lkml.org 
[lkml]   [2019]   [Jan]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v2 3/3] drm/panel: simple: add support for PDA 91-00156-A0 panel
Hi Eugen.

Patch looks good, but a small improvement proposal.

On Mon, Jan 14, 2019 at 09:43:31AM +0000, Eugen.Hristev@microchip.com wrote:
> From: Eugen Hristev <eugen.hristev@microchip.com>
>
> PDA 91-00156-A0 5.0 is a 5.0" WVGA TFT LCD panel.
> This panel with backlight is found in PDA 5" LCD screen (TM5000 series or
> AC320005-5).
>
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> ---
> drivers/gpu/drm/panel/panel-simple.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 9c69e73..61361ba 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -2008,6 +2008,30 @@ static const struct panel_desc ortustech_com43h4m85ulc = {
> .bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_POSEDGE,
> };
>
> +static const struct drm_display_mode pda_91_00156_a0_mode = {
> + .clock = 33300,
> + .hdisplay = 800,
> + .hsync_start = 800 + 1,
> + .hsync_end = 800 + 1 + 64,
> + .htotal = 800 + 1 + 64 + 64,
> + .vdisplay = 480,
> + .vsync_start = 480 + 1,
> + .vsync_end = 480 + 1 + 23,
> + .vtotal = 480 + 1 + 23 + 22,
> + .vrefresh = 60,
> +};
.flags are omitted, as it is for many panels in simple-panel.
drm_modes.h do not document any default, so we must assume default equals no flags.

I would expect two of these as a minimum:
DRM_MODE_FLAG_PHSYNC: horizontal sync is active high.
DRM_MODE_FLAG_NHSYNC: horizontal sync is active low.
DRM_MODE_FLAG_PVSYNC: vertical sync is active high.
DRM_MODE_FLAG_NVSYNC: vertical sync is active low.

But it obviously works for a lot of panel, so one
may say why bother with it.

> +
> +static const struct panel_desc pda_91_00156_a0 = {
> + .modes = &pda_91_00156_a0_mode,
> + .num_modes = 1,
> + .size = {
> + .width = 152,
> + .height = 91,
> + },
> + .bus_format = MEDIA_BUS_FMT_RGB888_1X24,
> +};
.bus_format is specified - good!

Consider if .bus_flags needs to be specified.
(More or less same argumentation like for .flags above).

I could not find any data-sheet on the panel,
so I could not check if it is OK that all delays are 0.

So to recap - things looks fine, but consider to be more explicit
in .flags, bus_flags, and check if it is OK that all timing parameters are 0.
Sam

\
 
 \ /
  Last update: 2019-01-15 23:13    [W:0.068 / U:2.552 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site