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authorAlessandro Rubini <rubini@gnudd.com>2011-11-18 17:50:21 +0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-18 22:31:22 +0400
commit1a087c6ad975bcc193b4bab2e9d61f9c6c547138 (patch)
tree207b0b121a2e5a48613e9225beb1c49ca67a92a7 /Documentation/filesystems/debugfs.txt
parentfe7484834bb614c2c205726647635171ce6cc070 (diff)
downloadlinux-1a087c6ad975bcc193b4bab2e9d61f9c6c547138.tar.xz
debugfs: add tools to printk 32-bit registers
Some debugfs file I deal with are mostly blocks of registers, i.e. lines of the form "<name> = 0x<value>". Some files are only registers, some include registers blocks among other material. This patch introduces data structures and functions to deal with both cases. I expect more users of this over time. Signed-off-by: Alessandro Rubini <rubini@gnudd.com> Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com> Cc: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/filesystems/debugfs.txt')
-rw-r--r--Documentation/filesystems/debugfs.txt32
1 files changed, 31 insertions, 1 deletions
diff --git a/Documentation/filesystems/debugfs.txt b/Documentation/filesystems/debugfs.txt
index 742cc06e138f..f04066a37f4c 100644
--- a/Documentation/filesystems/debugfs.txt
+++ b/Documentation/filesystems/debugfs.txt
@@ -97,7 +97,8 @@ A read on the resulting file will yield either Y (for non-zero values) or
N, followed by a newline. If written to, it will accept either upper- or
lower-case values, or 1 or 0. Any other input will be silently ignored.
-Finally, a block of arbitrary binary data can be exported with:
+Another option is exporting a block of arbitrary binary data, with
+this structure and function:
struct debugfs_blob_wrapper {
void *data;
@@ -115,6 +116,35 @@ can be used to export binary information, but there does not appear to be
any code which does so in the mainline. Note that all files created with
debugfs_create_blob() are read-only.
+If you want to dump a block of registers (something that happens quite
+often during development, even if little such code reaches mainline.
+Debugfs offers two functions: one to make a registers-only file, and
+another to insert a register block in the middle of another sequential
+file.
+
+ struct debugfs_reg32 {
+ char *name;
+ unsigned long offset;
+ };
+
+ struct debugfs_regset32 {
+ struct debugfs_reg32 *regs;
+ int nregs;
+ void __iomem *base;
+ };
+
+ struct dentry *debugfs_create_regset32(const char *name, mode_t mode,
+ struct dentry *parent,
+ struct debugfs_regset32 *regset);
+
+ int debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
+ int nregs, void __iomem *base, char *prefix);
+
+The "base" argument may be 0, but you may want to build the reg32 array
+using __stringify, and a number of register names (macros) are actually
+byte offsets over a base for the register block.
+
+
There are a couple of other directory-oriented helper functions:
struct dentry *debugfs_rename(struct dentry *old_dir,