[v2,18/21] drm/bridge: lvds-encoder: Implement basic bus format negotiation
diff mbox series

Message ID 20190826152649.13820-19-boris.brezillon@collabora.com
State New
Headers show
Series
  • drm: Add support for bus-format negotiation
Related show

Commit Message

Boris Brezillon Aug. 26, 2019, 3:26 p.m. UTC
Some LVDS encoder might support several input/output bus formats. Add
a way to describe the one used on a specific design by adding optional
'data-mapping' properties to the input/output ports.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
Changes in v2:
* Make the bus-format negotiation logic more generic
---
 .../display/bridge/lvds-transmitter.txt       |  12 ++
 drivers/gpu/drm/bridge/lvds-encoder.c         | 105 ++++++++++++++++++
 2 files changed, 117 insertions(+)

Comments

Jernej Skrabec Aug. 26, 2019, 4:15 p.m. UTC | #1
Hi Boris!

Dne ponedeljek, 26. avgust 2019 ob 17:26:46 CEST je Boris Brezillon 
napisal(a):
> Some LVDS encoder might support several input/output bus formats. Add
> a way to describe the one used on a specific design by adding optional
> 'data-mapping' properties to the input/output ports.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
> Changes in v2:
> * Make the bus-format negotiation logic more generic
> ---
>  .../display/bridge/lvds-transmitter.txt       |  12 ++
>  drivers/gpu/drm/bridge/lvds-encoder.c         | 105 ++++++++++++++++++
>  2 files changed, 117 insertions(+)
> 
> diff --git
> a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> index 60091db5dfa5..db51eab216f7 100644
> --- a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> +++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> @@ -36,6 +36,18 @@ graph bindings specified in
> Documentation/devicetree/bindings/graph.txt. - Video port 0 for parallel
> input
>  - Video port 1 for LVDS output
> 
> +Optional port 0 node properties:
> +
> +- data-mapping: can be one of the following values
> +	"rgb-24"
> +	"rgb-18"
> +
> +Optional port 0 node properties:

You probably mean port 1 ^^^ ?

Anyway, devicetree doc changes should be separate patch and be send to DT ML 
(I can't see it in CC).

Best regards,
Jernej

> +
> +- data-mapping: can be one of the following values
> +	"jeida-18"
> +	"jeida-24"
> +	"vesa-24"
> 
>  Example
>  -------
> diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c
> b/drivers/gpu/drm/bridge/lvds-encoder.c index 2ab2c234f26c..38cad7a7d828
> 100644
> --- a/drivers/gpu/drm/bridge/lvds-encoder.c
> +++ b/drivers/gpu/drm/bridge/lvds-encoder.c
> @@ -6,6 +6,7 @@
>  #include <linux/gpio/consumer.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/of_device.h>
>  #include <linux/of_graph.h>
>  #include <linux/platform_device.h>
> 
> @@ -16,6 +17,8 @@ struct lvds_encoder {
>  	struct drm_bridge bridge;
>  	struct drm_bridge *panel_bridge;
>  	struct gpio_desc *powerdown_gpio;
> +	u32 output_fmt;
> +	u32 input_fmt;
>  };
> 
>  static int lvds_encoder_attach(struct drm_bridge *bridge)
> @@ -48,12 +51,86 @@ static void lvds_encoder_disable(struct drm_bridge
> *bridge) gpiod_set_value_cansleep(lvds_encoder->powerdown_gpio, 1);
>  }
> 
> +static void lvds_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> +					   struct 
drm_bridge_state *bridge_state,
> +					   struct 
drm_crtc_state *crtc_state,
> +					   struct 
drm_connector_state *conn_state,
> +					   u32 output_fmt,
> +					   unsigned int 
*num_input_fmts,
> +					   u32 *input_fmts)
> +{
> +	struct lvds_encoder *lvds_encoder = container_of(bridge,
> +							 
struct lvds_encoder,
> +							 
bridge);
> +
> +	if (output_fmt == MEDIA_BUS_FMT_FIXED ||
> +	    output_fmt == lvds_encoder->output_fmt)
> +		*num_input_fmts = 1;
> +	else
> +		*num_input_fmts = 0;
> +
> +	if (*num_input_fmts && input_fmts)
> +		input_fmts[0] = lvds_encoder->input_fmt;
> +}
> +
> +static int lvds_encoder_atomic_check(struct drm_bridge *bridge,
> +				     struct drm_bridge_state 
*bridge_state,
> +				     struct drm_crtc_state 
*crtc_state,
> +				     struct drm_connector_state 
*conn_state)
> +{
> +	/* Propagate the bus_flags. */
> +	bridge_state->input_bus_cfg.flags = bridge_state-
>output_bus_cfg.flags;
> +	return 0;
> +}
> +
>  static struct drm_bridge_funcs funcs = {
>  	.attach = lvds_encoder_attach,
>  	.enable = lvds_encoder_enable,
>  	.disable = lvds_encoder_disable,
> +	.atomic_get_input_bus_fmts = lvds_atomic_get_input_bus_fmts,
> +	.atomic_check = lvds_encoder_atomic_check,
>  };
> 
> +struct of_data_mapping {
> +	const char *name;
> +	u32 id;
> +};
> +
> +static const struct of_data_mapping output_data_mappings[] = {
> +	{ "jeida-18", MEDIA_BUS_FMT_RGB666_1X7X3_SPWG },
> +	{ "jeida-24", MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA },
> +	{ "vesa-24", MEDIA_BUS_FMT_RGB888_1X7X4_SPWG },
> +};
> +
> +static const struct of_data_mapping input_data_mappings[] = {
> +	{ "rgb-24", MEDIA_BUS_FMT_RGB888_1X24 },
> +	{ "rgb-18", MEDIA_BUS_FMT_RGB666_1X18 },
> +};
> +
> +static int of_get_data_mapping(struct device_node *port,
> +			       const struct of_data_mapping 
*mappings,
> +			       unsigned int num_mappings,
> +			       u32 *fmt)
> +{
> +	const char *name = NULL;
> +	unsigned int i;
> +
> +	of_property_read_string(port, "data-mapping", &name);
> +	if (!name) {
> +		*fmt = MEDIA_BUS_FMT_FIXED;
> +		return 0;
> +	}
> +
> +	for (i = 0; i < num_mappings; i++) {
> +		if (!strcmp(mappings[i].name, name)) {
> +			*fmt = mappings[i].id;
> +			return 0;
> +		}
> +	}
> +
> +	return -ENOTSUPP;
> +}
> +
>  static int lvds_encoder_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -62,11 +139,15 @@ static int lvds_encoder_probe(struct platform_device
> *pdev) struct device_node *panel_node;
>  	struct drm_panel *panel;
>  	struct lvds_encoder *lvds_encoder;
> +	int ret;
> 
>  	lvds_encoder = devm_kzalloc(dev, sizeof(*lvds_encoder), 
GFP_KERNEL);
>  	if (!lvds_encoder)
>  		return -ENOMEM;
> 
> +	lvds_encoder->input_fmt = MEDIA_BUS_FMT_FIXED;
> +	lvds_encoder->output_fmt = MEDIA_BUS_FMT_FIXED;
> +
>  	lvds_encoder->powerdown_gpio = devm_gpiod_get_optional(dev, 
"powerdown",
>  							       
GPIOD_OUT_HIGH);
>  	if (IS_ERR(lvds_encoder->powerdown_gpio)) {
> @@ -77,6 +158,21 @@ static int lvds_encoder_probe(struct platform_device
> *pdev) return err;
>  	}
> 
> +	port = of_graph_get_port_by_id(dev->of_node, 0);
> +	if (!port) {
> +		dev_dbg(dev, "port 0 not found\n");
> +		return -ENXIO;
> +	}
> +
> +	ret = of_get_data_mapping(port, input_data_mappings,
> +				  ARRAY_SIZE(input_data_mappings),
> +				  &lvds_encoder->input_fmt);
> +	of_node_put(port);
> +	if (ret) {
> +		dev_dbg(dev, "unsupported input data-mapping\n");
> +		return ret;
> +	}
> +
>  	/* Locate the panel DT node. */
>  	port = of_graph_get_port_by_id(dev->of_node, 1);
>  	if (!port) {
> @@ -84,6 +180,15 @@ static int lvds_encoder_probe(struct platform_device
> *pdev) return -ENXIO;
>  	}
> 
> +	ret = of_get_data_mapping(port, output_data_mappings,
> +				  
ARRAY_SIZE(output_data_mappings),
> +				  &lvds_encoder->output_fmt);
> +	if (ret) {
> +		of_node_put(port);
> +		dev_dbg(dev, "unsupported output data-mapping\n");
> +		return ret;
> +	}
> +
>  	endpoint = of_get_child_by_name(port, "endpoint");
>  	of_node_put(port);
>  	if (!endpoint) {
Boris Brezillon Aug. 26, 2019, 6:17 p.m. UTC | #2
On Mon, 26 Aug 2019 18:15:41 +0200
Jernej Škrabec <jernej.skrabec@siol.net> wrote:

> Hi Boris!
> 
> Dne ponedeljek, 26. avgust 2019 ob 17:26:46 CEST je Boris Brezillon 
> napisal(a):
> > Some LVDS encoder might support several input/output bus formats. Add
> > a way to describe the one used on a specific design by adding optional
> > 'data-mapping' properties to the input/output ports.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> > ---
> > Changes in v2:
> > * Make the bus-format negotiation logic more generic
> > ---
> >  .../display/bridge/lvds-transmitter.txt       |  12 ++
> >  drivers/gpu/drm/bridge/lvds-encoder.c         | 105 ++++++++++++++++++
> >  2 files changed, 117 insertions(+)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > index 60091db5dfa5..db51eab216f7 100644
> > --- a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > +++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > @@ -36,6 +36,18 @@ graph bindings specified in
> > Documentation/devicetree/bindings/graph.txt. - Video port 0 for parallel
> > input
> >  - Video port 1 for LVDS output
> > 
> > +Optional port 0 node properties:
> > +
> > +- data-mapping: can be one of the following values
> > +	"rgb-24"
> > +	"rgb-18"
> > +
> > +Optional port 0 node properties:  
> 
> You probably mean port 1 ^^^ ?

Yes.

> 
> Anyway, devicetree doc changes should be separate patch and be send to DT ML 
> (I can't see it in CC).

I'll fix that in v3. In the meantime, I'd really like to have feedback
on patches 1 to 16 as this is where core changes are.

Patch
diff mbox series

diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
index 60091db5dfa5..db51eab216f7 100644
--- a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
+++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
@@ -36,6 +36,18 @@  graph bindings specified in Documentation/devicetree/bindings/graph.txt.
 - Video port 0 for parallel input
 - Video port 1 for LVDS output
 
+Optional port 0 node properties:
+
+- data-mapping: can be one of the following values
+	"rgb-24"
+	"rgb-18"
+
+Optional port 0 node properties:
+
+- data-mapping: can be one of the following values
+	"jeida-18"
+	"jeida-24"
+	"vesa-24"
 
 Example
 -------
diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
index 2ab2c234f26c..38cad7a7d828 100644
--- a/drivers/gpu/drm/bridge/lvds-encoder.c
+++ b/drivers/gpu/drm/bridge/lvds-encoder.c
@@ -6,6 +6,7 @@ 
 #include <linux/gpio/consumer.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/of_graph.h>
 #include <linux/platform_device.h>
 
@@ -16,6 +17,8 @@  struct lvds_encoder {
 	struct drm_bridge bridge;
 	struct drm_bridge *panel_bridge;
 	struct gpio_desc *powerdown_gpio;
+	u32 output_fmt;
+	u32 input_fmt;
 };
 
 static int lvds_encoder_attach(struct drm_bridge *bridge)
@@ -48,12 +51,86 @@  static void lvds_encoder_disable(struct drm_bridge *bridge)
 		gpiod_set_value_cansleep(lvds_encoder->powerdown_gpio, 1);
 }
 
+static void lvds_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+					   struct drm_bridge_state *bridge_state,
+					   struct drm_crtc_state *crtc_state,
+					   struct drm_connector_state *conn_state,
+					   u32 output_fmt,
+					   unsigned int *num_input_fmts,
+					   u32 *input_fmts)
+{
+	struct lvds_encoder *lvds_encoder = container_of(bridge,
+							 struct lvds_encoder,
+							 bridge);
+
+	if (output_fmt == MEDIA_BUS_FMT_FIXED ||
+	    output_fmt == lvds_encoder->output_fmt)
+		*num_input_fmts = 1;
+	else
+		*num_input_fmts = 0;
+
+	if (*num_input_fmts && input_fmts)
+		input_fmts[0] = lvds_encoder->input_fmt;
+}
+
+static int lvds_encoder_atomic_check(struct drm_bridge *bridge,
+				     struct drm_bridge_state *bridge_state,
+				     struct drm_crtc_state *crtc_state,
+				     struct drm_connector_state *conn_state)
+{
+	/* Propagate the bus_flags. */
+	bridge_state->input_bus_cfg.flags = bridge_state->output_bus_cfg.flags;
+	return 0;
+}
+
 static struct drm_bridge_funcs funcs = {
 	.attach = lvds_encoder_attach,
 	.enable = lvds_encoder_enable,
 	.disable = lvds_encoder_disable,
+	.atomic_get_input_bus_fmts = lvds_atomic_get_input_bus_fmts,
+	.atomic_check = lvds_encoder_atomic_check,
 };
 
+struct of_data_mapping {
+	const char *name;
+	u32 id;
+};
+
+static const struct of_data_mapping output_data_mappings[] = {
+	{ "jeida-18", MEDIA_BUS_FMT_RGB666_1X7X3_SPWG },
+	{ "jeida-24", MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA },
+	{ "vesa-24", MEDIA_BUS_FMT_RGB888_1X7X4_SPWG },
+};
+
+static const struct of_data_mapping input_data_mappings[] = {
+	{ "rgb-24", MEDIA_BUS_FMT_RGB888_1X24 },
+	{ "rgb-18", MEDIA_BUS_FMT_RGB666_1X18 },
+};
+
+static int of_get_data_mapping(struct device_node *port,
+			       const struct of_data_mapping *mappings,
+			       unsigned int num_mappings,
+			       u32 *fmt)
+{
+	const char *name = NULL;
+	unsigned int i;
+
+	of_property_read_string(port, "data-mapping", &name);
+	if (!name) {
+		*fmt = MEDIA_BUS_FMT_FIXED;
+		return 0;
+	}
+
+	for (i = 0; i < num_mappings; i++) {
+		if (!strcmp(mappings[i].name, name)) {
+			*fmt = mappings[i].id;
+			return 0;
+		}
+	}
+
+	return -ENOTSUPP;
+}
+
 static int lvds_encoder_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -62,11 +139,15 @@  static int lvds_encoder_probe(struct platform_device *pdev)
 	struct device_node *panel_node;
 	struct drm_panel *panel;
 	struct lvds_encoder *lvds_encoder;
+	int ret;
 
 	lvds_encoder = devm_kzalloc(dev, sizeof(*lvds_encoder), GFP_KERNEL);
 	if (!lvds_encoder)
 		return -ENOMEM;
 
+	lvds_encoder->input_fmt = MEDIA_BUS_FMT_FIXED;
+	lvds_encoder->output_fmt = MEDIA_BUS_FMT_FIXED;
+
 	lvds_encoder->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
 							       GPIOD_OUT_HIGH);
 	if (IS_ERR(lvds_encoder->powerdown_gpio)) {
@@ -77,6 +158,21 @@  static int lvds_encoder_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	port = of_graph_get_port_by_id(dev->of_node, 0);
+	if (!port) {
+		dev_dbg(dev, "port 0 not found\n");
+		return -ENXIO;
+	}
+
+	ret = of_get_data_mapping(port, input_data_mappings,
+				  ARRAY_SIZE(input_data_mappings),
+				  &lvds_encoder->input_fmt);
+	of_node_put(port);
+	if (ret) {
+		dev_dbg(dev, "unsupported input data-mapping\n");
+		return ret;
+	}
+
 	/* Locate the panel DT node. */
 	port = of_graph_get_port_by_id(dev->of_node, 1);
 	if (!port) {
@@ -84,6 +180,15 @@  static int lvds_encoder_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	ret = of_get_data_mapping(port, output_data_mappings,
+				  ARRAY_SIZE(output_data_mappings),
+				  &lvds_encoder->output_fmt);
+	if (ret) {
+		of_node_put(port);
+		dev_dbg(dev, "unsupported output data-mapping\n");
+		return ret;
+	}
+
 	endpoint = of_get_child_by_name(port, "endpoint");
 	of_node_put(port);
 	if (!endpoint) {