[PATCH v3] iio: light: Add support for Capella CM3323 color sensor

From: Daniel Baluta
Date: Sat Mar 14 2015 - 15:04:28 EST


Minimal implementation providing raw light intensity
and integration time attribute.

Userspace applications can use GREEN channel for raw
illuminance readings following this table:

Integration Time | G Sensitivity
================================
40 ms | 0.18
80 ms | 0.09
160 ms | 0.045
320 ms | 0.0225
640 ms | 0.01125
1280 ms | 0.005625

Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
Changes since v2:
* use iio_device_register instead of devm_* variant, in order
to better control call order at remove
* introduce cm3323_disable and call it in error path for cm3323_probe

Changes since v1:
* fixed nits after Peter's review - https://lkml.org/lkml/2015/1/22/196
* removed IIO_LIGHT channel since illuminance can be computed
in userspace based on GREEN channel

drivers/iio/light/Kconfig | 10 ++
drivers/iio/light/Makefile | 1 +
drivers/iio/light/cm3323.c | 286 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 297 insertions(+)
create mode 100644 drivers/iio/light/cm3323.c

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index ae68c64..cd937d9 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -59,6 +59,16 @@ config CM3232
To compile this driver as a module, choose M here:
the module will be called cm3232.

+config CM3323
+ depends on I2C
+ tristate "Capella CM3323 color light sensor"
+ help
+ Say Y here if you want to build a driver for Capela CM3323
+ color sensor.
+
+ To compile this driver as a module, choose M here: the module will
+ be called cm3323.
+
config CM36651
depends on I2C
tristate "CM36651 driver"
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index b12a516..ad7c30f 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_AL3320A) += al3320a.o
obj-$(CONFIG_APDS9300) += apds9300.o
obj-$(CONFIG_CM32181) += cm32181.o
obj-$(CONFIG_CM3232) += cm3232.o
+obj-$(CONFIG_CM3323) += cm3323.o
obj-$(CONFIG_CM36651) += cm36651.o
obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
diff --git a/drivers/iio/light/cm3323.c b/drivers/iio/light/cm3323.c
new file mode 100644
index 0000000..869033e
--- /dev/null
+++ b/drivers/iio/light/cm3323.c
@@ -0,0 +1,286 @@
+/*
+ * CM3323 - Capella Color Light Sensor
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * 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.
+ *
+ * IIO driver for CM3323 (7-bit I2C slave address 0x10)
+ *
+ * TODO: calibscale to correct the lens factor
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define CM3323_DRV_NAME "cm3323"
+
+#define CM3323_CMD_CONF 0x00
+#define CM3323_CMD_RED_DATA 0x08
+#define CM3323_CMD_GREEN_DATA 0x09
+#define CM3323_CMD_BLUE_DATA 0x0A
+#define CM3323_CMD_CLEAR_DATA 0x0B
+
+#define CM3323_CONF_SD_BIT BIT(0) /* sensor disable */
+#define CM3323_CONF_AF_BIT BIT(1) /* auto/manual force mode */
+#define CM3323_CONF_IT_MASK (BIT(4) | BIT(5) | BIT(6))
+#define CM3323_CONF_IT_SHIFT 4
+
+#define CM3323_INT_TIME_AVAILABLE "0.04 0.08 0.16 0.32 0.64 1.28"
+
+static const struct {
+ int val;
+ int val2;
+} cm3323_int_time[] = {
+ {0, 40000}, /* 40 ms */
+ {0, 80000}, /* 80 ms */
+ {0, 160000}, /* 160 ms */
+ {0, 320000}, /* 320 ms */
+ {0, 640000}, /* 640 ms */
+ {1, 280000}, /* 1280 ms */
+};
+
+struct cm3323_data {
+ struct i2c_client *client;
+ u16 reg_conf;
+ struct mutex mutex;
+};
+
+#define CM3323_COLOR_CHANNEL(_color, _addr) { \
+ .type = IIO_INTENSITY, \
+ .modified = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
+ .channel2 = IIO_MOD_LIGHT_##_color, \
+ .address = _addr, \
+}
+
+static const struct iio_chan_spec cm3323_channels[] = {
+ CM3323_COLOR_CHANNEL(RED, CM3323_CMD_RED_DATA),
+ CM3323_COLOR_CHANNEL(GREEN, CM3323_CMD_GREEN_DATA),
+ CM3323_COLOR_CHANNEL(BLUE, CM3323_CMD_BLUE_DATA),
+ CM3323_COLOR_CHANNEL(CLEAR, CM3323_CMD_CLEAR_DATA),
+};
+
+static IIO_CONST_ATTR_INT_TIME_AVAIL(CM3323_INT_TIME_AVAILABLE);
+
+static struct attribute *cm3323_attributes[] = {
+ &iio_const_attr_integration_time_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group cm3323_attribute_group = {
+ .attrs = cm3323_attributes,
+};
+
+static int cm3323_init(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct cm3323_data *data = iio_priv(indio_dev);
+
+ ret = i2c_smbus_read_word_data(data->client, CM3323_CMD_CONF);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_conf\n");
+ return ret;
+ }
+
+ /* enable sensor and set auto force mode */
+ ret &= ~(CM3323_CONF_SD_BIT | CM3323_CONF_AF_BIT);
+
+ ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF, ret);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error writing reg_conf\n");
+ return ret;
+ }
+
+ data->reg_conf = ret;
+
+ return 0;
+}
+
+static void cm3323_disable(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct cm3323_data *data = iio_priv(indio_dev);
+
+ ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF,
+ CM3323_CONF_SD_BIT);
+ if (ret < 0)
+ dev_err(&data->client->dev, "Error writing reg_conf\n");
+}
+
+static int cm3323_set_it_bits(struct cm3323_data *data, int val, int val2)
+{
+ int i, ret;
+ u16 reg_conf;
+
+ for (i = 0; i < ARRAY_SIZE(cm3323_int_time); i++) {
+ if (val == cm3323_int_time[i].val &&
+ val2 == cm3323_int_time[i].val2) {
+ reg_conf = data->reg_conf;
+ reg_conf |= i << CM3323_CONF_IT_SHIFT;
+
+ ret = i2c_smbus_write_word_data(data->client,
+ CM3323_CMD_CONF,
+ reg_conf);
+ if (ret < 0)
+ return ret;
+
+ data->reg_conf = reg_conf;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static int cm3323_get_it_bits(struct cm3323_data *data)
+{
+ int bits;
+
+ bits = (data->reg_conf & CM3323_CONF_IT_MASK) >>
+ CM3323_CONF_IT_SHIFT;
+
+ if (bits >= ARRAY_SIZE(cm3323_int_time))
+ return -EINVAL;
+ return bits;
+}
+
+static int cm3323_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ int i, ret;
+ struct cm3323_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&data->mutex);
+ ret = i2c_smbus_read_word_data(data->client, chan->address);
+ if (ret < 0) {
+ mutex_unlock(&data->mutex);
+ return ret;
+ }
+ *val = ret;
+ mutex_unlock(&data->mutex);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_INT_TIME:
+ mutex_lock(&data->mutex);
+ i = cm3323_get_it_bits(data);
+ if (i < 0) {
+ mutex_unlock(&data->mutex);
+ return -EINVAL;
+ }
+
+ *val = cm3323_int_time[i].val;
+ *val2 = cm3323_int_time[i].val2;
+ mutex_unlock(&data->mutex);
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int cm3323_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct cm3323_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ mutex_lock(&data->mutex);
+ ret = cm3323_set_it_bits(data, val, val2);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info cm3323_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = cm3323_read_raw,
+ .write_raw = cm3323_write_raw,
+ .attrs = &cm3323_attribute_group,
+};
+
+static int cm3323_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct cm3323_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+
+ mutex_init(&data->mutex);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &cm3323_info;
+ indio_dev->name = CM3323_DRV_NAME;
+ indio_dev->channels = cm3323_channels;
+ indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = cm3323_init(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "cm3323 chip init failed\n");
+ return ret;
+ }
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to register iio dev\n");
+ goto err_init;
+ }
+ return 0;
+err_init:
+ cm3323_disable(indio_dev);
+ return ret;
+}
+
+static int cm3323_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+ iio_device_unregister(indio_dev);
+ cm3323_disable(indio_dev);
+
+ return 0;
+}
+
+static const struct i2c_device_id cm3323_id[] = {
+ {"cm3323", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, cm3323_id);
+
+static struct i2c_driver cm3323_driver = {
+ .driver = {
+ .name = CM3323_DRV_NAME,
+ },
+ .probe = cm3323_probe,
+ .remove = cm3323_remove,
+ .id_table = cm3323_id,
+};
+
+module_i2c_driver(cm3323_driver);
+
+MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxxxx>");
+MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
+MODULE_LICENSE("GPL v2");
--
1.7.10.4

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