Re: [PATCH v4 2/2] iio: frequency: adf4350: add clk provider

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 12 Jun 2024 16:02:29 +0300
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add clk provider feature for the adf4350.
> 
> Even though the driver was sent as an IIO driver in most cases the
> device is actually seen as a clock provider.
> 
> This patch aims to cover actual usecases requested by users in order to
> completely control the output frequencies from userspace.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>

As Nuno reminded, this needs the clock maintainers in the loop

Trivial comments inline.

> +static int adf4350_clk_register(struct adf4350_state *st)
> +{
> +	struct spi_device *spi = st->spi;
> +	struct clk_init_data init;
> +	struct clk *clk;
> +	const char *parent_name;
> +	int ret;
> +
> +	if (!device_property_present(&spi->dev, "#clock-cells"))
> +		return 0;
> +
> +	init.name = devm_kasprintf(&spi->dev, GFP_KERNEL, "%s-clk",
> +				   fwnode_get_name(dev_fwnode(&spi->dev)));

Check for failure.

> +	device_property_read_string(&spi->dev, "clock-output-names",
> +				    &init.name);

Also check for failure.

> +
> +	parent_name = of_clk_get_parent_name(spi->dev.of_node, 0);
> +	if (!parent_name)
> +		return -EINVAL;
> +
> +	init.ops = &adf4350_clk_ops;
> +	init.parent_names = &parent_name;
> +	init.num_parents = 1;
> +	init.flags = CLK_SET_RATE_PARENT;
> +
> +	st->hw.init = &init;
> +	clk = devm_clk_register(&spi->dev, &st->hw);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
> +	ret = of_clk_add_provider(spi->dev.of_node, of_clk_src_simple_get, clk);
> +	if (ret)
> +		return ret;
> +
> +	st->clkout = clk;
> +
> +	return devm_add_action_or_reset(&spi->dev, adf4350_clk_del_provider, st);
> +}
> +
>  static struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
>  {
>  	struct adf4350_platform_data *pdata;
> @@ -522,7 +646,6 @@ static int adf4350_probe(struct spi_device *spi)
>  
>  	indio_dev->info = &adf4350_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
> -	indio_dev->channels = &adf4350_chan;
>  	indio_dev->num_channels = 1;
>  
>  	mutex_init(&st->lock);
> @@ -551,6 +674,15 @@ static int adf4350_probe(struct spi_device *spi)
>  			return ret;
>  	}
>  
> +	ret = adf4350_clk_register(st);
> +	if (ret)
> +		return ret;
> +
> +	if (st->clkout)
> +		indio_dev->channels = &adf4350_clk_chan;
> +	else
> +		indio_dev->channels = &adf4350_chan;
> +
>  	ret = devm_add_action_or_reset(&spi->dev, adf4350_power_down, indio_dev);
>  	if (ret)
>  		return dev_err_probe(&spi->dev, ret,