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| author |  Lukas Wunner <lukas@wunner.de>
| 2024-04-20 22:00:01 +0200 |
|---|---|---|
| committer |  Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| 2024-05-04 17:37:03 +0200 |
| commit | 3cc50d07be10f67aff836f8247a240ec132c6a67 (patch) | |
| tree | 524f6eab98357bcd09406f611a056f74acbeb846 /drivers/base | |
| parent | Merge 6.9-rc5 into driver-core-next (diff) | |
| download | linux-3cc50d07be10f67aff836f8247a240ec132c6a67.tar.gz linux-3cc50d07be10f67aff836f8247a240ec132c6a67.tar.bz2 linux-3cc50d07be10f67aff836f8247a240ec132c6a67.zip | |
driver core: Add device_show_string() helper for sysfs attributes
For drivers wishing to expose an unsigned long, int or bool at a static
memory location in sysfs, the driver core provides ready-made helpers
such as device_show_ulong() to be used as ->show() callback.
Some drivers need to expose a string and so far they all provide their
own ->show() implementation. arch/powerpc/perf/hv-24x7.c went so far
as to create a device_show_string() helper but kept it private.
Make it public for reuse by other drivers. The pattern seems to be
sufficiently frequent to merit a public helper.
Add a DEVICE_STRING_ATTR_RO() macro in line with the existing
DEVICE_ULONG_ATTR() and similar macros to ease declaration of string
attributes.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2e3eaaf2600bb55c0415c23ba301e809403a7aa2.1713608122.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/core.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 4d51928c4088..131d96c6090b 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2538,6 +2538,15 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, } EXPORT_SYMBOL_GPL(device_show_bool); +ssize_t device_show_string(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_ext_attribute *ea = to_ext_attr(attr); + + return sysfs_emit(buf, "%s\n", (char *)ea->var); +} +EXPORT_SYMBOL_GPL(device_show_string); + /** * device_release - free device structure. * @kobj: device's kobject. |