2 * CM3232 Ambient Light Sensor
4 * Copyright (C) 2014-2015 Capella Microsystems Inc.
5 * Author: Kevin Tsai <ktsai@capellamicro.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2, as published
9 * by the Free Software Foundation.
11 * IIO driver for CM3232 (7-bit I2C slave address 0x10).
14 #include <linux/i2c.h>
15 #include <linux/module.h>
16 #include <linux/iio/iio.h>
17 #include <linux/iio/sysfs.h>
18 #include <linux/init.h>
20 /* Registers Address */
21 #define CM3232_REG_ADDR_CMD 0x00
22 #define CM3232_REG_ADDR_ALS 0x50
23 #define CM3232_REG_ADDR_ID 0x53
25 #define CM3232_CMD_ALS_DISABLE BIT(0)
27 #define CM3232_CMD_ALS_IT_SHIFT 2
28 #define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4))
29 #define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)
31 #define CM3232_CMD_ALS_RESET BIT(6)
33 #define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT
35 #define CM3232_HW_ID 0x32
36 #define CM3232_CALIBSCALE_DEFAULT 100000
37 #define CM3232_CALIBSCALE_RESOLUTION 100000
38 #define CM3232_MLUX_PER_LUX 1000
40 #define CM3232_MLUX_PER_BIT_DEFAULT 64
41 #define CM3232_MLUX_PER_BIT_BASE_IT 100000
47 } cm3232_als_it_scales
[] = {
48 {0, 100000, 0}, /* 0.100000 */
49 {0, 200000, 1}, /* 0.200000 */
50 {0, 400000, 2}, /* 0.400000 */
51 {0, 800000, 3}, /* 0.800000 */
52 {1, 600000, 4}, /* 1.600000 */
53 {3, 200000, 5}, /* 3.200000 */
56 struct cm3232_als_info
{
61 int mlux_per_bit_base_it
;
64 static struct cm3232_als_info cm3232_als_info_default
= {
65 .regs_cmd_default
= CM3232_CMD_DEFAULT
,
66 .hw_id
= CM3232_HW_ID
,
67 .calibscale
= CM3232_CALIBSCALE_DEFAULT
,
68 .mlux_per_bit
= CM3232_MLUX_PER_BIT_DEFAULT
,
69 .mlux_per_bit_base_it
= CM3232_MLUX_PER_BIT_BASE_IT
,
73 struct i2c_client
*client
;
74 struct cm3232_als_info
*als_info
;
80 * cm3232_reg_init() - Initialize CM3232
81 * @chip: pointer of struct cm3232_chip.
83 * Check and initialize CM3232 ambient light sensor.
85 * Return: 0 for success; otherwise for error code.
87 static int cm3232_reg_init(struct cm3232_chip
*chip
)
89 struct i2c_client
*client
= chip
->client
;
92 chip
->als_info
= &cm3232_als_info_default
;
95 ret
= i2c_smbus_read_word_data(client
, CM3232_REG_ADDR_ID
);
97 dev_err(&chip
->client
->dev
, "Error reading addr_id\n");
101 if ((ret
& 0xFF) != chip
->als_info
->hw_id
)
104 /* Disable and reset device */
105 chip
->regs_cmd
= CM3232_CMD_ALS_DISABLE
| CM3232_CMD_ALS_RESET
;
106 ret
= i2c_smbus_write_byte_data(client
, CM3232_REG_ADDR_CMD
,
109 dev_err(&chip
->client
->dev
, "Error writing reg_cmd\n");
113 /* Register default value */
114 chip
->regs_cmd
= chip
->als_info
->regs_cmd_default
;
116 /* Configure register */
117 ret
= i2c_smbus_write_byte_data(client
, CM3232_REG_ADDR_CMD
,
120 dev_err(&chip
->client
->dev
, "Error writing reg_cmd\n");
126 * cm3232_read_als_it() - Get sensor integration time
127 * @chip: pointer of struct cm3232_chip
128 * @val: pointer of int to load the integration (sec).
129 * @val2: pointer of int to load the integration time (microsecond).
131 * Report the current integration time.
133 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
135 static int cm3232_read_als_it(struct cm3232_chip
*chip
, int *val
, int *val2
)
140 als_it
= chip
->regs_cmd
;
141 als_it
&= CM3232_CMD_ALS_IT_MASK
;
142 als_it
>>= CM3232_CMD_ALS_IT_SHIFT
;
143 for (i
= 0; i
< ARRAY_SIZE(cm3232_als_it_scales
); i
++) {
144 if (als_it
== cm3232_als_it_scales
[i
].it
) {
145 *val
= cm3232_als_it_scales
[i
].val
;
146 *val2
= cm3232_als_it_scales
[i
].val2
;
147 return IIO_VAL_INT_PLUS_MICRO
;
155 * cm3232_write_als_it() - Write sensor integration time
156 * @chip: pointer of struct cm3232_chip.
157 * @val: integration time in second.
158 * @val2: integration time in microsecond.
160 * Convert integration time to sensor value.
162 * Return: i2c_smbus_write_byte_data command return value.
164 static int cm3232_write_als_it(struct cm3232_chip
*chip
, int val
, int val2
)
166 struct i2c_client
*client
= chip
->client
;
171 for (i
= 0; i
< ARRAY_SIZE(cm3232_als_it_scales
); i
++) {
172 if (val
== cm3232_als_it_scales
[i
].val
&&
173 val2
== cm3232_als_it_scales
[i
].val2
) {
175 als_it
= cm3232_als_it_scales
[i
].it
;
176 als_it
<<= CM3232_CMD_ALS_IT_SHIFT
;
178 cmd
= chip
->regs_cmd
& ~CM3232_CMD_ALS_IT_MASK
;
180 ret
= i2c_smbus_write_byte_data(client
,
185 chip
->regs_cmd
= cmd
;
193 * cm3232_get_lux() - report current lux value
194 * @chip: pointer of struct cm3232_chip.
196 * Convert sensor data to lux. It depends on integration
197 * time and calibscale variable.
199 * Return: Zero or positive value is lux, otherwise error code.
201 static int cm3232_get_lux(struct cm3232_chip
*chip
)
203 struct i2c_client
*client
= chip
->client
;
204 struct cm3232_als_info
*als_info
= chip
->als_info
;
210 /* Calculate mlux per bit based on als_it */
211 ret
= cm3232_read_als_it(chip
, &val
, &val2
);
214 als_it
= val
* 1000000 + val2
;
215 lux
= (__force u64
)als_info
->mlux_per_bit
;
216 lux
*= als_info
->mlux_per_bit_base_it
;
217 lux
= div_u64(lux
, als_it
);
219 ret
= i2c_smbus_read_word_data(client
, CM3232_REG_ADDR_ALS
);
221 dev_err(&client
->dev
, "Error reading reg_addr_als\n");
225 chip
->regs_als
= (u16
)ret
;
226 lux
*= chip
->regs_als
;
227 lux
*= als_info
->calibscale
;
228 lux
= div_u64(lux
, CM3232_CALIBSCALE_RESOLUTION
);
229 lux
= div_u64(lux
, CM3232_MLUX_PER_LUX
);
237 static int cm3232_read_raw(struct iio_dev
*indio_dev
,
238 struct iio_chan_spec
const *chan
,
239 int *val
, int *val2
, long mask
)
241 struct cm3232_chip
*chip
= iio_priv(indio_dev
);
242 struct cm3232_als_info
*als_info
= chip
->als_info
;
246 case IIO_CHAN_INFO_PROCESSED
:
247 ret
= cm3232_get_lux(chip
);
252 case IIO_CHAN_INFO_CALIBSCALE
:
253 *val
= als_info
->calibscale
;
255 case IIO_CHAN_INFO_INT_TIME
:
256 return cm3232_read_als_it(chip
, val
, val2
);
262 static int cm3232_write_raw(struct iio_dev
*indio_dev
,
263 struct iio_chan_spec
const *chan
,
264 int val
, int val2
, long mask
)
266 struct cm3232_chip
*chip
= iio_priv(indio_dev
);
267 struct cm3232_als_info
*als_info
= chip
->als_info
;
270 case IIO_CHAN_INFO_CALIBSCALE
:
271 als_info
->calibscale
= val
;
273 case IIO_CHAN_INFO_INT_TIME
:
274 return cm3232_write_als_it(chip
, val
, val2
);
281 * cm3232_get_it_available() - Get available ALS IT value
282 * @dev: pointer of struct device.
283 * @attr: pointer of struct device_attribute.
284 * @buf: pointer of return string buffer.
286 * Display the available integration time in second.
288 * Return: string length.
290 static ssize_t
cm3232_get_it_available(struct device
*dev
,
291 struct device_attribute
*attr
, char *buf
)
295 for (i
= 0, len
= 0; i
< ARRAY_SIZE(cm3232_als_it_scales
); i
++)
296 len
+= scnprintf(buf
+ len
, PAGE_SIZE
- len
, "%u.%06u ",
297 cm3232_als_it_scales
[i
].val
,
298 cm3232_als_it_scales
[i
].val2
);
299 return len
+ scnprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
302 static const struct iio_chan_spec cm3232_channels
[] = {
305 .info_mask_separate
=
306 BIT(IIO_CHAN_INFO_PROCESSED
) |
307 BIT(IIO_CHAN_INFO_CALIBSCALE
) |
308 BIT(IIO_CHAN_INFO_INT_TIME
),
312 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available
,
313 S_IRUGO
, cm3232_get_it_available
, NULL
, 0);
315 static struct attribute
*cm3232_attributes
[] = {
316 &iio_dev_attr_in_illuminance_integration_time_available
.dev_attr
.attr
,
320 static const struct attribute_group cm3232_attribute_group
= {
321 .attrs
= cm3232_attributes
324 static const struct iio_info cm3232_info
= {
325 .driver_module
= THIS_MODULE
,
326 .read_raw
= &cm3232_read_raw
,
327 .write_raw
= &cm3232_write_raw
,
328 .attrs
= &cm3232_attribute_group
,
331 static int cm3232_probe(struct i2c_client
*client
,
332 const struct i2c_device_id
*id
)
334 struct cm3232_chip
*chip
;
335 struct iio_dev
*indio_dev
;
338 indio_dev
= devm_iio_device_alloc(&client
->dev
, sizeof(*chip
));
342 chip
= iio_priv(indio_dev
);
343 i2c_set_clientdata(client
, indio_dev
);
344 chip
->client
= client
;
346 indio_dev
->dev
.parent
= &client
->dev
;
347 indio_dev
->channels
= cm3232_channels
;
348 indio_dev
->num_channels
= ARRAY_SIZE(cm3232_channels
);
349 indio_dev
->info
= &cm3232_info
;
350 indio_dev
->name
= id
->name
;
351 indio_dev
->modes
= INDIO_DIRECT_MODE
;
353 ret
= cm3232_reg_init(chip
);
355 dev_err(&client
->dev
,
356 "%s: register init failed\n",
361 return iio_device_register(indio_dev
);
364 static int cm3232_remove(struct i2c_client
*client
)
366 struct iio_dev
*indio_dev
= i2c_get_clientdata(client
);
368 i2c_smbus_write_byte_data(client
, CM3232_REG_ADDR_CMD
,
369 CM3232_CMD_ALS_DISABLE
);
371 iio_device_unregister(indio_dev
);
376 static const struct i2c_device_id cm3232_id
[] = {
381 #ifdef CONFIG_PM_SLEEP
382 static int cm3232_suspend(struct device
*dev
)
384 struct iio_dev
*indio_dev
= i2c_get_clientdata(to_i2c_client(dev
));
385 struct cm3232_chip
*chip
= iio_priv(indio_dev
);
386 struct i2c_client
*client
= chip
->client
;
389 chip
->regs_cmd
|= CM3232_CMD_ALS_DISABLE
;
390 ret
= i2c_smbus_write_byte_data(client
, CM3232_REG_ADDR_CMD
,
396 static int cm3232_resume(struct device
*dev
)
398 struct iio_dev
*indio_dev
= i2c_get_clientdata(to_i2c_client(dev
));
399 struct cm3232_chip
*chip
= iio_priv(indio_dev
);
400 struct i2c_client
*client
= chip
->client
;
403 chip
->regs_cmd
&= ~CM3232_CMD_ALS_DISABLE
;
404 ret
= i2c_smbus_write_byte_data(client
, CM3232_REG_ADDR_CMD
,
405 chip
->regs_cmd
| CM3232_CMD_ALS_RESET
);
410 static const struct dev_pm_ops cm3232_pm_ops
= {
411 SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend
, cm3232_resume
)};
414 MODULE_DEVICE_TABLE(i2c
, cm3232_id
);
416 static const struct of_device_id cm3232_of_match
[] = {
417 {.compatible
= "capella,cm3232"},
420 MODULE_DEVICE_TABLE(of
, cm3232_of_match
);
422 static struct i2c_driver cm3232_driver
= {
425 .of_match_table
= of_match_ptr(cm3232_of_match
),
426 #ifdef CONFIG_PM_SLEEP
427 .pm
= &cm3232_pm_ops
,
430 .id_table
= cm3232_id
,
431 .probe
= cm3232_probe
,
432 .remove
= cm3232_remove
,
435 module_i2c_driver(cm3232_driver
);
437 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
438 MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
439 MODULE_LICENSE("GPL");