iio: add adjd_s311 I2C digital color sensor driver

sensor has 4 channels (10-bit each, R/G/B and clear), sensitivity
and gain is controlled in the driver by ext_info integration_time
and CHAN_INFO_HARDWAREGAIN

driver supports triggered buffer and IIO_CHAN_INFO_RAW to get the
sensor data

v5: address comments by Jonathan Cameron
* use macro for channel declaration
* get timestamp right before measurement
* cleanups

v4: address comments by Lars-Peter Clausen
* make sure trigger handler is exited with iio_trigger_notify_done()
  and IRQ_HANDLED
* kfree()/kalloc() -> krealloc()

v3:
* fix warnings

v2: address comments by Lars-Peter Clausen
* buffer allocation now in update_scan_mode instead of in trigger
  handler
* simplify trigger code (assume active_scan_mask is not empty, use
  for_each_set_bit, use iio_push_to_buffer)
* reorder entry in Makefile and Kconfig
* fix remove

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 377 insertions, 0 deletions

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index f3ea90d735b..91d15d2f694 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -3,6 +3,18 @@
 #
 menu "Light sensors"
 
+config ADJD_S311
+	tristate "ADJD-S311-CR999 digital color sensor"
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	depends on I2C
+	help
+	 If you say yes here you get support for the Avago ADJD-S311-CR999
+	 digital color light sensor.
+
+	 This driver can also be built as a module.  If so, the module
+	 will be called adjd_s311.
+
 config SENSORS_LM3533
 	tristate "LM3533 ambient light sensor"
 	depends on MFD_LM3533
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 06fa4d3f33e..13f8a782d29 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -2,5 +2,6 @@
 # Makefile for IIO Light sensors
 #
 
+obj-$(CONFIG_ADJD_S311)		+= adjd_s311.o
 obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
diff --git a/drivers/iio/light/adjd_s311.c b/drivers/iio/light/adjd_s311.c
new file mode 100644
index 00000000000..e4851427d72
--- /dev/null
+++ b/drivers/iio/light/adjd_s311.c
@@ -0,0 +1,364 @@
+/*
+ * adjd_s311.c - Support for ADJD-S311-CR999 digital color sensor
+ *
+ * Copyright (C) 2012 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.
+ *
+ * driver for ADJD-S311-CR999 digital color sensor (10-bit channels for
+ * red, green, blue, clear); 7-bit I2C slave address 0x74
+ *
+ * limitations: no calibration, no offset mode, no sleep mode
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/bitmap.h>
+#include <linux/err.h>
+#include <linux/irq.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 ADJD_S311_DRV_NAME "adjd_s311"
+
+#define ADJD_S311_CTRL		0x00
+#define ADJD_S311_CONFIG	0x01
+#define ADJD_S311_CAP_RED	0x06
+#define ADJD_S311_CAP_GREEN	0x07
+#define ADJD_S311_CAP_BLUE	0x08
+#define ADJD_S311_CAP_CLEAR	0x09
+#define ADJD_S311_INT_RED_LO	0x0a
+#define ADJD_S311_INT_RED_HI	0x0b
+#define ADJD_S311_INT_GREEN_LO	0x0c
+#define ADJD_S311_INT_GREEN_HI	0x0d
+#define ADJD_S311_INT_BLUE_LO	0x0e
+#define ADJD_S311_INT_BLUE_HI	0x0f
+#define ADJD_S311_INT_CLEAR_LO	0x10
+#define ADJD_S311_INT_CLEAR_HI	0x11
+#define ADJD_S311_DATA_RED_LO	0x40
+#define ADJD_S311_DATA_RED_HI	0x41
+#define ADJD_S311_DATA_GREEN_LO	0x42
+#define ADJD_S311_DATA_GREEN_HI	0x43
+#define ADJD_S311_DATA_BLUE_LO	0x44
+#define ADJD_S311_DATA_BLUE_HI	0x45
+#define ADJD_S311_DATA_CLEAR_LO	0x46
+#define ADJD_S311_DATA_CLEAR_HI	0x47
+#define ADJD_S311_OFFSET_RED	0x48
+#define ADJD_S311_OFFSET_GREEN	0x49
+#define ADJD_S311_OFFSET_BLUE	0x4a
+#define ADJD_S311_OFFSET_CLEAR	0x4b
+
+#define ADJD_S311_CTRL_GOFS	0x02
+#define ADJD_S311_CTRL_GSSR	0x01
+#define ADJD_S311_CAP_MASK	0x0f
+#define ADJD_S311_INT_MASK	0x0fff
+#define ADJD_S311_DATA_MASK	0x03ff
+
+struct adjd_s311_data {
+	struct i2c_client *client;
+	u16 *buffer;
+};
+
+enum adjd_s311_channel_idx {
+	IDX_RED, IDX_GREEN, IDX_BLUE, IDX_CLEAR
+};
+
+#define ADJD_S311_DATA_REG(chan) (ADJD_S311_DATA_RED_LO + (chan) * 2)
+#define ADJD_S311_INT_REG(chan) (ADJD_S311_INT_RED_LO + (chan) * 2)
+#define ADJD_S311_CAP_REG(chan) (ADJD_S311_CAP_RED + (chan))
+
+static int adjd_s311_req_data(struct iio_dev *indio_dev)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	int tries = 10;
+
+	int ret = i2c_smbus_write_byte_data(data->client, ADJD_S311_CTRL,
+		ADJD_S311_CTRL_GSSR);
+	if (ret < 0)
+		return ret;
+
+	while (tries--) {
+		ret = i2c_smbus_read_byte_data(data->client, ADJD_S311_CTRL);
+		if (ret < 0)
+			return ret;
+		if (!(ret & ADJD_S311_CTRL_GSSR))
+			break;
+		msleep(20);
+	}
+
+	if (tries < 0) {
+		dev_err(&data->client->dev,
+			"adjd_s311_req_data() failed, data not ready\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int adjd_s311_read_data(struct iio_dev *indio_dev, u8 reg, int *val)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+
+	int ret = adjd_s311_req_data(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_word_data(data->client, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret & ADJD_S311_DATA_MASK;
+
+	return 0;
+}
+
+static ssize_t adjd_s311_read_int_time(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	s32 ret;
+
+	ret = i2c_smbus_read_word_data(data->client,
+		ADJD_S311_INT_REG(chan->address));
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", ret & ADJD_S311_INT_MASK);
+}
+
+static ssize_t adjd_s311_write_int_time(struct iio_dev *indio_dev,
+	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
+	 size_t len)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	unsigned long int_time;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &int_time);
+	if (ret)
+		return ret;
+
+	if (int_time > ADJD_S311_INT_MASK)
+		return -EINVAL;
+
+	ret = i2c_smbus_write_word_data(data->client,
+		ADJD_S311_INT_REG(chan->address), int_time);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+
+static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	struct iio_buffer *buffer = indio_dev->buffer;
+	s64 time_ns = iio_get_time_ns();
+	int len = 0;
+	int i, j = 0;
+
+	int ret = adjd_s311_req_data(indio_dev);
+	if (ret < 0)
+		goto done;
+
+	for_each_set_bit(i, indio_dev->active_scan_mask,
+		indio_dev->masklength) {
+		ret = i2c_smbus_read_word_data(data->client,
+			ADJD_S311_DATA_REG(i));
+		if (ret < 0)
+			goto done;
+
+		data->buffer[j++] = ret & ADJD_S311_DATA_MASK;
+		len += 2;
+	}
+
+	if (indio_dev->scan_timestamp)
+		*(s64 *)((phys_addr_t)data->buffer + ALIGN(len, sizeof(s64)))
+			= time_ns;
+	iio_push_to_buffer(buffer, (u8 *)data->buffer, time_ns);
+
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_chan_spec_ext_info adjd_s311_ext_info[] = {
+	{
+		.name = "integration_time",
+		.read = adjd_s311_read_int_time,
+		.write = adjd_s311_write_int_time,
+	},
+	{ }
+};
+
+#define ADJD_S311_CHANNEL(_color, _scan_idx) { \
+	.type = IIO_INTENSITY, \
+	.modified = 1, \
+	.address = (IDX_##_color), \
+	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+		IIO_CHAN_INFO_HARDWAREGAIN_SEPARATE_BIT, \
+	.channel2 = (IIO_MOD_LIGHT_##_color), \
+	.scan_index = (_scan_idx), \
+	.scan_type = IIO_ST('u', 10, 16, 0), \
+	.ext_info = adjd_s311_ext_info, \
+}
+
+static const struct iio_chan_spec adjd_s311_channels[] = {
+	ADJD_S311_CHANNEL(RED, 0),
+	ADJD_S311_CHANNEL(GREEN, 1),
+	ADJD_S311_CHANNEL(BLUE, 2),
+	ADJD_S311_CHANNEL(CLEAR, 3),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static int adjd_s311_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = adjd_s311_read_data(indio_dev, chan->address, val);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = i2c_smbus_read_byte_data(data->client,
+			ADJD_S311_CAP_REG(chan->address));
+		if (ret < 0)
+			return ret;
+		*val = ret & ADJD_S311_CAP_MASK;
+		return IIO_VAL_INT;
+	}
+	return -EINVAL;
+}
+
+static int adjd_s311_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val, int val2, long mask)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		if (val < 0 || val > ADJD_S311_CAP_MASK)
+			return -EINVAL;
+
+		ret = i2c_smbus_write_byte_data(data->client,
+			ADJD_S311_CAP_REG(chan->address), val);
+		return ret;
+	}
+	return -EINVAL;
+}
+
+static int adjd_s311_update_scan_mode(struct iio_dev *indio_dev,
+	const unsigned long *scan_mask)
+{
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+	data->buffer = krealloc(data->buffer, indio_dev->scan_bytes,
+				GFP_KERNEL);
+	if (!data->buffer)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static const struct iio_info adjd_s311_info = {
+	.read_raw = adjd_s311_read_raw,
+	.write_raw = adjd_s311_write_raw,
+	.update_scan_mode = adjd_s311_update_scan_mode,
+	.driver_module = THIS_MODULE,
+};
+
+static int __devinit adjd_s311_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct adjd_s311_data *data;
+	struct iio_dev *indio_dev;
+	int err;
+
+	indio_dev = iio_device_alloc(sizeof(*data));
+	if (indio_dev == NULL) {
+		err = -ENOMEM;
+		goto exit;
+	}
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &adjd_s311_info;
+	indio_dev->name = ADJD_S311_DRV_NAME;
+	indio_dev->channels = adjd_s311_channels;
+	indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	err = iio_triggered_buffer_setup(indio_dev, NULL,
+		adjd_s311_trigger_handler, NULL);
+	if (err < 0)
+		goto exit_free_device;
+
+	err = iio_device_register(indio_dev);
+	if (err)
+		goto exit_unreg_buffer;
+
+	dev_info(&client->dev, "ADJD-S311 color sensor registered\n");
+
+	return 0;
+
+exit_unreg_buffer:
+	iio_triggered_buffer_cleanup(indio_dev);
+exit_free_device:
+	iio_device_free(indio_dev);
+exit:
+	return err;
+}
+
+static int __devexit adjd_s311_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct adjd_s311_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	kfree(data->buffer);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id adjd_s311_id[] = {
+	{ "adjd_s311", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, adjd_s311_id);
+
+static struct i2c_driver adjd_s311_driver = {
+	.driver = {
+		.name	= ADJD_S311_DRV_NAME,
+	},
+	.probe		= adjd_s311_probe,
+	.remove		= __devexit_p(adjd_s311_remove),
+	.id_table	= adjd_s311_id,
+};
+module_i2c_driver(adjd_s311_driver);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("ADJD-S311 color sensor");
+MODULE_LICENSE("GPL");