Messages in this thread | | | Date | Mon, 5 Jun 2023 08:20:26 +0200 | Subject | Re: [PATCH v2 3/3] drm/panel-simple: allow LVDS format override | From | Johannes Zink <> |
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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 <j.zink@pengutronix.de> >> >> --- >> >> Changes: >> >> v1 -> v2: - fix missing unwind goto found by test robot >> Reported-by: kernel test robot <lkp@intel.com> >> Reported-by: Dan Carpenter <error27@gmail.com> >> Link: https://lore.kernel.org/r/202304160359.4LHmFOlU-lkp@intel.com/ >> --- >> 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 |
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