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Kevin Tsai971672c2013-12-24 01:53:00 +00001/*
2 * Copyright (C) 2013 Capella Microsystems Inc.
3 * Author: Kevin Tsai <ktsai@capellamicro.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2, as published
7 * by the Free Software Foundation.
8 */
9
10#include <linux/delay.h>
11#include <linux/err.h>
12#include <linux/i2c.h>
13#include <linux/mutex.h>
14#include <linux/module.h>
15#include <linux/interrupt.h>
16#include <linux/regulator/consumer.h>
17#include <linux/iio/iio.h>
18#include <linux/iio/sysfs.h>
19#include <linux/iio/events.h>
20#include <linux/init.h>
21
22/* Registers Address */
23#define CM32181_REG_ADDR_CMD 0x00
24#define CM32181_REG_ADDR_ALS 0x04
25#define CM32181_REG_ADDR_STATUS 0x06
26#define CM32181_REG_ADDR_ID 0x07
27
28/* Number of Configurable Registers */
29#define CM32181_CONF_REG_NUM 0x01
30
31/* CMD register */
32#define CM32181_CMD_ALS_ENABLE 0x00
33#define CM32181_CMD_ALS_DISABLE 0x01
34#define CM32181_CMD_ALS_INT_EN 0x02
35
36#define CM32181_CMD_ALS_IT_SHIFT 6
37#define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT)
38#define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT)
39
40#define CM32181_CMD_ALS_SM_SHIFT 11
41#define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT)
42#define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT)
43
44#define CM32181_MLUX_PER_BIT 5 /* ALS_SM=01 IT=800ms */
45#define CM32181_MLUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */
46#define CM32181_CALIBSCALE_DEFAULT 1000
47#define CM32181_CALIBSCALE_RESOLUTION 1000
48#define MLUX_PER_LUX 1000
49
50static const u8 cm32181_reg[CM32181_CONF_REG_NUM] = {
51 CM32181_REG_ADDR_CMD,
52};
53
54static const int als_it_bits[] = {12, 8, 0, 1, 2, 3};
55static const int als_it_value[] = {25000, 50000, 100000, 200000, 400000,
56 800000};
57
58struct cm32181_chip {
59 struct i2c_client *client;
60 struct mutex lock;
61 u16 conf_regs[CM32181_CONF_REG_NUM];
62 int calibscale;
63};
64
65/**
66 * cm32181_reg_init() - Initialize CM32181 registers
67 * @cm32181: pointer of struct cm32181.
68 *
69 * Initialize CM32181 ambient light sensor register to default values.
70 *
71 * Return: 0 for success; otherwise for error code.
72 */
73static int cm32181_reg_init(struct cm32181_chip *cm32181)
74{
75 struct i2c_client *client = cm32181->client;
76 int i;
77 s32 ret;
78
79 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
80 if (ret < 0)
81 return ret;
82
83 /* check device ID */
84 if ((ret & 0xFF) != 0x81)
85 return -ENODEV;
86
87 /* Default Values */
88 cm32181->conf_regs[CM32181_REG_ADDR_CMD] = CM32181_CMD_ALS_ENABLE |
89 CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
90 cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
91
92 /* Initialize registers*/
93 for (i = 0; i < CM32181_CONF_REG_NUM; i++) {
94 ret = i2c_smbus_write_word_data(client, cm32181_reg[i],
95 cm32181->conf_regs[i]);
96 if (ret < 0)
97 return ret;
98 }
99
100 return 0;
101}
102
103/**
104 * cm32181_read_als_it() - Get sensor integration time (ms)
105 * @cm32181: pointer of struct cm32181
Beomho Seo1463a162014-02-14 10:04:00 +0000106 * @val2: pointer of int to load the als_it value.
Kevin Tsai971672c2013-12-24 01:53:00 +0000107 *
108 * Report the current integartion time by millisecond.
109 *
Beomho Seo1463a162014-02-14 10:04:00 +0000110 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
Kevin Tsai971672c2013-12-24 01:53:00 +0000111 */
Beomho Seo1463a162014-02-14 10:04:00 +0000112static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
Kevin Tsai971672c2013-12-24 01:53:00 +0000113{
114 u16 als_it;
115 int i;
116
117 als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
118 als_it &= CM32181_CMD_ALS_IT_MASK;
119 als_it >>= CM32181_CMD_ALS_IT_SHIFT;
120 for (i = 0; i < ARRAY_SIZE(als_it_bits); i++) {
121 if (als_it == als_it_bits[i]) {
Beomho Seo1463a162014-02-14 10:04:00 +0000122 *val2 = als_it_value[i];
123 return IIO_VAL_INT_PLUS_MICRO;
Kevin Tsai971672c2013-12-24 01:53:00 +0000124 }
125 }
126
127 return -EINVAL;
128}
129
130/**
131 * cm32181_write_als_it() - Write sensor integration time
132 * @cm32181: pointer of struct cm32181.
133 * @val: integration time by millisecond.
134 *
135 * Convert integration time (ms) to sensor value.
136 *
137 * Return: i2c_smbus_write_word_data command return value.
138 */
139static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
140{
141 struct i2c_client *client = cm32181->client;
142 u16 als_it;
143 int ret, i, n;
144
145 n = ARRAY_SIZE(als_it_value);
146 for (i = 0; i < n; i++)
147 if (val <= als_it_value[i])
148 break;
149 if (i >= n)
150 i = n - 1;
151
152 als_it = als_it_bits[i];
153 als_it <<= CM32181_CMD_ALS_IT_SHIFT;
154
155 mutex_lock(&cm32181->lock);
156 cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
157 ~CM32181_CMD_ALS_IT_MASK;
158 cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
159 als_it;
160 ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
161 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
162 mutex_unlock(&cm32181->lock);
163
164 return ret;
165}
166
167/**
168 * cm32181_get_lux() - report current lux value
169 * @cm32181: pointer of struct cm32181.
170 *
171 * Convert sensor raw data to lux. It depends on integration
Roberta Dobrescua86ea552015-01-16 00:24:41 +0200172 * time and calibscale variable.
Kevin Tsai971672c2013-12-24 01:53:00 +0000173 *
174 * Return: Positive value is lux, otherwise is error code.
175 */
176static int cm32181_get_lux(struct cm32181_chip *cm32181)
177{
178 struct i2c_client *client = cm32181->client;
179 int ret;
180 int als_it;
181 unsigned long lux;
182
183 ret = cm32181_read_als_it(cm32181, &als_it);
184 if (ret < 0)
185 return -EINVAL;
186
187 lux = CM32181_MLUX_PER_BIT;
188 lux *= CM32181_MLUX_PER_BIT_BASE_IT;
189 lux /= als_it;
190
191 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
192 if (ret < 0)
193 return ret;
194
195 lux *= ret;
196 lux *= cm32181->calibscale;
197 lux /= CM32181_CALIBSCALE_RESOLUTION;
198 lux /= MLUX_PER_LUX;
199
200 if (lux > 0xFFFF)
201 lux = 0xFFFF;
202
203 return lux;
204}
205
206static int cm32181_read_raw(struct iio_dev *indio_dev,
207 struct iio_chan_spec const *chan,
208 int *val, int *val2, long mask)
209{
210 struct cm32181_chip *cm32181 = iio_priv(indio_dev);
211 int ret;
212
213 switch (mask) {
214 case IIO_CHAN_INFO_PROCESSED:
215 ret = cm32181_get_lux(cm32181);
216 if (ret < 0)
217 return ret;
218 *val = ret;
219 return IIO_VAL_INT;
220 case IIO_CHAN_INFO_CALIBSCALE:
221 *val = cm32181->calibscale;
222 return IIO_VAL_INT;
223 case IIO_CHAN_INFO_INT_TIME:
Beomho Seo41c897f2014-12-03 00:57:00 +0000224 *val = 0;
Beomho Seo1463a162014-02-14 10:04:00 +0000225 ret = cm32181_read_als_it(cm32181, val2);
Kevin Tsai971672c2013-12-24 01:53:00 +0000226 return ret;
227 }
228
229 return -EINVAL;
230}
231
232static int cm32181_write_raw(struct iio_dev *indio_dev,
233 struct iio_chan_spec const *chan,
234 int val, int val2, long mask)
235{
236 struct cm32181_chip *cm32181 = iio_priv(indio_dev);
237 int ret;
238
239 switch (mask) {
240 case IIO_CHAN_INFO_CALIBSCALE:
241 cm32181->calibscale = val;
242 return val;
243 case IIO_CHAN_INFO_INT_TIME:
Beomho Seo1463a162014-02-14 10:04:00 +0000244 ret = cm32181_write_als_it(cm32181, val2);
Kevin Tsai971672c2013-12-24 01:53:00 +0000245 return ret;
246 }
247
248 return -EINVAL;
249}
250
251/**
252 * cm32181_get_it_available() - Get available ALS IT value
253 * @dev: pointer of struct device.
254 * @attr: pointer of struct device_attribute.
255 * @buf: pointer of return string buffer.
256 *
257 * Display the available integration time values by millisecond.
258 *
259 * Return: string length.
260 */
261static ssize_t cm32181_get_it_available(struct device *dev,
262 struct device_attribute *attr, char *buf)
263{
264 int i, n, len;
265
266 n = ARRAY_SIZE(als_it_value);
267 for (i = 0, len = 0; i < n; i++)
Beomho Seo1463a162014-02-14 10:04:00 +0000268 len += sprintf(buf + len, "0.%06u ", als_it_value[i]);
Kevin Tsai971672c2013-12-24 01:53:00 +0000269 return len + sprintf(buf + len, "\n");
270}
271
272static const struct iio_chan_spec cm32181_channels[] = {
273 {
274 .type = IIO_LIGHT,
275 .info_mask_separate =
276 BIT(IIO_CHAN_INFO_PROCESSED) |
277 BIT(IIO_CHAN_INFO_CALIBSCALE) |
278 BIT(IIO_CHAN_INFO_INT_TIME),
279 }
280};
281
282static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
283 S_IRUGO, cm32181_get_it_available, NULL, 0);
284
285static struct attribute *cm32181_attributes[] = {
286 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
287 NULL,
288};
289
290static const struct attribute_group cm32181_attribute_group = {
291 .attrs = cm32181_attributes
292};
293
294static const struct iio_info cm32181_info = {
295 .driver_module = THIS_MODULE,
296 .read_raw = &cm32181_read_raw,
297 .write_raw = &cm32181_write_raw,
298 .attrs = &cm32181_attribute_group,
299};
300
301static int cm32181_probe(struct i2c_client *client,
302 const struct i2c_device_id *id)
303{
304 struct cm32181_chip *cm32181;
305 struct iio_dev *indio_dev;
306 int ret;
307
308 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*cm32181));
309 if (!indio_dev) {
310 dev_err(&client->dev, "devm_iio_device_alloc failed\n");
311 return -ENOMEM;
312 }
313
314 cm32181 = iio_priv(indio_dev);
315 i2c_set_clientdata(client, indio_dev);
316 cm32181->client = client;
317
318 mutex_init(&cm32181->lock);
319 indio_dev->dev.parent = &client->dev;
320 indio_dev->channels = cm32181_channels;
321 indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
322 indio_dev->info = &cm32181_info;
323 indio_dev->name = id->name;
324 indio_dev->modes = INDIO_DIRECT_MODE;
325
326 ret = cm32181_reg_init(cm32181);
327 if (ret) {
328 dev_err(&client->dev,
329 "%s: register init failed\n",
330 __func__);
331 return ret;
332 }
333
Beomho Seob9785532014-06-18 07:21:00 +0100334 ret = devm_iio_device_register(&client->dev, indio_dev);
Kevin Tsai971672c2013-12-24 01:53:00 +0000335 if (ret) {
336 dev_err(&client->dev,
337 "%s: regist device failed\n",
338 __func__);
339 return ret;
340 }
341
342 return 0;
343}
344
Kevin Tsai971672c2013-12-24 01:53:00 +0000345static const struct i2c_device_id cm32181_id[] = {
346 { "cm32181", 0 },
347 { }
348};
349
350MODULE_DEVICE_TABLE(i2c, cm32181_id);
351
352static const struct of_device_id cm32181_of_match[] = {
353 { .compatible = "capella,cm32181" },
354 { }
355};
Javier Martinez Canillas119c4fc2015-07-30 18:18:42 +0200356MODULE_DEVICE_TABLE(of, cm32181_of_match);
Kevin Tsai971672c2013-12-24 01:53:00 +0000357
358static struct i2c_driver cm32181_driver = {
359 .driver = {
360 .name = "cm32181",
361 .of_match_table = of_match_ptr(cm32181_of_match),
Kevin Tsai971672c2013-12-24 01:53:00 +0000362 },
363 .id_table = cm32181_id,
364 .probe = cm32181_probe,
Kevin Tsai971672c2013-12-24 01:53:00 +0000365};
366
367module_i2c_driver(cm32181_driver);
368
369MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
370MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
371MODULE_LICENSE("GPL");