This patch adds a helper function that simplifies adding a sequence file for device drivers. The calling device driver needs to provide a read function and a device pointer. The field struct seq_file::private will reference the device pointer upon call to the read function so the driver can obtain his data from it and do its seq_printf() calls.
Signed-off-by: Arend van Spriel <[email protected]> --- fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/debugfs.h | 16 ++++++++++++++- 2 files changed, 69 insertions(+), 1 deletion(-) diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 76c08c2..088b3fc 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -22,6 +22,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/atomic.h> +#include <linux/device.h> static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -761,3 +762,56 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode, EXPORT_SYMBOL_GPL(debugfs_create_regset32); #endif /* CONFIG_HAS_IOMEM */ + +struct debugfs_devm_entry { + int (*read)(struct seq_file *seq, void *data); + struct device *dev; +}; + +static int debugfs_devm_entry_open(struct inode *inode, struct file *f) +{ + struct debugfs_devm_entry *entry = inode->i_private; + + return single_open(f, entry->read, entry->dev); +} + +static const struct file_operations debugfs_devm_entry_ops = { + .owner = THIS_MODULE, + .open = debugfs_devm_entry_open, + .release = single_release, + .read = seq_read, + .llseek = seq_lseek +}; + +/** + * debugfs_create_devm_seqfile - create a debugfs file that is bound to device. + * + * @dev: device related to this debugfs file. + * @name: name of the debugfs file. + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @read_fn: function pointer called to print the seq_file content. + */ +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)) +{ + struct debugfs_devm_entry *entry; + + if (IS_ERR(parent)) + return ERR_PTR(-ENOENT); + + entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); + if (!entry) + return ERR_PTR(-ENOMEM); + + entry->read = read_fn; + entry->dev = dev; + + return debugfs_create_file(name, S_IRUGO, parent, entry, + &debugfs_devm_entry_ops); +} +EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile); + diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 4d0b4d1..f8c0db4 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -99,13 +99,18 @@ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, struct dentry *parent, u32 *array, u32 elements); +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)); + bool debugfs_initialized(void); #else #include <linux/err.h> -/* +/* * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled * so users have a chance to detect if there was a real error or not. We don't * want to duplicate the design decision mistakes of procfs and devfs again. @@ -251,6 +256,15 @@ static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t return ERR_PTR(-ENODEV); } +static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, + const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)) +{ + return ERR_PTR(-ENODEV); +} + #endif #endif -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
