[PATCH 07/16] iio: adc: max1027: Create a helper to configure the trigger

From: Miquel Raynal
Date: Wed Aug 18 2021 - 07:12:40 EST


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@xxxxxxxxxxx>
---
drivers/iio/adc/max1027.c | 52 ++++++++++++++++++++++++++-------------
1 file changed, 35 insertions(+), 17 deletions(-)

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index a6ebc951c09a..59914fcfd320 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -232,10 +232,37 @@ struct max1027_state {
struct iio_trigger *trig;
__be16 *buffer;
struct mutex lock;
-
+ bool cnvst_trigger;
u8 reg ____cacheline_aligned;
};

+static int max1027_configure_trigger(struct iio_dev *indio_dev)
+{
+ struct max1027_state *st = iio_priv(indio_dev);
+ int ret;
+
+ 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 (st->cnvst_trigger)
+ st->reg |= MAX1027_CKS_MODE0;
+ else
+ st->reg |= MAX1027_CKS_MODE2;
+
+ ret = spi_write(st->spi, &st->reg, 1);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev,
+ "Failed to configure register (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
static int max1027_read_single_value(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val)
@@ -248,14 +275,9 @@ 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_configure_trigger(indio_dev);
+ if (ret)
return ret;
- }

/* Configure conversion register with the requested chan */
st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
@@ -363,12 +385,10 @@ static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
return -EINVAL;

+ st->cnvst_trigger = state;
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_configure_trigger(indio_dev);
+ if (ret)
return ret;

/*
@@ -382,10 +402,8 @@ 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_configure_trigger(indio_dev);
+ if (ret)
return ret;
}

--
2.27.0