Add Embedded USB Debugger (EUD) driver

Register the child node for dwc3 which is the "eud_usb_connector". The eud driver will be able to switch the usb role from device to host and vice versa using the role switch property of dwc3 node.

Signed-off-by Souradeep Chowdhury <[email protected]>

---
 drivers/usb/dwc3/drd.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

drivers/usb/dwc3/drd.c +1 -0

index d7f7683..b4ea55c 100644
@@ -8,6 +8,7 @@
  */
 
 #include <linux/extcon.h>
+#include <linux/of_platform.h>
 #include <linux/of_graph.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>

drivers/usb/dwc3/drd.c +12 -0

+	if (ret) {
+		dev_err(dev, "failed to register usb_connector - %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 void dwc3_otg_init(struct dwc3 *dwc)
 {
 	u32 reg;

@@ -580,6 +602,10 @@ int dwc3_drd_init(struct dwc3 *dwc)
 		ret = dwc3_setup_role_switch(dwc);
 		if (ret < 0)
 			return ret;
+
+		ret = dwc3_register_eud(dwc);
+		if (ret < 0)
+			return ret;
 	} else if (dwc->edev) {
 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,

Signature · 1 line

2.7.4

Quoted 25 lines · Souradeep Chowdhury

Register the child node for dwc3 which is the "eud_usb_connector". The eud driver will be able to switch the usb role from device to host and vice versa using the role switch property of dwc3 node.

Signed-off-by Souradeep Chowdhury <[email protected]>

---
  drivers/usb/dwc3/drd.c | 26 ++++++++++++++++++++++++++
  1 file changed, 26 insertions(+)

drivers/usb/dwc3/drd.c +1 -0

index d7f7683..b4ea55c 100644
@@ -8,6 +8,7 @@
   */
 
  #include <linux/extcon.h>
+#include <linux/of_platform.h>
  #include <linux/of_graph.h>
  #include <linux/platform_device.h>
  #include <linux/property.h>

@@ -164,6 +165,27 @@ static int dwc3_otg_get_irq(struct dwc3 *dwc)
  	return irq;
  }
 

drivers/usb/dwc3/drd.c static int dwc3_otg_get_irq(struct dwc3 *dwc) · line 174

Quoted 7 lines

drivers/usb/dwc3/drd.c +7 -0

+static int dwc3_register_eud(struct dwc3 *dwc)
+{
+	struct device		*dev = dwc->dev;
+	struct device_node	*np = dev->of_node;
+	int                     ret;
+
+	of_get_child_by_name(np, "eud_usb_connector");

Connector nodes are named 'connector' or possibly 'usb-connector'. If you are creating an ABI with the node name, it should be documented. However, it's preferred to use 'compatible' for identifying nodes rather than a node name.

drivers/usb/dwc3/drd.c static int dwc3_otg_get_irq(struct dwc3 *dwc) · line 180

Quoted 6 lines

drivers/usb/dwc3/drd.c +6 -0

+	if (!np) {
+		dev_dbg(dev, "no usb_connector child node specified\n");
+		return 0;
+	}
+
+	ret = of_platform_populate(np, NULL, NULL, dev);

But why is any of this needed. The connector doesn't have a driver (I expect eventually we will) and the EUD device is not a child.

Quoted 26 lines

drivers/usb/dwc3/drd.c +12 -0

+	if (ret) {
+		dev_err(dev, "failed to register usb_connector - %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
  void dwc3_otg_init(struct dwc3 *dwc)
  {
  	u32 reg;

@@ -580,6 +602,10 @@ int dwc3_drd_init(struct dwc3 *dwc)
  		ret = dwc3_setup_role_switch(dwc);
  		if (ret < 0)
  			return ret;
+
+		ret = dwc3_register_eud(dwc);
+		if (ret < 0)
+			return ret;
  	} else if (dwc->edev) {
  		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
  		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,

Signature · 1 line

2.7.4

Add support for control peripheral of EUD (Embedded USB Debugger) to listen to events such as USB attach/detach, pet EUD to indicate software is functional.Reusing the platform device kobj, sysfs entry 'enable' is created to enable or disable EUD.

To enable the eud the following needs to be done
echo 1 > /sys/bus/platform/.../enable

To disable eud, following is the command
echo 0 > /sys/bus/platform/.../enable

Signed-off-by Souradeep Chowdhury <[email protected]>

---
 Documentation/ABI/testing/sysfs-driver-eud |   9 +
 drivers/soc/qcom/Kconfig                   |  10 ++
 drivers/soc/qcom/Makefile                  |   1 +
 drivers/soc/qcom/qcom_eud.c                | 268 +++++++++++++++++++++++++++++
 4 files changed, 288 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-eud
 create mode 100644 drivers/soc/qcom/qcom_eud.c

Documentation/ABI/testing/sysfs-driver-eud new file +0 -0

new file mode 100644
index 0000000..eaf2e82

Documentation/ABI/testing/sysfs-driver-eud new file +7 -0

+Contact:        Souradeep Chowdhury <[email protected]>
+Description:
+		The Enable/Disable sysfs interface for Embedded
+		USB Debugger(EUD). This enables and disables the
+		EUD based on a 1 or a 0 value. By enabling EUD,
+		the user is able to activate the mini-usb hub of
+		EUD for debug and trace capabilities.

drivers/soc/qcom/Kconfig +10 -0

index 79b568f..a4db41b 100644
@@ -42,6 +42,16 @@ config QCOM_CPR
 	  To compile this driver as a module, choose M here: the module will
 	  be called qcom-cpr
 
+config QCOM_EUD
+	tristate "QCOM Embedded USB Debugger(EUD) Driver"
+	select USB_ROLE_SWITCH
+	help
+	  This module enables support for Qualcomm Technologies, Inc.
+	  Embedded USB Debugger (EUD). The EUD is a control peripheral
+	  which reports VBUS attach/detach events and has USB-based
+	  debug and trace capabilities. On selecting m, the module name
+	  that is built is qcom_eud.ko
+
 config QCOM_GENI_SE
 	tristate "QCOM GENI Serial Engine Driver"
 	depends on ARCH_QCOM || COMPILE_TEST

drivers/soc/qcom/Makefile +1 -0

index ad675a6..3331a40 100644
@@ -4,6 +4,7 @@ obj-$(CONFIG_QCOM_AOSS_QMP) +=	qcom_aoss.o
 obj-$(CONFIG_QCOM_GENI_SE) +=	qcom-geni-se.o
 obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o
 obj-$(CONFIG_QCOM_CPR)		+= cpr.o
+obj-$(CONFIG_QCOM_EUD)          += qcom_eud.o
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
 obj-$(CONFIG_QCOM_OCMEM)	+= ocmem.o

drivers/soc/qcom/qcom_eud.c new file +96 -0

new file mode 100644
index 0000000..613ac41
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/usb/role.h>
+
+#define EUD_REG_INT1_EN_MASK	0x0024
+#define EUD_REG_INT_STATUS_1	0x0044
+#define EUD_REG_CTL_OUT_1	0x0074
+#define EUD_REG_VBUS_INT_CLR	0x0080
+#define EUD_REG_CSR_EUD_EN	0x1014
+#define EUD_REG_SW_ATTACH_DET	0x1018
+#define EUD_REG_EUD_EN2         0x0000
+
+#define EUD_ENABLE		BIT(0)
+#define EUD_INT_PET_EUD		BIT(0)
+#define EUD_INT_VBUS		BIT(2)
+#define EUD_INT_SAFE_MODE	BIT(4)
+#define EUD_INT_ALL		(EUD_INT_VBUS|EUD_INT_SAFE_MODE)
+
+struct eud_chip {
+	struct device			*dev;
+	struct usb_role_switch		*role_sw;
+	void __iomem			*eud_reg_base;
+	void __iomem			*eud_mode_mgr2_phys_base;
+	unsigned int			int_status;
+	int				eud_irq;
+	bool				enable;
+	bool				usb_attach;
+
+};
+
+static int enable_eud(struct eud_chip *priv)
+{
+	writel(EUD_ENABLE, priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
+	writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE,
+			priv->eud_reg_base + EUD_REG_INT1_EN_MASK);
+	writel(1, priv->eud_mode_mgr2_phys_base + EUD_REG_EUD_EN2);
+
+	return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE);
+}
+
+static void disable_eud(struct eud_chip *priv)
+{
+	writel(0, priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
+	writel(0, priv->eud_mode_mgr2_phys_base + EUD_REG_EUD_EN2);
+}
+
+static ssize_t enable_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", chip->enable);
+}
+
+static ssize_t enable_store(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+	bool enable;
+	int ret;
+
+	if (kstrtobool(buf, &enable))
+		return -EINVAL;
+
+	if (enable) {
+		ret = enable_eud(chip);
+		if (!ret)
+			chip->enable = enable;
+	} else {
+		disable_eud(chip);
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(enable);
+
+static struct attribute *eud_attrs[] = {
+	&dev_attr_enable.attr,
+	NULL,

Quoted 21 lines · Souradeep Chowdhury

Add support for control peripheral of EUD (Embedded USB Debugger) to listen to events such as USB attach/detach, pet EUD to indicate software is functional.Reusing the platform device kobj, sysfs entry 'enable' is created to enable or disable EUD.

To enable the eud the following needs to be done
echo 1 > /sys/bus/platform/.../enable

To disable eud, following is the command
echo 0 > /sys/bus/platform/.../enable

Signed-off-by Souradeep Chowdhury <[email protected]>

---
  Documentation/ABI/testing/sysfs-driver-eud |   9 +
  drivers/soc/qcom/Kconfig                   |  10 ++
  drivers/soc/qcom/Makefile                  |   1 +
  drivers/soc/qcom/qcom_eud.c                | 268 +++++++++++++++++++++++++++++
  4 files changed, 288 insertions(+)

create mode 100644 Documentation/ABI/testing/sysfs-driver-eud create mode 100644 drivers/soc/qcom/qcom_eud.c

Documentation/ABI/testing/sysfs-driver-eud line 2

Quoted 8 lines

Documentation/ABI/testing/sysfs-driver-eud new file +2 -0

new file mode 100644
index 0000000..eaf2e82
@@ -0,0 +1,9 @@
+What:		/sys/bus/platform/drivers/eud/.../enable
+Date:           October 2021

You sent this patch in December 2021 :(

Quoted 146 lines

Documentation/ABI/testing/sysfs-driver-eud new file +7 -0

+Contact:        Souradeep Chowdhury <[email protected]>
+Description:
+		The Enable/Disable sysfs interface for Embedded
+		USB Debugger(EUD). This enables and disables the
+		EUD based on a 1 or a 0 value. By enabling EUD,
+		the user is able to activate the mini-usb hub of
+		EUD for debug and trace capabilities.

drivers/soc/qcom/Kconfig +10 -0

index 79b568f..a4db41b 100644
@@ -42,6 +42,16 @@ config QCOM_CPR
  	  To compile this driver as a module, choose M here: the module will
  	  be called qcom-cpr
 
+config QCOM_EUD
+	tristate "QCOM Embedded USB Debugger(EUD) Driver"
+	select USB_ROLE_SWITCH
+	help
+	  This module enables support for Qualcomm Technologies, Inc.
+	  Embedded USB Debugger (EUD). The EUD is a control peripheral
+	  which reports VBUS attach/detach events and has USB-based
+	  debug and trace capabilities. On selecting m, the module name
+	  that is built is qcom_eud.ko
+
  config QCOM_GENI_SE
  	tristate "QCOM GENI Serial Engine Driver"
  	depends on ARCH_QCOM || COMPILE_TEST

drivers/soc/qcom/Makefile +1 -0

index ad675a6..3331a40 100644
@@ -4,6 +4,7 @@ obj-$(CONFIG_QCOM_AOSS_QMP) +=	qcom_aoss.o
  obj-$(CONFIG_QCOM_GENI_SE) +=	qcom-geni-se.o
  obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o
  obj-$(CONFIG_QCOM_CPR)		+= cpr.o
+obj-$(CONFIG_QCOM_EUD)          += qcom_eud.o
  obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
  obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
  obj-$(CONFIG_QCOM_OCMEM)	+= ocmem.o

drivers/soc/qcom/qcom_eud.c new file +99 -0

new file mode 100644
index 0000000..613ac41
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/usb/role.h>
+
+#define EUD_REG_INT1_EN_MASK	0x0024
+#define EUD_REG_INT_STATUS_1	0x0044
+#define EUD_REG_CTL_OUT_1	0x0074
+#define EUD_REG_VBUS_INT_CLR	0x0080
+#define EUD_REG_CSR_EUD_EN	0x1014
+#define EUD_REG_SW_ATTACH_DET	0x1018
+#define EUD_REG_EUD_EN2         0x0000
+
+#define EUD_ENABLE		BIT(0)
+#define EUD_INT_PET_EUD		BIT(0)
+#define EUD_INT_VBUS		BIT(2)
+#define EUD_INT_SAFE_MODE	BIT(4)
+#define EUD_INT_ALL		(EUD_INT_VBUS|EUD_INT_SAFE_MODE)
+
+struct eud_chip {
+	struct device			*dev;
+	struct usb_role_switch		*role_sw;
+	void __iomem			*eud_reg_base;
+	void __iomem			*eud_mode_mgr2_phys_base;
+	unsigned int			int_status;
+	int				eud_irq;
+	bool				enable;
+	bool				usb_attach;
+
+};
+
+static int enable_eud(struct eud_chip *priv)
+{
+	writel(EUD_ENABLE, priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
+	writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE,
+			priv->eud_reg_base + EUD_REG_INT1_EN_MASK);
+	writel(1, priv->eud_mode_mgr2_phys_base + EUD_REG_EUD_EN2);
+
+	return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE);
+}
+
+static void disable_eud(struct eud_chip *priv)
+{
+	writel(0, priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
+	writel(0, priv->eud_mode_mgr2_phys_base + EUD_REG_EUD_EN2);
+}
+
+static ssize_t enable_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", chip->enable);
+}
+
+static ssize_t enable_store(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+	bool enable;
+	int ret;
+
+	if (kstrtobool(buf, &enable))
+		return -EINVAL;
+
+	if (enable) {
+		ret = enable_eud(chip);
+		if (!ret)
+			chip->enable = enable;
+	} else {
+		disable_eud(chip);
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(enable);
+
+static struct attribute *eud_attrs[] = {
+	&dev_attr_enable.attr,
+	NULL,
+};
+
+static struct attribute_group attr_group = {

drivers/soc/qcom/qcom_eud.c line 106

Quoted 7 lines

drivers/soc/qcom/qcom_eud.c new file +7 -0

+	.attrs = eud_attrs,
+};
+
+static const struct attribute_group *attr_groups[] = {
+	&attr_group,
+	NULL
+};

ATTRIBUTE_GROUPS()?

thanks,

greg k-h

Add the Embedded USB Debugger(EUD) device tree node. The node contains EUD base register region and EUD mode manager register regions along with the interrupt entry. Also add the connector to EUD which is mapped as the child of dwc3. The connector is attached to EUD via port. Also add the role-switch property to dwc3 node.

Signed-off-by Souradeep Chowdhury <[email protected]>

---
 arch/arm64/boot/dts/qcom/sc7280.dtsi | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

arch/arm64/boot/dts/qcom/sc7280.dtsi +0 -0

index 53a21d0..2d14e5c 100644

arch/arm64/boot/dts/qcom/sc7280.dtsi +19 -0

+							usb2_role_switch: endpoint {
+								remote-endpoint = <&eud_ep>;
+							};
+						};
+					};
+				};
 			};
 		};
 

@@ -1339,6 +1351,19 @@
 			interrupts = <GIC_SPI 582 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
+		eud:  eud@88e0000 {
+			compatible = "qcom,sc7280-eud","qcom,eud";
+			reg = <0 0x88e0000 0 0x2000>,
+			      <0 0x88e2000 0 0x1000>;
+			interrupt-parent = <&pdc>;
+			interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
+			port {
+				eud_ep: endpoint {
+					remote-endpoint = <&usb2_role_switch>;
+				};
+			};
+		};
+
 		nsp_noc: interconnect@a0c0000 {
 			reg = <0 0x0a0c0000 0 0x10000>;
 			compatible = "qcom,sc7280-nsp-noc";

Signature · 1 line

2.7.4

Quoted 12 lines · Souradeep Chowdhury

Add the Embedded USB Debugger(EUD) device tree node. The node contains EUD base register region and EUD mode manager register regions along with the interrupt entry. Also add the connector to EUD which is mapped as the child of dwc3. The connector is attached to EUD via port. Also add the role-switch property to dwc3 node.

Signed-off-by Souradeep Chowdhury <[email protected]>

---
  arch/arm64/boot/dts/qcom/sc7280.dtsi | 25 +++++++++++++++++++++++++
  1 file changed, 25 insertions(+)

Quoted 5 lines

arch/arm64/boot/dts/qcom/sc7280.dtsi +0 -0

index 53a21d0..2d14e5c 100644

arch/arm64/boot/dts/qcom/sc7280.dtsi line 1323

Quoted 9 lines

arch/arm64/boot/dts/qcom/sc7280.dtsi +6 -0

@@ -1315,6 +1315,18 @@
  				phys = <&usb_2_hsphy>;
  				phy-names = "usb2-phy";
  				maximum-speed = "high-speed";
+				usb-role-switch;
+				usb_con: eud_usb_connector {
+					compatible = "qcom,usb-connector-eud",
+						     "usb-c-connector";
+					ports {
+						port@0 {

It is already defined that port@0 of the connector is USB HS data. Is that the case here? What about the SS lines?

From the description, it sounds like the data path is DWC3 -> EUD ->
connector. The DT structure doesn't match that.

Quoted 34 lines

arch/arm64/boot/dts/qcom/sc7280.dtsi +19 -0

+							usb2_role_switch: endpoint {
+								remote-endpoint = <&eud_ep>;
+							};
+						};
+					};
+				};
  			};
  		};
 

@@ -1339,6 +1351,19 @@
  			interrupts = <GIC_SPI 582 IRQ_TYPE_LEVEL_HIGH>;
  		};
 
+		eud:  eud@88e0000 {
+			compatible = "qcom,sc7280-eud","qcom,eud";
+			reg = <0 0x88e0000 0 0x2000>,
+			      <0 0x88e2000 0 0x1000>;
+			interrupt-parent = <&pdc>;
+			interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
+			port {
+				eud_ep: endpoint {
+					remote-endpoint = <&usb2_role_switch>;
+				};
+			};
+		};
+
  		nsp_noc: interconnect@a0c0000 {
  			reg = <0 0x0a0c0000 0 0x10000>;
  			compatible = "qcom,sc7280-nsp-noc";

Signature · 1 line

2.7.4