On 18 July 2016 at 09:28, Vinay Simha BN <simha...@gmail.com> wrote: > Provide a small convenience wrapper that set/get the > display brightness value > > Cc: John Stultz <john.stu...@linaro.org> > Cc: Sumit Semwal <sumit.sem...@linaro.org> > Cc: Archit Taneja <archit.tan...@gmail.com> > Cc: Rob Clark <robdcl...@gmail.com> > Cc: Jani Nikula <jani.nik...@linux.intel.com> > Cc: Thierry Reding <thierry.red...@gmail.com> > Cc: Emil Velikov <emil.l.veli...@gmail.com> > Signed-off-by: Vinay Simha BN <simha...@gmail.com> > > --- > v1: > *tested in nexus7 2nd gen. > > v2: > * implemented jani review comments > -functions name mapped accordingly > -bl value increased from 0xff to 0xffff > -backlight interface will be handled in panel driver, > so it is moved from the mipi_dsi helper function > > v3: > * emil review comments > (err < 0) supposed to be (err <= 0) > --- > drivers/gpu/drm/drm_mipi_dsi.c | 49 > ++++++++++++++++++++++++++++++++++++++++++ > include/drm/drm_mipi_dsi.h | 4 ++++ > 2 files changed, 53 insertions(+) > > diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c > index af0d471..43aa743 100644 > --- a/drivers/gpu/drm/drm_mipi_dsi.c > +++ b/drivers/gpu/drm/drm_mipi_dsi.c > @@ -1041,6 +1041,55 @@ int mipi_dsi_dcs_set_pixel_format(struct > mipi_dsi_device *dsi, u8 format) > } > EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format); > > +/** > + * mipi_dsi_dcs_get_display_brightness() - gets the current brightness value > + * of the display > + * @dsi: DSI peripheral device > + * @brightness: brightness value > + * > + * Return: 0 on success or a negative error code on failure. > + */ > +int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi, > + u16 *brightness) > +{ > + ssize_t err; > + > + err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, > + brightness, sizeof(*brightness)); > + if (err <= 0) { > + if (err == 0) > + err = -ENODATA; > + Looks better now. Thank you.
> + return err; Side note: When sizeof(ssize_t) != sizeof(int) this might lead to some very annoying bugs. In practise I doubt anyone uses error codes in the SSIZE_MIN to INT_MIN range so we should be safe. Reviewed-by: Emil Velikov <emil.l.veli...@gmail.com> Regards, Emil