On 28-Jun-22 23:48, Max Krummenacher wrote:
From: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>
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 <max.krummenacher@xxxxxxxxxxx>
---
Changes in v3:
- Moved the bus-format property under the port/endpoint node as
suggested by Rob Herring
Changes in v2:
- Fix errors found by dt_binding_check
drivers/gpu/drm/panel/panel-simple.c | 49 ++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 4a2e580a2f7b..f1a457f1069e 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -21,9 +21,11 @@
* 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>
+#include <linux/of_graph.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
@@ -449,10 +451,12 @@ static int panel_dpi_probe(struct device *dev,
struct panel_simple *panel)
{
struct display_timing *timing;
+ struct device_node *endpoint;
const struct device_node *np;
struct panel_desc *desc;
unsigned int bus_flags;
struct videomode vm;
+ u32 bus_format;
int ret;
np = dev->of_node;
@@ -477,6 +481,51 @@ 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);
+ endpoint = of_graph_get_endpoint_by_regs(np, -1, -1);
+ if (endpoint &&
+ !of_property_read_u32(endpoint, "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;
+ }
+ }
+
+ of_node_put(endpoint);
+
/* Extract bus_flags from display_timing */
bus_flags = 0;
vm.flags = timing->flags;
I understand that it is important to add a bus-format property for dumb
dpi-panels, and I agree with the implementation in the patch-set.
However,
I do not yet fully understand Rob's comments on the dt-bindings side of
patch set (patch 1/4) and what consequences it may cause if that remains
unresolved.
Given that the bus-format property gets added, I do not see any concern
with the panel-simple driver patch.
Reviewed-by: Aradhya Bhatia <a-bhatia1@xxxxxx>
Regards
Aradhya
