On 26/04/2023 12:33, Bryan O'Donoghue wrote:
On Tue, Apr 25, 2023 at 4:40 AM Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> wrote:The QMP combo PHY sits in an of_graph connected between the DisplayPort controller and a USB Type-C connector (or possibly a redriver). The TCPM needs to be able to convey the HPD signal to the DisplayPort controller, but no directly link is provided by DeviceTree so the signal needs to "pass through" the QMP combo phy. Handle this by introducing a drm_bridge which upon initialization finds the next bridge (i.e. the usb-c-connector) and chain this together. This way HPD changes in the connector will propagate to the DisplayPort driver. The connector bridge is resolved lazily, as the TCPM is expected to be able to resolve the typec mux and switch at probe time, so the QMP combo phy will probe before the TCPM. Signed-off-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> --- drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 36 +++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c index 5d6d6ef3944b..84bc08002537 100644 --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c @@ -22,6 +22,8 @@ #include <linux/usb/typec.h> #include <linux/usb/typec_mux.h> +#include <drm/drm_bridge.h> + #include <dt-bindings/phy/phy-qcom-qmp.h> #include "phy-qcom-qmp.h" @@ -1332,6 +1334,8 @@ struct qmp_combo { struct clk_hw dp_link_hw; struct clk_hw dp_pixel_hw; + struct drm_bridge bridge; + struct typec_switch_dev *sw; enum typec_orientation orientation; }; @@ -3196,6 +3200,34 @@ static int qmp_combo_register_clocks(struct qmp_combo *qmp, struct device_node * return devm_add_action_or_reset(qmp->dev, phy_clk_release_provider, dp_np); } +static int qmp_combo_bridge_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct qmp_combo *qmp = container_of(bridge, struct qmp_combo, bridge); + struct drm_bridge *next_bridge; + + if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) + return -EINVAL; + + next_bridge = devm_drm_of_get_bridge(qmp->dev, qmp->dev->of_node, 0, 0); + if (IS_ERR(next_bridge)) + return dev_err_probe(qmp->dev, PTR_ERR(next_bridge), "failed to acquire drm_bridge\n"); + + return drm_bridge_attach(bridge->encoder, next_bridge, bridge, DRM_BRIDGE_ATTACH_NO_CONNECTOR); +} + +static const struct drm_bridge_funcs qmp_combo_bridge_funcs = { + .attach = qmp_combo_bridge_attach, +}; + +static int qmp_combo_dp_register_bridge(struct qmp_combo *qmp) +{ + qmp->bridge.funcs = &qmp_combo_bridge_funcs; + qmp->bridge.of_node = qmp->dev->of_node; + + return devm_drm_bridge_add(qmp->dev, &qmp->bridge); +} + static int qmp_combo_parse_dt_lecacy_dp(struct qmp_combo *qmp, struct device_node *np) { struct device *dev = qmp->dev; @@ -3459,6 +3491,10 @@ static int qmp_combo_probe(struct platform_device *pdev) if (ret) return ret; + ret = qmp_combo_dp_register_bridge(qmp); + if (ret) + return ret;
I think the DRM part should be only built if CONFIG_DRM is enabled, I don't have a strong opinion on this, I think Vinod could help here.
+ /* Check for legacy binding with child nodes. */ usb_np = of_get_child_by_name(dev->of_node, "usb3-phy"); if (usb_np) { -- 2.39.2You need to add some or all of these select DRM_DISPLAY_DP_HELPER select DRM_DISPLAY_HELPER select DRM_DP_AUX_BUS select DRM_KMS_HELPER select DRM_MIPI_DSI select DRM_PANEL /opt/linaro/gcc-linaro-7.5.0-2019.12-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-ld: Unexpected GOT/PLT entries detected! /opt/linaro/gcc-linaro-7.5.0-2019.12-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-ld: Unexpected run-time procedure linkages detected! drivers/phy/qualcomm/phy-qcom-qmp-combo.o: In function `qmp_combo_bridge_attach': phy-qcom-qmp-combo.c:(.text+0xb50): undefined reference to `devm_drm_of_get_bridge' phy-qcom-qmp-combo.c:(.text+0xb6c): undefined reference to `drm_bridge_attach' drivers/phy/qualcomm/phy-qcom-qmp-combo.o: In function `qmp_combo_probe': phy-qcom-qmp-combo.c:(.text+0x13fc): undefined reference to `devm_drm_bridge_add'
I think CONFIG_DRM_PANEL_BRIDGE in addition to CONFIG_DRM. should be enough. With this config added and my drm-bridge hat: Acked-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> Neil
--- bod
