iio: adc: max1027: Create a helper to enable/disable the cnvst trigger

There are two ways to physically trigger a conversion:
- A falling edge on the cnvst pin
- A write operation on the conversion register

Let's create a helper for this.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210921115408.66711-7-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index 94e096d..ad0ca63 100644 (file)
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -272,6 +272,25 @@ struct max1027_state {
        u8                              reg ____cacheline_aligned;
 };
 
+static int max1027_enable_trigger(struct iio_dev *indio_dev, bool enable)
+{
+       struct max1027_state *st = iio_priv(indio_dev);
+
+       st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2;
+
+       /*
+        * Start acquisition on:
+        * MODE0: external hardware trigger wired to the cnvst input pin
+        * MODE2: conversion register write
+        */
+       if (enable)
+               st->reg |= MAX1027_CKS_MODE0;
+       else
+               st->reg |= MAX1027_CKS_MODE2;
+
+       return spi_write(st->spi, &st->reg, 1);
+}
+
 static int max1027_read_single_value(struct iio_dev *indio_dev,
                                     struct iio_chan_spec const *chan,
                                     int *val)
@@ -284,14 +303,9 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
                return -EBUSY;
        }
 
-       /* Start acquisition on conversion register write */
-       st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
-       ret = spi_write(st->spi, &st->reg, 1);
-       if (ret < 0) {
-               dev_err(&indio_dev->dev,
-                       "Failed to configure setup register\n");
+       ret = max1027_enable_trigger(indio_dev, false);
+       if (ret)
                return ret;
-       }
 
        /* Configure conversion register with the requested chan */
        st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
@@ -397,11 +411,8 @@ static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
        int ret;
 
        if (state) {
-               /* Start acquisition on cnvst */
-               st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
-                         MAX1027_REF_MODE2;
-               ret = spi_write(st->spi, &st->reg, 1);
-               if (ret < 0)
+               ret = max1027_enable_trigger(indio_dev, state);
+               if (ret)
                        return ret;
 
                /*
@@ -418,10 +429,8 @@ static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
                        return ret;
        } else {
                /* Start acquisition on conversion register write */
-               st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 |
-                         MAX1027_REF_MODE2;
-               ret = spi_write(st->spi, &st->reg, 1);
-               if (ret < 0)
+               ret = max1027_enable_trigger(indio_dev, state);
+               if (ret)
                        return ret;
        }