1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * CM3323 - Capella Color Light Sensor
  4 *
  5 * Copyright (c) 2015, Intel Corporation.
  6 *
  7 * IIO driver for CM3323 (7-bit I2C slave address 0x10)
  8 *
  9 * TODO: calibscale to correct the lens factor
 10 */
 11#include <linux/module.h>
 12#include <linux/init.h>
 13#include <linux/i2c.h>
 14#include <linux/mutex.h>
 15
 16#include <linux/iio/iio.h>
 17#include <linux/iio/sysfs.h>
 18
 19#define CM3323_DRV_NAME "cm3323"
 20
 21#define CM3323_CMD_CONF		0x00
 22#define CM3323_CMD_RED_DATA	0x08
 23#define CM3323_CMD_GREEN_DATA	0x09
 24#define CM3323_CMD_BLUE_DATA	0x0A
 25#define CM3323_CMD_CLEAR_DATA	0x0B
 26
 27#define CM3323_CONF_SD_BIT	BIT(0) /* sensor disable */
 28#define CM3323_CONF_AF_BIT	BIT(1) /* auto/manual force mode */
 29#define CM3323_CONF_IT_MASK	GENMASK(6, 4)
 30#define CM3323_CONF_IT_SHIFT	4
 31
 32#define CM3323_INT_TIME_AVAILABLE "0.04 0.08 0.16 0.32 0.64 1.28"
 33
 34static const struct {
 35	int val;
 36	int val2;
 37} cm3323_int_time[] = {
 38	{0, 40000},  /* 40 ms */
 39	{0, 80000},  /* 80 ms */
 40	{0, 160000}, /* 160 ms */
 41	{0, 320000}, /* 320 ms */
 42	{0, 640000}, /* 640 ms */
 43	{1, 280000}, /* 1280 ms */
 44};
 45
 46struct cm3323_data {
 47	struct i2c_client *client;
 48	u16 reg_conf;
 49	struct mutex mutex;
 50};
 51
 52#define CM3323_COLOR_CHANNEL(_color, _addr) { \
 53	.type = IIO_INTENSITY, \
 54	.modified = 1, \
 55	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 56	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
 57	.channel2 = IIO_MOD_LIGHT_##_color, \
 58	.address = _addr, \
 59}
 60
 61static const struct iio_chan_spec cm3323_channels[] = {
 62	CM3323_COLOR_CHANNEL(RED, CM3323_CMD_RED_DATA),
 63	CM3323_COLOR_CHANNEL(GREEN, CM3323_CMD_GREEN_DATA),
 64	CM3323_COLOR_CHANNEL(BLUE, CM3323_CMD_BLUE_DATA),
 65	CM3323_COLOR_CHANNEL(CLEAR, CM3323_CMD_CLEAR_DATA),
 66};
 67
 68static IIO_CONST_ATTR_INT_TIME_AVAIL(CM3323_INT_TIME_AVAILABLE);
 69
 70static struct attribute *cm3323_attributes[] = {
 71	&iio_const_attr_integration_time_available.dev_attr.attr,
 72	NULL
 73};
 74
 75static const struct attribute_group cm3323_attribute_group = {
 76	.attrs = cm3323_attributes,
 77};
 78
 79static int cm3323_init(struct iio_dev *indio_dev)
 80{
 81	int ret;
 82	struct cm3323_data *data = iio_priv(indio_dev);
 83
 84	ret = i2c_smbus_read_word_data(data->client, CM3323_CMD_CONF);
 85	if (ret < 0) {
 86		dev_err(&data->client->dev, "Error reading reg_conf\n");
 87		return ret;
 88	}
 89
 90	/* enable sensor and set auto force mode */
 91	ret &= ~(CM3323_CONF_SD_BIT | CM3323_CONF_AF_BIT);
 92
 93	ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF, ret);
 94	if (ret < 0) {
 95		dev_err(&data->client->dev, "Error writing reg_conf\n");
 96		return ret;
 97	}
 98
 99	data->reg_conf = ret;
100
101	return 0;
102}
103
104static void cm3323_disable(void *data)
105{
106	int ret;
107	struct iio_dev *indio_dev = data;
108	struct cm3323_data *cm_data = iio_priv(indio_dev);
109
110	ret = i2c_smbus_write_word_data(cm_data->client, CM3323_CMD_CONF,
111					CM3323_CONF_SD_BIT);
112	if (ret < 0)
113		dev_err(&cm_data->client->dev, "Error writing reg_conf\n");
114}
115
116static int cm3323_set_it_bits(struct cm3323_data *data, int val, int val2)
117{
118	int i, ret;
119	u16 reg_conf;
120
121	for (i = 0; i < ARRAY_SIZE(cm3323_int_time); i++) {
122		if (val == cm3323_int_time[i].val &&
123		    val2 == cm3323_int_time[i].val2) {
124			reg_conf = data->reg_conf & ~CM3323_CONF_IT_MASK;
125			reg_conf |= i << CM3323_CONF_IT_SHIFT;
126
127			ret = i2c_smbus_write_word_data(data->client,
128							CM3323_CMD_CONF,
129							reg_conf);
130			if (ret < 0)
131				return ret;
132
133			data->reg_conf = reg_conf;
134
135			return 0;
136		}
137	}
138
139	return -EINVAL;
140}
141
142static int cm3323_get_it_bits(struct cm3323_data *data)
143{
144	int bits;
145
146	bits = (data->reg_conf & CM3323_CONF_IT_MASK) >>
147		CM3323_CONF_IT_SHIFT;
148
149	if (bits >= ARRAY_SIZE(cm3323_int_time))
150		return -EINVAL;
151
152	return bits;
153}
154
155static int cm3323_read_raw(struct iio_dev *indio_dev,
156			   struct iio_chan_spec const *chan, int *val,
157			   int *val2, long mask)
158{
159	int ret;
160	struct cm3323_data *data = iio_priv(indio_dev);
161
162	switch (mask) {
163	case IIO_CHAN_INFO_RAW:
164		mutex_lock(&data->mutex);
165		ret = i2c_smbus_read_word_data(data->client, chan->address);
166		if (ret < 0) {
167			mutex_unlock(&data->mutex);
168			return ret;
169		}
170		*val = ret;
171		mutex_unlock(&data->mutex);
172
173		return IIO_VAL_INT;
174	case IIO_CHAN_INFO_INT_TIME:
175		mutex_lock(&data->mutex);
176		ret = cm3323_get_it_bits(data);
177		if (ret < 0) {
178			mutex_unlock(&data->mutex);
179			return ret;
180		}
181
182		*val = cm3323_int_time[ret].val;
183		*val2 = cm3323_int_time[ret].val2;
184		mutex_unlock(&data->mutex);
185
186		return IIO_VAL_INT_PLUS_MICRO;
187	default:
188		return -EINVAL;
189	}
190}
191
192static int cm3323_write_raw(struct iio_dev *indio_dev,
193			    struct iio_chan_spec const *chan, int val,
194			    int val2, long mask)
195{
196	struct cm3323_data *data = iio_priv(indio_dev);
197	int ret;
198
199	switch (mask) {
200	case IIO_CHAN_INFO_INT_TIME:
201		mutex_lock(&data->mutex);
202		ret = cm3323_set_it_bits(data, val, val2);
203		mutex_unlock(&data->mutex);
204
205		return ret;
206	default:
207		return -EINVAL;
208	}
209}
210
211static const struct iio_info cm3323_info = {
212	.read_raw	= cm3323_read_raw,
213	.write_raw	= cm3323_write_raw,
214	.attrs		= &cm3323_attribute_group,
215};
216
217static int cm3323_probe(struct i2c_client *client,
218			const struct i2c_device_id *id)
219{
220	struct cm3323_data *data;
221	struct iio_dev *indio_dev;
222	int ret;
223
224	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
225	if (!indio_dev)
226		return -ENOMEM;
227
228	data = iio_priv(indio_dev);
229	i2c_set_clientdata(client, indio_dev);
230	data->client = client;
231
232	mutex_init(&data->mutex);
233
234	indio_dev->info = &cm3323_info;
235	indio_dev->name = CM3323_DRV_NAME;
236	indio_dev->channels = cm3323_channels;
237	indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
238	indio_dev->modes = INDIO_DIRECT_MODE;
239
240	ret = cm3323_init(indio_dev);
241	if (ret < 0) {
242		dev_err(&client->dev, "cm3323 chip init failed\n");
243		return ret;
244	}
245
246	ret = devm_add_action_or_reset(&client->dev, cm3323_disable, indio_dev);
247	if (ret < 0)
248		return ret;
249
250	return devm_iio_device_register(&client->dev, indio_dev);
251}
252
253static const struct i2c_device_id cm3323_id[] = {
254	{"cm3323", 0},
255	{}
256};
257MODULE_DEVICE_TABLE(i2c, cm3323_id);
258
259static struct i2c_driver cm3323_driver = {
260	.driver = {
261		.name = CM3323_DRV_NAME,
262	},
263	.probe		= cm3323_probe,
264	.id_table	= cm3323_id,
265};
266
267module_i2c_driver(cm3323_driver);
268
269MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
270MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
271MODULE_LICENSE("GPL v2");