Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

[Luca Weiss]

Hi Conor,

On Fri May 1, 2026 at 5:51 PM CEST, Conor Dooley wrote:
> On Fri, May 01, 2026 at 03:52:45PM +0200, Luca Weiss wrote:
>> Novatek NT37705 is a display driver IC used to drive AMOLED DSI panels.
>> 
>> Describe it and the panel in the Fairphone (Gen. 6) (BJ631JHM-T71-D900
>> from BOE) using it.
>> 
>> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
>> ---
>>  .../bindings/display/panel/novatek,nt37705.yaml    | 72 ++++++++++++++++++++++
>>  1 file changed, 72 insertions(+)
>> 
>> diff --git a/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>> new file mode 100644
>> index 000000000000..1c796599f6fc
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>> @@ -0,0 +1,72 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/display/panel/novatek,nt37705.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Novatek NT37705-based DSI display panels
>> +
>> +maintainers:
>> +  - Luca Weiss <luca.weiss@fairphone.com>
>> +
>> +description:
>> +  The Novatek NT37705 is a generic DSI Panel IC used to control AMOLED panels.
>> +
>> +allOf:
>> +  - $ref: panel-common.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    contains:
>> +      const: boe,bj631jhm-t71-d900
>
> Compatible doesn't match the filename, nor does the commit message match
> what you've got here. Sounds like you're missing a fallback to
> $filename.

The last times I was upstreaming panel drivers (Feb 2024 and June 2025),
this was the requested way of doing things.

Compatible being the company and model number making the actual panel
assembly (driver IC + touchscreen + glass etc), while the rest being
named after the driver IC manufacturer & number.

As seen in
* himax,hx83112b + djn,98-03057-6598b-i (Fairphone 3)
* himax,hx83112a + djn,9a-3r063-1102b (Fairphone 4)

Fairphone 5 panel (raydium,rm692e5) was upstreamed earlier and follows
different naming.

Has the way of doing things changed since then?

Regards
Luca

Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

[Krzysztof Kozlowski]

On 04/05/2026 15:36, Luca Weiss wrote:
> Hi Conor,
> 
> On Fri May 1, 2026 at 5:51 PM CEST, Conor Dooley wrote:
>> On Fri, May 01, 2026 at 03:52:45PM +0200, Luca Weiss wrote:
>>> Novatek NT37705 is a display driver IC used to drive AMOLED DSI panels.
>>>
>>> Describe it and the panel in the Fairphone (Gen. 6) (BJ631JHM-T71-D900
>>> from BOE) using it.
>>>
>>> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
>>> ---
>>>  .../bindings/display/panel/novatek,nt37705.yaml    | 72 ++++++++++++++++++++++
>>>  1 file changed, 72 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>>> new file mode 100644
>>> index 000000000000..1c796599f6fc
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>>> @@ -0,0 +1,72 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/display/panel/novatek,nt37705.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: Novatek NT37705-based DSI display panels
>>> +
>>> +maintainers:
>>> +  - Luca Weiss <luca.weiss@fairphone.com>
>>> +
>>> +description:
>>> +  The Novatek NT37705 is a generic DSI Panel IC used to control AMOLED panels.
>>> +
>>> +allOf:
>>> +  - $ref: panel-common.yaml#
>>> +
>>> +properties:
>>> +  compatible:
>>> +    contains:
>>> +      const: boe,bj631jhm-t71-d900
>>
>> Compatible doesn't match the filename, nor does the commit message match
>> what you've got here. Sounds like you're missing a fallback to
>> $filename.
> 
> The last times I was upstreaming panel drivers (Feb 2024 and June 2025),
> this was the requested way of doing things.

So this was requested that time and is requested now. What is here
uncertain?

> 
> Compatible being the company and model number making the actual panel
> assembly (driver IC + touchscreen + glass etc), while the rest being
> named after the driver IC manufacturer & number.

So exactly what was asked for...

> 
> As seen in
> * himax,hx83112b + djn,98-03057-6598b-i (Fairphone 3)
> * himax,hx83112a + djn,9a-3r063-1102b (Fairphone 4)
> 
> Fairphone 5 panel (raydium,rm692e5) was upstreamed earlier and follows
> different naming.



Best regards,
Krzysztof

Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

[Krzysztof Kozlowski]

On 04/05/2026 22:45, Krzysztof Kozlowski wrote:
> On 04/05/2026 15:36, Luca Weiss wrote:
>> Hi Conor,
>>
>> On Fri May 1, 2026 at 5:51 PM CEST, Conor Dooley wrote:
>>> On Fri, May 01, 2026 at 03:52:45PM +0200, Luca Weiss wrote:
>>>> Novatek NT37705 is a display driver IC used to drive AMOLED DSI panels.
>>>>
>>>> Describe it and the panel in the Fairphone (Gen. 6) (BJ631JHM-T71-D900
>>>> from BOE) using it.
>>>>
>>>> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
>>>> ---
>>>>  .../bindings/display/panel/novatek,nt37705.yaml    | 72 ++++++++++++++++++++++
>>>>  1 file changed, 72 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>>>> new file mode 100644
>>>> index 000000000000..1c796599f6fc
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>>>> @@ -0,0 +1,72 @@
>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>>> +%YAML 1.2
>>>> +---
>>>> +$id: http://devicetree.org/schemas/display/panel/novatek,nt37705.yaml#
>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>> +
>>>> +title: Novatek NT37705-based DSI display panels
>>>> +
>>>> +maintainers:
>>>> +  - Luca Weiss <luca.weiss@fairphone.com>
>>>> +
>>>> +description:
>>>> +  The Novatek NT37705 is a generic DSI Panel IC used to control AMOLED panels.
>>>> +
>>>> +allOf:
>>>> +  - $ref: panel-common.yaml#
>>>> +
>>>> +properties:
>>>> +  compatible:
>>>> +    contains:
>>>> +      const: boe,bj631jhm-t71-d900
>>>
>>> Compatible doesn't match the filename, nor does the commit message match
>>> what you've got here. Sounds like you're missing a fallback to
>>> $filename.
>>
>> The last times I was upstreaming panel drivers (Feb 2024 and June 2025),
>> this was the requested way of doing things.
> 
> So this was requested that time and is requested now. What is here
> uncertain?
> 
>>
>> Compatible being the company and model number making the actual panel
>> assembly (driver IC + touchscreen + glass etc), while the rest being
>> named after the driver IC manufacturer & number.
> 
> So exactly what was asked for...

Assuming "the rest" you mean the fallback. Just to remind - we talk here
about the bindings, not drivers.

Best regards,
Krzysztof

Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

[Luca Weiss]

Hi Krzysztof,

On Mon May 4, 2026 at 10:45 PM CEST, Krzysztof Kozlowski wrote:
> On 04/05/2026 15:36, Luca Weiss wrote:
>> Hi Conor,
>> 
>> On Fri May 1, 2026 at 5:51 PM CEST, Conor Dooley wrote:
>>> On Fri, May 01, 2026 at 03:52:45PM +0200, Luca Weiss wrote:
>>>> Novatek NT37705 is a display driver IC used to drive AMOLED DSI panels.
>>>>
>>>> Describe it and the panel in the Fairphone (Gen. 6) (BJ631JHM-T71-D900
>>>> from BOE) using it.
>>>>
>>>> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
>>>> ---
>>>>  .../bindings/display/panel/novatek,nt37705.yaml    | 72 ++++++++++++++++++++++
>>>>  1 file changed, 72 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>>>> new file mode 100644
>>>> index 000000000000..1c796599f6fc
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/display/panel/novatek,nt37705.yaml
>>>> @@ -0,0 +1,72 @@
>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>>> +%YAML 1.2
>>>> +---
>>>> +$id: http://devicetree.org/schemas/display/panel/novatek,nt37705.yaml#
>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>> +
>>>> +title: Novatek NT37705-based DSI display panels
>>>> +
>>>> +maintainers:
>>>> +  - Luca Weiss <luca.weiss@fairphone.com>
>>>> +
>>>> +description:
>>>> +  The Novatek NT37705 is a generic DSI Panel IC used to control AMOLED panels.
>>>> +
>>>> +allOf:
>>>> +  - $ref: panel-common.yaml#
>>>> +
>>>> +properties:
>>>> +  compatible:
>>>> +    contains:
>>>> +      const: boe,bj631jhm-t71-d900
>>>
>>> Compatible doesn't match the filename, nor does the commit message match
>>> what you've got here. Sounds like you're missing a fallback to
>>> $filename.
>> 
>> The last times I was upstreaming panel drivers (Feb 2024 and June 2025),
>> this was the requested way of doing things.
>
> So this was requested that time and is requested now. What is here
> uncertain?
>
>> 
>> Compatible being the company and model number making the actual panel
>> assembly (driver IC + touchscreen + glass etc), while the rest being
>> named after the driver IC manufacturer & number.
>
> So exactly what was asked for...

I don't quite understand what is asked for now, that's my issue.

1. Change the filename to boe,bj631jhm-t71-d900.yaml and leave the rest
   as-is.

2. Add a fallback compatible for novatek,nt37705. IIRC last time it was
   argued that a "generic" nt37705 driver will never be correct for a
   specific panel since it's missing a bunch of panel-specific init. So
   that's why there should not be a fallback to nt37705.

Either way, it's different to what I was working on with the two
examples I gave. Please help to clarify.

Regards
Luca

>> As seen in
>> * himax,hx83112b + djn,98-03057-6598b-i (Fairphone 3)
>> * himax,hx83112a + djn,9a-3r063-1102b (Fairphone 4)
>> 
>> Fairphone 5 panel (raydium,rm692e5) was upstreamed earlier and follows
>> different naming.

Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

[Krzysztof Kozlowski]

On 05/05/2026 08:40, Luca Weiss wrote:
>>>>> +  compatible:
>>>>> +    contains:
>>>>> +      const: boe,bj631jhm-t71-d900
>>>>
>>>> Compatible doesn't match the filename, nor does the commit message match
>>>> what you've got here. Sounds like you're missing a fallback to
>>>> $filename.
>>>
>>> The last times I was upstreaming panel drivers (Feb 2024 and June 2025),
>>> this was the requested way of doing things.
>>
>> So this was requested that time and is requested now. What is here
>> uncertain?
>>
>>>
>>> Compatible being the company and model number making the actual panel
>>> assembly (driver IC + touchscreen + glass etc), while the rest being
>>> named after the driver IC manufacturer & number.
>>
>> So exactly what was asked for...
> 
> I don't quite understand what is asked for now, that's my issue.
> 
> 1. Change the filename to boe,bj631jhm-t71-d900.yaml and leave the rest
>    as-is.
> 
> 2. Add a fallback compatible for novatek,nt37705. IIRC last time it was
>    argued that a "generic" nt37705 driver will never be correct for a
>    specific panel since it's missing a bunch of panel-specific init. So
>    that's why there should not be a fallback to nt37705.

To my limited knowledge the (2) with fallback describing the specific IC
is preferred, because that compatible although not currently usable is
still specific and describes actual IC used. I imagine that such
fallback still could be useful to some SW implementation to determine
the IC and act based on that.

If you have sources of other preference, please share, but I just gave
same review to Neil for his ayaneo,wt0600-2k panels.

Best regards,
Krzysztof

Re: [PATCH 1/4] dt-bindings: display: panel: Add Novatek NT37705

[Luca Weiss]

Hi Krzysztof,

On Tue May 5, 2026 at 9:25 AM CEST, Krzysztof Kozlowski wrote:
> On 05/05/2026 08:40, Luca Weiss wrote:
>>>>>> +  compatible:
>>>>>> +    contains:
>>>>>> +      const: boe,bj631jhm-t71-d900
>>>>>
>>>>> Compatible doesn't match the filename, nor does the commit message match
>>>>> what you've got here. Sounds like you're missing a fallback to
>>>>> $filename.
>>>>
>>>> The last times I was upstreaming panel drivers (Feb 2024 and June 2025),
>>>> this was the requested way of doing things.
>>>
>>> So this was requested that time and is requested now. What is here
>>> uncertain?
>>>
>>>>
>>>> Compatible being the company and model number making the actual panel
>>>> assembly (driver IC + touchscreen + glass etc), while the rest being
>>>> named after the driver IC manufacturer & number.
>>>
>>> So exactly what was asked for...
>> 
>> I don't quite understand what is asked for now, that's my issue.
>> 
>> 1. Change the filename to boe,bj631jhm-t71-d900.yaml and leave the rest
>>    as-is.
>> 
>> 2. Add a fallback compatible for novatek,nt37705. IIRC last time it was
>>    argued that a "generic" nt37705 driver will never be correct for a
>>    specific panel since it's missing a bunch of panel-specific init. So
>>    that's why there should not be a fallback to nt37705.
>
> To my limited knowledge the (2) with fallback describing the specific IC
> is preferred, because that compatible although not currently usable is
> still specific and describes actual IC used. I imagine that such
> fallback still could be useful to some SW implementation to determine
> the IC and act based on that.
>
> If you have sources of other preference, please share, but I just gave
> same review to Neil for his ayaneo,wt0600-2k panels.

I found the discussion from 2024 for the Fairphone 4 panel:

https://lore.kernel.org/lkml/f9164049-6529-42c1-a35a-e91132c823b9@linaro.org/

(quoting)

'''
  Not sure if "himax,hx83112a" is needed here, the "djn,9a-3r063-1102b"
  is enough to know the IC is hx83112a.

  I don't think you'll ever find a "djn,9a-3r063-1102b" with another
  controller IC ?

  And "himax,hx83112a" alone as fallback is not enough to describe the
  panel hardware, so I think it should be dropped.
'''

With Konrad replying "+1" to that.

Regards
Luca

Re: [PATCH 4/4] arm64: dts: qcom: milos-fairphone-fp6: Enable display

[Dmitry Baryshkov]

On Fri, May 01, 2026 at 03:52:48PM +0200, Luca Weiss wrote:
> Configure the MDSS nodes for the phone and add the panel node.
> 
> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
> ---
>  arch/arm64/boot/dts/qcom/milos-fairphone-fp6.dts | 64 ++++++++++++++++++++++++
>  1 file changed, 64 insertions(+)
> 

Modulo panel's compatible (which is discussed elsewhere):


Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>



-- 
With best wishes
Dmitry

Re: [PATCH 3/4] arm64: defconfig: Enable Novatek NT37705 panel

[Dmitry Baryshkov]

On Fri, May 01, 2026 at 03:52:47PM +0200, Luca Weiss wrote:
> Enable the NT37705 panel driver which is used on Fairphone (Gen. 6).
> 
> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
> ---
>  arch/arm64/configs/defconfig | 1 +
>  1 file changed, 1 insertion(+)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

Re: [PATCH 2/4] drm/panel: Add driver for Novatek NT37705 panel

[Thomas Zimmermann]

Hi

Am 01.05.26 um 15:52 schrieb Luca Weiss:
> Add support for the 2484x1116 AMOLED panel from BOE (BJ631JHM-T71-D900)
> bundled with a NT37705 driver IC, as found on the Fairphone (Gen. 6)
> smartphone.
>
> The panel can also be configured in 10-bit (RGB101010) mode, however
> currently it's configured in 8-bit (RGB888) since there's some issues in
> the Qualcomm DPU driver when driving this panel in 10-bit.
>
> Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
> ---
>   drivers/gpu/drm/panel/Kconfig                 |  11 +
>   drivers/gpu/drm/panel/Makefile                |   1 +
>   drivers/gpu/drm/panel/panel-novatek-nt37705.c | 413 ++++++++++++++++++++++++++
>   3 files changed, 425 insertions(+)
>
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 979109c27b9b..59ab3f29d8ef 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -624,6 +624,17 @@ config DRM_PANEL_NOVATEK_NT37700F
>   	  Say Y here if you want to enable support for Novatek NT37700F DSI
>   	  panel module. The panel has a resolution of 1080x2160.
>   
> +config DRM_PANEL_NOVATEK_NT37705
> +	tristate "Novatek NT37705-based DSI panel"
> +	depends on OF
> +	depends on DRM_MIPI_DSI
> +	depends on BACKLIGHT_CLASS_DEVICE
> +	select DRM_KMS_HELPER
> +	help
> +	  Say Y here if you want to enable support for Novatek NT37705-based
> +	  display panels, such as the one found in the The Fairphone (Gen. 6)

Duplicate 'the'

> +	  smartphone.
> +
>   config DRM_PANEL_NOVATEK_NT37801
>   	tristate "Novatek NT37801/NT37810 AMOLED DSI panel"
>   	depends on OF
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 0d694acbfbb6..94639bc58ca8 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36523) += panel-novatek-nt36523.o
>   obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672A) += panel-novatek-nt36672a.o
>   obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672E) += panel-novatek-nt36672e.o
>   obj-$(CONFIG_DRM_PANEL_NOVATEK_NT37700F) += panel-novatek-nt37700f.o
> +obj-$(CONFIG_DRM_PANEL_NOVATEK_NT37705) += panel-novatek-nt37705.o
>   obj-$(CONFIG_DRM_PANEL_NOVATEK_NT37801) += panel-novatek-nt37801.o
>   obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
>   obj-$(CONFIG_DRM_PANEL_MANTIX_MLAF057WE51) += panel-mantix-mlaf057we51.o
> diff --git a/drivers/gpu/drm/panel/panel-novatek-nt37705.c b/drivers/gpu/drm/panel/panel-novatek-nt37705.c
> new file mode 100644
> index 000000000000..27bd8072ccd1
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-novatek-nt37705.c
> @@ -0,0 +1,413 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Generated with linux-mdss-dsi-panel-driver-generator from vendor device tree.
> + * Copyright (c) 2026 Luca Weiss <luca.weiss@fairphone.com>
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <video/mipi_display.h>
> +
> +#include <drm/display/drm_dsc.h>
> +#include <drm/display/drm_dsc_helper.h>

IIRC this requires

  select DRM_DISPLAY_DSC_HELPER

in the Kconfig. Maybe double-check.

> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_probe_helper.h>
> +
> +struct nt37705_panel {
> +	struct drm_panel panel;
> +	struct mipi_dsi_device *dsi;
> +	struct drm_dsc_config dsc;
> +	struct regulator_bulk_data *supplies;
> +	struct gpio_desc *reset_gpio;
> +};
> +
> +static const struct regulator_bulk_data nt37705_supplies[] = {
> +	{ .supply = "vddio" },
> +	{ .supply = "dvdd" },
> +	{ .supply = "vci" },
> +};
> +
> +static inline struct nt37705_panel *to_nt37705_panel(struct drm_panel *panel)
> +{
> +	return container_of_const(panel, struct nt37705_panel, panel);

Either just use container_of or build something that respects the 
input's const-ness.

> +}
> +
> +static void nt37705_reset(struct nt37705_panel *ctx)
> +{
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +	usleep_range(10000, 11000);
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +	usleep_range(5000, 6000);
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +	usleep_range(10000, 11000);
> +}
> +
> +static int nt37705_on(struct nt37705_panel *ctx)
> +{
> +	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
> +
> +	ctx->dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0,
> +				     0x55, 0xaa, 0x52, 0x08, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x1b);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba, 0x18);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x1c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00,
> +				     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
> +				     0x00, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x2c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x00, 0x01, 0x01, 0x01, 0x00, 0x05, 0x05,
> +				     0x05, 0x00, 0x05, 0x05, 0x05, 0x00, 0x00,
> +				     0x00, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x3c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x0b,
> +				     0x0b, 0x00, 0x00, 0x0b, 0x0b, 0x00, 0x00,
> +				     0x00, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x4c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
> +				     0x1d, 0x00, 0x00, 0x00, 0x1d, 0x00, 0x00,
> +				     0x00, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x5c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
> +				     0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
> +				     0x01, 0x01);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x6c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x0b,
> +				     0x77, 0x77, 0x00, 0x00, 0x0b, 0x00, 0x1d,
> +				     0x00, 0x1d);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x7c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x0b,
> +				     0x77, 0x77, 0x00, 0x00, 0x0b, 0x00, 0x1d,
> +				     0x00, 0x1d);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x8c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
> +				     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
> +				     0x00, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x9c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x11, 0x11, 0x20, 0x02, 0x00, 0x03, 0x00,
> +				     0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0xa4);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba, 0x00, 0xc0, 0x40, 0x08);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0xa8);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
> +				     0x22);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0xb0);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xba,
> +				     0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
> +				     0x22);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0,
> +				     0x55, 0xaa, 0x52, 0x08, 0x01);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x05);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xc5, 0x15, 0x15, 0x15, 0xdd);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0,
> +				     0x55, 0xaa, 0x52, 0x08, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x0e);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb5, 0x32);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0,
> +				     0x55, 0xaa, 0x52, 0x00, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0xaa, 0x55, 0xa5, 0x80);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x19);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf2, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x1a);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf4, 0x55);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x11);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf8, 0x01, 0x7f);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x2d);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf8, 0x01, 0x20);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0xaa, 0x55, 0xa5, 0x81);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x05);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfe, 0x3c);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x02);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf9, 0x04);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x1e);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfb, 0x0f);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x0f);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf5, 0x20);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x0d);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfb, 0x80);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0xaa, 0x55, 0xa5, 0x83);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x12);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfe, 0x41);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x13);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfd, 0x21);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0xaa, 0x55, 0xa5, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x35);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY,
> +				     0x20);
> +	mipi_dsi_dcs_set_column_address_multi(&dsi_ctx, 0x0000, 0x045b);
> +	mipi_dsi_dcs_set_page_address_multi(&dsi_ctx, 0x0000, 0x09b3);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_SET_GAMMA_CURVE, 0x00);
> +	mipi_dsi_dcs_set_display_brightness_multi(&dsi_ctx, 0xbb0d);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6f, 0x04);
> +	mipi_dsi_dcs_set_display_brightness_multi(&dsi_ctx, 0xfe0f);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x81, 0x01, 0x19);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x03, 0x01);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x90, 0x03, 0x03);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x91,
> +				     0x89, 0x28, 0x00, 0x0c, 0xd2, 0x00, 0x02,
> +				     0x2f, 0x01, 0x18, 0x00, 0x07, 0x09, 0x75,
> +				     0x08, 0x34, 0x10, 0xf0);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x2f, 0x02);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x5a, 0x01);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x2f, 0x30);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6d, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x11, 0x00);
> +	mipi_dsi_msleep(&dsi_ctx, 120);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x29, 0x00);
> +	mipi_dsi_msleep(&dsi_ctx, 22);
> +
> +	return dsi_ctx.accum_err;
> +}
> +
> +static int nt37705_off(struct nt37705_panel *ctx)
> +{
> +	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
> +
> +	ctx->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x28, 0x00);
> +	mipi_dsi_msleep(&dsi_ctx, 20);
> +	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x10, 0x00);
> +	mipi_dsi_msleep(&dsi_ctx, 120);
> +
> +	return dsi_ctx.accum_err;
> +}
> +
> +static int nt37705_prepare(struct drm_panel *panel)
> +{
> +	struct nt37705_panel *ctx = to_nt37705_panel(panel);
> +	struct device *dev = &ctx->dsi->dev;
> +	struct drm_dsc_picture_parameter_set pps;
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(nt37705_supplies), ctx->supplies);
> +	if (ret < 0) {

Common style is to check for errors with

   if (ret)

Here and everywhere else.

Best regards
Thomas

> +		dev_err(dev, "Failed to enable regulators: %d\n", ret);
> +		return ret;
> +	}
> +
> +	nt37705_reset(ctx);
> +
> +	ret = nt37705_on(ctx);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to initialize panel: %d\n", ret);
> +		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +		regulator_bulk_disable(ARRAY_SIZE(nt37705_supplies), ctx->supplies);
> +		return ret;
> +	}
> +
> +	drm_dsc_pps_payload_pack(&pps, &ctx->dsc);
> +
> +	ret = mipi_dsi_picture_parameter_set(ctx->dsi, &pps);
> +	if (ret < 0) {
> +		dev_err(panel->dev, "failed to transmit PPS: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = mipi_dsi_compression_mode(ctx->dsi, true);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to enable compression mode: %d\n", ret);
> +		return ret;
> +	}
> +
> +	msleep(28); /* TODO: Is this panel-dependent? */
> +
> +	return 0;
> +}
> +
> +static int nt37705_unprepare(struct drm_panel *panel)
> +{
> +	struct nt37705_panel *ctx = to_nt37705_panel(panel);
> +	struct device *dev = &ctx->dsi->dev;
> +	int ret;
> +
> +	ret = nt37705_off(ctx);
> +	if (ret < 0)
> +		dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
> +
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(nt37705_supplies), ctx->supplies);
> +
> +	return 0;
> +}
> +
> +static const struct drm_display_mode nt37705_mode = {
> +	.clock = (1116 + 100 + 30 + 100) * (2484 + 70 + 48 + 70) * 120 / 1000,
> +	.hdisplay = 1116,
> +	.hsync_start = 1116 + 100,
> +	.hsync_end = 1116 + 100 + 30,
> +	.htotal = 1116 + 100 + 30 + 100,
> +	.vdisplay = 2484,
> +	.vsync_start = 2484 + 70,
> +	.vsync_end = 2484 + 70 + 48,
> +	.vtotal = 2484 + 70 + 48 + 70,
> +	.width_mm = 66,
> +	.height_mm = 146,
> +	.type = DRM_MODE_TYPE_DRIVER,
> +};
> +
> +static int nt37705_get_modes(struct drm_panel *panel,
> +			     struct drm_connector *connector)
> +{
> +	return drm_connector_helper_get_modes_fixed(connector, &nt37705_mode);
> +}
> +
> +static const struct drm_panel_funcs nt37705_panel_funcs = {
> +	.prepare = nt37705_prepare,
> +	.unprepare = nt37705_unprepare,
> +	.get_modes = nt37705_get_modes,
> +};
> +
> +static int nt37705_bl_update_status(struct backlight_device *bl)
> +{
> +	struct mipi_dsi_device *dsi = bl_get_data(bl);
> +	u16 brightness = backlight_get_brightness(bl);
> +	int ret;
> +
> +	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> +	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
> +	if (ret < 0)
> +		return ret;
> +
> +	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> +	return 0;
> +}
> +
> +static const struct backlight_ops nt37705_bl_ops = {
> +	.update_status = nt37705_bl_update_status,
> +};
> +
> +static struct backlight_device *
> +nt37705_create_backlight(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	const struct backlight_properties props = {
> +		.type = BACKLIGHT_RAW,
> +		.scale = BACKLIGHT_SCALE_NON_LINEAR,
> +		.brightness = 4095,
> +		.max_brightness = 4095,
> +	};
> +
> +	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
> +					      &nt37705_bl_ops, &props);
> +}
> +
> +static int nt37705_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	struct nt37705_panel *ctx;
> +	int ret;
> +
> +	ctx = devm_drm_panel_alloc(dev, struct nt37705_panel, panel,
> +				   &nt37705_panel_funcs,
> +				   DRM_MODE_CONNECTOR_DSI);
> +	if (IS_ERR(ctx))
> +		return PTR_ERR(ctx);
> +
> +	ret = devm_regulator_bulk_get_const(dev,
> +					    ARRAY_SIZE(nt37705_supplies),
> +					    nt37705_supplies,
> +					    &ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(ctx->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
> +				     "Failed to get reset-gpios\n");
> +
> +	ctx->dsi = dsi;
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	dsi->lanes = 4;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_NO_EOT_PACKET |
> +			  MIPI_DSI_CLOCK_NON_CONTINUOUS;
> +
> +	ctx->panel.prepare_prev_first = true;
> +
> +	ctx->panel.backlight = nt37705_create_backlight(dsi);
> +	if (IS_ERR(ctx->panel.backlight))
> +		return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
> +				     "Failed to create backlight\n");
> +
> +	drm_panel_add(&ctx->panel);
> +
> +	/* This panel only supports DSC; unconditionally enable it */
> +	dsi->dsc = &ctx->dsc;
> +
> +	ctx->dsc.dsc_version_major = 1;
> +	ctx->dsc.dsc_version_minor = 1;
> +
> +	/* TODO: Pass slice_per_pkt = 2 */
> +	ctx->dsc.slice_height = 12;
> +	ctx->dsc.slice_width = 558;
> +	/*
> +	 * TODO: hdisplay should be read from the selected mode once
> +	 * it is passed back to drm_panel (in prepare?)
> +	 */
> +	WARN_ON(1116 % ctx->dsc.slice_width);
> +	ctx->dsc.slice_count = 1116 / ctx->dsc.slice_width;
> +	ctx->dsc.bits_per_component = 8;
> +	ctx->dsc.bits_per_pixel = 8 << 4; /* 4 fractional bits */
> +	ctx->dsc.block_pred_enable = true;
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret < 0) {
> +		drm_panel_remove(&ctx->panel);
> +		return dev_err_probe(dev, ret, "Failed to attach to DSI host\n");
> +	}
> +
> +	return 0;
> +}
> +
> +static void nt37705_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct nt37705_panel *ctx = mipi_dsi_get_drvdata(dsi);
> +	int ret;
> +
> +	ret = mipi_dsi_detach(dsi);
> +	if (ret < 0)
> +		dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
> +
> +	drm_panel_remove(&ctx->panel);
> +}
> +
> +static const struct of_device_id nt37705_of_match[] = {
> +	{ .compatible = "boe,bj631jhm-t71-d900" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, nt37705_of_match);
> +
> +static struct mipi_dsi_driver nt37705_driver = {
> +	.probe = nt37705_probe,
> +	.remove = nt37705_remove,
> +	.driver = {
> +		.name = "panel-novatek-nt37705",
> +		.of_match_table = nt37705_of_match,
> +	},
> +};
> +module_mipi_dsi_driver(nt37705_driver);
> +
> +MODULE_DESCRIPTION("DRM driver for NT37705-equipped DSI panels");
> +MODULE_LICENSE("GPL");
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)