[PATCH v2 18/21] drm/bridge: lvds-encoder: Implement basic bus format negotiation
Jernej Škrabec
jernej.skrabec at siol.net
Mon Aug 26 16:15:41 UTC 2019
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 at 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) {
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