Re: [PATCH v7 25/38] iio/scmi: port driver to the new scmi_sensor_proto_ops interface

[Jyoti Bhayana <jbhayana@google.com>]

Hi Christian,

Thanks for porting this driver to the new interface. I have two questions:

1)  In the following code snippet, can the sensor_ops be made as part
of struct scmi_iio_priv as scmi_protocol_handle is also part of that
struct. Not sure if there are any particular reasons for having the
protocol handle as part of the struct but the sensor_ops as global?

> +static const struct scmi_sensor_proto_ops *sensor_ops;
>+
 >.struct scmi_iio_priv {
>-       struct scmi_handle *handle;
>+       struct scmi_protocol_handle *ph;
>      const struct scmi_sensor_info *sensor_info;
>     struct iio_dev *indio_dev;

2)  Looks like the event notifier registration is SCMI device managed
and that's why there is no call to unregister. I am assuming that you
have tested the logic of inserting the module, removing it and then
again inserting it to make sure that when the event is registered a
second time , the logic is all good.

   > ret = handle->notify_ops->devm_event_notifier_register(sdev,

Thanks,
Jyoti

On Tue, Mar 16, 2021 at 5:50 AM Cristian Marussi
<cristian.marussi@arm.com> wrote:
>
> Port driver to the new SCMI Sensor interface based on protocol handles
> and common devm_get_ops().
>
> Cc: Jyoti Bhayana <jbhayana@google.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---
>  drivers/iio/common/scmi_sensors/scmi_iio.c | 91 ++++++++++------------
>  1 file changed, 41 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
> index 872d87ca6256..b4bdc3f3a946 100644
> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
> @@ -21,8 +21,10 @@
>
>  #define SCMI_IIO_NUM_OF_AXIS 3
>
> +static const struct scmi_sensor_proto_ops *sensor_ops;
> +
>  struct scmi_iio_priv {
> -       struct scmi_handle *handle;
> +       struct scmi_protocol_handle *ph;
>         const struct scmi_sensor_info *sensor_info;
>         struct iio_dev *indio_dev;
>         /* adding one additional channel for timestamp */
> @@ -82,7 +84,6 @@ static int scmi_iio_sensor_update_cb(struct notifier_block *nb,
>  static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
>  {
>         struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> -       u32 sensor_id = sensor->sensor_info->id;
>         u32 sensor_config = 0;
>         int err;
>
> @@ -92,27 +93,11 @@ static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
>
>         sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
>                                     SCMI_SENS_CFG_SENSOR_ENABLE);
> -
> -       err = sensor->handle->notify_ops->register_event_notifier(sensor->handle,
> -                       SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> -                       &sensor_id, &sensor->sensor_update_nb);
> -       if (err) {
> -               dev_err(&iio_dev->dev,
> -                       "Error in registering sensor update notifier for sensor %s err %d",
> -                       sensor->sensor_info->name, err);
> -               return err;
> -       }
> -
> -       err = sensor->handle->sensor_ops->config_set(sensor->handle,
> -                       sensor->sensor_info->id, sensor_config);
> -       if (err) {
> -               sensor->handle->notify_ops->unregister_event_notifier(sensor->handle,
> -                               SCMI_PROTOCOL_SENSOR,
> -                               SCMI_EVENT_SENSOR_UPDATE, &sensor_id,
> -                               &sensor->sensor_update_nb);
> +       err = sensor_ops->config_set(sensor->ph, sensor->sensor_info->id,
> +                                    sensor_config);
> +       if (err)
>                 dev_err(&iio_dev->dev, "Error in enabling sensor %s err %d",
>                         sensor->sensor_info->name, err);
> -       }
>
>         return err;
>  }
> @@ -120,25 +105,13 @@ static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
>  static int scmi_iio_buffer_postdisable(struct iio_dev *iio_dev)
>  {
>         struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> -       u32 sensor_id = sensor->sensor_info->id;
>         u32 sensor_config = 0;
>         int err;
>
>         sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
>                                     SCMI_SENS_CFG_SENSOR_DISABLE);
> -
> -       err = sensor->handle->notify_ops->unregister_event_notifier(sensor->handle,
> -                       SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> -                       &sensor_id, &sensor->sensor_update_nb);
> -       if (err) {
> -               dev_err(&iio_dev->dev,
> -                       "Error in unregistering sensor update notifier for sensor %s err %d",
> -                       sensor->sensor_info->name, err);
> -               return err;
> -       }
> -
> -       err = sensor->handle->sensor_ops->config_set(sensor->handle, sensor_id,
> -                                                    sensor_config);
> +       err = sensor_ops->config_set(sensor->ph, sensor->sensor_info->id,
> +                                    sensor_config);
>         if (err) {
>                 dev_err(&iio_dev->dev,
>                         "Error in disabling sensor %s with err %d",
> @@ -161,8 +134,8 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
>         u32 sensor_config;
>         char buf[32];
>
> -       int err = sensor->handle->sensor_ops->config_get(sensor->handle,
> -                       sensor->sensor_info->id, &sensor_config);
> +       int err = sensor_ops->config_get(sensor->ph, sensor->sensor_info->id,
> +                                        &sensor_config);
>         if (err) {
>                 dev_err(&iio_dev->dev,
>                         "Error in getting sensor config for sensor %s err %d",
> @@ -208,8 +181,8 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
>         sensor_config |=
>                 FIELD_PREP(SCMI_SENS_CFG_ROUND_MASK, SCMI_SENS_CFG_ROUND_AUTO);
>
> -       err = sensor->handle->sensor_ops->config_set(sensor->handle,
> -                       sensor->sensor_info->id, sensor_config);
> +       err = sensor_ops->config_set(sensor->ph, sensor->sensor_info->id,
> +                                    sensor_config);
>         if (err)
>                 dev_err(&iio_dev->dev,
>                         "Error in setting sensor update interval for sensor %s value %u err %d",
> @@ -274,8 +247,8 @@ static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
>         u32 sensor_config;
>         int mult;
>
> -       int err = sensor->handle->sensor_ops->config_get(sensor->handle,
> -                       sensor->sensor_info->id, &sensor_config);
> +       int err = sensor_ops->config_get(sensor->ph, sensor->sensor_info->id,
> +                                        &sensor_config);
>         if (err) {
>                 dev_err(&iio_dev->dev,
>                         "Error in getting sensor config for sensor %s err %d",
> @@ -542,15 +515,17 @@ static int scmi_iio_buffers_setup(struct iio_dev *scmi_iiodev)
>         return 0;
>  }
>
> -static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
> -                                        struct scmi_handle *handle,
> -                                        const struct scmi_sensor_info *sensor_info)
> +static struct iio_dev *
> +scmi_alloc_iiodev(struct scmi_device *sdev, struct scmi_protocol_handle *ph,
> +                 const struct scmi_sensor_info *sensor_info)
>  {
>         struct iio_chan_spec *iio_channels;
>         struct scmi_iio_priv *sensor;
>         enum iio_modifier modifier;
>         enum iio_chan_type type;
>         struct iio_dev *iiodev;
> +       struct device *dev = &sdev->dev;
> +       const struct scmi_handle *handle = sdev->handle;
>         int i, ret;
>
>         iiodev = devm_iio_device_alloc(dev, sizeof(*sensor));
> @@ -560,7 +535,7 @@ static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
>         iiodev->modes = INDIO_DIRECT_MODE;
>         iiodev->dev.parent = dev;
>         sensor = iio_priv(iiodev);
> -       sensor->handle = handle;
> +       sensor->ph = ph;
>         sensor->sensor_info = sensor_info;
>         sensor->sensor_update_nb.notifier_call = scmi_iio_sensor_update_cb;
>         sensor->indio_dev = iiodev;
> @@ -595,6 +570,17 @@ static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
>                                           sensor_info->axis[i].id);
>         }
>
> +       ret = handle->notify_ops->devm_event_notifier_register(sdev,
> +                               SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> +                               &sensor->sensor_info->id,
> +                               &sensor->sensor_update_nb);
> +       if (ret) {
> +               dev_err(&iiodev->dev,
> +                       "Error in registering sensor update notifier for sensor %s err %d",
> +                       sensor->sensor_info->name, ret);
> +               return ERR_PTR(ret);
> +       }
> +
>         scmi_iio_set_timestamp_channel(&iio_channels[i], i);
>         iiodev->channels = iio_channels;
>         return iiodev;
> @@ -604,24 +590,29 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
>  {
>         const struct scmi_sensor_info *sensor_info;
>         struct scmi_handle *handle = sdev->handle;
> +       struct scmi_protocol_handle *ph;
>         struct device *dev = &sdev->dev;
>         struct iio_dev *scmi_iio_dev;
>         u16 nr_sensors;
>         int err = -ENODEV, i;
>
> -       if (!handle || !handle->sensor_ops) {
> +       if (!handle)
> +               return -ENODEV;
> +
> +       sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
> +       if (IS_ERR(sensor_ops)) {
>                 dev_err(dev, "SCMI device has no sensor interface\n");
> -               return -EINVAL;
> +               return PTR_ERR(sensor_ops);
>         }
>
> -       nr_sensors = handle->sensor_ops->count_get(handle);
> +       nr_sensors = sensor_ops->count_get(ph);
>         if (!nr_sensors) {
>                 dev_dbg(dev, "0 sensors found via SCMI bus\n");
>                 return -ENODEV;
>         }
>
>         for (i = 0; i < nr_sensors; i++) {
> -               sensor_info = handle->sensor_ops->info_get(handle, i);
> +               sensor_info = sensor_ops->info_get(ph, i);
>                 if (!sensor_info) {
>                         dev_err(dev, "SCMI sensor %d has missing info\n", i);
>                         return -EINVAL;
> @@ -636,7 +627,7 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
>                     sensor_info->axis[0].type != RADIANS_SEC)
>                         continue;
>
> -               scmi_iio_dev = scmi_alloc_iiodev(dev, handle, sensor_info);
> +               scmi_iio_dev = scmi_alloc_iiodev(sdev, ph, sensor_info);
>                 if (IS_ERR(scmi_iio_dev)) {
>                         dev_err(dev,
>                                 "failed to allocate IIO device for sensor %s: %ld\n",
> --
> 2.17.1
>