Messages in this thread | | | Date | Fri, 8 Feb 2008 22:45:31 -0800 | From | Greg KH <> | Subject | Re: [PATCH 1/8] LinuxPPS core support. |
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On Fri, Feb 08, 2008 at 07:00:37PM +0100, Rodolfo Giometti wrote: > This patch adds the kernel side of the PPS support currently named > "LinuxPPS". > > PPS means "pulse per second" and a PPS source is just a device which > provides a high precision signal each second so that an application > can use it to adjust system clock time. > > Common use is the combination of the NTPD as userland program with a > GPS receiver as PPS source to obtain a wallclock-time with > sub-millisecond synchronisation to UTC. > > To obtain this goal the userland programs shoud use the PPS API > specification (RFC 2783 - Pulse-Per-Second API for UNIX-like Operating > Systems, Version 1.0) which in part is implemented by this patch. It > provides a set of chars devices, one per PPS source, which can be used > to get the time signal. The RFC's functions can be implemented by > accessing to these char devices. > > Signed-off-by: Rodolfo Giometti <giometti@linux.it> > --- > MAINTAINERS | 7 + > drivers/Kconfig | 2 + > drivers/Makefile | 1 + > drivers/pps/Kconfig | 32 +++++ > drivers/pps/Makefile | 10 ++ > drivers/pps/kapi.c | 272 +++++++++++++++++++++++++++++++++++++++ > drivers/pps/pps.c | 342 ++++++++++++++++++++++++++++++++++++++++++++++++++ > drivers/pps/sysfs.c | 142 +++++++++++++++++++++
As you are adding sysfs files, please also describe them in Documentation/ABI/ in this same series of patches.
> +void pps_sysfs_remove_source_entry(struct pps_device *pps) > +{ > + /* Delete info files */ > + if (pps->info.mode & PPS_CAPTUREASSERT) > + device_remove_file(pps->dev, &dev_attr_assert); > + > + if (pps->info.mode & PPS_CAPTURECLEAR) > + device_remove_file(pps->dev, &dev_attr_clear); > + > + device_remove_file(pps->dev, &dev_attr_mode); > + device_remove_file(pps->dev, &dev_attr_echo); > + device_remove_file(pps->dev, &dev_attr_name); > + device_remove_file(pps->dev, &dev_attr_path); > +} > + > +int pps_sysfs_create_source_entry(struct pps_device *pps) > +{ > + int ret; > + > + /* Create file "assert" and "clear" according to source capability */ > + if (pps->info.mode & PPS_CAPTUREASSERT) { > + ret = device_create_file(pps->dev, &dev_attr_assert); > + if (ret) > + dev_err(pps->dev, "unable to create \"assert\" " > + "sysfs entry"); > + } > + > + if (pps->info.mode & PPS_CAPTURECLEAR) { > + ret = device_create_file(pps->dev, &dev_attr_clear); > + if (ret) > + dev_err(pps->dev, "unable to create \"clear\" " > + "sysfs entry"); > + } > + > + ret = device_create_file(pps->dev, &dev_attr_mode); > + if (ret) > + dev_err(pps->dev, "unable to create \"mode\" sysfs entry"); > + ret = device_create_file(pps->dev, &dev_attr_echo); > + if (ret) > + dev_err(pps->dev, "unable to create \"echo\" sysfs entry"); > + ret = device_create_file(pps->dev, &dev_attr_name); > + if (ret) > + dev_err(pps->dev, "unable to create \"name\" sysfs entry"); > + ret = device_create_file(pps->dev, &dev_attr_path); > + if (ret) > + dev_err(pps->dev, "unable to create \"path\" sysfs entry");
Why not use a default attribute group?
That way the files are created before the uevent is issued, and the amount of code you have to write is much smaller.
thanks,
greg k-h
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