From: Max Krummenacher <[email protected]>
Commit 4a1d0dbc8332 ("drm/panel: simple: add panel-dpi support") added
support for defining a panel from device tree provided data.
However support for setting the bus format is missing, so that with
the current implementation a 'panel-dpi' panel can only be used
if the driver of the display interface connected can cope with a
missing bus_format.
This patch series defines the new property bus-format and adds it to
the panel-dpi implementation.
Check initial discussions [1] and [2].
[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/
Changes in v2:
- Fix errors found by dt_binding_check
Max Krummenacher (3):
dt-bindings: display: add new bus-format property for panel-dpi
dt-bindings: display: startek,startek-kd050c: allow bus-format
property
drm/panel: simple: add bus-format support for panel-dpi
.../bindings/display/panel/panel-dpi.yaml | 11 +++++
.../display/panel/startek,startek-kd050c.yaml | 1 +
drivers/gpu/drm/panel/panel-simple.c | 43 +++++++++++++++++++
.../dt-bindings/display/dt-media-bus-format.h | 23 ++++++++++
4 files changed, 78 insertions(+)
create mode 100644 include/dt-bindings/display/dt-media-bus-format.h
--
2.20.1
From: Max Krummenacher <[email protected]>
The property is used to set the enum bus_format and infer the bpc
for a panel defined by 'panel-dpi'.
This specifies how the panel is connected to the display interface.
Signed-off-by: Max Krummenacher <[email protected]>
---
Changes in v2:
- Fix errors found by dt_binding_check
.../bindings/display/panel/panel-dpi.yaml | 11 +++++++++
.../dt-bindings/display/dt-media-bus-format.h | 23 +++++++++++++++++++
2 files changed, 34 insertions(+)
create mode 100644 include/dt-bindings/display/dt-media-bus-format.h
diff --git a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
index dae0676b5c6e..a20b5898941e 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
@@ -21,6 +21,14 @@ properties:
- {}
- const: panel-dpi
+ bus-format:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Describes how the display panel is connected to the display interface.
+ Valid values are defined in <dt-bindings/display/dt-media-bus-format.h>.
+ The mapping between the color/significance of the panel lines to the
+ parallel data lines are defined in [1].
+ [1] https://www.kernel.org/doc/html/v5.17/userspace-api/media/v4l/subdev-formats.html#packed-rgb-formats
backlight: true
enable-gpios: true
height-mm: true
@@ -39,11 +47,14 @@ additionalProperties: false
examples:
- |
+ #include <dt-bindings/display/dt-media-bus-format.h>
+
panel {
compatible = "startek,startek-kd050c", "panel-dpi";
label = "osddisplay";
power-supply = <&vcc_supply>;
backlight = <&backlight>;
+ bus-format = <DT_MEDIA_BUS_FMT_RGB888_1X24>;
port {
lcd_in: endpoint {
diff --git a/include/dt-bindings/display/dt-media-bus-format.h b/include/dt-bindings/display/dt-media-bus-format.h
new file mode 100644
index 000000000000..c0f2a7b59aa1
--- /dev/null
+++ b/include/dt-bindings/display/dt-media-bus-format.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
+/*
+ * Copyright 2022 Max Krummenacher <[email protected]>
+ */
+
+#ifndef __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H
+#define __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H
+
+/*
+ * Attention: Keep these macro names in sync with
+ * include/uapi/linux/media-bus-format.h
+ */
+
+#define DT_MEDIA_BUS_FMT_RGB565_1X16 1
+#define DT_MEDIA_BUS_FMT_RGB666_1X18 2
+#define DT_MEDIA_BUS_FMT_RBG888_1X24 3
+#define DT_MEDIA_BUS_FMT_RGB666_1X24_CPADHI 4
+#define DT_MEDIA_BUS_FMT_BGR888_1X24 5
+#define DT_MEDIA_BUS_FMT_GBR888_1X24 6
+#define DT_MEDIA_BUS_FMT_RGB888_1X24 7
+#define DT_MEDIA_BUS_FMT_RGB888_1X32_PADHI 8
+
+#endif /* __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H */
--
2.20.1
From: Max Krummenacher <[email protected]>
Allow to specify the optional bus-format property newly added to
panel-dpi.
Signed-off-by: Max Krummenacher <[email protected]>
---
Changes in v2:
- New commit
.../bindings/display/panel/startek,startek-kd050c.yaml | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/display/panel/startek,startek-kd050c.yaml b/Documentation/devicetree/bindings/display/panel/startek,startek-kd050c.yaml
index fd668640afd1..05306713044e 100644
--- a/Documentation/devicetree/bindings/display/panel/startek,startek-kd050c.yaml
+++ b/Documentation/devicetree/bindings/display/panel/startek,startek-kd050c.yaml
@@ -19,6 +19,7 @@ properties:
- {} # panel-dpi, but not listed here to avoid false select
backlight: true
+ bus-format: true
enable-gpios: true
height-mm: true
label: true
--
2.20.1
From: Max Krummenacher <[email protected]>
Evaluate the device tree bus-format property to set bus_format for
a 'panel-dpi' panel. Additionally infer the bpc value from the
given bus-format.
Valid values for bus-format are found in:
<include/dt-bindings/display/dt-media-bus-format.h>
This completes the addition of panel-dpi to completely specify
a panel-simple panel from the device tree.
Signed-off-by: Max Krummenacher <[email protected]>
---
Changes in v2:
None
drivers/gpu/drm/panel/panel-simple.c | 43 ++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index a34f4198a534..090c60abb014 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -21,6 +21,7 @@
* DEALINGS IN THE SOFTWARE.
*/
+#include <dt-bindings/display/dt-media-bus-format.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
@@ -453,6 +454,7 @@ static int panel_dpi_probe(struct device *dev,
struct panel_desc *desc;
unsigned int bus_flags;
struct videomode vm;
+ u32 bus_format;
int ret;
np = dev->of_node;
@@ -477,6 +479,47 @@ static int panel_dpi_probe(struct device *dev,
of_property_read_u32(np, "width-mm", &desc->size.width);
of_property_read_u32(np, "height-mm", &desc->size.height);
+ if (!of_property_read_u32(np, "bus-format", &bus_format)) {
+ /* infer bpc from bus-format */
+ switch (bus_format) {
+ case DT_MEDIA_BUS_FMT_RGB565_1X16:
+ desc->bus_format = MEDIA_BUS_FMT_RGB565_1X16;
+ desc->bpc = 6;
+ break;
+ case DT_MEDIA_BUS_FMT_RGB666_1X18:
+ desc->bus_format = MEDIA_BUS_FMT_RGB666_1X18;
+ desc->bpc = 6;
+ break;
+ case DT_MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
+ desc->bus_format = MEDIA_BUS_FMT_RGB666_1X24_CPADHI;
+ desc->bpc = 6;
+ break;
+ case DT_MEDIA_BUS_FMT_BGR888_1X24:
+ desc->bus_format = MEDIA_BUS_FMT_BGR888_1X24;
+ desc->bpc = 8;
+ break;
+ case DT_MEDIA_BUS_FMT_GBR888_1X24:
+ desc->bus_format = MEDIA_BUS_FMT_GBR888_1X24;
+ desc->bpc = 8;
+ break;
+ case DT_MEDIA_BUS_FMT_RBG888_1X24:
+ desc->bus_format = MEDIA_BUS_FMT_RBG888_1X24;
+ desc->bpc = 8;
+ break;
+ case DT_MEDIA_BUS_FMT_RGB888_1X24:
+ desc->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+ desc->bpc = 8;
+ break;
+ case DT_MEDIA_BUS_FMT_RGB888_1X32_PADHI:
+ desc->bus_format = MEDIA_BUS_FMT_RGB888_1X32_PADHI;
+ desc->bpc = 8;
+ break;
+ default:
+ dev_err(dev, "%pOF: unknown bus-format property\n", np);
+ return -EINVAL;
+ }
+ }
+
/* Extract bus_flags from display_timing */
bus_flags = 0;
vm.flags = timing->flags;
--
2.20.1
On Wed, May 18, 2022 at 01:55:38PM +0200, Max Krummenacher wrote:
> From: Max Krummenacher <[email protected]>
>
> The property is used to set the enum bus_format and infer the bpc
> for a panel defined by 'panel-dpi'.
> This specifies how the panel is connected to the display interface.
>
> Signed-off-by: Max Krummenacher <[email protected]>
>
> ---
>
> Changes in v2:
> - Fix errors found by dt_binding_check
>
> .../bindings/display/panel/panel-dpi.yaml | 11 +++++++++
> .../dt-bindings/display/dt-media-bus-format.h | 23 +++++++++++++++++++
> 2 files changed, 34 insertions(+)
> create mode 100644 include/dt-bindings/display/dt-media-bus-format.h
>
> diff --git a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> index dae0676b5c6e..a20b5898941e 100644
> --- a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> +++ b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> @@ -21,6 +21,14 @@ properties:
> - {}
> - const: panel-dpi
>
> + bus-format:
> + $ref: /schemas/types.yaml#/definitions/uint32
Constraints?
> + description: |
> + Describes how the display panel is connected to the display interface.
> + Valid values are defined in <dt-bindings/display/dt-media-bus-format.h>.
> + The mapping between the color/significance of the panel lines to the
> + parallel data lines are defined in [1].
Just drop the [1] and use a colon.
> + [1] https://www.kernel.org/doc/html/v5.17/userspace-api/media/v4l/subdev-formats.html#packed-rgb-formats
Why not just use the V4L number space rather than invent yet another
number space?
Need a blank line here too.
> backlight: true
> enable-gpios: true
> height-mm: true
> @@ -39,11 +47,14 @@ additionalProperties: false
>
> examples:
> - |
> + #include <dt-bindings/display/dt-media-bus-format.h>
> +
> panel {
> compatible = "startek,startek-kd050c", "panel-dpi";
> label = "osddisplay";
> power-supply = <&vcc_supply>;
> backlight = <&backlight>;
> + bus-format = <DT_MEDIA_BUS_FMT_RGB888_1X24>;
Other properties describing the interface have been put in the endpoint
node. This should too I think.
>
> port {
> lcd_in: endpoint {
> diff --git a/include/dt-bindings/display/dt-media-bus-format.h b/include/dt-bindings/display/dt-media-bus-format.h
> new file mode 100644
> index 000000000000..c0f2a7b59aa1
> --- /dev/null
> +++ b/include/dt-bindings/display/dt-media-bus-format.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
> +/*
> + * Copyright 2022 Max Krummenacher <[email protected]>
> + */
> +
> +#ifndef __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H
> +#define __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H
> +
> +/*
> + * Attention: Keep these macro names in sync with
> + * include/uapi/linux/media-bus-format.h
> + */
> +
> +#define DT_MEDIA_BUS_FMT_RGB565_1X16 1
> +#define DT_MEDIA_BUS_FMT_RGB666_1X18 2
> +#define DT_MEDIA_BUS_FMT_RBG888_1X24 3
> +#define DT_MEDIA_BUS_FMT_RGB666_1X24_CPADHI 4
> +#define DT_MEDIA_BUS_FMT_BGR888_1X24 5
> +#define DT_MEDIA_BUS_FMT_GBR888_1X24 6
> +#define DT_MEDIA_BUS_FMT_RGB888_1X24 7
> +#define DT_MEDIA_BUS_FMT_RGB888_1X32_PADHI 8
> +
> +#endif /* __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H */
> --
> 2.20.1
>
>
Hi Rob
Thanks for the feedback.
On Wed, Jun 1, 2022 at 10:17 PM Rob Herring <[email protected]> wrote:
>
> On Wed, May 18, 2022 at 01:55:38PM +0200, Max Krummenacher wrote:
> > From: Max Krummenacher <[email protected]>
> >
> > The property is used to set the enum bus_format and infer the bpc
> > for a panel defined by 'panel-dpi'.
> > This specifies how the panel is connected to the display interface.
> >
> > Signed-off-by: Max Krummenacher <[email protected]>
> >
> > ---
> >
> > Changes in v2:
> > - Fix errors found by dt_binding_check
> >
> > .../bindings/display/panel/panel-dpi.yaml | 11 +++++++++
> > .../dt-bindings/display/dt-media-bus-format.h | 23 +++++++++++++++++++
> > 2 files changed, 34 insertions(+)
> > create mode 100644 include/dt-bindings/display/dt-media-bus-format.h
> >
> > diff --git a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> > index dae0676b5c6e..a20b5898941e 100644
> > --- a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> > +++ b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> > @@ -21,6 +21,14 @@ properties:
> > - {}
> > - const: panel-dpi
> >
> > + bus-format:
> > + $ref: /schemas/types.yaml#/definitions/uint32
>
> Constraints?
Will limit the range to the one used for RGB formats in v3.
>
> > + description: |
> > + Describes how the display panel is connected to the display interface.
> > + Valid values are defined in <dt-bindings/display/dt-media-bus-format.h>.
> > + The mapping between the color/significance of the panel lines to the
> > + parallel data lines are defined in [1].
>
> Just drop the [1] and use a colon.
Done in v3.
>
> > + [1] https://www.kernel.org/doc/html/v5.17/userspace-api/media/v4l/subdev-formats.html#packed-rgb-formats
>
> Why not just use the V4L number space rather than invent yet another
> number space?
That was a proposal from here:
https://lore.kernel.org/all/20220323155817.xcsqxothziot7ba3@houat/
But probably it makes more sense to use the number space as is, changed in v3.
>
> Need a blank line here too.
>
> > backlight: true
> > enable-gpios: true
> > height-mm: true
> > @@ -39,11 +47,14 @@ additionalProperties: false
> >
> > examples:
> > - |
> > + #include <dt-bindings/display/dt-media-bus-format.h>
> > +
> > panel {
> > compatible = "startek,startek-kd050c", "panel-dpi";
> > label = "osddisplay";
> > power-supply = <&vcc_supply>;
> > backlight = <&backlight>;
> > + bus-format = <DT_MEDIA_BUS_FMT_RGB888_1X24>;
>
> Other properties describing the interface have been put in the endpoint
> node. This should too I think.
That makes a lot of sense. Changed to be part of the endpoint node in v3.
Cheers
Max
>
> >
> > port {
> > lcd_in: endpoint {
> > diff --git a/include/dt-bindings/display/dt-media-bus-format.h b/include/dt-bindings/display/dt-media-bus-format.h
> > new file mode 100644
> > index 000000000000..c0f2a7b59aa1
> > --- /dev/null
> > +++ b/include/dt-bindings/display/dt-media-bus-format.h
> > @@ -0,0 +1,23 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
> > +/*
> > + * Copyright 2022 Max Krummenacher <[email protected]>
> > + */
> > +
> > +#ifndef __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H
> > +#define __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H
> > +
> > +/*
> > + * Attention: Keep these macro names in sync with
> > + * include/uapi/linux/media-bus-format.h
> > + */
> > +
> > +#define DT_MEDIA_BUS_FMT_RGB565_1X16 1
> > +#define DT_MEDIA_BUS_FMT_RGB666_1X18 2
> > +#define DT_MEDIA_BUS_FMT_RBG888_1X24 3
> > +#define DT_MEDIA_BUS_FMT_RGB666_1X24_CPADHI 4
> > +#define DT_MEDIA_BUS_FMT_BGR888_1X24 5
> > +#define DT_MEDIA_BUS_FMT_GBR888_1X24 6
> > +#define DT_MEDIA_BUS_FMT_RGB888_1X24 7
> > +#define DT_MEDIA_BUS_FMT_RGB888_1X32_PADHI 8
> > +
> > +#endif /* __DT_BINDINGS_DT_MEDIA_BUS_FORMAT_H */
> > --
> > 2.20.1
> >
> >