From 0e09cd3599153a865e87e212ffed6d485488dd4f Mon Sep 17 00:00:00 2001 From: David Hsu Date: Sun, 30 Apr 2017 22:10:56 -0500 Subject: [PATCH] pwm: Create device class for pwm channels #https://lkml.org/lkml/2016/6/14/967 Pwm channels don't send uevents when exported, this change adds the channels to a pwm class and set their device type to pwm_channel so uevents are sent. To do this properly, the device names need to change to uniquely identify a channel. This change is from pwmN to pwm-(chip->base):N Signed-off-by: David Hsu Signed-off-by: Greg Kroah-Hartman Signed-off-by: Robert Nelson --- Documentation/pwm.txt | 6 ++++-- drivers/pwm/sysfs.c | 15 ++++++++++++--- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 8fbf0aa3ba2d5..72db8dd15f53b 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -85,9 +85,11 @@ will find: The PWM channels are numbered using a per-chip index from 0 to npwm-1. -When a PWM channel is exported a pwmX directory will be created in the +When a PWM channel is exported a pwm-N:X directory will be created in the pwmchipN directory it is associated with, where X is the number of the -channel that was exported. The following properties will then be available: +channel that was exported. It will also be exposed at /sys/class/pwm/ and +can be identified by the pwm_channel device type. +The following properties will then be available: period The total period of the PWM signal (read/write). diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index a813239300c3d..7a7b9d8ae4e54 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -23,6 +23,8 @@ #include #include +static struct class pwm_class; + struct pwm_export { struct device child; struct pwm_device *pwm; @@ -239,6 +241,10 @@ static struct attribute *pwm_attrs[] = { }; ATTRIBUTE_GROUPS(pwm); +static const struct device_type pwm_channel_type = { + .name = "pwm_channel", +}; + static void pwm_export_release(struct device *child) { struct pwm_export *export = child_to_pwm_export(child); @@ -248,6 +254,7 @@ static void pwm_export_release(struct device *child) static int pwm_export_child(struct device *parent, struct pwm_device *pwm) { + struct pwm_chip *chip = dev_get_drvdata(parent); struct pwm_export *export; int ret; @@ -265,9 +272,11 @@ static int pwm_export_child(struct device *parent, struct pwm_device *pwm) export->child.release = pwm_export_release; export->child.parent = parent; + export->child.type = &pwm_channel_type; export->child.devt = MKDEV(0, 0); + export->child.class = &pwm_class; export->child.groups = pwm_groups; - dev_set_name(&export->child, "pwm%u", pwm->hwpwm); + dev_set_name(&export->child, "pwm-%d:%u", chip->base, pwm->hwpwm); ret = device_register(&export->child); if (ret) { @@ -372,7 +381,6 @@ ATTRIBUTE_GROUPS(pwm_chip); static struct class pwm_class = { .name = "pwm", .owner = THIS_MODULE, - .dev_groups = pwm_chip_groups, }; static int pwmchip_sysfs_match(struct device *parent, const void *data) @@ -388,7 +396,8 @@ void pwmchip_sysfs_export(struct pwm_chip *chip) * If device_create() fails the pwm_chip is still usable by * the kernel its just not exported. */ - parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip, + parent = device_create_with_groups(&pwm_class, chip->dev, MKDEV(0, 0), + chip, pwm_chip_groups, "pwmchip%d", chip->base); if (IS_ERR(parent)) { dev_warn(chip->dev,