Re: [PATCH 1/5] drm/panel: Add helper for reading DT rotation

Sam Ravnborg
2019-06-12T21:20:54Z

Hi Derek.

On Mon, Jun 10, 2019 at 09:03:46PM -0700, Derek Basehore wrote:
> This adds a helper function for reading the rotation (panel
> orientation) from the device tree.
>
> Signed-off-by: Derek Basehore <dbasehore@chromium.org>
> ---
> drivers/gpu/drm/drm_panel.c | 41 +++++++++++++++++++++++++++++++++++++
> include/drm/drm_panel.h | 7 +++++++
> 2 files changed, 48 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
> index dbd5b873e8f2..3b689ce4a51a 100644
> --- a/drivers/gpu/drm/drm_panel.c
> +++ b/drivers/gpu/drm/drm_panel.c
> @@ -172,6 +172,47 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
> return ERR_PTR(-EPROBE_DEFER);
> }
> EXPORT_SYMBOL(of_drm_find_panel);
> +
> +/**
> + * of_drm_get_panel_orientation - look up the rotation of the panel using a
> + * device tree node
> + * @np: device tree node of the panel
> + * @orientation: orientation enum to be filled in
> + *
> + * Looks up the rotation of a panel in the device tree. The rotation in the
> + * device tree is counter clockwise.
> + *
> + * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the
> + * rotation property doesn't exist. -EERROR otherwise.
> + */
> +int of_drm_get_panel_orientation(const struct device_node *np, int *orientation)
> +{
> + int rotation, ret;
> +
> + ret = of_property_read_u32(np, "rotation", &rotation);

I just noticed that everywhere this code talks about orientation,
but the property that it reads are rotation.
To my best understanding these are not the same.

Sam