[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

On Wed, Aug 20, 2014 at 02:29:17PM -0500, Dmitry Torokhov wrote:

On August 20, 2014 1:54:11 PM CDT, Doug Anderson [off-list ref] wrote:

quoted

On Wed, Aug 20, 2014 at 3:04 AM, Thierry Reding
[off-list ref] wrote:

quoted

On Tue, Aug 19, 2014 at 09:07:54AM -0700, Doug Anderson wrote:

quoted

The rk3288 has the ability to invert 
+     struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+
+     if (!pc->data->has_invert)
+             return -ENOSYS;
+

At the kernel summit hpa also mentioned that ENOSYS should only be
used for missing syscalls. Not sure what error code would suit better
here though...

I'd be interested in the rationale why ENOSYS shouldn't be used within
the kernel. As long as it doesn't leak to userspace where it could
possibly confuse applications I don't see any harm in using it.

Thierry
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