Hi Boris,
Thank you for the patch.
On Tue, Jan 28, 2020 at 02:55:10PM +0100, Boris Brezillon wrote:
> Some DPI -> LVDS encoders might support several input bus width. Add a
> DT property to describe the bus width used on a specific design.
>
> v10:
> * Add changelog to the commit message
>
> v8 -> v9:
> * No changes
>
> v7:
> * Fix a use-after-release problem
> * Get rid of the data-mapping parsing
> * Use kmalloc instead of kcalloc.
>
> v4 -> v6:
> * Not part of the series
>
> v3:
> * Use bus-width for the rgb24/rgb18 distinction
> * Adjust code to match core changes
> * Get rid of of_get_data_mapping()
> * Don't implement ->atomic_check() (the core now takes care of bus
> flags propagation)
>
> v2:
> * Make the bus-format negotiation logic more generic
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/lvds-codec.c | 64 ++++++++++++++++++++++++++---
> 1 file changed, 58 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> index 5f04cc11227e..f4fd8472c335 100644
> --- a/drivers/gpu/drm/bridge/lvds-codec.c
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -11,6 +11,7 @@
> #include <linux/of_graph.h>
> #include <linux/platform_device.h>
>
> +#include <drm/drm_atomic_helper.h>
> #include <drm/drm_bridge.h>
> #include <drm/drm_panel.h>
>
> @@ -19,6 +20,7 @@ struct lvds_codec {
> struct drm_bridge *panel_bridge;
> struct gpio_desc *powerdown_gpio;
> u32 connector_type;
> + u32 input_fmt;
> };
>
> static int lvds_codec_attach(struct drm_bridge *bridge)
> @@ -48,18 +50,47 @@ static void lvds_codec_disable(struct drm_bridge *bridge)
> gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
> }
>
> +static u32 *
> +lvds_codec_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)
> +{
> + struct lvds_codec *lvds_codec = container_of(bridge,
> + struct lvds_codec, bridge);
> + u32 *input_fmts;
> +
> + input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
> + if (!input_fmts) {
> + *num_input_fmts = 0;
> + return NULL;
> + }
> +
> + *num_input_fmts = 1;
> + input_fmts[0] = lvds_codec->input_fmt;
> + return input_fmts;
> +}
> +
> static struct drm_bridge_funcs funcs = {
> .attach = lvds_codec_attach,
> .enable = lvds_codec_enable,
> .disable = lvds_codec_disable,
> + .atomic_reset = drm_atomic_helper_bridge_reset,
> + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> + .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
> };
>
> static int lvds_codec_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> - struct device_node *panel_node;
> + struct device_node *np;
> struct drm_panel *panel;
> struct lvds_codec *lvds_codec;
> + u32 input_bus_width;
> + int err;
>
> lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
> if (!lvds_codec)
> @@ -69,22 +100,43 @@ static int lvds_codec_probe(struct platform_device *pdev)
> lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
> GPIOD_OUT_HIGH);
> if (IS_ERR(lvds_codec->powerdown_gpio)) {
> - int err = PTR_ERR(lvds_codec->powerdown_gpio);
> + err = PTR_ERR(lvds_codec->powerdown_gpio);
>
> if (err != -EPROBE_DEFER)
> dev_err(dev, "powerdown GPIO failure: %d\n", err);
> return err;
> }
>
> + np = of_graph_get_port_by_id(dev->of_node, 0);
> + if (!np) {
> + dev_dbg(dev, "port 0 not found\n");
> + return -ENXIO;
> + }
> +
> + err = of_property_read_u32(np, "bus-width", &input_bus_width);
> + of_node_put(np);
> +
> + if (err) {
> + lvds_codec->input_fmt = MEDIA_BUS_FMT_FIXED;
> + } else if (input_bus_width == 18) {
> + lvds_codec->input_fmt = MEDIA_BUS_FMT_RGB666_1X18;
> + } else if (input_bus_width == 24) {
> + lvds_codec->input_fmt = MEDIA_BUS_FMT_RGB888_1X24;
> + } else {
> + dev_dbg(dev, "unsupported bus-width value %u on port 0\n",
> + input_bus_width);
> + return -ENOTSUPP;
ENOTSUPP is "Operation not supported", I'd go for -EINVAL.
> + }
Doesn't this apply to LVDS encoders only ? For LVDS decoders I don't
think we want to report an RGB format on the input.
> +
> /* Locate the panel DT node. */
> - panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
> - if (!panel_node) {
> + np = of_graph_get_remote_node(dev->of_node, 1, 0);
> + if (!np) {
> dev_dbg(dev, "panel DT node not found\n");
> return -ENXIO;
> }
>
> - panel = of_drm_find_panel(panel_node);
> - of_node_put(panel_node);
> + panel = of_drm_find_panel(np);
> + of_node_put(np);
> if (IS_ERR(panel)) {
> dev_dbg(dev, "panel not found, deferring probe\n");
> return PTR_ERR(panel);
--
Regards,
Laurent Pinchart
