[PATCH 1/4] OF: Add helper for matching against linux, stdout-path

[s.hauer@pengutronix.de (Sascha Hauer)]

On Wed, Nov 21, 2012 at 04:57:05PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> From: Sascha Hauer <s.hauer@pengutronix.de>
> 
> devicetrees may have a linux,stdout-path or stdout-path property
> in the chosen node describing the console device. This adds a helper
> function to match a device against this property and retrieve the options
> so a driver can call add_preferred_console for a matching device.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: linux-serial at vger.kernel.org
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: kernel at pengutronix.de
> Cc: Alan Cox <alan@linux.intel.com>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
>  drivers/of/base.c  |   46 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h |    7 +++++++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index f2f63c8..72c49ce 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -1470,3 +1470,49 @@ const char *of_prop_next_string(struct property *prop, const char *cur)
>  	return curv;
>  }
>  EXPORT_SYMBOL_GPL(of_prop_next_string);
> +
> +/**
> + * of_device_is_stdout_path - check if a device node matches the
> + *			      linux,stdout-path property
> + * @np:		Pointer to the given device_node
> + * @option:	parsed option
> + *
> + * Check if this device node matches the linux,stdout-path property
> + * in the chosen node. return true if yes, false otherwise.
> + */
> +int of_device_is_stdout_path(struct device_node *dn, char **option)
> +{
> +	const char *name;
> +	struct device_node *dn_stdout;
> +	bool is_stdout = 0;
> +	const char *tmp;
> +	const char *tmp_option;
> +
> +	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
> +	if (name == NULL)
> +		name = of_get_property(of_chosen, "stdout-path", NULL);
> +
> +	if (name == NULL)
> +		return 0;
> +
> +	tmp_option = strchr(name, ':');
> +
> +	tmp = kstrndup(name, strlen(name) - strlen(tmp_option), GFP_KERNEL);

tmp_option may be NULL.

> +	if (!tmp)
> +		return 0;
> +
> +	dn_stdout = of_find_node_by_path(tmp);
> +
> +	if (dn_stdout && dn_stdout == dn) {
> +		is_stdout = 1;
> +		tmp_option++;
> +		*option = kstrdup(tmp_option, GFP_KERNEL);
> +	}
> +
> +	of_node_put(dn_stdout);

dn_stdout may be NULL aswell.

Sascha

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