On Thu, Dec 09, 2010 at 04:55:18PM -0800, Ping Cheng wrote: > On Thu, Dec 9, 2010 at 4:03 PM, Peter Hutterer <[email protected]> > wrote: > > Have a look at the drivers/input/mouse/synaptics. > > commit ec20a022aa24fc63d3ab59584cb1e5aa9a21d46c > > Refs: v2.6.30-36-gec20a02 > > > > Input: synaptics - add support for reporting x/y resolution > > So, resolution was added to the driver in 2.6.30. But > input_abs_set_res() was only added in 2.6.35.
yeah, if you look at the commit message for the input_abs_* this was part of a larger refacturing so drivers don't access the struct fields directly but use input_abs_set_min(), etc. before that, the drivers wrote straight to dev->absres[ABS_X]. my guess that input_abs_set_params() doesn't have a resolution field is that there's not that many devices that do resolution, so for most drivers it'd just be 0 anyway. just a guess. > > the driver currently uses input_abs_set_res(), added in > > commit 987a6c0298260b7aa40702b349282554d6180e4b > > Refs: v2.6.35-rc3-59-g987a6c0 > > > > Input: switch to input_abs_*() access functions > > > > > > synaptics and evdev both get the resolution from the kernel, if the > > respective kernel driver sets it. > > This means a valid resolution will be received if LINUX_VERSION_CODE > >= KERNEL_VERSION(2,6,35) instead of > 2.6.30. no, any kernel > 2.6.30 will expose resolution to the client. that's when the ABI for struct absinfo changed. it's just become more convenient to set resolution in kernel drivers with .35, but for userspace there was no difference. ec20a022aa24f did it for synaptics in 2.6.31 and the same approach could be backported to all kernel versions wacom cares about, you'll just have to do it manually through dev->absres[]. Cheers, Peter > This is still good news. Thank you, Peter, for the heads up. > > Ping > ------------------------------------------------------------------------------ _______________________________________________ Linuxwacom-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
