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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/iio/iio.h>
14#include <linux/iio/sysfs.h>
15#include <linux/init.h>
16
17/* Registers Address */
18#define CM3232_REG_ADDR_CMD 0x00
19#define CM3232_REG_ADDR_ALS 0x50
20#define CM3232_REG_ADDR_ID 0x53
21
22#define CM3232_CMD_ALS_DISABLE BIT(0)
23
24#define CM3232_CMD_ALS_IT_SHIFT 2
25#define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4))
26#define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)
27
28#define CM3232_CMD_ALS_RESET BIT(6)
29
30#define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT
31
32#define CM3232_HW_ID 0x32
33#define CM3232_CALIBSCALE_DEFAULT 100000
34#define CM3232_CALIBSCALE_RESOLUTION 100000
35#define CM3232_MLUX_PER_LUX 1000
36
37#define CM3232_MLUX_PER_BIT_DEFAULT 64
38#define CM3232_MLUX_PER_BIT_BASE_IT 100000
39
40static const struct {
41 int val;
42 int val2;
43 u8 it;
44} cm3232_als_it_scales[] = {
45 {0, 100000, 0}, /* 0.100000 */
46 {0, 200000, 1}, /* 0.200000 */
47 {0, 400000, 2}, /* 0.400000 */
48 {0, 800000, 3}, /* 0.800000 */
49 {1, 600000, 4}, /* 1.600000 */
50 {3, 200000, 5}, /* 3.200000 */
51};
52
53struct cm3232_als_info {
54 u8 regs_cmd_default;
55 u8 hw_id;
56 int calibscale;
57 int mlux_per_bit;
58 int mlux_per_bit_base_it;
59};
60
61static struct cm3232_als_info cm3232_als_info_default = {
62 .regs_cmd_default = CM3232_CMD_DEFAULT,
63 .hw_id = CM3232_HW_ID,
64 .calibscale = CM3232_CALIBSCALE_DEFAULT,
65 .mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
66 .mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
67};
68
69struct cm3232_chip {
70 struct i2c_client *client;
71 struct cm3232_als_info *als_info;
72 u8 regs_cmd;
73 u16 regs_als;
74};
75
76/**
77 * cm3232_reg_init() - Initialize CM3232
78 * @chip: pointer of struct cm3232_chip.
79 *
80 * Check and initialize CM3232 ambient light sensor.
81 *
82 * Return: 0 for success; otherwise for error code.
83 */
84static int cm3232_reg_init(struct cm3232_chip *chip)
85{
86 struct i2c_client *client = chip->client;
87 s32 ret;
88
89 chip->als_info = &cm3232_als_info_default;
90
91 /* Identify device */
92 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
93 if (ret < 0) {
94 dev_err(&chip->client->dev, "Error reading addr_id\n");
95 return ret;
96 }
97
98 if ((ret & 0xFF) != chip->als_info->hw_id)
99 return -ENODEV;
100
101 /* Disable and reset device */
102 chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
103 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
104 chip->regs_cmd);
105 if (ret < 0) {
106 dev_err(&chip->client->dev, "Error writing reg_cmd\n");
107 return ret;
108 }
109
110 /* Register default value */
111 chip->regs_cmd = chip->als_info->regs_cmd_default;
112
113 /* Configure register */
114 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
115 chip->regs_cmd);
116 if (ret < 0)
117 dev_err(&chip->client->dev, "Error writing reg_cmd\n");
118
119 return ret;
120}
121
122/**
123 * cm3232_read_als_it() - Get sensor integration time
124 * @chip: pointer of struct cm3232_chip
125 * @val: pointer of int to load the integration (sec).
126 * @val2: pointer of int to load the integration time (microsecond).
127 *
128 * Report the current integration time.
129 *
130 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
131 */
132static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)
133{
134 u16 als_it;
135 int i;
136
137 als_it = chip->regs_cmd;
138 als_it &= CM3232_CMD_ALS_IT_MASK;
139 als_it >>= CM3232_CMD_ALS_IT_SHIFT;
140 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
141 if (als_it == cm3232_als_it_scales[i].it) {
142 *val = cm3232_als_it_scales[i].val;
143 *val2 = cm3232_als_it_scales[i].val2;
144 return IIO_VAL_INT_PLUS_MICRO;
145 }
146 }
147
148 return -EINVAL;
149}
150
151/**
152 * cm3232_write_als_it() - Write sensor integration time
153 * @chip: pointer of struct cm3232_chip.
154 * @val: integration time in second.
155 * @val2: integration time in microsecond.
156 *
157 * Convert integration time to sensor value.
158 *
159 * Return: i2c_smbus_write_byte_data command return value.
160 */
161static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
162{
163 struct i2c_client *client = chip->client;
164 u16 als_it, cmd;
165 int i;
166 s32 ret;
167
168 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
169 if (val == cm3232_als_it_scales[i].val &&
170 val2 == cm3232_als_it_scales[i].val2) {
171
172 als_it = cm3232_als_it_scales[i].it;
173 als_it <<= CM3232_CMD_ALS_IT_SHIFT;
174
175 cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
176 cmd |= als_it;
177 ret = i2c_smbus_write_byte_data(client,
178 CM3232_REG_ADDR_CMD,
179 cmd);
180 if (ret < 0)
181 return ret;
182 chip->regs_cmd = cmd;
183 return 0;
184 }
185 }
186 return -EINVAL;
187}
188
189/**
190 * cm3232_get_lux() - report current lux value
191 * @chip: pointer of struct cm3232_chip.
192 *
193 * Convert sensor data to lux. It depends on integration
194 * time and calibscale variable.
195 *
196 * Return: Zero or positive value is lux, otherwise error code.
197 */
198static int cm3232_get_lux(struct cm3232_chip *chip)
199{
200 struct i2c_client *client = chip->client;
201 struct cm3232_als_info *als_info = chip->als_info;
202 int ret;
203 int val, val2;
204 int als_it;
205 u64 lux;
206
207 /* Calculate mlux per bit based on als_it */
208 ret = cm3232_read_als_it(chip, &val, &val2);
209 if (ret < 0)
210 return -EINVAL;
211 als_it = val * 1000000 + val2;
212 lux = (__force u64)als_info->mlux_per_bit;
213 lux *= als_info->mlux_per_bit_base_it;
214 lux = div_u64(lux, als_it);
215
216 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
217 if (ret < 0) {
218 dev_err(&client->dev, "Error reading reg_addr_als\n");
219 return ret;
220 }
221
222 chip->regs_als = (u16)ret;
223 lux *= chip->regs_als;
224 lux *= als_info->calibscale;
225 lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
226 lux = div_u64(lux, CM3232_MLUX_PER_LUX);
227
228 if (lux > 0xFFFF)
229 lux = 0xFFFF;
230
231 return (int)lux;
232}
233
234static int cm3232_read_raw(struct iio_dev *indio_dev,
235 struct iio_chan_spec const *chan,
236 int *val, int *val2, long mask)
237{
238 struct cm3232_chip *chip = iio_priv(indio_dev);
239 struct cm3232_als_info *als_info = chip->als_info;
240 int ret;
241
242 switch (mask) {
243 case IIO_CHAN_INFO_PROCESSED:
244 ret = cm3232_get_lux(chip);
245 if (ret < 0)
246 return ret;
247 *val = ret;
248 return IIO_VAL_INT;
249 case IIO_CHAN_INFO_CALIBSCALE:
250 *val = als_info->calibscale;
251 return IIO_VAL_INT;
252 case IIO_CHAN_INFO_INT_TIME:
253 return cm3232_read_als_it(chip, val, val2);
254 }
255
256 return -EINVAL;
257}
258
259static int cm3232_write_raw(struct iio_dev *indio_dev,
260 struct iio_chan_spec const *chan,
261 int val, int val2, long mask)
262{
263 struct cm3232_chip *chip = iio_priv(indio_dev);
264 struct cm3232_als_info *als_info = chip->als_info;
265
266 switch (mask) {
267 case IIO_CHAN_INFO_CALIBSCALE:
268 als_info->calibscale = val;
269 return 0;
270 case IIO_CHAN_INFO_INT_TIME:
271 return cm3232_write_als_it(chip, val, val2);
272 }
273
274 return -EINVAL;
275}
276
277/**
278 * cm3232_get_it_available() - Get available ALS IT value
279 * @dev: pointer of struct device.
280 * @attr: pointer of struct device_attribute.
281 * @buf: pointer of return string buffer.
282 *
283 * Display the available integration time in second.
284 *
285 * Return: string length.
286 */
287static ssize_t cm3232_get_it_available(struct device *dev,
288 struct device_attribute *attr, char *buf)
289{
290 int i, len;
291
292 for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
293 len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
294 cm3232_als_it_scales[i].val,
295 cm3232_als_it_scales[i].val2);
296 return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
297}
298
299static const struct iio_chan_spec cm3232_channels[] = {
300 {
301 .type = IIO_LIGHT,
302 .info_mask_separate =
303 BIT(IIO_CHAN_INFO_PROCESSED) |
304 BIT(IIO_CHAN_INFO_CALIBSCALE) |
305 BIT(IIO_CHAN_INFO_INT_TIME),
306 }
307};
308
309static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
310 S_IRUGO, cm3232_get_it_available, NULL, 0);
311
312static struct attribute *cm3232_attributes[] = {
313 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
314 NULL,
315};
316
317static const struct attribute_group cm3232_attribute_group = {
318 .attrs = cm3232_attributes
319};
320
321static const struct iio_info cm3232_info = {
322 .read_raw = &cm3232_read_raw,
323 .write_raw = &cm3232_write_raw,
324 .attrs = &cm3232_attribute_group,
325};
326
327static int cm3232_probe(struct i2c_client *client,
328 const struct i2c_device_id *id)
329{
330 struct cm3232_chip *chip;
331 struct iio_dev *indio_dev;
332 int ret;
333
334 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
335 if (!indio_dev)
336 return -ENOMEM;
337
338 chip = iio_priv(indio_dev);
339 i2c_set_clientdata(client, indio_dev);
340 chip->client = client;
341
342 indio_dev->dev.parent = &client->dev;
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
360static int 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 return 0;
370}
371
372static const struct i2c_device_id cm3232_id[] = {
373 {"cm3232", 0},
374 {}
375};
376
377#ifdef CONFIG_PM_SLEEP
378static int cm3232_suspend(struct device *dev)
379{
380 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
381 struct cm3232_chip *chip = iio_priv(indio_dev);
382 struct i2c_client *client = chip->client;
383 int ret;
384
385 chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;
386 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
387 chip->regs_cmd);
388
389 return ret;
390}
391
392static int cm3232_resume(struct device *dev)
393{
394 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
395 struct cm3232_chip *chip = iio_priv(indio_dev);
396 struct i2c_client *client = chip->client;
397 int ret;
398
399 chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
400 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
401 chip->regs_cmd | CM3232_CMD_ALS_RESET);
402
403 return ret;
404}
405
406static const struct dev_pm_ops cm3232_pm_ops = {
407 SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend, cm3232_resume)};
408#endif
409
410MODULE_DEVICE_TABLE(i2c, cm3232_id);
411
412static const struct of_device_id cm3232_of_match[] = {
413 {.compatible = "capella,cm3232"},
414 {}
415};
416MODULE_DEVICE_TABLE(of, cm3232_of_match);
417
418static struct i2c_driver cm3232_driver = {
419 .driver = {
420 .name = "cm3232",
421 .of_match_table = of_match_ptr(cm3232_of_match),
422#ifdef CONFIG_PM_SLEEP
423 .pm = &cm3232_pm_ops,
424#endif
425 },
426 .id_table = cm3232_id,
427 .probe = cm3232_probe,
428 .remove = cm3232_remove,
429};
430
431module_i2c_driver(cm3232_driver);
432
433MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
434MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
435MODULE_LICENSE("GPL");