From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: Re: [PATCH v2] dt: add of_alias_scan and of_alias_get_id Date: Mon, 19 Sep 2011 23:18:24 +0800 Message-ID: <20110919151823.GD28084@S2100-06.ap.freescale.net> References: <1313371817-5135-1-git-send-email-shawn.guo@linaro.org> <1313393294-8867-1-git-send-email-shawn.guo@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1313393294-8867-1-git-send-email-shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Shawn Guo Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, David Miller List-Id: devicetree@vger.kernel.org On Mon, Aug 15, 2011 at 03:28:14PM +0800, Shawn Guo wrote: > The patch adds function of_alias_scan to populate a global lookup > table with the properties of 'aliases' node and function > of_alias_get_id for drivers to find alias id from the lookup table. > > Signed-off-by: Shawn Guo > [grant.likey: add locking and rework parse loop] > Signed-off-by: Grant Likely Hi Grant, Any comments on this patch? Regards, Shawn > --- > Changes since v1: > * Add of_chosen/of_aliases populating and of_alias_scan() invocation > for OF_PROMTREE (non-tested). > > drivers/of/base.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++ > drivers/of/fdt.c | 12 +++-- > drivers/of/pdt.c | 12 ++++ > include/linux/of.h | 8 +++ > include/linux/of_fdt.h | 1 - > 5 files changed, 163 insertions(+), 6 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 3ff22e3..5e6ce02 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -17,14 +17,39 @@ > * as published by the Free Software Foundation; either version > * 2 of the License, or (at your option) any later version. > */ > +#include > #include > #include > #include > #include > #include > > +/** > + * struct alias_prop - Alias property in 'aliases' node > + * @link: List node to link the structure in aliases_lookup list > + * @alias: Alias property name > + * @np: Pointer to device_node that the alias stands for > + * @id: Index value from end of alias name > + * @stem: Alias string without the index > + * > + * The structure represents one alias property of 'aliases' node as > + * an entry in aliases_lookup list. > + */ > +struct alias_prop { > + struct list_head link; > + const char *alias; > + struct device_node *np; > + int id; > + char stem[0]; > +}; > + > +static LIST_HEAD(aliases_lookup); > + > struct device_node *allnodes; > struct device_node *of_chosen; > +struct device_node *of_aliases; > + > +static DEFINE_MUTEX(of_aliases_mutex); > > /* use when traversing tree through the allnext, child, sibling, > * or parent members of struct device_node. > @@ -988,3 +1013,114 @@ out_unlock: > } > #endif /* defined(CONFIG_OF_DYNAMIC) */ > > +static void of_alias_add(struct alias_prop *ap, struct device_node *np, > + int id, const char *stem, int stem_len) > +{ > + ap->np = np; > + ap->id = id; > + strncpy(ap->stem, stem, stem_len); > + ap->stem[stem_len] = 0; > + list_add_tail(&ap->link, &aliases_lookup); > + pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n", > + ap->alias, ap->stem, ap->id, np ? np->full_name : NULL); > +} > + > +/** > + * of_alias_scan - Scan all properties of 'aliases' node > + * > + * The function scans all the properties of 'aliases' node and populate > + * the the global lookup table with the properties. It returns the > + * number of alias_prop found, or error code in error case. > + * > + * @dt_alloc: An allocator that provides a virtual address to memory > + * for the resulting tree > + */ > +void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) > +{ > + struct property *pp; > + > + if (!of_aliases) > + return; > + > + for_each_property(pp, of_aliases->properties) { > + const char *start = pp->name; > + const char *end = start + strlen(start); > + struct device_node *np; > + struct alias_prop *ap; > + int id, len; > + > + /* Skip those we do not want to proceed */ > + if (!strcmp(pp->name, "name") || > + !strcmp(pp->name, "phandle") || > + !strcmp(pp->name, "linux,phandle")) > + continue; > + > + np = of_find_node_by_path(pp->value); > + if (!np) > + continue; > + > + /* walk the alias backwards to extract the id and work out > + * the 'stem' string */ > + while (isdigit(*(end-1)) && end > start) > + end--; > + len = end - start; > + > + if (kstrtoint(end, 10, &id) < 0) > + continue; > + > + /* Allocate an alias_prop with enough space for the stem */ > + ap = dt_alloc(sizeof(*ap) + len + 1, 4); > + if (!ap) > + continue; > + ap->alias = start; > + of_alias_add(ap, np, id, start, len); > + } > +} > + > +/** > + * of_alias_get_id - Get alias id for the given device_node > + * @np: Pointer to the given device_node > + * @stem: Alias stem of the given device_node > + * > + * The function travels the lookup table to get alias id for the given > + * device_node and alias stem. It returns the alias id if find it. > + * If not, dynamically creates one in the lookup table and returns it, > + * or returns error code if fail to create. > + */ > +int of_alias_get_id(struct device_node *np, const char *stem) > +{ > + struct alias_prop *app; > + int id = 0; > + bool found = false; > + > + mutex_lock(&of_aliases_mutex); > + list_for_each_entry(app, &aliases_lookup, link) { > + if (strcmp(app->stem, stem) != 0) > + continue; > + > + if (np == app->np) { > + found = true; > + id = app->id; > + break; > + } > + > + if (id <= app->id) > + id = app->id + 1; > + } > + > + /* If an id is not found, then allocate a new one */ > + if (!found) { > + app = kzalloc(sizeof(*app) + strlen(stem) + 1, 4); > + if (!app) { > + id = -ENODEV; > + goto out; > + } > + of_alias_add(app, np, id, stem, strlen(stem)); > + } > + > + out: > + mutex_unlock(&of_aliases_mutex); > + > + return id; > +} > +EXPORT_SYMBOL_GPL(of_alias_get_id); > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 65200af..98b6fb1 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -404,6 +404,13 @@ static void __unflatten_device_tree(struct boot_param_header *blob, > be32_to_cpu(((__be32 *)mem)[size / 4])); > *allnextp = NULL; > > + /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */ > + of_chosen = of_find_node_by_path("/chosen"); > + if (of_chosen == NULL) > + of_chosen = of_find_node_by_path("/chosen@0"); > + of_aliases = of_find_node_by_path("/aliases"); > + of_alias_scan(dt_alloc); > + > pr_debug(" <- unflatten_device_tree()\n"); > } > > @@ -706,11 +713,6 @@ void __init unflatten_device_tree(void) > { > __unflatten_device_tree(initial_boot_params, &allnodes, > early_init_dt_alloc_memory_arch); > - > - /* Get pointer to OF "/chosen" node for use everywhere */ > - of_chosen = of_find_node_by_path("/chosen"); > - if (of_chosen == NULL) > - of_chosen = of_find_node_by_path("/chosen@0"); > } > > #endif /* CONFIG_OF_EARLY_FLATTREE */ > diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c > index 4d87b5d..686a4b3 100644 > --- a/drivers/of/pdt.c > +++ b/drivers/of/pdt.c > @@ -229,6 +229,11 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent, > return ret; > } > > +static void *kernel_tree_alloc(u64 size, u64 align) > +{ > + return prom_early_alloc(size); > +} > + > void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops) > { > struct device_node **nextp; > @@ -245,4 +250,11 @@ void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops) > nextp = &allnodes->allnext; > allnodes->child = of_pdt_build_tree(allnodes, > of_pdt_prom_ops->getchild(allnodes->phandle), &nextp); > + > + /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */ > + of_chosen = of_find_node_by_path("/chosen"); > + if (of_chosen == NULL) > + of_chosen = of_find_node_by_path("/chosen@0"); > + of_aliases = of_find_node_by_path("/aliases"); > + of_alias_scan(kernel_tree_alloc); > } > diff --git a/include/linux/of.h b/include/linux/of.h > index 9180dc5..4ea7d81 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -68,6 +68,7 @@ struct device_node { > /* Pointer for first entry in chain of all nodes. */ > extern struct device_node *allnodes; > extern struct device_node *of_chosen; > +extern struct device_node *of_aliases; > extern rwlock_t devtree_lock; > > static inline bool of_have_populated_dt(void) > @@ -209,6 +210,9 @@ extern int of_device_is_available(const struct device_node *device); > extern const void *of_get_property(const struct device_node *node, > const char *name, > int *lenp); > +#define for_each_property(pp, properties) \ > + for (pp = properties; pp != NULL; pp = pp->next) > + > extern int of_n_addr_cells(struct device_node *np); > extern int of_n_size_cells(struct device_node *np); > extern const struct of_device_id *of_match_node( > @@ -221,6 +225,10 @@ extern int of_parse_phandles_with_args(struct device_node *np, > const char *list_name, const char *cells_name, int index, > struct device_node **out_node, const void **out_args); > > +extern void *early_init_dt_alloc_memory_arch(u64 size, u64 align); > +extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); > +extern int of_alias_get_id(struct device_node *np, const char *stem); > + > extern int of_machine_is_compatible(const char *compat); > > extern int prom_add_property(struct device_node* np, struct property* prop); > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > index c84d900..b74b74f 100644 > --- a/include/linux/of_fdt.h > +++ b/include/linux/of_fdt.h > @@ -97,7 +97,6 @@ extern void early_init_dt_check_for_initrd(unsigned long node); > extern int early_init_dt_scan_memory(unsigned long node, const char *uname, > int depth, void *data); > extern void early_init_dt_add_memory_arch(u64 base, u64 size); > -extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align); > extern u64 dt_mem_next_cell(int s, __be32 **cellp); > > /* > -- > 1.7.4.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >