On 6/14/23 00:55, Leonard Göhrs wrote:
Enable buffered reading of samples from the LMP92064 ADC.
The main benefit of this change is being able to read out current and
voltage measurements in a single transfer, allowing instantaneous power
measurements.
Reads into the buffer can be triggered by any software triggers, e.g.
the iio-trig-hrtimer:
$ mkdir /sys/kernel/config/iio/triggers/hrtimer/my-trigger
$ cat /sys/bus/iio/devices/iio\:device3/name
lmp92064
$ iio_readdev -t my-trigger -b 16 iio:device3 | hexdump
WARNING: High-speed mode not enabled
0000000 0000 0176 0101 0001 5507 abd5 7645 1768
0000010 0000 016d 0101 0001 ee1e ac6b 7645 1768
...
Signed-off-by: Leonard Göhrs <l.goehrs@xxxxxxxxxxxxxx>
Patch looks good. A small comment for an improvement, but not a most have.
---
drivers/iio/adc/ti-lmp92064.c | 54 +++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
diff --git a/drivers/iio/adc/ti-lmp92064.c b/drivers/iio/adc/ti-lmp92064.c
index c30ed824924f3..03765c4057dda 100644
--- a/drivers/iio/adc/ti-lmp92064.c
+++ b/drivers/iio/adc/ti-lmp92064.c
@@ -16,7 +16,10 @@
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
#include <linux/iio/driver.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
#define TI_LMP92064_REG_CONFIG_A 0x0000
#define TI_LMP92064_REG_CONFIG_B 0x0001
@@ -91,6 +94,13 @@ static const struct iio_chan_spec lmp92064_adc_channels[] = {
.address = TI_LMP92064_CHAN_INC,
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 12,
+ .storagebits = 16,
+ .shift = 0,
+ },
.datasheet_name = "INC",
},
{
@@ -98,8 +108,16 @@ static const struct iio_chan_spec lmp92064_adc_channels[] = {
.address = TI_LMP92064_CHAN_INV,
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 12,
+ .storagebits = 16,
+ .shift = 0,
+ },
.datasheet_name = "INV",
},
+ IIO_CHAN_SOFT_TIMESTAMP(2),
};
static int lmp92064_read_meas(struct lmp92064_adc_priv *priv, u16 *res)
@@ -171,6 +189,37 @@ static int lmp92064_read_raw(struct iio_dev *indio_dev,
}
}
+static irqreturn_t lmp92064_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct lmp92064_adc_priv *priv = iio_priv(indio_dev);
+ int i = 0, j, ret;
+ u16 raw[2];
+ u16 *data;
+
+ ret = lmp92064_read_meas(priv, raw);
+ if (ret < 0)
+ goto done;
+
+ data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
+ if (!data)
+ goto done;
If you want to avoid allocating the buffer each time a sample-set is
captured you can register the `update_scan_mode` callback and allocate
the buffer in there. Or if you know the upper limit of your buffer size,
base on number of channels, and its small you can also use a one time
allocation directly embedded in the priv struct.
+
+ for_each_set_bit(j, indio_dev->active_scan_mask, indio_dev->masklength)
+ data[i++] = raw[j];
+
+ iio_push_to_buffers_with_timestamp(indio_dev, data,
+ iio_get_time_ns(indio_dev));
+
+ kfree(data);
+
+done:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
]...\
