| Message ID | 1538400237-28766-3-git-send-email-fabrice.gasnier@st.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | pwm: sysfs: fix exporting PWM channel | expand |
On 1.10.2018 15:23, Fabrice Gasnier wrote: > 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>
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 4726d43..ceb233d 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);
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> --- drivers/pwm/sysfs.c | 11 +++++++++++ 1 file changed, 11 insertions(+)