[PATCH] drm/meson: add support for 2560x1440 resolution output

[PATCH] drm/meson: add support for 2560x1440 resolution output

[Christian Hewitt]

From: Dongjin Kim <tobetter@gmail.com>

Add support for Quad HD (QHD) 2560x1440 resolution output. Timings
have been adapted from the vendor kernel.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
---
 drivers/gpu/drm/meson/meson_vclk.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/meson/meson_vclk.c b/drivers/gpu/drm/meson/meson_vclk.c
index dfe0c28a0f05..f5385b3e3796 100644
--- a/drivers/gpu/drm/meson/meson_vclk.c
+++ b/drivers/gpu/drm/meson/meson_vclk.c
@@ -357,6 +357,8 @@ enum {
 	MESON_VCLK_HDMI_594000,
 /* 2970 /1 /1 /1 /5 /1  => /1 /2 */
 	MESON_VCLK_HDMI_594000_YUV420,
+/* 4830 /2 /1 /2 /5 /1  => /1 /1 */
+	MESON_VCLK_HDMI_241500,
 };
 
 struct meson_vclk_params {
@@ -467,6 +469,18 @@ struct meson_vclk_params {
 		.vid_pll_div = VID_PLL_DIV_5,
 		.vclk_div = 1,
 	},
+	[MESON_VCLK_HDMI_241500] = {
+		.pll_freq = 4830000000,
+		.phy_freq = 2415000000,
+		.venc_freq = 241500000,
+		.vclk_freq = 241500000,
+		.pixel_freq = 241500000,
+		.pll_od1 = 2,
+		.pll_od2 = 1,
+		.pll_od3 = 2,
+		.vid_pll_div = VID_PLL_DIV_5,
+		.vclk_div = 1,
+	},
 	{ /* sentinel */ },
 };
 
@@ -894,6 +908,10 @@ static void meson_vclk_set(struct meson_drm *priv,
 			m = 0xf7;
 			frac = vic_alternate_clock ? 0x8148 : 0x10000;
 			break;
+		case 4830000:
+			m = 0xc9;
+			frac = 0xd560;
+			break;
 		}
 
 		meson_hdmi_pll_set_params(priv, m, frac, od1, od2, od3);
-- 
2.34.1


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Re: [PATCH] drm/meson: add support for 2560x1440 resolution output

[Martin Blumenstingl]

Hi Christian,

On Sat, Sep 27, 2025 at 3:02 PM Christian Hewitt
<christianshewitt@gmail.com> wrote:
[...]
> @@ -894,6 +908,10 @@ static void meson_vclk_set(struct meson_drm *priv,
>                         m = 0xf7;
>                         frac = vic_alternate_clock ? 0x8148 : 0x10000;
>                         break;
> +               case 4830000:
> +                       m = 0xc9;
> +                       frac = 0xd560;
> +                       break;
Initially I thought this was wrong because it's only added for the
G12A (which is also used on G12B and SM1) code-path, leaving out the
GX SoCs.

Was the 2560x1440 mode tested on a computer monitor or a TV?
I suspect it's the former, so I think it expected the code to take the
MESON_VCLK_TARGET_DMT path, which automatically calculates m and frac.

I'll give it a try on Friday as I do have a computer monitor with that
resolution - so any hints for testing are welcome!


Best regards,
Martin

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Re: [PATCH] drm/meson: add support for 2560x1440 resolution output

[Christian Hewitt]

> On 29 Sep 2025, at 1:24 am, Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote:
> 
> Hi Christian,
> 
> On Sat, Sep 27, 2025 at 3:02 PM Christian Hewitt
> <christianshewitt@gmail.com> wrote:
> [...]
>> @@ -894,6 +908,10 @@ static void meson_vclk_set(struct meson_drm *priv,
>>                        m = 0xf7;
>>                        frac = vic_alternate_clock ? 0x8148 : 0x10000;
>>                        break;
>> +               case 4830000:
>> +                       m = 0xc9;
>> +                       frac = 0xd560;
>> +                       break;
> Initially I thought this was wrong because it's only added for the
> G12A (which is also used on G12B and SM1) code-path, leaving out the
> GX SoCs.
> 
> Was the 2560x1440 mode tested on a computer monitor or a TV?
> I suspect it's the former, so I think it expected the code to take the
> MESON_VCLK_TARGET_DMT path, which automatically calculates m and frac.
> 
> I'll give it a try on Friday as I do have a computer monitor with that
> resolution - so any hints for testing are welcome!

The original patch is from Hardkernel sources - I’ve picked it several
years ago and then updated values semi-recently after 1000ULL changes.
The user who originally requested that I cherry-pick it (and tested it)
was using an Odroid N2+ board (G12B) with a Dell monitor IIRC. It’s not
tested by myself as I only have TV’s not monitors, so it will be good
to have your confirmation (either way). If it’s wrong I’ll be happy to
drop it - I’m just trying to upstream and offload some longer-running
and allegedly good patches in the LibreELEC kernel patchset.

Christian
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Re: [PATCH] drm/meson: add support for 2560x1440 resolution output

[Martin Blumenstingl]

[-- Attachment #1: Type: text/plain, Size: 2576 bytes --]

Hi Christian,

On Mon, Sep 29, 2025 at 1:58 AM Christian Hewitt
<christianshewitt@gmail.com> wrote:
>
> > On 29 Sep 2025, at 1:24 am, Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote:
> >
> > Hi Christian,
> >
> > On Sat, Sep 27, 2025 at 3:02 PM Christian Hewitt
> > <christianshewitt@gmail.com> wrote:
> > [...]
> >> @@ -894,6 +908,10 @@ static void meson_vclk_set(struct meson_drm *priv,
> >>                        m = 0xf7;
> >>                        frac = vic_alternate_clock ? 0x8148 : 0x10000;
> >>                        break;
> >> +               case 4830000:
> >> +                       m = 0xc9;
> >> +                       frac = 0xd560;
> >> +                       break;
> > Initially I thought this was wrong because it's only added for the
> > G12A (which is also used on G12B and SM1) code-path, leaving out the
> > GX SoCs.
> >
> > Was the 2560x1440 mode tested on a computer monitor or a TV?
> > I suspect it's the former, so I think it expected the code to take the
> > MESON_VCLK_TARGET_DMT path, which automatically calculates m and frac.
> >
> > I'll give it a try on Friday as I do have a computer monitor with that
> > resolution - so any hints for testing are welcome!
>
> The original patch is from Hardkernel sources - I’ve picked it several
> years ago and then updated values semi-recently after 1000ULL changes.
> The user who originally requested that I cherry-pick it (and tested it)
> was using an Odroid N2+ board (G12B) with a Dell monitor IIRC. It’s not
> tested by myself as I only have TV’s not monitors, so it will be good
> to have your confirmation (either way). If it’s wrong I’ll be happy to
> drop it - I’m just trying to upstream and offload some longer-running
> and allegedly good patches in the LibreELEC kernel patchset.
So I've tried it on a Le Potato (S905X SoC) board. This patch doesn't
do anything here (as expected, since it only targets the G12A and
later code-path).

Doing some more analysis, it seems that
meson_venc_hdmi_supported_mode() simply prevents using any mode with
more than 1920 pixels.
I attached a simple patch to overcome this (discarding any
meson_vclk.c changes):
$ cat /sys/class/drm/card1-HDMI-A-1/modes
2560x1440
2048x1152
1920x1200
1920x1080
...

My monitor's OSD tells me that I'm running at 2560x1440@60Hz.

@Neil, should we bump the limits in meson_venc.c to "4Kx2K@60" (that's
a quote from both, S905/GXBB and S905D3/SM1 datasheets), most likely
meaning: 4096x2160?


Best regards,
Martin

[-- Attachment #2: meson_venc-hdmi-support-1440p-screen.diff --]
[-- Type: text/x-patch, Size: 661 bytes --]

diff --git a/drivers/gpu/drm/meson/meson_venc.c b/drivers/gpu/drm/meson/meson_venc.c
index 3bf0d6e4fc30..8a1110377a18 100644
--- a/drivers/gpu/drm/meson/meson_venc.c
+++ b/drivers/gpu/drm/meson/meson_venc.c
@@ -868,10 +868,10 @@ meson_venc_hdmi_supported_mode(const struct drm_display_mode *mode)
 			    DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC))
 		return MODE_BAD;
 
-	if (mode->hdisplay < 400 || mode->hdisplay > 1920)
+	if (mode->hdisplay < 400 || mode->hdisplay > 2560)
 		return MODE_BAD_HVALUE;
 
-	if (mode->vdisplay < 480 || mode->vdisplay > 1920)
+	if (mode->vdisplay < 480 || mode->vdisplay > 2560)
 		return MODE_BAD_VVALUE;
 
 	return MODE_OK;

[-- Attachment #3: Type: text/plain, Size: 167 bytes --]

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Re: [PATCH] drm/meson: add support for 2560x1440 resolution output

[Christian Hewitt]

> On 5 Oct 2025, at 12:22 am, Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote:
> 
> Hi Christian,
> 
> On Mon, Sep 29, 2025 at 1:58 AM Christian Hewitt
> <christianshewitt@gmail.com> wrote:
>> 
>>> On 29 Sep 2025, at 1:24 am, Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote:
>>> 
>>> Hi Christian,
>>> 
>>> On Sat, Sep 27, 2025 at 3:02 PM Christian Hewitt
>>> <christianshewitt@gmail.com> wrote:
>>> [...]
>>>> @@ -894,6 +908,10 @@ static void meson_vclk_set(struct meson_drm *priv,
>>>>                       m = 0xf7;
>>>>                       frac = vic_alternate_clock ? 0x8148 : 0x10000;
>>>>                       break;
>>>> +               case 4830000:
>>>> +                       m = 0xc9;
>>>> +                       frac = 0xd560;
>>>> +                       break;
>>> Initially I thought this was wrong because it's only added for the
>>> G12A (which is also used on G12B and SM1) code-path, leaving out the
>>> GX SoCs.
>>> 
>>> Was the 2560x1440 mode tested on a computer monitor or a TV?
>>> I suspect it's the former, so I think it expected the code to take the
>>> MESON_VCLK_TARGET_DMT path, which automatically calculates m and frac.
>>> 
>>> I'll give it a try on Friday as I do have a computer monitor with that
>>> resolution - so any hints for testing are welcome!
>> 
>> The original patch is from Hardkernel sources - I’ve picked it several
>> years ago and then updated values semi-recently after 1000ULL changes.
>> The user who originally requested that I cherry-pick it (and tested it)
>> was using an Odroid N2+ board (G12B) with a Dell monitor IIRC. It’s not
>> tested by myself as I only have TV’s not monitors, so it will be good
>> to have your confirmation (either way). If it’s wrong I’ll be happy to
>> drop it - I’m just trying to upstream and offload some longer-running
>> and allegedly good patches in the LibreELEC kernel patchset.
> So I've tried it on a Le Potato (S905X SoC) board. This patch doesn't
> do anything here (as expected, since it only targets the G12A and
> later code-path).

Thanks for testing. Let’s ignore this patch then :)

> Doing some more analysis, it seems that
> meson_venc_hdmi_supported_mode() simply prevents using any mode with
> more than 1920 pixels.
> I attached a simple patch to overcome this (discarding any
> meson_vclk.c changes):
> $ cat /sys/class/drm/card1-HDMI-A-1/modes
> 2560x1440
> 2048x1152
> 1920x1200
> 1920x1080
> ...
> 
> My monitor's OSD tells me that I'm running at 2560x1440@60Hz.

I’ll pick that for wider testing, but it looks sensible. Thanks.

CH.

> @Neil, should we bump the limits in meson_venc.c to "4Kx2K@60" (that's
> a quote from both, S905/GXBB and S905D3/SM1 datasheets), most likely
> meaning: 4096x2160?
> 
> 
> Best regards,
> Martin
> <meson_venc-hdmi-support-1440p-screen.diff>


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