Re: [PATCH v4 1/2] clk: Provide managed helper to get and enable bulk clocks

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Wed, Jan 24, 2024 at 04:08:37PM +0530, Shradha Todi wrote:
> Provide a managed devm_clk_bulk* wrapper to get and enable all
> bulk clocks in order to simplify drivers that keeps all clocks
> enabled for the time of driver operation.
> 
> Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Shradha Todi <shradha.t@samsung.com>
> ---
>  drivers/clk/clk-devres.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/clk.h      | 24 ++++++++++++++++++++++++
>  2 files changed, 64 insertions(+)
> 
> diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
> index 4fb4fd4b06bd..cbbd2cc339c3 100644
> --- a/drivers/clk/clk-devres.c
> +++ b/drivers/clk/clk-devres.c
> @@ -182,6 +182,46 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
>  }
>  EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all);
>  
> +static void devm_clk_bulk_release_all_enable(struct device *dev, void *res)
> +{
> +	struct clk_bulk_devres *devres = res;
> +
> +	clk_bulk_disable_unprepare(devres->num_clks, devres->clks);
> +	clk_bulk_put_all(devres->num_clks, devres->clks);
> +}
> +
> +int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
> +					      struct clk_bulk_data **clks)
> +{
> +	struct clk_bulk_devres *devres;
> +	int ret;
> +
> +	devres = devres_alloc(devm_clk_bulk_release_all_enable,
> +			      sizeof(*devres), GFP_KERNEL);
> +	if (!devres)
> +		return -ENOMEM;
> +
> +	ret = clk_bulk_get_all(dev, &devres->clks);
> +	if (ret > 0) {
> +		*clks = devres->clks;
> +		devres->num_clks = ret;
> +	} else {
> +		devres_free(devres);
> +		return ret;
> +	}

How about:

	ret = clk_bulk_get_all(dev, &devres->clks);
	if (ret <= 0) {
		devres_free(devres);
		return ret;
	}

	*clks = devres->clks;
	devres->num_clks = ret;

Even though this patch follows the pattern used by the rest of the APIs in the
driver, IMO above makes it more readable.

> +
> +	ret = clk_bulk_prepare_enable(devres->num_clks, *clks);
> +	if (!ret) {
> +		devres_add(dev, devres);
> +	} else {
> +		clk_bulk_put_all(devres->num_clks, devres->clks);
> +		devres_free(devres);
> +	}
> +

Same as above:

	ret = clk_bulk_prepare_enable(devres->num_clks, *clks);
	if (ret) {
		clk_bulk_put_all(devres->num_clks, devres->clks);
		devres_free(devres);
		return ret;
	}

	devres_add(dev, devres);

> +	return ret;

	return 0;

> +}
> +EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all_enable);
> +
>  static int devm_clk_match(struct device *dev, void *res, void *data)
>  {
>  	struct clk **c = res;
> diff --git a/include/linux/clk.h b/include/linux/clk.h
> index 1ef013324237..a005e709b7bd 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -438,6 +438,23 @@ int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
>  int __must_check devm_clk_bulk_get_all(struct device *dev,
>  				       struct clk_bulk_data **clks);
>  
> +/**
> + * devm_clk_bulk_get_all_enable - managed get multiple clk consumers and
> + *				  enable all clks

"Get and enable all clocks of the consumer (managed)"

> + * @dev: device for clock "consumer"
> + * @clks: pointer to the clk_bulk_data table of consumer
> + *
> + * Returns success (0) or negative errno.
> + *
> + * This helper function allows drivers to get several clk

"This helper function allows drivers to get all clocks of the consumer and
enables them..."

- Mani

> + * consumers and enable all of them in one operation with management.
> + * The clks will automatically be disabled and freed when the device
> + * is unbound.
> + */
> +
> +int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
> +					      struct clk_bulk_data **clks);
> +
>  /**
>   * devm_clk_get - lookup and obtain a managed reference to a clock producer.
>   * @dev: device for clock "consumer"
> @@ -960,6 +977,13 @@ static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
>  	return 0;
>  }
>  
> +static inline int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
> +						struct clk_bulk_data **clks)
> +{
> +
> +	return 0;
> +}
> +
>  static inline struct clk *devm_get_clk_from_child(struct device *dev,
>  				struct device_node *np, const char *con_id)
>  {
> -- 
> 2.17.1
> 

-- 
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