Re: [PATCH v8 8/8] iio: dac: adi-axi-dac: add registering of child fdt node

["Nuno Sá" <noname.nuno@gmail.com>]

On Fri, 2024-10-25 at 11:49 +0200, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Change to obtain the fdt use case as reported in the
> adi,ad3552r.yaml file in this patchset.
> 
> The DAC device is defined as a child node of the backend.
> Registering the child fdt node as a platform devices.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---

LGTM,

Reviewed-by: Nuno Sa <nuno.sa@analog.com>

>  drivers/iio/dac/adi-axi-dac.c | 56 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 56 insertions(+)
> 
> diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> index 148e40a8ab2a..dc9f881bf9ce 100644
> --- a/drivers/iio/dac/adi-axi-dac.c
> +++ b/drivers/iio/dac/adi-axi-dac.c
> @@ -29,6 +29,8 @@
>  #include <linux/iio/buffer.h>
>  #include <linux/iio/iio.h>
>  
> +#include "ad3552r-hs.h"
> +
>  /*
>   * Register definitions:
>   *   https://wiki.analog.com/resources/fpga/docs/axi_dac_ip#register_map
> @@ -97,6 +99,7 @@ struct axi_dac_info {
>  	unsigned int version;
>  	const struct iio_backend_info *backend_info;
>  	bool has_dac_clk;
> +	bool has_child_nodes;
>  };
>  
>  struct axi_dac_state {
> @@ -699,6 +702,36 @@ static int axi_dac_bus_reg_read(struct iio_backend *back, u32
> reg, u32 *val,
>  	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
>  }
>  
> +static void axi_dac_child_remove(void *data)
> +{
> +	platform_device_unregister(data);
> +}
> +
> +static int axi_dac_create_platform_device(struct axi_dac_state *st,
> +					  struct fwnode_handle *child)
> +{
> +	struct ad3552r_hs_platform_data pdata = {
> +		.bus_reg_read = axi_dac_bus_reg_read,
> +		.bus_reg_write = axi_dac_bus_reg_write,
> +		.bus_sample_data_clock_hz = st->dac_clk_rate,
> +	};
> +	struct platform_device_info pi = {
> +		.parent = st->dev,
> +		.name = fwnode_get_name(child),
> +		.id = PLATFORM_DEVID_AUTO,
> +		.fwnode = child,
> +		.data = &pdata,
> +		.size_data = sizeof(pdata),
> +	};
> +	struct platform_device *pdev;
> +
> +	pdev = platform_device_register_full(&pi);
> +	if (IS_ERR(pdev))
> +		return PTR_ERR(pdev);
> +
> +	return devm_add_action_or_reset(st->dev, axi_dac_child_remove, pdev);
> +}
> +
>  static const struct iio_backend_ops axi_dac_generic_ops = {
>  	.enable = axi_dac_enable,
>  	.disable = axi_dac_disable,
> @@ -840,6 +873,28 @@ static int axi_dac_probe(struct platform_device *pdev)
>  		return dev_err_probe(&pdev->dev, ret,
>  				     "failed to register iio backend\n");
>  
> +	device_for_each_child_node_scoped(&pdev->dev, child) {
> +		int val;
> +
> +		if (!st->info->has_child_nodes)
> +			return dev_err_probe(&pdev->dev, -EINVAL,
> +					     "invalid fdt axi-dac compatible.");
> +
> +		/* Processing only reg 0 node */
> +		ret = fwnode_property_read_u32(child, "reg", &val);
> +		if (ret)
> +			return dev_err_probe(&pdev->dev, ret,
> +						"invalid reg property.");
> +		if (val != 0)
> +			return dev_err_probe(&pdev->dev, -EINVAL,
> +						"invalid node address.");
> +
> +		ret = axi_dac_create_platform_device(st, child);
> +		if (ret)
> +			return dev_err_probe(&pdev->dev, -EINVAL,
> +						"cannot create device.");
> +	}
> +
>  	dev_info(&pdev->dev, "AXI DAC IP core (%d.%.2d.%c) probed\n",
>  		 ADI_AXI_PCORE_VER_MAJOR(ver),
>  		 ADI_AXI_PCORE_VER_MINOR(ver),
> @@ -857,6 +912,7 @@ static const struct axi_dac_info dac_ad3552r = {
>  	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
>  	.backend_info = &axi_ad3552r,
>  	.has_dac_clk = true,
> +	.has_child_nodes = true,
>  };
>  
>  static const struct of_device_id axi_dac_of_match[] = {
>