Re: [PATCH 5/5] max44000: Initial triggered buffer support

From: Peter Meerwald-Stadler
Date: Thu Apr 07 2016 - 15:59:18 EST



comments below

> Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
> ---
> drivers/iio/light/max44000.c | 63 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 63 insertions(+)
>
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> index e479c53..7b1f8bc 100644
> --- a/drivers/iio/light/max44000.c
> +++ b/drivers/iio/light/max44000.c
> @@ -19,6 +19,9 @@
> #include <linux/util_macros.h>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> #include <linux/acpi.h>
>
> #define MAX44000_DRV_NAME "max44000"
> @@ -123,24 +126,41 @@ static const char max44000_scale_avail_str[] =
> "0.5 "
> "4";
>
> +#define MAX44000_SCAN_INDEX_ALS 0
> +#define MAX44000_SCAN_INDEX_PRX 1
> +
> static const struct iio_chan_spec max44000_channels[] = {
> {
> .type = IIO_LIGHT,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
> BIT(IIO_CHAN_INFO_INT_TIME),
> + .scan_index = MAX44000_SCAN_INDEX_ALS,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 14,
> + .storagebits = 16,
> + }
> },
> {
> .type = IIO_PROXIMITY,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = MAX44000_SCAN_INDEX_PRX,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 8,
> + .storagebits = 8,

code would get simpler if storagebits = 16

> + }
> },
> + IIO_CHAN_SOFT_TIMESTAMP(2),
> {
> .type = IIO_CURRENT,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> BIT(IIO_CHAN_INFO_SCALE),
> .extend_name = "led",
> .output = 1,
> + .scan_index = -1,
> },
> };
>
> @@ -456,6 +476,42 @@ static int max44000_force_write_defaults(struct max44000_data *data)
> return 0;
> }
>
> +static irqreturn_t max44000_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct max44000_data *data = iio_priv(indio_dev);
> + u16 buf[indio_dev->scan_bytes / 2];
> + u8 *pos = (u8 *)buf;

int i = 0;

> + unsigned int regval;
> + int ret;
> +
> + mutex_lock(&data->lock);
> + if (*indio_dev->active_scan_mask & (1 << MAX44000_SCAN_INDEX_ALS)) {

BIT(MAX44000_SCAN_INDEX_ALS)

> + ret = max44000_read_alsval(data);
> + if (ret < 0)
> + goto out_unlock;
> + *((u16 *)pos) = ret;

buf[i++] = ret;

> + pos += 2;
> + }
> + if (*indio_dev->active_scan_mask & (1 << MAX44000_SCAN_INDEX_PRX)) {
> + ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
> + if (ret < 0)
> + goto out_unlock;
buf[i++] = retval;

> + *pos = regval;
> + }
> + mutex_unlock(&data->lock);
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());

moving iio_push_to_buffers_with_timestamp() before mutex_unlock() would
allow simpler code (not sure if it's worth)

> + iio_trigger_notify_done(indio_dev->trig);
> + return IRQ_HANDLED;
> +
> +out_unlock:
> + mutex_unlock(&data->lock);
> + iio_trigger_notify_done(indio_dev->trig);
> + return IRQ_HANDLED;
> +}
> +
> static int max44000_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -513,6 +569,12 @@ static int max44000_probe(struct i2c_client *client,
> return ret;
> }
>
> + ret = iio_triggered_buffer_setup(indio_dev, NULL, max44000_trigger_handler, NULL);
> + if (ret < 0) {
> + dev_err(&client->dev, "iio triggered buffer setup failed\n");
> + return ret;
> + }
> +
> return iio_device_register(indio_dev);

no devm_ possible anymore :-)

> }
>
> @@ -521,6 +583,7 @@ static int max44000_remove(struct i2c_client *client)
> struct iio_dev *indio_dev = i2c_get_clientdata(client);
>
> iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
> return 0;
> }
>
>

--

Peter Meerwald-Stadler
+43-664-2444418 (mobile)