iio: Add Intersil isl29125 digital color light sensor driver

datasheet: http://www.intersil.com/content/dam/Intersil/documents/isl2/isl29125.pdf

Signed-off-by: Peter Meerwald <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/light/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called gp2ap020a00f.
 
+config ISL29125
+	tristate "Intersil ISL29125 digital color light sensor"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here if you want to build a driver for the Intersil ISL29125
+	  RGB light sensor for I2C.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called isl29125.
+
 config HID_SENSOR_ALS
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER

drivers/iio/light/Makefile

···
 obj-$(CONFIG_GP2AP020A00F)	+= gp2ap020a00f.o
 obj-$(CONFIG_HID_SENSOR_ALS)	+= hid-sensor-als.o
 obj-$(CONFIG_HID_SENSOR_PROX)	+= hid-sensor-prox.o
+obj-$(CONFIG_ISL29125)		+= isl29125.o
 obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
 obj-$(CONFIG_LTR501)		+= ltr501.o
 obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o

drivers/iio/light/isl29125.c

···
+/*
+ * isl29125.c - Support for Intersil ISL29125 RGB light sensor
+ *
+ * Copyright (c) 2014 Peter Meerwald <[e-mail]>
+ *
+ * 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.
+ *
+ * RGB light sensor with 16-bit channels for red, green, blue);
+ * 7-bit I2C slave address 0x44
+ *
+ * TODO: interrupt support, IR compensation, thresholds, 12bit
+ */
+
+#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 ISL29125_DRV_NAME "isl29125"
+
+#define ISL29125_DEVICE_ID 0x00
+#define ISL29125_CONF1 0x01
+#define ISL29125_CONF2 0x02
+#define ISL29125_CONF3 0x03
+#define ISL29125_STATUS 0x08
+#define ISL29125_GREEN_DATA 0x09
+#define ISL29125_RED_DATA 0x0b
+#define ISL29125_BLUE_DATA 0x0d
+
+#define ISL29125_ID 0x7d
+
+#define ISL29125_MODE_MASK GENMASK(2, 0)
+#define ISL29125_MODE_PD 0x0
+#define ISL29125_MODE_G 0x1
+#define ISL29125_MODE_R 0x2
+#define ISL29125_MODE_B 0x3
+#define ISL29125_MODE_RGB 0x5
+
+#define ISL29125_MODE_RANGE BIT(3)
+
+#define ISL29125_STATUS_CONV BIT(1)
+
+struct isl29125_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	u8 conf1;
+	u16 buffer[8]; /* 3x 16-bit, padding, 8 bytes timestamp */
+};
+
+#define ISL29125_CHANNEL(_color, _si) { \
+	.type = IIO_INTENSITY, \
+	.modified = 1, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.channel2 = IIO_MOD_LIGHT_##_color, \
+	.scan_index = _si, \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 16, \
+		.storagebits = 16, \
+		.endianness = IIO_CPU, \
+	}, \
+}
+
+static const struct iio_chan_spec isl29125_channels[] = {
+	ISL29125_CHANNEL(GREEN, 0),
+	ISL29125_CHANNEL(RED, 1),
+	ISL29125_CHANNEL(BLUE, 2),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const struct {
+	u8 mode, data;
+} isl29125_regs[] = {
+	{ISL29125_MODE_G, ISL29125_GREEN_DATA},
+	{ISL29125_MODE_R, ISL29125_RED_DATA},
+	{ISL29125_MODE_B, ISL29125_BLUE_DATA},
+};
+
+static int isl29125_read_data(struct isl29125_data *data, int si)
+{
+	int tries = 5;
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+		data->conf1 | isl29125_regs[si].mode);
+	if (ret < 0)
+		return ret;
+
+	msleep(101);
+
+	while (tries--) {
+		ret = i2c_smbus_read_byte_data(data->client, ISL29125_STATUS);
+		if (ret < 0)
+			goto fail;
+		if (ret & ISL29125_STATUS_CONV)
+			break;
+		msleep(20);
+	}
+
+	if (tries < 0) {
+		dev_err(&data->client->dev, "data not ready\n");
+		ret = -EIO;
+		goto fail;
+	}
+
+	ret = i2c_smbus_read_word_data(data->client, isl29125_regs[si].data);
+
+fail:
+	i2c_smbus_write_byte_data(data->client, ISL29125_CONF1, data->conf1);
+	return ret;
+}
+
+static int isl29125_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	struct isl29125_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (iio_buffer_enabled(indio_dev))
+			return -EBUSY;
+		mutex_lock(&data->lock);
+		ret = isl29125_read_data(data, chan->scan_index);
+		mutex_unlock(&data->lock);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		if (data->conf1 & ISL29125_MODE_RANGE)
+			*val2 = 152590; /* 10k lux full range */
+		else
+			*val2 = 5722; /* 375 lux full range */
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+	return -EINVAL;
+}
+
+static int isl29125_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val, int val2, long mask)
+{
+	struct isl29125_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		if (val != 0)
+			return -EINVAL;
+		if (val2 == 152590)
+			data->conf1 |= ISL29125_MODE_RANGE;
+		else if (val2 == 5722)
+			data->conf1 &= ~ISL29125_MODE_RANGE;
+		else
+			return -EINVAL;
+		return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+			data->conf1);
+	default:
+		return -EINVAL;
+	}
+}
+
+static irqreturn_t isl29125_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct isl29125_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,
+			isl29125_regs[i].data);
+		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 const struct iio_info isl29125_info = {
+	.read_raw = isl29125_read_raw,
+	.write_raw = isl29125_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int isl29125_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct isl29125_data *data = iio_priv(indio_dev);
+
+	data->conf1 |= ISL29125_MODE_RGB;
+	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+		data->conf1);
+}
+
+static int isl29125_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct isl29125_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = iio_triggered_buffer_predisable(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	data->conf1 &= ~ISL29125_MODE_MASK;
+	data->conf1 |= ISL29125_MODE_PD;
+	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+		data->conf1);
+}
+
+static const struct iio_buffer_setup_ops isl29125_buffer_setup_ops = {
+	.preenable = isl29125_buffer_preenable,
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = isl29125_buffer_predisable,
+};
+
+static int isl29125_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
+{
+	struct isl29125_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 = &isl29125_info;
+	indio_dev->name = ISL29125_DRV_NAME;
+	indio_dev->channels = isl29125_channels;
+	indio_dev->num_channels = ARRAY_SIZE(isl29125_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = i2c_smbus_read_byte_data(data->client, ISL29125_DEVICE_ID);
+	if (ret < 0)
+		return ret;
+	if (ret != ISL29125_ID)
+		return -ENODEV;
+
+	data->conf1 = ISL29125_MODE_PD | ISL29125_MODE_RANGE;
+	ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+		data->conf1);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, ISL29125_STATUS, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+		isl29125_trigger_handler, &isl29125_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 isl29125_powerdown(struct isl29125_data *data)
+{
+	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+		(data->conf1 & ~ISL29125_MODE_MASK) | ISL29125_MODE_PD);
+}
+
+static int isl29125_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);
+	isl29125_powerdown(iio_priv(indio_dev));
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int isl29125_suspend(struct device *dev)
+{
+	struct isl29125_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
+	return isl29125_powerdown(data);
+}
+
+static int isl29125_resume(struct device *dev)
+{
+	struct isl29125_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
+	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
+		data->conf1);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(isl29125_pm_ops, isl29125_suspend, isl29125_resume);
+
+static const struct i2c_device_id isl29125_id[] = {
+	{ "isl29125", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, isl29125_id);
+
+static struct i2c_driver isl29125_driver = {
+	.driver = {
+		.name	= ISL29125_DRV_NAME,
+		.pm	= &isl29125_pm_ops,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= isl29125_probe,
+	.remove		= isl29125_remove,
+	.id_table	= isl29125_id,
+};
+module_i2c_driver(isl29125_driver);
+
+MODULE_AUTHOR("Peter Meerwald <[e-mail]>");
+MODULE_DESCRIPTION("ISL29125 RGB light sensor driver");
+MODULE_LICENSE("GPL");