Some panels support multiple LVDS data mapping formats, which can be
used e.g. run displays on jeida-18 format when only 3 LVDS lanes are
available.
Add parsing of an optional data-mapping devicetree property, which also
touches up the bits per color to match the bus format.
Signed-off-by: Johannes Zink <[email protected]>
---
Changes:
v1 -> v2: - fix missing unwind goto found by test robot
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]/
---
drivers/gpu/drm/panel/panel-simple.c | 39 +++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 2a9c1a785a5c..0a35fdb49ccb 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -40,6 +40,7 @@
#include <drm/drm_edid.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>
+#include <drm/drm_of.h>
/**
* struct panel_desc - Describes a simple panel.
@@ -559,7 +560,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
struct device_node *ddc;
int connector_type;
u32 bus_flags;
- int err;
+ int err, ret;
panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
if (!panel)
@@ -605,6 +606,42 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
panel_simple_parse_panel_timing_node(dev, panel, &dt);
}
+
+ /* optional data-mapping property for overriding bus format */
+ ret = drm_of_lvds_get_data_mapping(dev->of_node);
+ if (ret == -EINVAL) {
+ dev_warn(dev, "Ignore invalid data-mapping property");
+ } else if (ret != -ENODEV) {
+ int bpc;
+
+ switch (ret) {
+ default:
+ WARN_ON(1);
+ fallthrough;
+ case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+ fallthrough;
+ case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+ bpc = 8;
+ break;
+ case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+ bpc = 6;
+ }
+
+ if (desc->bpc != bpc || desc->bus_format != ret) {
+ struct panel_desc *override_desc;
+
+ override_desc = devm_kmemdup(dev, desc, sizeof(*desc), GFP_KERNEL);
+ if (!override_desc) {
+ err = -ENOMEM;
+ goto free_ddc;
+ }
+
+ override_desc->bus_format = ret;
+ override_desc->bpc = bpc;
+ panel->desc = override_desc;
+ }
+ }
+
connector_type = desc->connector_type;
/* Catch common mistakes for panels. */
switch (connector_type) {
--
2.39.2
Hi,
gentle ping here - Do you have any feedback for me on this patch?
Thanks and best regards
Johannes
On 5/23/23 10:19, Johannes Zink wrote:
> Some panels support multiple LVDS data mapping formats, which can be
> used e.g. run displays on jeida-18 format when only 3 LVDS lanes are
> available.
>
> Add parsing of an optional data-mapping devicetree property, which also
> touches up the bits per color to match the bus format.
>
> Signed-off-by: Johannes Zink <[email protected]>
>
> ---
>
> Changes:
>
> v1 -> v2: - fix missing unwind goto found by test robot
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]/
> ---
> drivers/gpu/drm/panel/panel-simple.c | 39 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 2a9c1a785a5c..0a35fdb49ccb 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -40,6 +40,7 @@
> #include <drm/drm_edid.h>
> #include <drm/drm_mipi_dsi.h>
> #include <drm/drm_panel.h>
> +#include <drm/drm_of.h>
>
> /**
> * struct panel_desc - Describes a simple panel.
> @@ -559,7 +560,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
> struct device_node *ddc;
> int connector_type;
> u32 bus_flags;
> - int err;
> + int err, ret;
>
> panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
> if (!panel)
> @@ -605,6 +606,42 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
> panel_simple_parse_panel_timing_node(dev, panel, &dt);
> }
>
> +
> + /* optional data-mapping property for overriding bus format */
> + ret = drm_of_lvds_get_data_mapping(dev->of_node);
> + if (ret == -EINVAL) {
> + dev_warn(dev, "Ignore invalid data-mapping property");
> + } else if (ret != -ENODEV) {
> + int bpc;
> +
> + switch (ret) {
> + default:
> + WARN_ON(1);
> + fallthrough;
> + case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
> + fallthrough;
> + case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
> + bpc = 8;
> + break;
> + case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
> + bpc = 6;
> + }
> +
> + if (desc->bpc != bpc || desc->bus_format != ret) {
> + struct panel_desc *override_desc;
> +
> + override_desc = devm_kmemdup(dev, desc, sizeof(*desc), GFP_KERNEL);
> + if (!override_desc) {
> + err = -ENOMEM;
> + goto free_ddc;
> + }
> +
> + override_desc->bus_format = ret;
> + override_desc->bpc = bpc;
> + panel->desc = override_desc;
> + }
> + }
> +
> connector_type = desc->connector_type;
> /* Catch common mistakes for panels. */
> switch (connector_type) {
>
--
Pengutronix e.K. | Johannes Zink |
Steuerwalder Str. 21 | https://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686| Fax: +49-5121-206917-5555 |
Hi Johannes,
Thank you for the patch.
On Tue, May 23, 2023 at 10:19:43AM +0200, Johannes Zink wrote:
> Some panels support multiple LVDS data mapping formats, which can be
> used e.g. run displays on jeida-18 format when only 3 LVDS lanes are
> available.
>
> Add parsing of an optional data-mapping devicetree property, which also
> touches up the bits per color to match the bus format.
Of course one could argue that the innolux,g101ice-l01 panel should have
used the panel-lvds bindings... :-)
> Signed-off-by: Johannes Zink <[email protected]>
>
> ---
>
> Changes:
>
> v1 -> v2: - fix missing unwind goto found by test robot
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]/
> ---
> drivers/gpu/drm/panel/panel-simple.c | 39 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 2a9c1a785a5c..0a35fdb49ccb 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -40,6 +40,7 @@
> #include <drm/drm_edid.h>
> #include <drm/drm_mipi_dsi.h>
> #include <drm/drm_panel.h>
> +#include <drm/drm_of.h>
>
> /**
> * struct panel_desc - Describes a simple panel.
> @@ -559,7 +560,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
> struct device_node *ddc;
> int connector_type;
> u32 bus_flags;
> - int err;
> + int err, ret;
>
> panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
> if (!panel)
> @@ -605,6 +606,42 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
> panel_simple_parse_panel_timing_node(dev, panel, &dt);
> }
>
> +
Double blank line.
> + /* optional data-mapping property for overriding bus format */
s/optional/Optional/
> + ret = drm_of_lvds_get_data_mapping(dev->of_node);
> + if (ret == -EINVAL) {
> + dev_warn(dev, "Ignore invalid data-mapping property");
> + } else if (ret != -ENODEV) {
If someone incorrectly sets the property in DT for a non-LVDS panel,
the result won't be nice. That's of course a DT issue, but I wonder if
we could/should protect against it. You could move this code to a
separate function (which would have the added benefit of lowering the
indentation level as you can return early in error cases), and call it
from panel_simple_probe() only if the panel is an LVDS panel (as
reported by its desc->bus_format value).
> + int bpc;
> +
> + switch (ret) {
> + default:
> + WARN_ON(1);
> + fallthrough;
> + case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
> + fallthrough;
> + case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
> + bpc = 8;
> + break;
> + case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
> + bpc = 6;
> + }
> +
> + if (desc->bpc != bpc || desc->bus_format != ret) {
> + struct panel_desc *override_desc;
> +
> + override_desc = devm_kmemdup(dev, desc, sizeof(*desc), GFP_KERNEL);
> + if (!override_desc) {
> + err = -ENOMEM;
> + goto free_ddc;
> + }
> +
> + override_desc->bus_format = ret;
> + override_desc->bpc = bpc;
> + panel->desc = override_desc;
> + }
> + }
> +
> connector_type = desc->connector_type;
> /* Catch common mistakes for panels. */
> switch (connector_type) {
--
Regards,
Laurent Pinchart
Hi Laurent,
thanks for your review and your feedback.
On 6/2/23 17:39, Laurent Pinchart wrote:
> Hi Johannes,
>
> Thank you for the patch.
>
> On Tue, May 23, 2023 at 10:19:43AM +0200, Johannes Zink wrote:
>> Some panels support multiple LVDS data mapping formats, which can be
>> used e.g. run displays on jeida-18 format when only 3 LVDS lanes are
>> available.
>>
>> Add parsing of an optional data-mapping devicetree property, which also
>> touches up the bits per color to match the bus format.
>
> Of course one could argue that the innolux,g101ice-l01 panel should have
> used the panel-lvds bindings... :-)
I would prefer to add it in the panel-simple, if ever possible, as this already
has the timing information etc. in the driver. I would probably opt to use the
panel-lvds for an entirely new LVDS display, but as the innolux,g101ice-l01 is
already supported in panel-simple, imho there should be no harm in supporting
the jeida-18 operating mode as well. Also other displays in panel-simple
_might_ benefit from supporting non-default LVDS mapping modes, though I have
not researched whether they have actual hardware support for doing so.
>
>> Signed-off-by: Johannes Zink <[email protected]>
>>
>> ---
>>
>> Changes:
>>
>> v1 -> v2: - fix missing unwind goto found by test robot
>> Reported-by: kernel test robot <[email protected]>
>> Reported-by: Dan Carpenter <[email protected]>
>> Link: https://lore.kernel.org/r/[email protected]/
>> ---
>> drivers/gpu/drm/panel/panel-simple.c | 39 +++++++++++++++++++++++++++++++++++-
>> 1 file changed, 38 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
>> index 2a9c1a785a5c..0a35fdb49ccb 100644
>> --- a/drivers/gpu/drm/panel/panel-simple.c
>> +++ b/drivers/gpu/drm/panel/panel-simple.c
>> @@ -40,6 +40,7 @@
>> #include <drm/drm_edid.h>
>> #include <drm/drm_mipi_dsi.h>
>> #include <drm/drm_panel.h>
>> +#include <drm/drm_of.h>
>>
>> /**
>> * struct panel_desc - Describes a simple panel.
>> @@ -559,7 +560,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
>> struct device_node *ddc;
>> int connector_type;
>> u32 bus_flags;
>> - int err;
>> + int err, ret;
>>
>> panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
>> if (!panel)
>> @@ -605,6 +606,42 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
>> panel_simple_parse_panel_timing_node(dev, panel, &dt);
>> }
>>
>> +
>
> Double blank line.
ack, gonna fix in v3.
>
>> + /* optional data-mapping property for overriding bus format */
>
> s/optional/Optional/
ack, gonna fix in v3.
>
>> + ret = drm_of_lvds_get_data_mapping(dev->of_node);
>> + if (ret == -EINVAL) {
>> + dev_warn(dev, "Ignore invalid data-mapping property");
>> + } else if (ret != -ENODEV) {
>
> If someone incorrectly sets the property in DT for a non-LVDS panel,
> the result won't be nice. That's of course a DT issue, but I wonder if
> we could/should protect against it. You could move this code to a
> separate function (which would have the added benefit of lowering the
> indentation level as you can return early in error cases), and call it
> from panel_simple_probe() only if the panel is an LVDS panel (as
> reported by its desc->bus_format value).
>
that's a good idea, gonna change it for v3.
>> + int bpc;
>> +
>> + switch (ret) {
>> + default:
>> + WARN_ON(1);
>> + fallthrough;
>> + case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
>> + fallthrough;
>> + case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
>> + bpc = 8;
>> + break;
>> + case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
>> + bpc = 6;
>> + }
>> +
>> + if (desc->bpc != bpc || desc->bus_format != ret) {
>> + struct panel_desc *override_desc;
>> +
>> + override_desc = devm_kmemdup(dev, desc, sizeof(*desc), GFP_KERNEL);
>> + if (!override_desc) {
>> + err = -ENOMEM;
>> + goto free_ddc;
>> + }
>> +
>> + override_desc->bus_format = ret;
>> + override_desc->bpc = bpc;
>> + panel->desc = override_desc;
>> + }
>> + }
>> +
>> connector_type = desc->connector_type;
>> /* Catch common mistakes for panels. */
>> switch (connector_type) {
>
--
Pengutronix e.K. | Johannes Zink |
Steuerwalder Str. 21 | https://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686| Fax: +49-5121-206917-5555 |