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]/
Max Krummenacher (2):
dt-bindings: display: add new bus-format property for panel-dpi
drm/panel: simple: add bus-format support for panel-dpi
.../bindings/display/panel/panel-dpi.yaml | 11 +++++
drivers/gpu/drm/panel/panel-simple.c | 43 +++++++++++++++++++
.../dt-bindings/display/dt-media-bus-format.h | 23 ++++++++++
3 files changed, 77 insertions(+)
create mode 100644 include/dt-bindings/display/dt-media-bus-format.h
--
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]>
---
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
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]>
---
.../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..ca44e96c3001 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
On Mon, 16 May 2022 18:28:25 +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]>
> ---
>
> .../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
>
My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):
yamllint warnings/errors:
dtschema/dtc warnings/errors:
Error: Documentation/devicetree/bindings/display/panel/panel-dpi.example.dts:20.9-10 syntax error
FATAL ERROR: Unable to parse input tree
make[1]: *** [scripts/Makefile.lib:364: Documentation/devicetree/bindings/display/panel/panel-dpi.example.dtb] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:1401: dt_binding_check] Error 2
doc reference errors (make refcheckdocs):
See https://patchwork.ozlabs.org/patch/
This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.
If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:
pip3 install dtschema --upgrade
Please check and re-submit.