| Message ID | 1454641552-12576-17-git-send-email-zhaoshenglong@huawei.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Feb 4, 2016 at 9:05 PM, Shannon Zhao <zhaoshenglong@huawei.com> wrote: > From: Shannon Zhao <shannon.zhao@linaro.org> > > Sometimes it needs to check if there is a node in FDT by full path. I'm confused. Are you searching by full path or... > Introduce this helper to get the specified name subnode if it exists. name of sub node? Either way, fdt_subnode_offset or fdt_path_offset doesn't work? > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > --- > CC: Rob Herring <robh@kernel.org> > --- > drivers/of/fdt.c | 25 +++++++++++++++++++++++++ > include/linux/of_fdt.h | 2 ++ > 2 files changed, 27 insertions(+) > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 655f79d..eacb188 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -645,6 +645,31 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node, > } > > /** > + * of_get_flat_dt_subnode_by_name - get subnode of specified node by name > + * > + * @node: the parent node > + * @uname: the name of subnode > + * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none > + */ > + > +int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) > +{ > + const void *blob = initial_boot_params; > + int offset; > + const char *pathp; > + > + for (offset = fdt_first_subnode(blob, node); > + offset >= 0; > + offset = fdt_next_subnode(blob, offset)) { > + pathp = fdt_get_name(blob, offset, NULL); > + if (strcmp(pathp, uname) == 0) > + return offset; > + } > + > + return -FDT_ERR_NOTFOUND; > +} > + > +/** > * of_get_flat_dt_root - find the root node in the flat blob > */ > unsigned long __init of_get_flat_dt_root(void) > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > index df9ef38..fc28162 100644 > --- a/include/linux/of_fdt.h > +++ b/include/linux/of_fdt.h > @@ -52,6 +52,8 @@ extern char __dtb_end[]; > extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname, > int depth, void *data), > void *data); > +extern int of_get_flat_dt_subnode_by_name(unsigned long node, > + const char *uname); > extern const void *of_get_flat_dt_prop(unsigned long node, const char *name, > int *size); > extern int of_flat_dt_is_compatible(unsigned long node, const char *name); > -- > 2.0.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Feb 23, 2016 at 5:13 AM, Shannon Zhao <zhaoshenglong@huawei.com> wrote: > > > On 2016/2/9 13:04, Rob Herring wrote: >> On Thu, Feb 4, 2016 at 9:05 PM, Shannon Zhao <zhaoshenglong@huawei.com> wrote: >>> From: Shannon Zhao <shannon.zhao@linaro.org> >>> >>> Sometimes it needs to check if there is a node in FDT by full path. >> >> I'm confused. Are you searching by full path or... >> >>> Introduce this helper to get the specified name subnode if it exists. >> >> name of sub node? >> > get the offset of sub node by specified name. > >> Either way, fdt_subnode_offset or fdt_path_offset doesn't work? >> > Ah，right，both of them should work. Does it need to add a wrapper in > drivers/of/fdt.c for them or directly use them with the parameter > initial_boot_params? Add a wrapper in fdt.c. Rob
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 655f79d..eacb188 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -645,6 +645,31 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node, } /** + * of_get_flat_dt_subnode_by_name - get subnode of specified node by name + * + * @node: the parent node + * @uname: the name of subnode + * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none + */ + +int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) +{ + const void *blob = initial_boot_params; + int offset; + const char *pathp; + + for (offset = fdt_first_subnode(blob, node); + offset >= 0; + offset = fdt_next_subnode(blob, offset)) { + pathp = fdt_get_name(blob, offset, NULL); + if (strcmp(pathp, uname) == 0) + return offset; + } + + return -FDT_ERR_NOTFOUND; +} + +/** * of_get_flat_dt_root - find the root node in the flat blob */ unsigned long __init of_get_flat_dt_root(void) diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index df9ef38..fc28162 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -52,6 +52,8 @@ extern char __dtb_end[]; extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname, int depth, void *data), void *data); +extern int of_get_flat_dt_subnode_by_name(unsigned long node, + const char *uname); extern const void *of_get_flat_dt_prop(unsigned long node, const char *name, int *size); extern int of_flat_dt_is_compatible(unsigned long node, const char *name);