[PATCH] drm/bridge/synopsys: dsi: use mipi_dsi_device to find panel or bridge

[Yannick FERTRE]

Hello Heiko,
I test with success your patch on a board stm32mp1 with a panel raydium 
rm68200.
I need more time to test with a HDMI bridge  like ad7533.

Best regards

Yannick Fertré



On 12/17/19 11:41 PM, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner at theobroma-systems.com>
>
> Right now the dsi driver uses drm_of_find_panel_or_bridge() to find a
> connected panel or bridge. But this requires an of-graph connection
> between the dsi-host and dsi-device, where normal bindings for regular
> panels just expect the dsi device to be a subnode of the actual dsi host
> not requiring ports.
>
> drm_of_find_panel_or_bridge is used to find panel/bridge under the actual
> device-node of the dsi device, but as this happens in the dsi_host_attach
> callback we already have the dsi-device and its device-node available and
> therefore can just call the relevant panel+bridge functions ourself,
> making it work as well in setups without port-connections.
>
> Tested on a Rockchip px30 single-dsi with panels form Leadtek and Xinpeng
> as well on Gru-Scarlet (rk3399) with dual-dsi (and thus port-connections
> to both dsi controllers) connected to the Innotek display variant.
>
> changes in v2:
> - rework commit message, rereading what I had written was just too
>    cringe-worthy ;-)
>
> Signed-off-by: Heiko Stuebner <heiko.stuebner at theobroma-systems.com>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 17 ++++++++++-------
>   1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 981d532cdd59..4b4961e7c680 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -26,6 +26,7 @@
>   #include <drm/drm_mipi_dsi.h>
>   #include <drm/drm_modes.h>
>   #include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
>   #include <drm/drm_print.h>
>   #include <drm/drm_probe_helper.h>
>   
> @@ -310,16 +311,16 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
>   	dsi->format = device->format;
>   	dsi->mode_flags = device->mode_flags;
>   
> -	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
> -					  &panel, &bridge);
> -	if (ret)
> -		return ret;
> -
> -	if (panel) {
> +	panel = of_drm_find_panel(device->dev.of_node);
> +	if (!IS_ERR(panel)) {
>   		bridge = drm_panel_bridge_add_typed(panel,
>   						    DRM_MODE_CONNECTOR_DSI);
>   		if (IS_ERR(bridge))
>   			return PTR_ERR(bridge);
> +	} else {
> +		bridge = of_drm_find_bridge(device->dev.of_node);
> +		if (!bridge)
> +			return -EPROBE_DEFER;
>   	}
>   
>   	dsi->panel_bridge = bridge;
> @@ -340,6 +341,7 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
>   {
>   	struct dw_mipi_dsi *dsi = host_to_dsi(host);
>   	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
> +	struct drm_bridge *bridge;
>   	int ret;
>   
>   	if (pdata->host_ops && pdata->host_ops->detach) {
> @@ -348,7 +350,8 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
>   			return ret;
>   	}
>   
> -	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
> +	bridge = of_drm_find_bridge(device->dev.of_node);
> +	drm_panel_bridge_remove(bridge);
>   
>   	drm_bridge_remove(&dsi->bridge);
>