| Message ID | 20180104070534.16248-1-zajec5@gmail.com |
|---|---|
| State | Rejected |
| Delegated to: | Boris Brezillon |
| Headers | show |
| Series | [V7,1/2] mtd: partitions: add of_match_table parser matching | expand |
On Thu, 4 Jan 2018 08:05:33 +0100 Rafał Miłecki <zajec5@gmail.com> wrote: > From: Brian Norris <computersforpeace@gmail.com> > > Partition parsers can now provide an of_match_table to enable > flash<-->parser matching via device tree as documented in the > mtd/partition.txt. > > It works by looking for a matching parser for every string in the > "compatibility" property (starting with the most specific one). > > This support is currently limited to built-in parsers as it uses > request_module() and friends. This should be sufficient for most cases > though as compiling parsers as modules isn't a common choice. > Applied both patches. Thanks, Boris > Signed-off-by: Brian Norris <computersforpeace@gmail.com> > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > --- > This is based on Brian's patches: > [RFC PATCH 4/7] mtd: add of_match_mtd_parser() and of_mtd_match_mtd_parser() helpers > [RFC PATCH 6/7] RFC: mtd: partitions: enable of_match_table matching > > V1: Put helpers in mtdpart.c instead of drivers/of/of_mtd.c > Merge helpers into a single of_mtd_match_mtd_parser > V3: Add a simple comment to note we will need the best match in the future > V4: Rework new functions to pick parser with the best match > Move new code in parse_mtd_partitions up so it has precedence over flash > driver defaults and MTD defaults > V5: Rework matching code to start checking with the most specific string in the > "compatibility" property. > V6: Initialize "ret" variable in mtd_part_get_parser_by_cp to NULL > V7: Rename function "mtd_part_get_parser_by_cp" to use "_compatible_" > Rename "cp" variable to "compat" > Drop unneeded if (np) check from the parse_mtd_partitions > --- > drivers/mtd/mtdpart.c | 59 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/mtd/partitions.h | 1 + > 2 files changed, 60 insertions(+) > > diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c > index be088bccd593..76e12fb81563 100644 > --- a/drivers/mtd/mtdpart.c > +++ b/drivers/mtd/mtdpart.c > @@ -30,6 +30,7 @@ > #include <linux/mtd/mtd.h> > #include <linux/mtd/partitions.h> > #include <linux/err.h> > +#include <linux/of.h> > > #include "mtdcore.h" > > @@ -880,6 +881,45 @@ static int mtd_part_do_parse(struct mtd_part_parser *parser, > } > > /** > + * mtd_part_get_compatible_parser - find MTD parser by a compatible string > + * > + * @compat: compatible string describing partitions in a device tree > + * > + * MTD parsers can specify supported partitions by providing a table of > + * compatibility strings. This function finds a parser that advertises support > + * for a passed value of "compatible". > + */ > +static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat) > +{ > + struct mtd_part_parser *p, *ret = NULL; > + > + spin_lock(&part_parser_lock); > + > + list_for_each_entry(p, &part_parsers, list) { > + const struct of_device_id *matches; > + > + matches = p->of_match_table; > + if (!matches) > + continue; > + > + for (; matches->compatible[0]; matches++) { > + if (!strcmp(matches->compatible, compat) && > + try_module_get(p->owner)) { > + ret = p; > + break; > + } > + } > + > + if (ret) > + break; > + } > + > + spin_unlock(&part_parser_lock); > + > + return ret; > +} > + > +/** > * parse_mtd_partitions - parse MTD partitions > * @master: the master partition (describes whole MTD device) > * @types: names of partition parsers to try or %NULL > @@ -905,8 +945,27 @@ int parse_mtd_partitions(struct mtd_info *master, const char *const *types, > struct mtd_part_parser_data *data) > { > struct mtd_part_parser *parser; > + struct device_node *np; > + struct property *prop; > + const char *compat; > int ret, err = 0; > > + np = of_get_child_by_name(mtd_get_of_node(master), "partitions"); > + of_property_for_each_string(np, "compatible", prop, compat) { > + parser = mtd_part_get_compatible_parser(compat); > + if (!parser) > + continue; > + ret = mtd_part_do_parse(parser, master, pparts, data); > + if (ret > 0) { > + of_node_put(np); > + return 0; > + } > + mtd_part_parser_put(parser); > + if (ret < 0 && !err) > + err = ret; > + } > + of_node_put(np); > + > if (!types) > types = default_mtd_part_types; > > diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h > index c4beb70dacbd..11cb0c50cd84 100644 > --- a/include/linux/mtd/partitions.h > +++ b/include/linux/mtd/partitions.h > @@ -77,6 +77,7 @@ struct mtd_part_parser { > struct list_head list; > struct module *owner; > const char *name; > + const struct of_device_id *of_match_table; > int (*parse_fn)(struct mtd_info *, const struct mtd_partition **, > struct mtd_part_parser_data *); > void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index be088bccd593..76e12fb81563 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -30,6 +30,7 @@ #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include <linux/err.h> +#include <linux/of.h> #include "mtdcore.h" @@ -880,6 +881,45 @@ static int mtd_part_do_parse(struct mtd_part_parser *parser, } /** + * mtd_part_get_compatible_parser - find MTD parser by a compatible string + * + * @compat: compatible string describing partitions in a device tree + * + * MTD parsers can specify supported partitions by providing a table of + * compatibility strings. This function finds a parser that advertises support + * for a passed value of "compatible". + */ +static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat) +{ + struct mtd_part_parser *p, *ret = NULL; + + spin_lock(&part_parser_lock); + + list_for_each_entry(p, &part_parsers, list) { + const struct of_device_id *matches; + + matches = p->of_match_table; + if (!matches) + continue; + + for (; matches->compatible[0]; matches++) { + if (!strcmp(matches->compatible, compat) && + try_module_get(p->owner)) { + ret = p; + break; + } + } + + if (ret) + break; + } + + spin_unlock(&part_parser_lock); + + return ret; +} + +/** * parse_mtd_partitions - parse MTD partitions * @master: the master partition (describes whole MTD device) * @types: names of partition parsers to try or %NULL @@ -905,8 +945,27 @@ int parse_mtd_partitions(struct mtd_info *master, const char *const *types, struct mtd_part_parser_data *data) { struct mtd_part_parser *parser; + struct device_node *np; + struct property *prop; + const char *compat; int ret, err = 0; + np = of_get_child_by_name(mtd_get_of_node(master), "partitions"); + of_property_for_each_string(np, "compatible", prop, compat) { + parser = mtd_part_get_compatible_parser(compat); + if (!parser) + continue; + ret = mtd_part_do_parse(parser, master, pparts, data); + if (ret > 0) { + of_node_put(np); + return 0; + } + mtd_part_parser_put(parser); + if (ret < 0 && !err) + err = ret; + } + of_node_put(np); + if (!types) types = default_mtd_part_types; diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h index c4beb70dacbd..11cb0c50cd84 100644 --- a/include/linux/mtd/partitions.h +++ b/include/linux/mtd/partitions.h @@ -77,6 +77,7 @@ struct mtd_part_parser { struct list_head list; struct module *owner; const char *name; + const struct of_device_id *of_match_table; int (*parse_fn)(struct mtd_info *, const struct mtd_partition **, struct mtd_part_parser_data *); void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);