[PATCH 5/7] state: backend: support phandle and of_path references

[Sascha Hauer]

On Wed, May 13, 2015 at 12:12:30PM +0200, Marc Kleine-Budde wrote:
> This patch improves the backend property, it can be either a phandle or a
> of_path. During probe() of the state driver the backend property is
> dereferenced and the resulting of_path is saved in the state context. In a
> later patch it will be used to generate a phandle reference to the backend
> during DT fixup.
> 
> Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
> ---
>  common/state.c       |  9 ++++---
>  drivers/misc/state.c | 70 ++++++++++++++++++++++++++++++++++++++++++----------
>  include/state.h      |  7 +++---
>  3 files changed, 67 insertions(+), 19 deletions(-)
> 
> diff --git a/common/state.c b/common/state.c
> index 744a6f8250c4..d6060bb7dff4 100644
> --- a/common/state.c
> +++ b/common/state.c
> @@ -54,6 +54,7 @@ struct state_backend {
>  	int (*load)(struct state_backend *backend, struct state *state);
>  	int (*save)(struct state_backend *backend, struct state *state);
>  	const char *name;
> +	const char *of_path;
>  	const char *path;
>  };
>  
> @@ -903,7 +904,7 @@ out:
>   * @state	The state instance to work on
>   * @path	The path where the state will be stored to
>   */
> -int state_backend_dtb_file(struct state *state, const char *path)
> +int state_backend_dtb_file(struct state *state, const char *of_path, const char *path)
>  {
>  	struct state_backend_dtb *backend_dtb;
>  	struct state_backend *backend;
> @@ -918,6 +919,7 @@ int state_backend_dtb_file(struct state *state, const char *path)
>  
>  	backend->load = state_backend_dtb_load;
>  	backend->save = state_backend_dtb_save;
> +	backend->of_path = xstrdup(of_path);
>  	backend->path = xstrdup(path);
>  	backend->name = "dtb";
>  
> @@ -1133,8 +1135,8 @@ out_free:
>   * device @size may be 0. The two copies are spread to different
>   * eraseblocks if approriate for this device.
>   */
> -int state_backend_raw_file(struct state *state, const char *path, off_t offset,
> -		size_t size)
> +int state_backend_raw_file(struct state *state, const char *of_path,
> +		const char *path, off_t offset, size_t size)
>  {
>  	struct state_backend_raw *backend_raw;
>  	struct state_backend *backend;
> @@ -1159,6 +1161,7 @@ int state_backend_raw_file(struct state *state, const char *path, off_t offset,
>  
>  	backend->load = state_backend_raw_load;
>  	backend->save = state_backend_raw_save;
> +	backend->of_path = xstrdup(of_path);
>  	backend->path = xstrdup(path);
>  	backend->name = "raw";
>  
> diff --git a/drivers/misc/state.c b/drivers/misc/state.c
> index 3b07bb93d725..9e8a40255348 100644
> --- a/drivers/misc/state.c
> +++ b/drivers/misc/state.c
> @@ -24,10 +24,12 @@
>  static int state_probe(struct device_d *dev)
>  {
>  	struct device_node *np = dev->device_node;
> +	struct device_node *partition_node;
>  	struct state *state;
>  	const char *alias;
>  	const char *backend_type = NULL;
>  	int ret;
> +	const char *of_path;
>  	char *path;
>  
>  	if (!np)
> @@ -41,28 +43,70 @@ static int state_probe(struct device_d *dev)
>  	if (IS_ERR(state))
>  		return PTR_ERR(state);
>  
> -	ret = of_find_path(np, "backend", &path, 0);
> -	if (ret)
> -		return ret;
> +	of_path = of_get_property(np, "backend", NULL);
> +	if (!of_path) {
> +		ret = -ENODEV;
> +		goto out_release;
> +	}
> +
> +	/* guess if of_path is a path, not a phandle */
> +	if (of_path[0] == '/') {

Since this also matches to the 47th phandle in the device tree I made
this:

	if (of_path[0] == '/' && len > 1)

And applied up to 6/7

Sascha

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