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author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-07-06 12:42:00 +0300 |
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committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-07-07 14:14:10 +0300 |
commit | 3068a254d5519cd5116f61297462da6d1aa84c20 (patch) | |
tree | 996896001b788c362f3de5e63c5ed9141f661754 /drivers/rtc/class.c | |
parent | b91336df8ac2f5d15a2132074ba596580526db1d (diff) | |
download | linux-3068a254d5519cd5116f61297462da6d1aa84c20.tar.xz |
rtc: introduce new registration method
Introduce rtc_register_device() to register an already allocated and
initialized struct rtc_device. It automatically sets up the owner and the
two steps allocation/registration will allow to remove race conditions in
the IRQ handling of some driver. It also allows to properly extend the core
without adding more arguments to rtc_device_register().
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc/class.c')
-rw-r--r-- | drivers/rtc/class.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 93ce88e1b1cb..58e2a05765bb 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -150,6 +150,7 @@ static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); #define RTC_CLASS_DEV_PM_OPS NULL #endif +/* Ensure the caller will set the id before releasing the device */ static struct rtc_device *rtc_allocate_device(void) { struct rtc_device *rtc; @@ -372,6 +373,89 @@ void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc) } EXPORT_SYMBOL_GPL(devm_rtc_device_unregister); +static void devm_rtc_release_device(struct device *dev, void *res) +{ + struct rtc_device *rtc = *(struct rtc_device **)res; + + if (rtc->registered) + rtc_device_unregister(rtc); + else + put_device(&rtc->dev); +} + +struct rtc_device *devm_rtc_allocate_device(struct device *dev) +{ + struct rtc_device **ptr, *rtc; + int id, err; + + id = rtc_device_get_id(dev); + if (id < 0) + return ERR_PTR(id); + + ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL); + if (!ptr) { + err = -ENOMEM; + goto exit_ida; + } + + rtc = rtc_allocate_device(); + if (!rtc) { + err = -ENOMEM; + goto exit_devres; + } + + *ptr = rtc; + devres_add(dev, ptr); + + rtc->id = id; + rtc->dev.parent = dev; + dev_set_name(&rtc->dev, "rtc%d", id); + + return rtc; + +exit_devres: + devres_free(ptr); +exit_ida: + ida_simple_remove(&rtc_ida, id); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(devm_rtc_allocate_device); + +int __rtc_register_device(struct module *owner, struct rtc_device *rtc) +{ + struct rtc_wkalrm alrm; + int err; + + if (!rtc->ops) + return -EINVAL; + + rtc->owner = owner; + + /* Check to see if there is an ALARM already set in hw */ + err = __rtc_read_alarm(rtc, &alrm); + if (!err && !rtc_valid_tm(&alrm.time)) + rtc_initialize_alarm(rtc, &alrm); + + rtc_dev_prepare(rtc); + + err = cdev_device_add(&rtc->char_dev, &rtc->dev); + if (err) + dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n", + MAJOR(rtc->dev.devt), rtc->id); + else + dev_dbg(rtc->dev.parent, "char device (%d:%d)\n", + MAJOR(rtc->dev.devt), rtc->id); + + rtc_proc_add_device(rtc); + + rtc->registered = true; + dev_info(rtc->dev.parent, "registered as %s\n", + dev_name(&rtc->dev)); + + return 0; +} +EXPORT_SYMBOL_GPL(__rtc_register_device); + static int __init rtc_init(void) { rtc_class = class_create(THIS_MODULE, "rtc"); |