[PATCH 0/2] drm/bridge: it66121: Add it66122 support

[PATCH 0/2] drm/bridge: it66121: Add it66122 support

[Nishanth Menon]

Hi,

Add support for IT66122, which for all practical purposes is
drop in replacement for IT66121 except for the ID register
definition.

BeagleY-AI uses this new part as the old part is no longer in production
as far as I understand.

Now, BeaglePlay uses it66121 at the moment, but at some point, it might
end up flipping over to the new part.

An alternate implementation could be to drop the revision check or make
it66121 check include alternate ID check.. but that seems a little
non-standard.. Anyways, I suppose mediatek platforms will face this
problem as well at some point.

Nishanth Menon (2):
  dt-bindings: display: bridge: it66121: Add compatible string for
    IT66122
  drm/bridge: it66121: Add it66122 support

 .../devicetree/bindings/display/bridge/ite,it66121.yaml   | 1 +
 drivers/gpu/drm/bridge/ite-it66121.c                      | 8 ++++++++
 2 files changed, 9 insertions(+)

-- 
2.47.0

[PATCH 1/2] dt-bindings: display: bridge: it66121: Add compatible string for IT66122

[Nishanth Menon]

Add a new ite,it66122 compatible string to the IT66121 binding
documentation, since the two chips are practically same except for id
register difference.

Signed-off-by: Nishanth Menon <nm@ti.com>
---
 .../devicetree/bindings/display/bridge/ite,it66121.yaml          | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it66121.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it66121.yaml
index a7eb2603691f..c99b67f0bb73 100644
--- a/Documentation/devicetree/bindings/display/bridge/ite,it66121.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ite,it66121.yaml
@@ -19,6 +19,7 @@ properties:
   compatible:
     enum:
       - ite,it66121
+      - ite,it66122
       - ite,it6610
 
   reg:
-- 
2.47.0

Re: [PATCH 1/2] dt-bindings: display: bridge: it66121: Add compatible string for IT66122

[Krzysztof Kozlowski]

On 13/08/2025 21:08, Nishanth Menon wrote:
> Add a new ite,it66122 compatible string to the IT66121 binding
> documentation, since the two chips are practically same except for id
> register difference.
> 
> Signed-off-by: Nishanth Menon <nm@ti.com>
> ---

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 2/2] drm/bridge: it66121: Add it66122 support

[Nishanth Menon]

The IT66122 is a drop in replacement for the IT66122. The part is
register compatible with what we use of the IT66121. The only relevant
change being the PID is now 0x0622 vs 0x0612. Add this extra PID so
probe does not fail during the PID check with these new parts.

Signed-off-by: Nishanth Menon <nm@ti.com>
---

Note: checkpatch --strict reports:
CHECK: No space is necessary after a cast
#45: FILE: drivers/gpu/drm/bridge/ite-it66121.c:1643:
+	{ "it66122", (kernel_ulong_t) &it66122_chip_info },

I chose to retain existing style - let me know if we want to clean this
up as well.

NOTE: .id = ID_IT66121 is explicitly used as indication of reuse of
existing it66121 compatibility.

 drivers/gpu/drm/bridge/ite-it66121.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index aa7b1dcc5d70..329fa47a5701 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -1618,6 +1618,12 @@ static const struct it66121_chip_info it66121_chip_info = {
 	.pid = 0x0612,
 };
 
+static const struct it66121_chip_info it66122_chip_info = {
+	.id = ID_IT66121,
+	.vid = 0x4954,
+	.pid = 0x0622,
+};
+
 static const struct it66121_chip_info it6610_chip_info = {
 	.id = ID_IT6610,
 	.vid = 0xca00,
@@ -1626,6 +1632,7 @@ static const struct it66121_chip_info it6610_chip_info = {
 
 static const struct of_device_id it66121_dt_match[] = {
 	{ .compatible = "ite,it66121", &it66121_chip_info },
+	{ .compatible = "ite,it66122", &it66122_chip_info },
 	{ .compatible = "ite,it6610", &it6610_chip_info },
 	{ }
 };
@@ -1633,6 +1640,7 @@ MODULE_DEVICE_TABLE(of, it66121_dt_match);
 
 static const struct i2c_device_id it66121_id[] = {
 	{ "it66121", (kernel_ulong_t) &it66121_chip_info },
+	{ "it66122", (kernel_ulong_t) &it66122_chip_info },
 	{ "it6610", (kernel_ulong_t) &it6610_chip_info },
 	{ }
 };
-- 
2.47.0

Re: [PATCH 2/2] drm/bridge: it66121: Add it66122 support

[devarsh]

Hi Nishanth,

Thanks for the patch.

On 14/08/25 00:38, Nishanth Menon wrote:
> The IT66122 is a drop in replacement for the IT66122. 

The IT66122 is a drop in replacement for the IT66121

The part is
> register compatible with what we use of the IT66121. The only relevant
> change being the PID is now 0x0622 vs 0x0612. Add this extra PID so
> probe does not fail during the PID check with these new parts.
> 
> Signed-off-by: Nishanth Menon <nm@ti.com>
> ---
> 
> Note: checkpatch --strict reports:
> CHECK: No space is necessary after a cast
> #45: FILE: drivers/gpu/drm/bridge/ite-it66121.c:1643:
> +	{ "it66122", (kernel_ulong_t) &it66122_chip_info },
> 
> I chose to retain existing style - let me know if we want to clean this
> up as well.
> 
> NOTE: .id = ID_IT66121 is explicitly used as indication of reuse of
> existing it66121 compatibility.
> 
>  drivers/gpu/drm/bridge/ite-it66121.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
> index aa7b1dcc5d70..329fa47a5701 100644
> --- a/drivers/gpu/drm/bridge/ite-it66121.c
> +++ b/drivers/gpu/drm/bridge/ite-it66121.c
> @@ -1618,6 +1618,12 @@ static const struct it66121_chip_info it66121_chip_info = {
>  	.pid = 0x0612,
>  };
>  
> +static const struct it66121_chip_info it66122_chip_info = {
> +	.id = ID_IT66121,

I think better to create separate .id as done for other chip_info structs :

.id = ID_IT66122

Regards
Devarsh

> +	.vid = 0x4954,
> +	.pid = 0x0622,
> +};
> +
>  static const struct it66121_chip_info it6610_chip_info = {
>  	.id = ID_IT6610,
>  	.vid = 0xca00,
> @@ -1626,6 +1632,7 @@ static const struct it66121_chip_info it6610_chip_info = {
>  
>  static const struct of_device_id it66121_dt_match[] = {
>  	{ .compatible = "ite,it66121", &it66121_chip_info },
> +	{ .compatible = "ite,it66122", &it66122_chip_info },
>  	{ .compatible = "ite,it6610", &it6610_chip_info },
>  	{ }
>  };
> @@ -1633,6 +1640,7 @@ MODULE_DEVICE_TABLE(of, it66121_dt_match);
>  
>  static const struct i2c_device_id it66121_id[] = {
>  	{ "it66121", (kernel_ulong_t) &it66121_chip_info },
> +	{ "it66122", (kernel_ulong_t) &it66122_chip_info },
>  	{ "it6610", (kernel_ulong_t) &it6610_chip_info },
>  	{ }
>  };

Re: [PATCH 0/2] drm/bridge: it66121: Add it66122 support

[Andrew Davis]

On 8/13/25 2:08 PM, Nishanth Menon wrote:
> Hi,
> 
> Add support for IT66122, which for all practical purposes is
> drop in replacement for IT66121 except for the ID register
> definition.
> 
> BeagleY-AI uses this new part as the old part is no longer in production
> as far as I understand.
> 
> Now, BeaglePlay uses it66121 at the moment, but at some point, it might
> end up flipping over to the new part.
> 
> An alternate implementation could be to drop the revision check or make
> it66121 check include alternate ID check.. but that seems a little
> non-standard.. Anyways, I suppose mediatek platforms will face this
> problem as well at some point.
> 

Hmmm, since these boards will probably have to switch parts mid-production
it would cause us to need to have a new DT with the updated compatible
just for a otherwise transparent revision. Might be better to just
loosen the PID check so the alternative part work just the same.

Andrew

> Nishanth Menon (2):
>    dt-bindings: display: bridge: it66121: Add compatible string for
>      IT66122
>    drm/bridge: it66121: Add it66122 support
> 
>   .../devicetree/bindings/display/bridge/ite,it66121.yaml   | 1 +
>   drivers/gpu/drm/bridge/ite-it66121.c                      | 8 ++++++++
>   2 files changed, 9 insertions(+)
> 

Re: [PATCH 0/2] drm/bridge: it66121: Add it66122 support

[Nishanth Menon]

On 14:32-20250813, Andrew Davis wrote:
> On 8/13/25 2:08 PM, Nishanth Menon wrote:
> > Hi,
> > 
> > Add support for IT66122, which for all practical purposes is
> > drop in replacement for IT66121 except for the ID register
> > definition.
> > 
> > BeagleY-AI uses this new part as the old part is no longer in production
> > as far as I understand.
> > 
> > Now, BeaglePlay uses it66121 at the moment, but at some point, it might
> > end up flipping over to the new part.
> > 
> > An alternate implementation could be to drop the revision check or make
> > it66121 check include alternate ID check.. but that seems a little
> > non-standard.. Anyways, I suppose mediatek platforms will face this
> > problem as well at some point.
> > 
> 
> Hmmm, since these boards will probably have to switch parts mid-production
> it would cause us to need to have a new DT with the updated compatible
> just for a otherwise transparent revision. Might be better to just
> loosen the PID check so the alternative part work just the same.

I think we can get both world.. respinning this up in v2

-- 
Regards,
Nishanth Menon
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