From 2a86487786b5c9ce7bee21efc9ce196bb7fe0aed Mon Sep 17 00:00:00 2001
From: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Date: Wed, 9 May 2018 20:17:18 +0200
Subject: [PATCH] iio: adc: ti-ads8688: add trigger and buffer support

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/adc/ti-ads8688.c | 48 +++++++++++++++++++++++++++++++++---
 1 file changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/ti-ads8688.c b/drivers/iio/adc/ti-ads8688.c
index 079f133144b0..184d686ebd99 100644
--- a/drivers/iio/adc/ti-ads8688.c
+++ b/drivers/iio/adc/ti-ads8688.c
@@ -17,6 +17,9 @@
 #include <linux/of.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/iio/sysfs.h>
 
 #define ADS8688_CMD_REG(x)		(x << 8)
@@ -155,6 +158,13 @@ static const struct attribute_group ads8688_attribute_group = {
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)		\
 			      | BIT(IIO_CHAN_INFO_SCALE)	\
 			      | BIT(IIO_CHAN_INFO_OFFSET),	\
+	.scan_index = index,					\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = 16,					\
+		.storagebits = 16,				\
+		.endianness = IIO_BE,				\
+	},							\
 }
 
 static const struct iio_chan_spec ads8684_channels[] = {
@@ -371,6 +381,28 @@ static const struct iio_info ads8688_info = {
 	.attrs = &ads8688_attribute_group,
 };
 
+static irqreturn_t ads8688_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	u16 buffer[8];
+	int i, j = 0;
+
+	for (i = 0; i < indio_dev->masklength; i++) {
+		if (!test_bit(i, indio_dev->active_scan_mask))
+			continue;
+		buffer[j] = ads8688_read(indio_dev, i);
+		j++;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
+			pf->timestamp);
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static const struct ads8688_chip_info ads8688_chip_info_tbl[] = {
 	[ID_ADS8684] = {
 		.channels = ads8684_channels,
@@ -402,7 +434,7 @@ static int ads8688_probe(struct spi_device *spi)
 
 		ret = regulator_get_voltage(st->reg);
 		if (ret < 0)
-			goto error_out;
+			goto err_regulator_disable;
 
 		st->vref_mv = ret / 1000;
 	} else {
@@ -430,13 +462,22 @@ static int ads8688_probe(struct spi_device *spi)
 
 	mutex_init(&st->lock);
 
+	ret = iio_triggered_buffer_setup(indio_dev, NULL, ads8688_trigger_handler, NULL);
+	if (ret < 0) {
+		dev_err(&spi->dev, "iio triggered buffer setup failed\n");
+		goto err_regulator_disable;
+	}
+
 	ret = iio_device_register(indio_dev);
 	if (ret)
-		goto error_out;
+		goto err_buffer_cleanup;
 
 	return 0;
 
-error_out:
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+err_regulator_disable:
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);
 
@@ -449,6 +490,7 @@ static int ads8688_remove(struct spi_device *spi)
 	struct ads8688_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
 
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);