Re: [PATCH v2] misc: Add driver for GP2AP002 proximity/ambient light sensor

[Jonathan Cameron <jic23@cam.ac.uk>]

On 09/09/11 09:31, Greg KH wrote:
> On Fri, Sep 09, 2011 at 05:22:26PM +0900, Donggeun Kim wrote:
>> SHARP GP2AP002 is proximity and ambient light sensor.
>> This patch supports it.
>>
>> Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>> Changes for v2
>>   - changed to expose lux
>>   - changed request_irq to request_threaded_irq function
>>   - added sysfs_notify function call
> 
> Why?  You should never do that unless you _really_ know what you are
> doing.
My bad.  I suggested it was a better bet than doing a uevent to act
as a data ready notifier...

Greg, for future reference can you clarify why it's a bad idea or
give a reference (if it's been clarified elsewhere and I missed it!)
> 
> 
>>   - cleaned up code
>>
>>  Documentation/misc-devices/gp2ap002    |   44 +++
>>  drivers/misc/Kconfig                   |   10 +
>>  drivers/misc/Makefile                  |    1 +
>>  drivers/misc/gp2ap002.c                |  488 ++++++++++++++++++++++++++++++++
>>  include/linux/platform_data/gp2ap002.h |   69 +++++
> 
> 
> Shouldn't this be an iio driver instead of some random misc driver with
> an undocumented sysfs file (hint, use Documentation/ABI for documenting
> stuff...) ?
Would certainly be welcome in IIO. We have a couple of similar sensors in there already.
I'm just aware some people/firms are really anti having
their drivers in staging (because the subsystem is there rather than because of issues
in the driver.