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.pdf

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

3 files changed, 418 insertions, 0 deletions

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 7d83dca6d080..bf05ca5b0a57 100644
--- a/drivers/iio/light/Kconfig
+++ b/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
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index f3d1857b2083..8b8c09f9c1f8 100644
--- a/drivers/iio/light/Makefile
+++ b/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
diff --git a/drivers/iio/light/tcs3414.c b/drivers/iio/light/tcs3414.c
new file mode 100644
index 000000000000..a9e449b0be0c
--- /dev/null
+++ b/drivers/iio/light/tcs3414.c
@@ -0,0 +1,405 @@
+/*
+ * 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");