Re: [PATCH 3/4] iio: adc: xilinx-ams: use device_* to iterate over device child nodes

From: Jonathan Cameron
Date: Sat Aug 03 2024 - 07:17:53 EST


On Thu, 01 Aug 2024 08:13:52 +0200
Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx> wrote:

> Use `device_for_each_child_node_scoped()` in `ams_parse_firmware()`
> to explicitly state device child node access, and simplify the child
> node handling as it is not required outside the loop.
>
> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
> ---
> drivers/iio/adc/xilinx-ams.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/adc/xilinx-ams.c b/drivers/iio/adc/xilinx-ams.c
> index f051358d6b50..27d5e4a6f9d6 100644
> --- a/drivers/iio/adc/xilinx-ams.c
> +++ b/drivers/iio/adc/xilinx-ams.c
> @@ -1275,7 +1275,6 @@ static int ams_parse_firmware(struct iio_dev *indio_dev)
> struct ams *ams = iio_priv(indio_dev);
> struct iio_chan_spec *ams_channels, *dev_channels;
> struct device *dev = indio_dev->dev.parent;
> - struct fwnode_handle *child = NULL;
> struct fwnode_handle *fwnode = dev_fwnode(dev);
> size_t ams_size;
> int ret, ch_cnt = 0, i, rising_off, falling_off;
> @@ -1297,13 +1296,11 @@ static int ams_parse_firmware(struct iio_dev *indio_dev)
> num_channels += ret;
> }
>
> - fwnode_for_each_child_node(fwnode, child) {
> + device_for_each_child_node_scoped(dev, child) {
> if (fwnode_device_is_available(child)) {
This is fun. should have been fwnode_for_each_available_child_node()
in the first place rather than iterating over all nodes, and only
doing stuff for the available ones.

Can use the device_for_each_child_node_scoped() but that only includes
available nodes anyway, so my understanding is that we can also drop
this if statement as it will always be true.


> ret = ams_init_module(indio_dev, child, ams_channels + num_channels);
> - if (ret < 0) {
> - fwnode_handle_put(child);
> + if (ret < 0)
> return ret;
> - }
>
> num_channels += ret;
> }
>