max44000: Support controlling LED current output

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@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index 4bce7e152f9c..f0f1a8a6c615 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)