Hi!
The background for these patches is that our PCB interface between the SAMA5D3 and the ds90c185 lvds encoder is only using 16 bits, and this has to be described somewhere, or the atmel-hlcdc driver have no chance of selecting the correct output mode. Since we have similar problems with a tda19988 HDMI encoder I added patches to override the atmel-hlcdc output format via DT properties compatible with the media video-interface binding and things start to play together.
There is still an open question regardning the binding in patch 2/3, where Laurent wondered about plans Sakari might have for explicit bus types for parallel buses. See https://lkml.org/lkml/2018/8/3/278
Cheers, Peter
Changes since (the shortened) v5 https://lkml.org/lkml/2018/8/3/182 - add reg properties (and #*-cells) to the example in patch 2/3 - prohibit bus-width 0 in the device-tree in patch 3/3 - added reviewed-by from Jacopo to patch 2/3 and 3/3
Peter Rosin (3): dt-bindings: display: bridge: lvds-transmitter: add ti,ds90c185 dt-bindings: display: atmel: optional video-interface of endpoints drm/atmel-hlcdc: support bus-width (12/16/18/24) in endpoint nodes
.../devicetree/bindings/display/atmel/hlcdc-dc.txt | 30 ++++++++++ .../bindings/display/bridge/lvds-transmitter.txt | 8 ++- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 70 +++++++++++++++------- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h | 1 + drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c | 70 +++++++++++++++++++--- 5 files changed, 151 insertions(+), 28 deletions(-)
Start list of actual chips compatible with "lvds-encoder".
Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Rob Herring robh@kernel.org Signed-off-by: Peter Rosin peda@axentia.se --- .../devicetree/bindings/display/bridge/lvds-transmitter.txt | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt index fd39ad34c383..50220190c203 100644 --- a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt +++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt @@ -22,7 +22,13 @@ among others.
Required properties:
-- compatible: Must be "lvds-encoder" +- compatible: Must be one or more of the following + - "ti,ds90c185" for the TI DS90C185 FPD-Link Serializer + - "lvds-encoder" for a generic LVDS encoder device + + When compatible with the generic version, nodes must list the + device-specific version corresponding to the device first + followed by the generic version.
Required nodes:
With bus-type/bus-width properties in the endpoint nodes, the video- interface of the connection can be specified for cases where the heuristic fails to select the correct output mode. This can happen e.g. if not all RGB pins are routed on the PCB; the driver has no way of knowing this, and needs to be told explicitly.
This is critical for the devices that have the "conflicting output formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant RGB bits move around depending on the selected output mode. For devices that do not have the "conflicting output formats" issue (SAMA5D2, SAMA5D4), this is completely irrelevant.
Acked-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Rob Herring robh@kernel.org Reviewed-by: Jacopo Mondi jacopo+renesas@jmondi.org Signed-off-by: Peter Rosin peda@axentia.se --- .../devicetree/bindings/display/atmel/hlcdc-dc.txt | 30 ++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt index 82f2acb3d374..10e8707d1443 100644 --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt +++ b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt @@ -15,6 +15,14 @@ Required children nodes: to external devices using the OF graph reprensentation (see ../graph.txt). At least one port node is required.
+Optional properties in grandchild nodes: + Any endpoint grandchild node may specify a desired video interface + according to ../../media/video-interfaces.txt, specifically + - bus-type: must be <0>. + - bus-width: recognized values are <12>, <16>, <18> and <24>, and + override any output mode selection heuristic, forcing "rgb444", + "rgb565", "rgb666" and "rgb888" respectively. + Example:
hlcdc: hlcdc@f0030000 { @@ -50,3 +58,25 @@ Example: #pwm-cells = <3>; }; }; + +Example 2: With a video interface override to force rgb565; as above +but with these changes/additions: + + &hlcdc { + hlcdc-display-controller { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>; + + port@0 { + #address-cells = <1>; + #size-cells = <0>; + reg = <0>; + + hlcdc_panel_output: endpoint@0 { + reg = <0>; + bus-type = <0>; + bus-width = <16>; + }; + }; + }; + };
Hi Peter,
Thanks for cc'ing me.
On Fri, Aug 03, 2018 at 12:11:23PM +0200, Peter Rosin wrote:
With bus-type/bus-width properties in the endpoint nodes, the video- interface of the connection can be specified for cases where the heuristic fails to select the correct output mode. This can happen e.g. if not all RGB pins are routed on the PCB; the driver has no way of knowing this, and needs to be told explicitly.
This is critical for the devices that have the "conflicting output formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant RGB bits move around depending on the selected output mode. For devices that do not have the "conflicting output formats" issue (SAMA5D2, SAMA5D4), this is completely irrelevant.
Acked-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Rob Herring robh@kernel.org Reviewed-by: Jacopo Mondi jacopo+renesas@jmondi.org Signed-off-by: Peter Rosin peda@axentia.se
.../devicetree/bindings/display/atmel/hlcdc-dc.txt | 30 ++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt index 82f2acb3d374..10e8707d1443 100644 --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt +++ b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt @@ -15,6 +15,14 @@ Required children nodes: to external devices using the OF graph reprensentation (see ../graph.txt). At least one port node is required.
+Optional properties in grandchild nodes:
- Any endpoint grandchild node may specify a desired video interface
- according to ../../media/video-interfaces.txt, specifically
- bus-type: must be <0>.
bus-type won't tell anything in this case, you could simply drop it. If your hardware only supports parallel or Bt.656 bus then the code parsing the properties can (and should) know the bus type as well.
Looking at your implementation, bus-type is not being used. This supports the suggestion.
The V4L2 implementation is about to change as well and there's a bit of discussion ongoing related to the bus-type property:
URL:https://www.spinics.net/lists/linux-media/msg137980.html URL:https://www.spinics.net/lists/linux-media/msg137979.html
- bus-width: recognized values are <12>, <16>, <18> and <24>, and
- override any output mode selection heuristic, forcing "rgb444",
- "rgb565", "rgb666" and "rgb888" respectively.
Example:
hlcdc: hlcdc@f0030000 { @@ -50,3 +58,25 @@ Example: #pwm-cells = <3>; }; };
+Example 2: With a video interface override to force rgb565; as above +but with these changes/additions:
- &hlcdc {
hlcdc-display-controller {pinctrl-names = "default";pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;port@0 {#address-cells = <1>;#size-cells = <0>;reg = <0>;hlcdc_panel_output: endpoint@0 {reg = <0>;bus-type = <0>;bus-width = <16>;};};};- };
On 2018-08-03 12:32, Sakari Ailus wrote:
Hi Peter,
Thanks for cc'ing me.
You're welcome, but Laurent is the one to "blame" for hooking you up... :-)
On Fri, Aug 03, 2018 at 12:11:23PM +0200, Peter Rosin wrote:
With bus-type/bus-width properties in the endpoint nodes, the video- interface of the connection can be specified for cases where the heuristic fails to select the correct output mode. This can happen e.g. if not all RGB pins are routed on the PCB; the driver has no way of knowing this, and needs to be told explicitly.
This is critical for the devices that have the "conflicting output formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant RGB bits move around depending on the selected output mode. For devices that do not have the "conflicting output formats" issue (SAMA5D2, SAMA5D4), this is completely irrelevant.
Acked-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Rob Herring robh@kernel.org Reviewed-by: Jacopo Mondi jacopo+renesas@jmondi.org Signed-off-by: Peter Rosin peda@axentia.se
.../devicetree/bindings/display/atmel/hlcdc-dc.txt | 30 ++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt index 82f2acb3d374..10e8707d1443 100644 --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt +++ b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt @@ -15,6 +15,14 @@ Required children nodes: to external devices using the OF graph reprensentation (see ../graph.txt). At least one port node is required.
+Optional properties in grandchild nodes:
- Any endpoint grandchild node may specify a desired video interface
- according to ../../media/video-interfaces.txt, specifically
- bus-type: must be <0>.
bus-type won't tell anything in this case, you could simply drop it. If your hardware only supports parallel or Bt.656 bus then the code parsing the properties can (and should) know the bus type as well.
Looking at your implementation, bus-type is not being used. This supports the suggestion.
I only added the "bus-type = <0>;" in order to disallow any other value for the bus-type to make it clear that any non-zero value would be a bug in the device-tree and not in the driver...
The V4L2 implementation is about to change as well and there's a bit of discussion ongoing related to the bus-type property:
URL:https://www.spinics.net/lists/linux-media/msg137980.html URL:https://www.spinics.net/lists/linux-media/msg137979.html
...but I can certainly drop "bus-type = <0>;" from the binding if it is going away anyway. However, I wonder why it's ok to silently drop the autodetect meaning of zero? What about old device-trees that do have that zero there? Are those suddenly not conforming? Wouldn't a deprecation notice be better so that old existing device-trees can be parsed/understood even when using modern bindings documentation?
Cheers, Peter
- bus-width: recognized values are <12>, <16>, <18> and <24>, and
- override any output mode selection heuristic, forcing "rgb444",
- "rgb565", "rgb666" and "rgb888" respectively.
Example:
hlcdc: hlcdc@f0030000 { @@ -50,3 +58,25 @@ Example: #pwm-cells = <3>; }; };
+Example 2: With a video interface override to force rgb565; as above +but with these changes/additions:
- &hlcdc {
hlcdc-display-controller {pinctrl-names = "default";pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;port@0 {#address-cells = <1>;#size-cells = <0>;reg = <0>;hlcdc_panel_output: endpoint@0 {reg = <0>;bus-type = <0>;bus-width = <16>;};};};- };
This beats the heuristic that the connector is involved in what format should be output for cases where this fails.
E.g. if there is a bridge that changes format between the encoder and the connector, or if some of the RGB pins between the lcd controller and the encoder are not routed on the PCB.
This is critical for the devices that have the "conflicting output formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant RGB bits move around depending on the selected output mode. For devices that do not have the "conflicting output formats" issue (SAMA5D2, SAMA5D4), this is completely irrelevant.
Acked-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Jacopo Mondi jacopo+renesas@jmondi.org Signed-off-by: Peter Rosin peda@axentia.se --- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 70 +++++++++++++++++------- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h | 1 + drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c | 70 +++++++++++++++++++++--- 3 files changed, 114 insertions(+), 27 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c index d73281095fac..c38a479ada98 100644 --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c @@ -226,6 +226,55 @@ static void atmel_hlcdc_crtc_atomic_enable(struct drm_crtc *c, #define ATMEL_HLCDC_RGB888_OUTPUT BIT(3) #define ATMEL_HLCDC_OUTPUT_MODE_MASK GENMASK(3, 0)
+static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state) +{ + struct drm_connector *connector = state->connector; + struct drm_display_info *info = &connector->display_info; + struct drm_encoder *encoder; + unsigned int supported_fmts = 0; + int j; + + encoder = state->best_encoder; + if (!encoder) + encoder = connector->encoder; + + switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) { + case 0: + break; + case MEDIA_BUS_FMT_RGB444_1X12: + return ATMEL_HLCDC_RGB444_OUTPUT; + case MEDIA_BUS_FMT_RGB565_1X16: + return ATMEL_HLCDC_RGB565_OUTPUT; + case MEDIA_BUS_FMT_RGB666_1X18: + return ATMEL_HLCDC_RGB666_OUTPUT; + case MEDIA_BUS_FMT_RGB888_1X24: + return ATMEL_HLCDC_RGB888_OUTPUT; + default: + return -EINVAL; + } + + for (j = 0; j < info->num_bus_formats; j++) { + switch (info->bus_formats[j]) { + case MEDIA_BUS_FMT_RGB444_1X12: + supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT; + break; + case MEDIA_BUS_FMT_RGB565_1X16: + supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT; + break; + case MEDIA_BUS_FMT_RGB666_1X18: + supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT; + break; + case MEDIA_BUS_FMT_RGB888_1X24: + supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT; + break; + default: + break; + } + } + + return supported_fmts; +} + static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state) { unsigned int output_fmts = ATMEL_HLCDC_OUTPUT_MODE_MASK; @@ -238,31 +287,12 @@ static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state) crtc = drm_crtc_to_atmel_hlcdc_crtc(state->crtc);
for_each_new_connector_in_state(state->state, connector, cstate, i) { - struct drm_display_info *info = &connector->display_info; unsigned int supported_fmts = 0; - int j;
if (!cstate->crtc) continue;
- for (j = 0; j < info->num_bus_formats; j++) { - switch (info->bus_formats[j]) { - case MEDIA_BUS_FMT_RGB444_1X12: - supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT; - break; - case MEDIA_BUS_FMT_RGB565_1X16: - supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT; - break; - case MEDIA_BUS_FMT_RGB666_1X18: - supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT; - break; - case MEDIA_BUS_FMT_RGB888_1X24: - supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT; - break; - default: - break; - } - } + supported_fmts = atmel_hlcdc_connector_output_mode(cstate);
if (crtc->dc->desc->conflicting_output_formats) output_fmts &= supported_fmts; diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h index 60c937f42114..4cc1e03f0aee 100644 --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h @@ -441,5 +441,6 @@ void atmel_hlcdc_crtc_irq(struct drm_crtc *c); int atmel_hlcdc_crtc_create(struct drm_device *dev);
int atmel_hlcdc_create_outputs(struct drm_device *dev); +int atmel_hlcdc_encoder_get_bus_fmt(struct drm_encoder *encoder);
#endif /* DRM_ATMEL_HLCDC_H */ diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c index 8db51fb131db..f587ae596791 100644 --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c @@ -27,33 +27,89 @@
#include "atmel_hlcdc_dc.h"
+struct atmel_hlcdc_rgb_output { + struct drm_encoder encoder; + int bus_fmt; +}; + static const struct drm_encoder_funcs atmel_hlcdc_panel_encoder_funcs = { .destroy = drm_encoder_cleanup, };
+static struct atmel_hlcdc_rgb_output * +atmel_hlcdc_encoder_to_rgb_output(struct drm_encoder *encoder) +{ + return container_of(encoder, struct atmel_hlcdc_rgb_output, encoder); +} + +int atmel_hlcdc_encoder_get_bus_fmt(struct drm_encoder *encoder) +{ + struct atmel_hlcdc_rgb_output *output; + + output = atmel_hlcdc_encoder_to_rgb_output(encoder); + + return output->bus_fmt; +} + +static int atmel_hlcdc_of_bus_fmt(struct device_node *ep) +{ + u32 bus_width; + int ret; + + ret = of_property_read_u32(ep, "bus-width", &bus_width); + if (ret == -EINVAL) + return 0; + if (ret) + return ret; + + switch (bus_width) { + case 12: + return MEDIA_BUS_FMT_RGB444_1X12; + case 16: + return MEDIA_BUS_FMT_RGB565_1X16; + case 18: + return MEDIA_BUS_FMT_RGB666_1X18; + case 24: + return MEDIA_BUS_FMT_RGB888_1X24; + default: + return -EINVAL; + } +} + static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint) { - struct drm_encoder *encoder; + struct atmel_hlcdc_rgb_output *output; + struct device_node *ep; struct drm_panel *panel; struct drm_bridge *bridge; int ret;
+ ep = of_graph_get_endpoint_by_regs(dev->dev->of_node, 0, endpoint); + if (!ep) + return -ENODEV; + ret = drm_of_find_panel_or_bridge(dev->dev->of_node, 0, endpoint, &panel, &bridge); if (ret) return ret;
- encoder = devm_kzalloc(dev->dev, sizeof(*encoder), GFP_KERNEL); - if (!encoder) + output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL); + if (!output) return -EINVAL;
- ret = drm_encoder_init(dev, encoder, + output->bus_fmt = atmel_hlcdc_of_bus_fmt(ep); + if (output->bus_fmt < 0) { + dev_err(dev->dev, "invalid bus width\n"); + return -EINVAL; + } + + ret = drm_encoder_init(dev, &output->encoder, &atmel_hlcdc_panel_encoder_funcs, DRM_MODE_ENCODER_NONE, NULL); if (ret) return ret;
- encoder->possible_crtcs = 0x1; + output->encoder.possible_crtcs = 0x1;
if (panel) { bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_Unknown); @@ -62,7 +118,7 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint) }
if (bridge) { - ret = drm_bridge_attach(encoder, bridge, NULL); + ret = drm_bridge_attach(&output->encoder, bridge, NULL); if (!ret) return 0;
@@ -70,7 +126,7 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint) drm_panel_bridge_remove(bridge); }
- drm_encoder_cleanup(encoder); + drm_encoder_cleanup(&output->encoder);
return ret; }
dri-devel@lists.freedesktop.org
-
Peter Rosin -
Sakari Ailus