[PATCH v2 03/10] iio: adc: mcp3911: add support for buffers

Marcus Folkesson
2022-06-25T10:37:29Z

Add support for buffers to make the driver fit for more usecases.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

Notes:
v2:
- No changes

drivers/iio/adc/mcp3911.c | 58 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 25a235cce56c..2a4bf374f140 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -9,6 +9,10 @@
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/trigger.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
@@ -54,6 +58,10 @@ struct mcp3911 {
struct regulator *vref;
struct clk *clki;
u32 dev_addr;
+ struct {
+ u32 channels[2];
+ s64 ts __aligned(8);
+ } scan;
};

static int mcp3911_read(struct mcp3911 *adc, u8 reg, u32 *val, u8 len)
@@ -187,16 +195,58 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = idx, \
+ .scan_index = idx, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_SCALE), \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 24, \
+ .storagebits = 32, \
+ }, \
}

static const struct iio_chan_spec mcp3911_channels[] = {
MCP3911_CHAN(0),
MCP3911_CHAN(1),
+ IIO_CHAN_SOFT_TIMESTAMP(2),
};

+static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct mcp3911 *adc = iio_priv(indio_dev);
+ int scan_index;
+ int i = 0;
+ u32 val;
+
+ mutex_lock(&adc->lock);
+ for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ const struct iio_chan_spec *scan_chan =
+ &indio_dev->channels[scan_index];
+ int ret = mcp3911_read(adc,
+ MCP3911_CHANNEL(scan_chan->channel), &val, 3);
+
+ if (ret < 0) {
+ dev_warn(&adc->spi->dev,
+ "failed to get conversion data\n");
+ goto out;
+ }
+
+ adc->scan.channels[i] = val;
+ i++;
+ }
+ iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan,
+ iio_get_time_ns(indio_dev));
+out:
+ mutex_unlock(&adc->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
static const struct iio_info mcp3911_info = {
.read_raw = mcp3911_read_raw,
.write_raw = mcp3911_write_raw,
@@ -303,7 +353,7 @@ static int mcp3911_probe(struct spi_device *spi)
goto clk_disable;

indio_dev->name = spi_get_device_id(spi)->name;
- indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED;
indio_dev->info = &mcp3911_info;
spi_set_drvdata(spi, indio_dev);

@@ -312,6 +362,12 @@ static int mcp3911_probe(struct spi_device *spi)

mutex_init(&adc->lock);

+ ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+ NULL,
+ mcp3911_trigger_handler, NULL);
+ if (ret)
+ goto clk_disable;
+
ret = devm_iio_device_register(&adc->spi->dev, indio_dev);
if (ret)
goto clk_disable;
--
2.36.1