| Message ID | 1308938676-31121-2-git-send-email-shawn.guo@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Jun 25, 2011 at 02:04:32AM +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 <shawn.guo@linaro.org> > Cc: Grant Likely <grant.likely@secretlab.ca> Hey Shawn, Comments below, but I've gone ahead and fixed them because I'm keen to get this patch merged. I just wanted to let you know what I changed. I'll post the modified version so you can test it. > --- > drivers/of/base.c | 181 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > drivers/of/fdt.c | 6 ++ > include/linux/of.h | 7 ++ > 3 files changed, 194 insertions(+), 0 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 632ebae..89efd10 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -17,14 +17,38 @@ > * as published by the Free Software Foundation; either version > * 2 of the License, or (at your option) any later version. > */ > +#include <linux/bootmem.h> > +#include <linux/ctype.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/spinlock.h> > #include <linux/slab.h> > #include <linux/proc_fs.h> > > +/** > + * 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 > + * @alias_id: Alias id decoded from alias > + * @alias_stem: Alias stem name decoded from alias > + * > + * 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 alias_id; > + char alias_stem[0]; > +}; > + > +static LIST_HEAD(aliases_lookup); > + > struct device_node *allnodes; > struct device_node *of_chosen; > +struct device_node *of_aliases; > > /* use when traversing tree through the allnext, child, sibling, > * or parent members of struct device_node. > @@ -922,3 +946,160 @@ out_unlock: > } > #endif /* defined(CONFIG_OF_DYNAMIC) */ > > +/* > + * of_alias_find_available_id - Find an available id for the given device_node Nit: kerneldoc format is "/**" to start the comment, and function names should have '()' on it. > + * @np: Pointer to the given device_node > + * @stem: Alias stem of the given device_node > + * > + * The function travels the lookup table to find an available id for the > + * given device_node with given alias stem. It returns the id found. > + */ > +static int of_alias_find_available_id(struct device_node *np, const char *stem) > +{ > + struct alias_prop *app; > + int id = 0; > + > + while (1) { > + bool used = false; > + list_for_each_entry(app, &aliases_lookup, link) { > + if (!strcmp(app->alias_stem, stem) && > + app->alias_id == id) { > + used = true; > + break; > + } > + } > + > + if (used) > + id++; > + else > + return id; > + } > +} I've simplified this somewhat to do the list_for_each_entry() only once, and to bump up the id to +1 the largest entry: list_for_each_entry(app, &aliases_lookup, link) if ((strcmp(app->stem, stem) == 0) && id <= app->id) id = app->id + 1; .... actually, after looking further, I've rolled this code into the of_alias_get_id() function. > + > +/** > + * of_alias_lookup_add - Add alias into lookup table > + * @alias: Alias name > + * @id: Alias id > + * @stem: Alias stem name > + * @np: Pointer to device_node > + * > + * The function adds one alias into the lookup table and populate it > + * with the info passed in. It returns 0 in sucess, or error code. > + */ > +static int of_alias_lookup_add(char *alias, int id, const char *stem, > + struct device_node *np) > +{ > + struct alias_prop *app; > + size_t sz = sizeof(*app) + strlen(stem) + 1; > + > + app = kzalloc(sz, GFP_KERNEL); > + if (!app) { > + /* > + * It may fail due to being called by boot code, > + * so try alloc_bootmem before return error. > + */ > + app = alloc_bootmem(sz); > + if (!app) > + return -ENOMEM; > + } I'm not too fond of this since we *know* when this is going to be called from early boot. So, instead, I've changed the code to use the already existing dt_alloc functions as an argument to of_alias_lookup_add(). Also, alloc_bootmem() doesn't work on all platforms. early_init_dt_alloc_memory_arch() needs to be used instead. > + > + app->np = np; > + app->alias = alias; > + app->alias_id = id; > + strcpy(app->alias_stem, stem); > + list_add_tail(&app->link, &aliases_lookup); > + > + return 0; > +} > + > +/** > + * of_alias_decode - Decode alias stem and id from alias name > + * @alias: Alias name to be decoded > + * @stem: Pointer used to return stem name > + * > + * The function decodes alias stem name and alias id from the given > + * alias name. It returns stem name via parameter 'stem', and stem id > + * via the return value. If no id is found in alias name, it returns 0 > + * as the default. > + */ > +static int of_alias_decode(char *alias, char *stem) > +{ > + int len = strlen(alias); > + char *end = alias + len; > + > + while (isdigit(*--end)) > + len--; Need to protect against len < 0 > + > + strncpy(stem, alias, len); > + stem[len] = '\0'; > + > + return strlen(++end) ? simple_strtoul(end, NULL, 10) : 0; > +} > + > +/** > + * 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. > + */ > +int of_alias_scan(void) Changed to '__init void of_aliases_scan(void)'. There is no point in returning an error code since it is never checked, and there is no point in bailing on an error just in case it is a problem with only one alias. > +{ > + struct property *pp; > + int ret, num = 0; > + > + if (!of_aliases) > + return -ENODEV; > + > + for_each_property(pp, of_aliases->properties) { > + char stem[32]; > + int id = of_alias_decode(pp->name, stem); > + > + /* Skip those we do not want to proceed */ > + if (!strcmp(pp->name, "name") || > + !strcmp(pp->name, "phandle") || > + !strcmp(pp->name, "linux,phandle")) > + continue; > + > + ret = of_alias_lookup_add(pp->name, id, stem, > + of_find_node_by_path(pp->value)); > + if (ret < 0) > + return ret; > + else > + num++; > + } > + > + return num; > +} > + > +/** > + * 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 = -1; > + > + list_for_each_entry(app, &aliases_lookup, link) { > + if (np == app->np) { > + id = app->alias_id; > + break; > + } > + } > + > + if (id == -1) { > + id = of_alias_find_available_id(np, stem); > + if (of_alias_lookup_add(NULL, id, stem, np) < 0) > + return -ENODEV; > + } > + > + return id; > +} This whole function needs to be protected by a mutex. > +EXPORT_SYMBOL_GPL(of_alias_get_id); > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 65200af..998dc63 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -711,6 +711,12 @@ void __init unflatten_device_tree(void) > 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"); > + if (of_aliases == NULL) > + of_aliases = of_find_node_by_path("/aliases@0"); I don't think the /aliases@0 variant is necessary. I've dropped it. g. > + > + of_alias_scan(); > } > > #endif /* CONFIG_OF_EARLY_FLATTREE */ > diff --git a/include/linux/of.h b/include/linux/of.h > index bfc0ed1..c35cc47 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) > @@ -201,6 +202,9 @@ 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( > @@ -213,6 +217,9 @@ 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 int of_alias_scan(void); > +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); > -- > 1.7.4.1 >
On Thu, Jul 14, 2011 at 08:53:20PM -0600, Grant Likely wrote: > On Sat, Jun 25, 2011 at 02:04:32AM +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 <shawn.guo@linaro.org> > > Cc: Grant Likely <grant.likely@secretlab.ca> > > Hey Shawn, > > Comments below, but I've gone ahead and fixed them because I'm keen to > get this patch merged. I just wanted to let you know what I changed. > I'll post the modified version so you can test it. > Thanks for doing this. It makes the wheel spin fast. I respect changes you made, and will give it a test once you post it. Regards, Shawn > > --- > > drivers/of/base.c | 181 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > > drivers/of/fdt.c | 6 ++ > > include/linux/of.h | 7 ++ > > 3 files changed, 194 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > index 632ebae..89efd10 100644 > > --- a/drivers/of/base.c > > +++ b/drivers/of/base.c > > @@ -17,14 +17,38 @@ > > * as published by the Free Software Foundation; either version > > * 2 of the License, or (at your option) any later version. > > */ > > +#include <linux/bootmem.h> > > +#include <linux/ctype.h> > > #include <linux/module.h> > > #include <linux/of.h> > > #include <linux/spinlock.h> > > #include <linux/slab.h> > > #include <linux/proc_fs.h> > > > > +/** > > + * 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 > > + * @alias_id: Alias id decoded from alias > > + * @alias_stem: Alias stem name decoded from alias > > + * > > + * 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 alias_id; > > + char alias_stem[0]; > > +}; > > + > > +static LIST_HEAD(aliases_lookup); > > + > > struct device_node *allnodes; > > struct device_node *of_chosen; > > +struct device_node *of_aliases; > > > > /* use when traversing tree through the allnext, child, sibling, > > * or parent members of struct device_node. > > @@ -922,3 +946,160 @@ out_unlock: > > } > > #endif /* defined(CONFIG_OF_DYNAMIC) */ > > > > +/* > > + * of_alias_find_available_id - Find an available id for the given device_node > > Nit: kerneldoc format is "/**" to start the comment, and function > names should have '()' on it. > > > + * @np: Pointer to the given device_node > > + * @stem: Alias stem of the given device_node > > + * > > + * The function travels the lookup table to find an available id for the > > + * given device_node with given alias stem. It returns the id found. > > + */ > > +static int of_alias_find_available_id(struct device_node *np, const char *stem) > > +{ > > + struct alias_prop *app; > > + int id = 0; > > + > > + while (1) { > > + bool used = false; > > + list_for_each_entry(app, &aliases_lookup, link) { > > + if (!strcmp(app->alias_stem, stem) && > > + app->alias_id == id) { > > + used = true; > > + break; > > + } > > + } > > + > > + if (used) > > + id++; > > + else > > + return id; > > + } > > +} > > I've simplified this somewhat to do the list_for_each_entry() only > once, and to bump up the id to +1 the largest entry: > > list_for_each_entry(app, &aliases_lookup, link) > if ((strcmp(app->stem, stem) == 0) && id <= app->id) > id = app->id + 1; > > .... actually, after looking further, I've rolled this code into the > of_alias_get_id() function. > > > + > > +/** > > + * of_alias_lookup_add - Add alias into lookup table > > + * @alias: Alias name > > + * @id: Alias id > > + * @stem: Alias stem name > > + * @np: Pointer to device_node > > + * > > + * The function adds one alias into the lookup table and populate it > > + * with the info passed in. It returns 0 in sucess, or error code. > > + */ > > +static int of_alias_lookup_add(char *alias, int id, const char *stem, > > + struct device_node *np) > > +{ > > + struct alias_prop *app; > > + size_t sz = sizeof(*app) + strlen(stem) + 1; > > + > > + app = kzalloc(sz, GFP_KERNEL); > > + if (!app) { > > + /* > > + * It may fail due to being called by boot code, > > + * so try alloc_bootmem before return error. > > + */ > > + app = alloc_bootmem(sz); > > + if (!app) > > + return -ENOMEM; > > + } > > I'm not too fond of this since we *know* when this is going to be > called from early boot. So, instead, I've changed the code to use the > already existing dt_alloc functions as an argument to of_alias_lookup_add(). > > Also, alloc_bootmem() doesn't work on all platforms. > early_init_dt_alloc_memory_arch() needs to be used instead. > > > > + > > + app->np = np; > > + app->alias = alias; > > + app->alias_id = id; > > + strcpy(app->alias_stem, stem); > > + list_add_tail(&app->link, &aliases_lookup); > > + > > + return 0; > > +} > > + > > +/** > > + * of_alias_decode - Decode alias stem and id from alias name > > + * @alias: Alias name to be decoded > > + * @stem: Pointer used to return stem name > > + * > > + * The function decodes alias stem name and alias id from the given > > + * alias name. It returns stem name via parameter 'stem', and stem id > > + * via the return value. If no id is found in alias name, it returns 0 > > + * as the default. > > + */ > > +static int of_alias_decode(char *alias, char *stem) > > +{ > > + int len = strlen(alias); > > + char *end = alias + len; > > + > > + while (isdigit(*--end)) > > + len--; > > Need to protect against len < 0 > > > + > > + strncpy(stem, alias, len); > > + stem[len] = '\0'; > > + > > + return strlen(++end) ? simple_strtoul(end, NULL, 10) : 0; > > +} > > + > > +/** > > + * 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. > > + */ > > +int of_alias_scan(void) > > Changed to '__init void of_aliases_scan(void)'. There is no point in > returning an error code since it is never checked, and there is no > point in bailing on an error just in case it is a problem with only > one alias. > > > +{ > > + struct property *pp; > > + int ret, num = 0; > > + > > + if (!of_aliases) > > + return -ENODEV; > > + > > + for_each_property(pp, of_aliases->properties) { > > + char stem[32]; > > + int id = of_alias_decode(pp->name, stem); > > + > > + /* Skip those we do not want to proceed */ > > + if (!strcmp(pp->name, "name") || > > + !strcmp(pp->name, "phandle") || > > + !strcmp(pp->name, "linux,phandle")) > > + continue; > > + > > + ret = of_alias_lookup_add(pp->name, id, stem, > > + of_find_node_by_path(pp->value)); > > + if (ret < 0) > > + return ret; > > + else > > + num++; > > + } > > + > > + return num; > > +} > > + > > +/** > > + * 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 = -1; > > + > > + list_for_each_entry(app, &aliases_lookup, link) { > > + if (np == app->np) { > > + id = app->alias_id; > > + break; > > + } > > + } > > + > > + if (id == -1) { > > + id = of_alias_find_available_id(np, stem); > > + if (of_alias_lookup_add(NULL, id, stem, np) < 0) > > + return -ENODEV; > > + } > > + > > + return id; > > +} > > This whole function needs to be protected by a mutex. > > > +EXPORT_SYMBOL_GPL(of_alias_get_id); > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > > index 65200af..998dc63 100644 > > --- a/drivers/of/fdt.c > > +++ b/drivers/of/fdt.c > > @@ -711,6 +711,12 @@ void __init unflatten_device_tree(void) > > 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"); > > + if (of_aliases == NULL) > > + of_aliases = of_find_node_by_path("/aliases@0"); > > I don't think the /aliases@0 variant is necessary. I've dropped it. > > g. > > > + > > + of_alias_scan(); > > } > > > > #endif /* CONFIG_OF_EARLY_FLATTREE */ > > diff --git a/include/linux/of.h b/include/linux/of.h > > index bfc0ed1..c35cc47 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) > > @@ -201,6 +202,9 @@ 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( > > @@ -213,6 +217,9 @@ 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 int of_alias_scan(void); > > +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); > > -- > > 1.7.4.1 > > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
diff --git a/drivers/of/base.c b/drivers/of/base.c index 632ebae..89efd10 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -17,14 +17,38 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ +#include <linux/bootmem.h> +#include <linux/ctype.h> #include <linux/module.h> #include <linux/of.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/proc_fs.h> +/** + * 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 + * @alias_id: Alias id decoded from alias + * @alias_stem: Alias stem name decoded from alias + * + * 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 alias_id; + char alias_stem[0]; +}; + +static LIST_HEAD(aliases_lookup); + struct device_node *allnodes; struct device_node *of_chosen; +struct device_node *of_aliases; /* use when traversing tree through the allnext, child, sibling, * or parent members of struct device_node. @@ -922,3 +946,160 @@ out_unlock: } #endif /* defined(CONFIG_OF_DYNAMIC) */ +/* + * of_alias_find_available_id - Find an available 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 find an available id for the + * given device_node with given alias stem. It returns the id found. + */ +static int of_alias_find_available_id(struct device_node *np, const char *stem) +{ + struct alias_prop *app; + int id = 0; + + while (1) { + bool used = false; + list_for_each_entry(app, &aliases_lookup, link) { + if (!strcmp(app->alias_stem, stem) && + app->alias_id == id) { + used = true; + break; + } + } + + if (used) + id++; + else + return id; + } +} + +/** + * of_alias_lookup_add - Add alias into lookup table + * @alias: Alias name + * @id: Alias id + * @stem: Alias stem name + * @np: Pointer to device_node + * + * The function adds one alias into the lookup table and populate it + * with the info passed in. It returns 0 in sucess, or error code. + */ +static int of_alias_lookup_add(char *alias, int id, const char *stem, + struct device_node *np) +{ + struct alias_prop *app; + size_t sz = sizeof(*app) + strlen(stem) + 1; + + app = kzalloc(sz, GFP_KERNEL); + if (!app) { + /* + * It may fail due to being called by boot code, + * so try alloc_bootmem before return error. + */ + app = alloc_bootmem(sz); + if (!app) + return -ENOMEM; + } + + app->np = np; + app->alias = alias; + app->alias_id = id; + strcpy(app->alias_stem, stem); + list_add_tail(&app->link, &aliases_lookup); + + return 0; +} + +/** + * of_alias_decode - Decode alias stem and id from alias name + * @alias: Alias name to be decoded + * @stem: Pointer used to return stem name + * + * The function decodes alias stem name and alias id from the given + * alias name. It returns stem name via parameter 'stem', and stem id + * via the return value. If no id is found in alias name, it returns 0 + * as the default. + */ +static int of_alias_decode(char *alias, char *stem) +{ + int len = strlen(alias); + char *end = alias + len; + + while (isdigit(*--end)) + len--; + + strncpy(stem, alias, len); + stem[len] = '\0'; + + return strlen(++end) ? simple_strtoul(end, NULL, 10) : 0; +} + +/** + * 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. + */ +int of_alias_scan(void) +{ + struct property *pp; + int ret, num = 0; + + if (!of_aliases) + return -ENODEV; + + for_each_property(pp, of_aliases->properties) { + char stem[32]; + int id = of_alias_decode(pp->name, stem); + + /* Skip those we do not want to proceed */ + if (!strcmp(pp->name, "name") || + !strcmp(pp->name, "phandle") || + !strcmp(pp->name, "linux,phandle")) + continue; + + ret = of_alias_lookup_add(pp->name, id, stem, + of_find_node_by_path(pp->value)); + if (ret < 0) + return ret; + else + num++; + } + + return num; +} + +/** + * 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 = -1; + + list_for_each_entry(app, &aliases_lookup, link) { + if (np == app->np) { + id = app->alias_id; + break; + } + } + + if (id == -1) { + id = of_alias_find_available_id(np, stem); + if (of_alias_lookup_add(NULL, id, stem, np) < 0) + return -ENODEV; + } + + return id; +} +EXPORT_SYMBOL_GPL(of_alias_get_id); diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 65200af..998dc63 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -711,6 +711,12 @@ void __init unflatten_device_tree(void) 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"); + if (of_aliases == NULL) + of_aliases = of_find_node_by_path("/aliases@0"); + + of_alias_scan(); } #endif /* CONFIG_OF_EARLY_FLATTREE */ diff --git a/include/linux/of.h b/include/linux/of.h index bfc0ed1..c35cc47 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) @@ -201,6 +202,9 @@ 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( @@ -213,6 +217,9 @@ 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 int of_alias_scan(void); +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);
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 <shawn.guo@linaro.org> Cc: Grant Likely <grant.likely@secretlab.ca> --- drivers/of/base.c | 181 ++++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/of/fdt.c | 6 ++ include/linux/of.h | 7 ++ 3 files changed, 194 insertions(+), 0 deletions(-)