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| author | Fabrice Gasnier <fabrice.gasnier@st.com> | 2018-10-01 15:23:57 +0200 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2018-10-12 13:51:33 +0200 |
| commit | 552c02e3e7cfe2744b59de285aaea70021ae95c9 (patch) | |
| tree | 53a28e6dca26ab1e000c1ae4e6ed1ad8c72e665e /drivers/pwm | |
| parent | c289d6625237aa785b484b4e94c23b3b91ea7e60 (diff) | |
| download | linux-0-day-552c02e3e7cfe2744b59de285aaea70021ae95c9.tar.gz linux-0-day-552c02e3e7cfe2744b59de285aaea70021ae95c9.tar.xz | |
pwm: Send a uevent on the pwmchip device upon channel sysfs (un)export
This patch sends a uevent (KOBJ_CHANGE) on the pwmchipN device,
everytime a pwmX channel has been exported/unexported via sysfs. This
allows udev to implement rules on such events, like:
SUBSYSTEM=="pwm*", PROGRAM="/bin/sh -c '\
chown -R root:gpio /sys/class/pwm && chmod -R 770 /sys/class/pwm;\
chown -R root:gpio
/sys/devices/platform/soc/*.pwm/pwm/pwmchip* && chmod -R 770
/sys/devices/platform/soc/*.pwm/pwm/pwmchip*\
'"
This is a replacement patch for commit 7e5d1fd75c3d ("pwm: Set class for
exported channels in sysfs"), see [1].
basic testing:
$ udevadm monitor --environment &
$ echo 0 > /sys/class/pwm/pwmchip0/export
KERNEL[197.321736] change /devices/.../pwm/pwmchip0 (pwm)
ACTION=change
DEVPATH=/devices/.../pwm/pwmchip0
EXPORT=pwm0
SEQNUM=2045
SUBSYSTEM=pwm
[1] https://lkml.org/lkml/2018/9/25/713
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Tested-by: Gottfried Haider <gottfried.haider@gmail.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/sysfs.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 4726d43aaa0cb..ceb233dd60484 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -249,6 +249,7 @@ static void pwm_export_release(struct device *child) static int pwm_export_child(struct device *parent, struct pwm_device *pwm) { struct pwm_export *export; + char *pwm_prop[2]; int ret; if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags)) @@ -276,6 +277,10 @@ static int pwm_export_child(struct device *parent, struct pwm_device *pwm) export = NULL; return ret; } + pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm); + pwm_prop[1] = NULL; + kobject_uevent_env(&parent->kobj, KOBJ_CHANGE, pwm_prop); + kfree(pwm_prop[0]); return 0; } @@ -288,6 +293,7 @@ static int pwm_unexport_match(struct device *child, void *data) static int pwm_unexport_child(struct device *parent, struct pwm_device *pwm) { struct device *child; + char *pwm_prop[2]; if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags)) return -ENODEV; @@ -296,6 +302,11 @@ static int pwm_unexport_child(struct device *parent, struct pwm_device *pwm) if (!child) return -ENODEV; + pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm); + pwm_prop[1] = NULL; + kobject_uevent_env(&parent->kobj, KOBJ_CHANGE, pwm_prop); + kfree(pwm_prop[0]); + /* for device_find_child() */ put_device(child); device_unregister(child); |