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authorFabrice Gasnier <fabrice.gasnier@st.com>2018-10-01 13:23:57 (GMT)
committerThierry Reding <thierry.reding@gmail.com>2018-10-12 11:51:33 (GMT)
commit552c02e3e7cfe2744b59de285aaea70021ae95c9 (patch)
tree53a28e6dca26ab1e000c1ae4e6ed1ad8c72e665e /drivers/pwm
parentc289d6625237aa785b484b4e94c23b3b91ea7e60 (diff)
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.c11
1 files changed, 11 insertions, 0 deletions
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);

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