[PATCH v3 3/5] max44000: Support controlling LED current output

From: Crestez Dan Leonard
Date: Mon Apr 18 2016 - 10:32:58 EST


This is exposed as an output channel with "led" as an extend_name.

Other sensors also have support for controlling an external LED. It's
not clear that simply exposing an undecorated output channel is the
correct approach.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
---
drivers/iio/light/max44000.c | 53 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index dc63de2..0ccd110 100644
--- a/drivers/iio/light/max44000.c
+++ b/drivers/iio/light/max44000.c
@@ -85,6 +85,13 @@ static const struct iio_chan_spec max44000_channels[] = {
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
},
+ {
+ .type = IIO_CURRENT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .extend_name = "led",
+ .output = 1,
+ },
};

static int max44000_read_alsval(struct max44000_data *data)
@@ -125,6 +132,20 @@ static int max44000_write_led_current_raw(struct max44000_data *data, int val)
MAX44000_LED_CURRENT_MASK, val);
}

+static int max44000_read_led_current_raw(struct max44000_data *data)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
+ if (ret < 0)
+ return ret;
+ regval &= MAX44000_LED_CURRENT_MASK;
+ if (regval >= 8)
+ regval -= 4;
+ return regval;
+}
+
static int max44000_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
@@ -154,12 +175,26 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
*val = regval;
return IIO_VAL_INT;

+ case IIO_CURRENT:
+ mutex_lock(&data->lock);
+ ret = max44000_read_led_current_raw(data);
+ mutex_unlock(&data->lock);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+
default:
return -EINVAL;
}

case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
+ case IIO_CURRENT:
+ /* Output register is in 10s of miliamps */
+ *val = 10;
+ return IIO_VAL_INT;
+
case IIO_LIGHT:
*val = 1;
*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
@@ -174,9 +209,27 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
}
}

+static int max44000_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct max44000_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
+ mutex_lock(&data->lock);
+ ret = max44000_write_led_current_raw(data, val);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
static const struct iio_info max44000_info = {
.driver_module = THIS_MODULE,
.read_raw = max44000_read_raw,
+ .write_raw = max44000_write_raw,
};

static bool max44000_readable_reg(struct device *dev, unsigned int reg)
--
2.5.5