Re: [PATCH v5 3/6] reset: hide reset control arrays behind struct reset_control

[Vivek Gautam]

Hi Philipp,


On 06/01/2017 10:22 PM, Philipp Zabel wrote:
> Reset controls already may control multiple reset lines with a single
> hardware bit. So from the user perspective, reset control arrays are not
> at all different from single reset controls.
> Therefore, hide reset control arrays behind struct reset_control to
> avoid having to introduce new API functions for array (de)assert/reset.
>
> Cc: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
> Cc: Jon Hunter <jonathanh@xxxxxxxxxx>
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> ---
>   drivers/reset/core.c  | 225 ++++++++++++++++++++++++++------------------------
>   include/linux/reset.h |  44 +++-------
>   2 files changed, 128 insertions(+), 141 deletions(-)
>
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 1747000757211..c8fb4426b218a 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -43,11 +43,24 @@ struct reset_control {
>   	unsigned int id;
>   	struct kref refcnt;
>   	bool shared;
> +	bool array;
>   	atomic_t deassert_count;
>   	atomic_t triggered_count;
>   };
>   
>   /**
> + * struct reset_control_array - an array of reset controls
> + * @base: reset control for compatibility with reset control API functions
> + * @num_rstcs: number of reset controls
> + * @rstc: array of reset controls
> + */
> +struct reset_control_array {
> +	struct reset_control base;
> +	unsigned int num_rstcs;
> +	struct reset_control *rstc[];
> +};
> +
> +/**
>    * of_reset_simple_xlate - translate reset_spec to the reset line number
>    * @rcdev: a pointer to the reset controller device
>    * @reset_spec: reset line specifier as found in the device tree
> @@ -135,6 +148,65 @@ int devm_reset_controller_register(struct device *dev,
>   }
>   EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>   
> +static inline struct reset_control_array *
> +rstc_to_array(struct reset_control *rstc) {
> +	return container_of(rstc, struct reset_control_array, base);
> +}
> +
> +static int reset_control_array_reset(struct reset_control_array *resets)
> +{
> +	int ret, i;
> +
> +	for (i = 0; i < resets->num_rstcs; i++) {
> +		ret = reset_control_reset(resets->rstc[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int reset_control_array_assert(struct reset_control_array *resets)
> +{
> +	int ret, i;
> +
> +	for (i = 0; i < resets->num_rstcs; i++) {
> +		ret = reset_control_assert(resets->rstc[i]);
> +		if (ret)
> +			goto err;
> +	}
> +
> +	return 0;
> +
> +err:
> +	while (i--)
> +		reset_control_deassert(resets->rstc[i]);
> +	return ret;
> +}
> +
> +static int reset_control_array_deassert(struct reset_control_array *resets)
> +{
> +	int ret, i;
> +
> +	for (i = 0; i < resets->num_rstcs; i++) {
> +		ret = reset_control_deassert(resets->rstc[i]);
> +		if (ret)
> +			goto err;
> +	}
> +
> +	return 0;
> +
> +err:
> +	while (i--)
> +		reset_control_assert(resets->rstc[i]);
> +	return ret;
> +}
> +
> +static inline bool reset_control_is_array(struct reset_control *rstc)
> +{
> +	return rstc->array;
> +}
> +
>   /**
>    * reset_control_reset - reset the controlled device
>    * @rstc: reset controller
> @@ -158,6 +230,9 @@ int reset_control_reset(struct reset_control *rstc)
>   	if (WARN_ON(IS_ERR(rstc)))
>   		return -EINVAL;
>   
> +	if (reset_control_is_array(rstc))
> +		return reset_control_array_reset(rstc_to_array(rstc));
> +
>   	if (!rstc->rcdev->ops->reset)
>   		return -ENOTSUPP;
>   
> @@ -202,6 +277,9 @@ int reset_control_assert(struct reset_control *rstc)
>   	if (WARN_ON(IS_ERR(rstc)))
>   		return -EINVAL;
>   
> +	if (reset_control_is_array(rstc))
> +		return reset_control_array_assert(rstc_to_array(rstc));
> +
>   	if (!rstc->rcdev->ops->assert)
>   		return -ENOTSUPP;
>   
> @@ -240,6 +318,9 @@ int reset_control_deassert(struct reset_control *rstc)
>   	if (WARN_ON(IS_ERR(rstc)))
>   		return -EINVAL;
>   
> +	if (reset_control_is_array(rstc))
> +		return reset_control_array_deassert(rstc_to_array(rstc));
> +
>   	if (!rstc->rcdev->ops->deassert)
>   		return -ENOTSUPP;
>   
> @@ -266,7 +347,7 @@ int reset_control_status(struct reset_control *rstc)
>   	if (!rstc)
>   		return 0;
>   
> -	if (WARN_ON(IS_ERR(rstc)))
> +	if (WARN_ON(IS_ERR(rstc)) || reset_control_is_array(rstc))
>   		return -EINVAL;
>   
>   	if (rstc->rcdev->ops->status)
> @@ -404,6 +485,16 @@ struct reset_control *__reset_control_get(struct device *dev, const char *id,
>   }
>   EXPORT_SYMBOL_GPL(__reset_control_get);
>   
> +static void reset_control_array_put(struct reset_control_array *resets)
> +{
> +	int i;
> +
> +	mutex_lock(&reset_list_mutex);
> +	for (i = 0; i < resets->num_rstcs; i++)
> +		__reset_control_put_internal(resets->rstc[i]);
> +	mutex_unlock(&reset_list_mutex);
> +}
> +
>   /**
>    * reset_control_put - free the reset controller
>    * @rstc: reset controller
> @@ -413,6 +504,11 @@ void reset_control_put(struct reset_control *rstc)
>   	if (IS_ERR_OR_NULL(rstc))
>   		return;
>   
> +	if (reset_control_is_array(rstc)) {
> +		reset_control_array_put(rstc_to_array(rstc));
> +		return;
> +	}
> +
>   	mutex_lock(&reset_list_mutex);
>   	__reset_control_put_internal(rstc);
>   	mutex_unlock(&reset_list_mutex);
> @@ -499,81 +595,6 @@ static int of_reset_control_get_count(struct device_node *node)
>   }
>   
>   /**
> - * reset_control_array_assert: assert a list of resets
> - *
> - * @resets: reset control array holding info about the list of resets
> - *
> - * This API doesn't guarantee that the reset lines controlled by
> - * the reset array are asserted in any particular order.
> - *
> - * Returns 0 on success or error number on failure.
> - */
> -int reset_control_array_assert(struct reset_control_array *resets)
> -{
> -	int ret, i;
> -
> -	if (!resets)
> -		return 0;
> -
> -	if (IS_ERR(resets))
> -		return -EINVAL;
> -
> -	for (i = 0; i < resets->num_rstcs; i++) {
> -		ret = reset_control_assert(resets->rstc[i]);
> -		if (ret)
> -			goto err;
> -	}
> -
> -	return 0;
> -
> -err:
> -	while (i--)
> -		reset_control_deassert(resets->rstc[i]);
> -	return ret;
> -}
> -EXPORT_SYMBOL_GPL(reset_control_array_assert);
> -
> -/**
> - * reset_control_array_deassert: deassert a list of resets
> - *
> - * @resets: reset control array holding info about the list of resets
> - *
> - * This API doesn't guarantee that the reset lines controlled by
> - * the reset array are deasserted in any particular order.
> - *
> - * Returns 0 on success or error number on failure.
> - */
> -int reset_control_array_deassert(struct reset_control_array *resets)
> -{
> -	int ret, i;
> -
> -	if (!resets)
> -		return 0;
> -
> -	if (IS_ERR(resets))
> -		return -EINVAL;
> -
> -	for (i = 0; i < resets->num_rstcs; i++) {
> -		ret = reset_control_deassert(resets->rstc[i]);
> -		if (ret)
> -			goto err;
> -	}
> -
> -	return 0;
> -
> -err:
> -	while (i--)
> -		reset_control_assert(resets->rstc[i]);
> -	return ret;
> -}
> -EXPORT_SYMBOL_GPL(reset_control_array_deassert);
> -
> -static void devm_reset_control_array_release(struct device *dev, void *res)
> -{
> -	reset_control_array_put(*(struct reset_control_array **)res);
> -}
> -
> -/**
>    * of_reset_control_array_get - Get a list of reset controls using
>    *				device node.
>    *
> @@ -584,13 +605,12 @@ static void devm_reset_control_array_release(struct device *dev, void *res)
>    * Returns pointer to allocated reset_control_array on success or
>    * error on failure
>    */
> -struct reset_control_array *
> +struct reset_control *
>   of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
>   {
>   	struct reset_control_array *resets;
>   	struct reset_control *rstc;
>   	int num, i;
> -	void *err;
>   
>   	num = of_reset_control_get_count(np);
>   	if (num < 0)
> @@ -603,23 +623,24 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
>   
>   	for (i = 0; i < num; i++) {
>   		rstc = __of_reset_control_get(np, NULL, i, shared, optional);
> -		if (IS_ERR(rstc)) {
> -			err = ERR_CAST(rstc);
> +		if (IS_ERR(rstc))
>   			goto err_rst;
> -		}
>   		resets->rstc[i] = rstc;
>   	}
>   	resets->num_rstcs = num;
> +	resets->base.array = true;
>   
> -	return resets;
> +	return &resets->base;
>   
>   err_rst:
> +	mutex_lock(&reset_list_mutex);
>   	while (--i >= 0)
> -		reset_control_put(resets->rstc[i]);
> +		__reset_control_put_internal(resets->rstc[i]);
> +	mutex_unlock(&reset_list_mutex);
>   
>   	kfree(resets);
>   
> -	return err;
> +	return rstc;
>   }
>   EXPORT_SYMBOL_GPL(of_reset_control_array_get);
>   
> @@ -637,40 +658,26 @@ EXPORT_SYMBOL_GPL(of_reset_control_array_get);
>    * Returns pointer to allocated reset_control_array on success or
>    * error on failure
>    */
> -struct reset_control_array *
> +struct reset_control *
>   devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
>   {
> -	struct reset_control_array **devres;
> -	struct reset_control_array *resets;
> +	struct reset_control **devres;
> +	struct reset_control *rstc;
>   
> -	devres = devres_alloc(devm_reset_control_array_release,
> -			      sizeof(*devres), GFP_KERNEL);
> +	devres = devres_alloc(devm_reset_control_release, sizeof(*devres),
> +			      GFP_KERNEL);
>   	if (!devres)
>   		return ERR_PTR(-ENOMEM);
>   
> -	resets = of_reset_control_array_get(dev->of_node, shared, optional);
> -	if (IS_ERR(resets)) {
> -		devres_free(resets);
> -		return resets;
> +	rstc = of_reset_control_array_get(dev->of_node, shared, optional);
> +	if (IS_ERR(rstc)) {
> +		devres_free(devres);
> +		return rstc;
>   	}
>   
> -	*devres = resets;
> +	*devres = rstc;
>   	devres_add(dev, devres);
>   
> -	return resets;
> +	return rstc;
>   }
>   EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
> -
> -void reset_control_array_put(struct reset_control_array *resets)
> -{
> -	int i;
> -
> -	if (IS_ERR_OR_NULL(resets))
> -		return;
> -
> -	for (i = 0; i < resets->num_rstcs; i++)
> -		reset_control_put(resets->rstc[i]);
> -
> -	kfree(resets);
> -}
> -EXPORT_SYMBOL_GPL(reset_control_array_put);
> diff --git a/include/linux/reset.h b/include/linux/reset.h
> index df75fe50f765d..0f1be13e66e46 100644
> --- a/include/linux/reset.h
> +++ b/include/linux/reset.h
> @@ -5,11 +5,6 @@
>   
>   struct reset_control;
>   
> -struct reset_control_array {
> -	unsigned int num_rstcs;
> -	struct reset_control *rstc[];
> -};
> -
>   #ifdef CONFIG_RESET_CONTROLLER
>   
>   int reset_control_reset(struct reset_control *rstc);
> @@ -30,13 +25,10 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
>   
>   int __must_check device_reset(struct device *dev);
>   
> -int reset_control_array_assert(struct reset_control_array *resets);
> -int reset_control_array_deassert(struct reset_control_array *resets);
> -struct reset_control_array *devm_reset_control_array_get(struct device *dev,
> -						bool shared, bool optional);
> -struct reset_control_array *of_reset_control_array_get(struct device_node *np,
> -						bool shared, bool optional);
> -void reset_control_array_put(struct reset_control_array *resets);
> +struct reset_control *devm_reset_control_array_get(struct device *dev,
> +						   bool shared, bool optional);
> +struct reset_control *of_reset_control_array_get(struct device_node *np,
> +						 bool shared, bool optional);
>   
>   static inline int device_reset_optional(struct device *dev)
>   {
> @@ -102,18 +94,6 @@ static inline struct reset_control *__devm_reset_control_get(
>   	return optional ? NULL : ERR_PTR(-ENOTSUPP);
>   }
>   
> -static inline
> -int reset_control_array_assert(struct reset_control_array *resets)
> -{
> -	return 0;
> -}
> -
> -static inline
> -int reset_control_array_deassert(struct reset_control_array *resets)
> -{
> -	return 0;
> -}
> -
>   static inline struct reset_control_array *

This has to return just 'struct reset_control *'.
That should resolve kbuild errors.

Rest looks good to me.
Reviewed-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>

BRs
Vivek

>   devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
>   {
> @@ -420,49 +400,49 @@ static inline struct reset_control *devm_reset_control_get_by_index(
>   /*
>    * APIs to manage a list of reset controllers
>    */
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   devm_reset_control_array_get_exclusive(struct device *dev)
>   {
>   	return devm_reset_control_array_get(dev, false, false);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   devm_reset_control_array_get_shared(struct device *dev)
>   {
>   	return devm_reset_control_array_get(dev, true, false);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   devm_reset_control_array_get_optional_exclusive(struct device *dev)
>   {
>   	return devm_reset_control_array_get(dev, false, true);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   devm_reset_control_array_get_optional_shared(struct device *dev)
>   {
>   	return devm_reset_control_array_get(dev, true, true);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   of_reset_control_array_get_exclusive(struct device_node *node)
>   {
>   	return of_reset_control_array_get(node, false, false);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   of_reset_control_array_get_shared(struct device_node *node)
>   {
>   	return of_reset_control_array_get(node, true, false);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   of_reset_control_array_get_optional_exclusive(struct device_node *node)
>   {
>   	return of_reset_control_array_get(node, false, true);
>   }
>   
> -static inline struct reset_control_array *
> +static inline struct reset_control *
>   of_reset_control_array_get_optional_shared(struct device_node *node)
>   {
>   	return of_reset_control_array_get(node, true, true);

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