244 case IIO_CHAN_INFO_PROCESSED:
245 ret = cm3232_get_lux(chip);
246 if (ret < 0)
247 return ret;
248 *val = ret;
249 return IIO_VAL_INT;
250 case IIO_CHAN_INFO_CALIBSCALE:
251 *val = als_info->calibscale;
252 return IIO_VAL_INT;
253 case IIO_CHAN_INFO_INT_TIME:
254 return cm3232_read_als_it(chip, val, val2);
255 }
256
257 return -EINVAL;
258 }
259
cm3232_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)260 static int cm3232_write_raw(struct iio_dev *indio_dev,
261 struct iio_chan_spec const *chan,
262 int val, int val2, long mask)
263 {
264 struct cm3232_chip *chip = iio_priv(indio_dev);
265 struct cm3232_als_info *als_info = chip->als_info;
266
267 switch (mask) {
268 case IIO_CHAN_INFO_CALIBSCALE:
269 als_info->calibscale = val;
270 return 0;
271 case IIO_CHAN_INFO_INT_TIME:
272 return cm3232_write_als_it(chip, val, val2);
273 }
274
275 return -EINVAL;
276 }
277
278 /**
279 * cm3232_get_it_available() - Get available ALS IT value
280 * @dev: pointer of struct device.
281 * @attr: pointer of struct device_attribute.
282 * @buf: pointer of return string buffer.
283 *
284 * Display the available integration time in second.
285 *
286 * Return: string length.
287 */
cm3232_get_it_available(struct device * dev,struct device_attribute * attr,char * buf)288 static ssize_t cm3232_get_it_available(struct device *dev,
289 struct device_attribute *attr, char *buf)
290 {
291 int i, len;
292
293 for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
294 len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
295 cm3232_als_it_scales[i].val,
296 cm3232_als_it_scales[i].val2);
297 return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
298 }
299
300 static const struct iio_chan_spec cm3232_channels[] = {
301 {
302 .type = IIO_LIGHT,
303 .info_mask_separate =
304 BIT(IIO_CHAN_INFO_PROCESSED) |
305 BIT(IIO_CHAN_INFO_CALIBSCALE) |
306 BIT(IIO_CHAN_INFO_INT_TIME),
307 }
308 };
309
310 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
311 S_IRUGO, cm3232_get_it_available, NULL, 0);
312
313 static struct attribute *cm3232_attributes[] = {
314 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
315 NULL,
316 };
317
318 static const struct attribute_group cm3232_attribute_group = {
319 .attrs = cm3232_attributes
320 };
321
322 static const struct iio_info cm3232_info = {
323 .read_raw = &cm3232_read_raw,
324 .write_raw = &cm3232_write_raw,
325 .attrs = &cm3232_attribute_group,
326 };
327
cm3232_probe(struct i2c_client * client)328 static int cm3232_probe(struct i2c_client *client)
329 {
330 const struct i2c_device_id *id = i2c_client_get_device_id(client);
331 struct cm3232_chip *chip;
332 struct iio_dev *indio_dev;
333 int ret;
334
335 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
336 if (!indio_dev)
337 return -ENOMEM;
338
339 chip = iio_priv(indio_dev);
340 i2c_set_clientdata(client, indio_dev);
341 chip->client = client;
342
343 indio_dev->channels = cm3232_channels;
344 indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
345 indio_dev->info = &cm3232_info;
346 indio_dev->name = id->name;
347 indio_dev->modes = INDIO_DIRECT_MODE;
348
349 ret = cm3232_reg_init(chip);
350 if (ret) {
351 dev_err(&client->dev,
352 "%s: register init failed\n",
353 __func__);
354 return ret;
355 }
356
357 return iio_device_register(indio_dev);
358 }
359
cm3232_remove(struct i2c_client * client)360 static void cm3232_remove(struct i2c_client *client)
361 {
362 struct iio_dev *indio_dev = i2c_get_clientdata(client);
363
364 i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
365 CM3232_CMD_ALS_DISABLE);
366
367 iio_device_unregister(indio_dev);
368 }
369
370 static const struct i2c_device_id cm3232_id[] = {
371 { "cm3232" },
372 {}
373 };
374
cm3232_suspend(struct device * dev)375 static int cm3232_suspend(struct device *dev)
376 {
377 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
378 struct cm3232_chip *chip = iio_priv(indio_dev);
379 struct i2c_client *client = chip->client;
380 int ret;
381
382 chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;
383 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
384 chip->regs_cmd);
385
386 return ret;
387 }
388
cm3232_resume(struct device * dev)389 static int cm3232_resume(struct device *dev)
390 {
391 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
392 struct cm3232_chip *chip = iio_priv(indio_dev);
393 struct i2c_client *client = chip->client;
394 int ret;
395
396 chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
397 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
398 chip->regs_cmd | CM3232_CMD_ALS_RESET);
399
400 return ret;
401 }
402
403 static DEFINE_SIMPLE_DEV_PM_OPS(cm3232_pm_ops, cm3232_suspend, cm3232_resume);
404
405 MODULE_DEVICE_TABLE(i2c, cm3232_id);
406
407 static const struct of_device_id cm3232_of_match[] = {
408 {.compatible = "capella,cm3232"},
409 {}
410 };
411 MODULE_DEVICE_TABLE(of, cm3232_of_match);
412
413 static struct i2c_driver cm3232_driver = {
414 .driver = {
415 .name = "cm3232",
416 .of_match_table = cm3232_of_match,
417 .pm = pm_sleep_ptr(&cm3232_pm_ops),
418 },
419 .id_table = cm3232_id,
420 .probe = cm3232_probe,
421 .remove = cm3232_remove,
422 };
423
424 module_i2c_driver(cm3232_driver);
425
426 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
427 MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
428 MODULE_LICENSE("GPL");
429