Commit 1904c3f5 authored by Bjorn Andersson's avatar Bjorn Andersson Committed by Vinod Koul
Browse files

phy: qcom-qmp-combo: Introduce drm_bridge 



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.

Acked-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Tested-by: default avatarBryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: default avatarBryan O'Donoghue <bryan.odonoghue@linaro.org>
Tested-by: default avatarAbel Vesa <abel.vesa@linaro.org>
Tested-by: default avatarSteev Klimaszewski <steev@kali.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on HDK8450
Tested-by: Johan Hovold <johan+linaro@kernel.org>	# X13s
Reviewed-by: default avatarJohan Hovold <johan+linaro@kernel.org>
Signed-off-by: default avatarBjorn Andersson <quic_bjorande@quicinc.com>
Link: https://lore.kernel.org/r/20230515032743.400170-7-quic_bjorande@quicinc.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 2851117f

drivers/phy/qualcomm/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -60,8 +60,10 @@ config PHY_QCOM_QMP_COMBO 
	tristate "Qualcomm QMP Combo PHY Driver"

	default PHY_QCOM_QMP

	depends on TYPEC || TYPEC=n

	depends on DRM || DRM=n

	select GENERIC_PHY

	select MFD_SYSCON

	select DRM_PANEL_BRIDGE if DRM

	help

	  Enable this to support the QMP Combo PHY transceiver that is used

	  with USB3 and DisplayPort controllers on Qualcomm chips.

drivers/phy/qualcomm/phy-qcom-qmp-combo.c

+46 −0
Original line number Diff line number Diff line
@@ -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;

};
@@ -3274,6 +3278,44 @@ static int qmp_combo_typec_switch_register(struct qmp_combo *qmp) 
}

#endif



#if IS_ENABLED(CONFIG_DRM)

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)) {

		dev_err(qmp->dev, "failed to acquire drm_bridge: %pe\n", next_bridge);

		return PTR_ERR(next_bridge);

	}



	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);

}

#else

static int qmp_combo_dp_register_bridge(struct qmp_combo *qmp)

{

	return 0;

}

#endif



static int qmp_combo_parse_dt_lecacy_dp(struct qmp_combo *qmp, struct device_node *np)

{

	struct device *dev = qmp->dev;
@@ -3478,6 +3520,10 @@ static int qmp_combo_probe(struct platform_device *pdev) 
	if (ret)

		return ret;



	ret = qmp_combo_dp_register_bridge(qmp);

	if (ret)

		return ret;



	/* Check for legacy binding with child nodes. */

	usb_np = of_get_child_by_name(dev->of_node, "usb3-phy");

	if (usb_np) {