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.brezil...@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:
+
+- 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) {
--
2.21.0
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