LinuxLists.cc - [PATCH 2/2] drm/panel-simple: allow LVDS format override

2023-04-14 16:18:00

Subject: [PATCH 2/2] drm/panel-simple: allow LVDS format override

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]>
---
drivers/gpu/drm/panel/panel-simple.c | 37 +++++++++++++++++++++++++++-
1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 065f378bba9d..7366ad13b3f1 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 +606,40 @@ 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)
+ return -ENOMEM;
+
+ 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

2023-04-17 05:03:46

by Dan Carpenter

[permalink] [raw]

Subject: Re: [PATCH 2/2] drm/panel-simple: allow LVDS format override

Hi Johannes,

kernel test robot noticed
If you fix the issue, | Reported-by: kernel | Reported-by: Dan | Link: the following build warnings:
m/docs/git-format-patch#_base_tree_information]">https://git-scm.com/docs/git-format-patch#_base_tree_information]
thub.com/intel-lab-lkp/linux/commits/Johannes-Zink/dt-bindings-display-simple-support-non-default-data-mapping/20230415-001256">https://github.com/intel-lab-lkp/linux/commits/Johannes-Zink/dt-bindings-display-simple-support-non-default-data-mapping/20230415-001256
sktop.org/drm/drm-misc drm-misc-next
href="https://lore.kernel.org/r/20230414161116.3673911-3-j.zink%40pengutronix.de">https://lore.kernel.org/r/20230414161116.3673911-3-j.zink%40pengutronix.de
2/2] drm/panel-simple: allow LVDS format override
-m031-20230415 (https://download.01.org/0day-ci/archive/20230416/[email protected]/config)
(GCC) 12.1.0
kindly add following tag where applicable
test robot <[email protected]>
Carpenter <[email protected]>
re.kernel.org/r/202304160359.4LHmFOlU-lkp@intel.com/">https://lore.kernel.org/r/[email protected]/
panel_simple_probe() warn: missing unwind goto?
el/panel-simple.c
2021-09-14 556 static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
2013-08-30 557 {
2013-08-30 558 struct panel_simple *panel;
2019-07-11 559 struct display_timing dt;
2019-12-07 560 struct device_node *ddc;
2020-07-26 561 int connector_type;
2020-07-26 562 u32 bus_flags;
2023-04-14 563 int err, ret;
2013-08-30 564
2013-08-30 565 panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
2013-08-30 566 if (!panel)
2013-08-30 567 return -ENOMEM;
2013-08-30 568
2013-08-30 569 panel->enabled = false;
2020-11-09 570 panel->prepared_time = 0;
2013-08-30 571 panel->desc = desc;
2013-08-30 572
2013-08-30 573 panel->supply = devm_regulator_get(dev, "power");
2013-08-30 574 if (IS_ERR(panel->supply))
2013-08-30 575 return PTR_ERR(panel->supply);
2013-08-30 576
2014-10-23 577 panel->enable_gpio = devm_gpiod_get_optional(dev, "enable",
2014-10-23 578 GPIOD_OUT_LOW);
2022-09-29 579 if (IS_ERR(panel->enable_gpio))
2022-09-29 580 return dev_err_probe(dev, PTR_ERR(panel->enable_gpio),
2022-09-29 581 "failed to request GPIO\n");
2013-08-30 582
2020-08-14 583 err = of_drm_get_panel_orientation(dev->of_node, &panel->orientation);
2020-08-14 584 if (err) {
2020-08-14 585 dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err);
2020-08-14 586 return err;
2020-08-14 587 }
2020-08-14 588
2013-08-30 589 ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);
2013-08-30 590 if (ddc) {
2013-08-30 591 panel->ddc = of_find_i2c_adapter_by_node(ddc);
2013-08-30 592 of_node_put(ddc);
2013-08-30 593
2019-12-07 594 if (!panel->ddc)
2019-12-07 595 return -EPROBE_DEFER;
2013-08-30 596 }
2013-08-30 597
2020-02-16 598 if (desc == &panel_dpi) {
2020-02-16 599 /* Handle the generic panel-dpi binding */
2020-02-16 600 err = panel_dpi_probe(dev, panel);
2020-02-16 601 if (err)
2020-02-16 602 goto free_ddc;
Niedermaier 2022-02-01 603 desc = panel->desc;
2020-02-16 604 } else {
2019-07-11 605 if (!of_get_display_timing(dev->of_node, "panel-timing", &dt))
2019-07-12 606 panel_simple_parse_panel_timing_node(dev, panel, &dt);
2020-02-16 607 }
2019-07-11 608
2023-04-14 609
2023-04-14 610 /* optional data-mapping property for overriding bus format */
2023-04-14 611 ret = drm_of_lvds_get_data_mapping(dev->of_node);
2023-04-14 612 if (ret == -EINVAL) {
2023-04-14 613 dev_warn(dev, "Ignore invalid data-mapping property");
2023-04-14 614 } else if (ret != -ENODEV) {
2023-04-14 615 int bpc;
2023-04-14 616
2023-04-14 617 switch (ret) {
2023-04-14 618 default:
2023-04-14 619 WARN_ON(1);
2023-04-14 620 fallthrough;
2023-04-14 621 case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
2023-04-14 622 fallthrough;
2023-04-14 623 case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
2023-04-14 624 bpc = 8;
2023-04-14 625 break;
2023-04-14 626 case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
2023-04-14 627 bpc = 6;
2023-04-14 628 }
2023-04-14 629
2023-04-14 630 if (desc->bpc != bpc || desc->bus_format != ret) {
2023-04-14 631 struct panel_desc *override_desc;
2023-04-14 632
2023-04-14 633 override_desc = devm_kmemdup(dev, desc, sizeof(*desc), GFP_KERNEL);
2023-04-14 634 if (!override_desc)
2023-04-14 @635 return -ENOMEM;
2023-04-14 636
2023-04-14 637 override_desc->bus_format = ret;
2023-04-14 638 override_desc->bpc = bpc;
2023-04-14 639 panel->desc = override_desc;
2023-04-14 640 }
2023-04-14 641 }
2023-04-14 642
2020-07-26 643 connector_type = desc->connector_type;
2020-07-26 644 /* Catch common mistakes for panels. */
2020-07-26 645 switch (connector_type) {
2020-07-26 646 case 0:
2020-07-26 647 dev_warn(dev, "Specify missing connector_type\n");
2020-07-26 648 connector_type = DRM_MODE_CONNECTOR_DPI;
2020-07-26 649 break;
2020-07-26 650 case DRM_MODE_CONNECTOR_LVDS:
2020-06-30 651 WARN_ON(desc->bus_flags &
2020-06-30 652 ~(DRM_BUS_FLAG_DE_LOW |
2020-06-30 653 DRM_BUS_FLAG_DE_HIGH |
2020-06-30 654 DRM_BUS_FLAG_DATA_MSB_TO_LSB |
2020-06-30 655 DRM_BUS_FLAG_DATA_LSB_TO_MSB));
2020-06-30 656 WARN_ON(desc->bus_format != MEDIA_BUS_FMT_RGB666_1X7X3_SPWG &&
2020-06-30 657 desc->bus_format != MEDIA_BUS_FMT_RGB888_1X7X4_SPWG &&
2020-06-30 658 desc->bus_format != MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA);
2020-06-30 659 WARN_ON(desc->bus_format == MEDIA_BUS_FMT_RGB666_1X7X3_SPWG &&
2020-06-30 660 desc->bpc != 6);
2020-06-30 661 WARN_ON((desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_SPWG ||
2020-06-30 662 desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA) &&
2020-06-30 663 desc->bpc != 8);
2020-07-26 664 break;
2020-07-26 665 case DRM_MODE_CONNECTOR_eDP:
2021-09-14 666 dev_warn(dev, "eDP panels moved to panel-edp\n");
2021-09-14 667 err = -EINVAL;
2021-09-14 668 goto free_ddc;
2020-07-26 669 case DRM_MODE_CONNECTOR_DSI:
2020-07-26 670 if (desc->bpc != 6 && desc->bpc != 8)
2020-07-26 671 dev_warn(dev, "Expected bpc in {6,8} but got: %u\n", desc->bpc);
2020-07-26 672 break;
2020-07-26 673 case DRM_MODE_CONNECTOR_DPI:
2020-07-26 674 bus_flags = DRM_BUS_FLAG_DE_LOW |
2020-07-26 675 DRM_BUS_FLAG_DE_HIGH |
2020-07-26 676 DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE |
2020-07-26 677 DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE |
2020-07-26 678 DRM_BUS_FLAG_DATA_MSB_TO_LSB |
2020-07-26 679 DRM_BUS_FLAG_DATA_LSB_TO_MSB |
2020-07-26 680 DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE |
2020-07-26 681 DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
2020-07-26 682 if (desc->bus_flags & ~bus_flags)
2020-07-26 683 dev_warn(dev, "Unexpected bus_flags(%d)\n", desc->bus_flags & ~bus_flags);
2020-07-26 684 if (!(desc->bus_flags & bus_flags))
2020-07-26 685 dev_warn(dev, "Specify missing bus_flags\n");
2020-07-26 686 if (desc->bus_format == 0)
2020-07-26 687 dev_warn(dev, "Specify missing bus_format\n");
2020-07-26 688 if (desc->bpc != 6 && desc->bpc != 8)
2020-07-26 689 dev_warn(dev, "Expected bpc in {6,8} but got: %u\n", desc->bpc);
2020-07-26 690 break;
2020-07-26 691 default:
2020-07-26 692 dev_warn(dev, "Specify a valid connector_type: %d\n", desc->connector_type);
2020-07-26 693 connector_type = DRM_MODE_CONNECTOR_DPI;
2020-07-26 694 break;
2020-06-30 695 }
2020-06-30 696
2021-04-16 697 dev_set_drvdata(dev, panel);
2021-04-16 698
2021-04-16 699 /*
2021-04-16 700 * We use runtime PM for prepare / unprepare since those power the panel
2021-04-16 701 * on and off and those can be very slow operations. This is important
2021-04-16 702 * to optimize powering the panel on briefly to read the EDID before
2021-04-16 703 * fully enabling the panel.
2021-04-16 704 */
2021-04-16 705 pm_runtime_enable(dev);
2021-04-16 706 pm_runtime_set_autosuspend_delay(dev, 1000);
2021-04-16 707 pm_runtime_use_autosuspend(dev);
2021-04-16 708
2020-07-26 709 drm_panel_init(&panel->base, dev, &panel_simple_funcs, connector_type);
2013-08-30 710
2019-12-07 711 err = drm_panel_of_backlight(&panel->base);
2022-06-21 712 if (err) {
2022-06-21 713 dev_err_probe(dev, err, "Could not find backlight\n");
2021-04-23 714 goto disable_pm_runtime;
2022-06-21 715 }
2019-12-07 716
2020-08-01 717 drm_panel_add(&panel->base);
2013-08-30 718
2013-08-30 719 return 0;
2013-08-30 720
2021-04-23 721 disable_pm_runtime:
2021-05-17 722 pm_runtime_dont_use_autosuspend(dev);
2021-04-23 723 pm_runtime_disable(dev);
2013-08-30 724 free_ddc:
2021-09-14 725 if (panel->ddc)
2013-08-30 726 put_device(&panel->ddc->dev);
2013-08-30 727
2013-08-30 728 return err;
2013-08-30 729 }
/intel/lkp-tests">https://github.com/intel/lkp-tests