iio: Add driver for AMS/TAOS tcs3414 digital color sensor

16-bit digital color sensor with red, green, blue and clear channel

datasheet: http://ams.com/eng/content/download/250258/975997/TCS3414_Datasheet_EN_v1.pdfSigned-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/light/Kconfig

@@ -128,6 +128,18 @@ config LTR501
 	 This driver can also be built as a module.  If so, the module
          will be called ltr501.
 
+config TCS3414
+	tristate "TAOS TCS3414 digital color sensor"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	 If you say yes here you get support for the TAOS TCS3414
+	 family of digital color sensors.
+
+	 This driver can also be built as a module.  If so, the module
+	 will be called tcs3414.
+
 config TCS3472
 	tristate "TAOS TCS3472 color light-to-digital converter"
 	depends on I2C

drivers/iio/light/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_ISL29125)		+= isl29125.o
 obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
 obj-$(CONFIG_LTR501)		+= ltr501.o
 obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
+obj-$(CONFIG_TCS3414)		+= tcs3414.o
 obj-$(CONFIG_TCS3472)		+= tcs3472.o
 obj-$(CONFIG_TSL4531)		+= tsl4531.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o

drivers/iio/light/tcs3414.c

+/*
+ * tcs3414.c - Support for TAOS TCS3414 digital color sensor
+ *
+ * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Digital color sensor with 16-bit channels for red, green, blue, clear);
+ * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
+ * TCS3415, TCS3416, resp.)
+ *
+ * TODO: sync, interrupt support, thresholds, prescaler
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/pm.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define TCS3414_DRV_NAME "tcs3414"
+
+#define TCS3414_COMMAND BIT(7)
+#define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
+
+#define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
+#define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
+#define TCS3414_ID (TCS3414_COMMAND | 0x04)
+#define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
+#define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
+#define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
+#define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
+#define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
+
+#define TCS3414_CONTROL_ADC_VALID BIT(4)
+#define TCS3414_CONTROL_ADC_EN BIT(1)
+#define TCS3414_CONTROL_POWER BIT(0)
+
+#define TCS3414_INTEG_MASK GENMASK(1, 0)
+#define TCS3414_INTEG_12MS 0x0
+#define TCS3414_INTEG_100MS 0x1
+#define TCS3414_INTEG_400MS 0x2
+
+#define TCS3414_GAIN_MASK GENMASK(5, 4)
+#define TCS3414_GAIN_SHIFT 4
+
+struct tcs3414_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	u8 control;
+	u8 gain;
+	u8 timing;
+	u16 buffer[8]; /* 4x 16-bit + 8 bytes timestamp */
+};
+
+#define TCS3414_CHANNEL(_color, _si, _addr) { \
+	.type = IIO_INTENSITY, \
+	.modified = 1, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+		BIT(IIO_CHAN_INFO_INT_TIME), \
+	.channel2 = IIO_MOD_LIGHT_##_color, \
+	.address = _addr, \
+	.scan_index = _si, \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 16, \
+		.storagebits = 16, \
+		.endianness = IIO_CPU, \
+	}, \
+}
+
+/* scale factors: 1/gain */
+static const int tcs3414_scales[][2] = {
+	{1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
+};
+
+/* integration time in ms */
+static const int tcs3414_times[] = { 12, 100, 400 };
+
+static const struct iio_chan_spec tcs3414_channels[] = {
+	TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
+	TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
+	TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
+	TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static int tcs3414_req_data(struct tcs3414_data *data)
+{
+	int tries = 25;
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control | TCS3414_CONTROL_ADC_EN);
+	if (ret < 0)
+		return ret;
+
+	while (tries--) {
+		ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
+		if (ret < 0)
+			return ret;
+		if (ret & TCS3414_CONTROL_ADC_VALID)
+			break;
+		msleep(20);
+	}
+
+	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control);
+	if (ret < 0)
+		return ret;
+
+	if (tries < 0) {
+		dev_err(&data->client->dev, "data not ready\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int tcs3414_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	struct tcs3414_data *data = iio_priv(indio_dev);
+	int i, ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (iio_buffer_enabled(indio_dev))
+			return -EBUSY;
+		mutex_lock(&data->lock);
+		ret = tcs3414_req_data(data);
+		if (ret < 0) {
+			mutex_unlock(&data->lock);
+			return ret;
+		}
+		ret = i2c_smbus_read_word_data(data->client, chan->address);
+		mutex_unlock(&data->lock);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+	i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
+	*val = tcs3414_scales[i][0];
+		*val2 = tcs3414_scales[i][1];
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_INT_TIME:
+		*val = 0;
+		*val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+	return -EINVAL;
+}
+
+static int tcs3414_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val, int val2, long mask)
+{
+	struct tcs3414_data *data = iio_priv(indio_dev);
+	int i;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
+			if (val == tcs3414_scales[i][0] &&
+				val2 == tcs3414_scales[i][1]) {
+				data->gain &= ~TCS3414_GAIN_MASK;
+				data->gain |= i << TCS3414_GAIN_SHIFT;
+				return i2c_smbus_write_byte_data(
+					data->client, TCS3414_GAIN,
+					data->gain);
+			}
+		}
+		return -EINVAL;
+	case IIO_CHAN_INFO_INT_TIME:
+		if (val != 0)
+			return -EINVAL;
+		for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
+			if (val == tcs3414_times[i] * 1000) {
+				data->timing &= ~TCS3414_INTEG_MASK;
+				data->timing |= i;
+				return i2c_smbus_write_byte_data(
+					data->client, TCS3414_TIMING,
+					data->timing);
+			}
+		}
+		return -EINVAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct tcs3414_data *data = iio_priv(indio_dev);
+	int i, j = 0;
+
+	for_each_set_bit(i, indio_dev->active_scan_mask,
+		indio_dev->masklength) {
+		int ret = i2c_smbus_read_word_data(data->client,
+			TCS3414_DATA_GREEN + 2*i);
+		if (ret < 0)
+			goto done;
+
+		data->buffer[j++] = ret;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+		iio_get_time_ns());
+
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
+static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
+
+static struct attribute *tcs3414_attributes[] = {
+	&iio_const_attr_scale_available.dev_attr.attr,
+	&iio_const_attr_integration_time_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group tcs3414_attribute_group = {
+	.attrs = tcs3414_attributes,
+};
+
+static const struct iio_info tcs3414_info = {
+	.read_raw = tcs3414_read_raw,
+	.write_raw = tcs3414_write_raw,
+	.attrs = &tcs3414_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+static int tcs3414_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct tcs3414_data *data = iio_priv(indio_dev);
+
+	data->control |= TCS3414_CONTROL_ADC_EN;
+	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control);
+}
+
+static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct tcs3414_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = iio_triggered_buffer_predisable(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	data->control &= ~TCS3414_CONTROL_ADC_EN;
+	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control);
+}
+
+static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
+	.preenable = tcs3414_buffer_preenable,
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = tcs3414_buffer_predisable,
+};
+
+static int tcs3414_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
+{
+	struct tcs3414_data *data;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &tcs3414_info;
+	indio_dev->name = TCS3414_DRV_NAME;
+	indio_dev->channels = tcs3414_channels;
+	indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
+	if (ret < 0)
+		return ret;
+
+	switch (ret & 0xf0) {
+	case 0x00:
+		dev_info(&client->dev, "TCS3404 found\n");
+		break;
+	case 0x10:
+		dev_info(&client->dev, "TCS3413/14/15/16 found\n");
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	data->control = TCS3414_CONTROL_POWER;
+	ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control);
+	if (ret < 0)
+		return ret;
+
+	data->timing = TCS3414_INTEG_12MS; /* free running */
+	ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
+		data->timing);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
+	if (ret < 0)
+		return ret;
+	data->gain = ret;
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+		tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto buffer_cleanup;
+
+	return 0;
+
+buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+	return ret;
+}
+
+static int tcs3414_powerdown(struct tcs3414_data *data)
+{
+	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control & ~(TCS3414_CONTROL_POWER |
+		TCS3414_CONTROL_ADC_EN));
+}
+
+static int tcs3414_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	tcs3414_powerdown(iio_priv(indio_dev));
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tcs3414_suspend(struct device *dev)
+{
+	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
+	return tcs3414_powerdown(data);
+}
+
+static int tcs3414_resume(struct device *dev)
+{
+	struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
+	return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
+		data->control);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
+
+static const struct i2c_device_id tcs3414_id[] = {
+	{ "tcs3414", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tcs3414_id);
+
+static struct i2c_driver tcs3414_driver = {
+	.driver = {
+		.name	= TCS3414_DRV_NAME,
+		.pm	= &tcs3414_pm_ops,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= tcs3414_probe,
+	.remove		= tcs3414_remove,
+	.id_table	= tcs3414_id,
+};
+module_i2c_driver(tcs3414_driver);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
+MODULE_LICENSE("GPL");