Add Embedded USB Debugger (EUD) driver

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 |   7 +
 drivers/usb/common/Kconfig                 |   9 +
 drivers/usb/common/Makefile                |   1 +
 drivers/usb/common/qcom_eud.c              | 256 +++++++++++++++++++++++++++++
 4 files changed, 273 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-eud
 create mode 100644 drivers/usb/common/qcom_eud.c

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

new file mode 100644
index 0000000..14a02da

drivers/usb/common/Kconfig +0 -0

index 5e8a04e..669b3fe 100644
@@ -50,3 +50,12 @@ config USB_CONN_GPIO
 
 	  To compile the driver as a module, choose M here: the module will

drivers/usb/common/Makefile +1 -0

index 8ac4d21..eb66045 100644
@@ -11,3 +11,4 @@ usb-common-$(CONFIG_USB_LED_TRIG) += led.o
 obj-$(CONFIG_USB_CONN_GPIO)	+= usb-conn-gpio.o
 obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o
 obj-$(CONFIG_USB_ULPI_BUS)	+= ulpi.o
+obj-$(CONFIG_USB_QCOM_EUD)      += qcom_eud.o

drivers/usb/common/qcom_eud.c new file +30 -0

new file mode 100644
index 0000000..7a92fff
@@ -0,0 +1,256 @@
+// 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)

drivers/usb/common/qcom_eud.c new file +14 -0

+};
+
+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)
+{

drivers/usb/common/qcom_eud.c new file +10 -0

+
+	if (enable == 1) {
+		ret = enable_eud(chip);
+		if (!ret)
+			chip->enable = enable;
+	} else if (enable == 0) {
+		disable_eud(chip);
+	} else {
+		return -EINVAL;
+	}

drivers/usb/common/qcom_eud.c new file +111 -0

+
+static void usb_attach_detach(struct eud_chip *chip)
+{
+	u32 reg;
+
+	/* read ctl_out_1[4] to find USB attach or detach event */
+	reg = readl(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
+	if (reg & EUD_INT_SAFE_MODE)
+		chip->usb_attach = true;
+	else
+		chip->usb_attach = false;
+
+	/* set and clear vbus_int_clr[0] to clear interrupt */
+	writel(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+	writel(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+}
+
+static void pet_eud(struct eud_chip *chip)
+{
+	u32 reg;
+	int ret;
+
+	/* read sw_attach_det[0] to find attach/detach event */
+	reg = readl(chip->eud_reg_base +  EUD_REG_SW_ATTACH_DET);
+	if (reg & EUD_INT_PET_EUD) {
+		/* Detach & Attach pet for EUD */
+		writel(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
+		/* Delay to make sure detach pet is done before attach pet */
+		ret = readl_poll_timeout(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET,
+					reg, (reg == 0), 1, 100);
+		if (ret) {
+			dev_err(chip->dev, "Detach pet failed\n");
+			return;
+		}
+
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	} else {
+		/* Attach pet for EUD */
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	}
+}
+
+static irqreturn_t handle_eud_irq(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	u32 reg;
+
+	/* read status register and find out which interrupt triggered */
+	reg = readl(chip->eud_reg_base +  EUD_REG_INT_STATUS_1);
+	switch (reg & EUD_INT_ALL) {
+	case EUD_INT_VBUS:
+		chip->int_status = EUD_INT_VBUS;
+		usb_attach_detach(chip);
+		return IRQ_WAKE_THREAD;
+	case EUD_INT_SAFE_MODE:
+		pet_eud(chip);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t handle_eud_irq_thread(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	int ret;
+
+	if (chip->int_status == EUD_INT_VBUS) {
+		if (chip->usb_attach)
+			ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE);
+		else
+			ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST);
+		if (ret)
+			dev_err(chip->dev, "failed to set role switch\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int eud_probe(struct platform_device *pdev)
+{
+	struct eud_chip *chip;
+	int ret;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &pdev->dev;
+
+	chip->role_sw = usb_role_switch_get(chip->dev);
+	if (IS_ERR(chip->role_sw)) {
+		if (PTR_ERR(chip->role_sw) != -EPROBE_DEFER)
+			dev_err(chip->dev, "failed to get role switch\n");
+
+		return PTR_ERR(chip->role_sw);
+	}
+
+	chip->eud_reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(chip->eud_reg_base))
+		return PTR_ERR(chip->eud_reg_base);
+
+	chip->eud_mode_mgr2_phys_base = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(chip->eud_mode_mgr2_phys_base))
+		return PTR_ERR(chip->eud_mode_mgr2_phys_base);
+
+	chip->eud_irq = platform_get_irq(pdev, 0);
+	ret = devm_request_threaded_irq(&pdev->dev, chip->eud_irq, handle_eud_irq,

Adding the address size,cell size and ranges property for EUD connector. Adding the connector property for EUD which is child of dwc3 node.

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

---
 Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Documentation/devicetree/bindings/usb/snps,dwc3.yaml +15 -0

index 078fb78..3e71205 100644
@@ -36,6 +36,14 @@ properties:
         - const: synopsys,dwc3
           deprecated: true
 
+  "#address-cells":
+    enum: [ 1, 2 ]
+
+  "#size-cells":
+    enum: [ 1, 2 ]
+
+  ranges: true
+
   interrupts:
     description:
       It's either a single common DWC3 interrupt (dwc_usb3) or individual

@@ -318,6 +326,13 @@ properties:
     items:
       enum: [1, 4, 8, 16, 32, 64, 128, 256]
 
+  connector:
+    type: object
+    $ref: /connector/usb-connector.yaml#
+    description:
+      Connector for dual role switch, especially for "eud-usb-c-connector"
+
+
 unevaluatedProperties: false
 
 required:

Signature · 2 lines

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Added the property for EUD(Embedded USB Debug) connector.Added the "reg" and "interrupts" property which is needed for EUD.

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

---
 .../devicetree/bindings/connector/usb-connector.yaml      | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Documentation/devicetree/bindings/connector/usb-connector.yaml +0 -0

index 7eb8659..908129f 100644
@@ -30,6 +30,21 @@ properties:
           - const: samsung,usb-connector-11pin
           - const: usb-b-connector
 

Documentation/devicetree/bindings/connector/usb-connector.yaml +5 -0

+
+  interrupts:
+    description:
+      EUD interrupt
+
   label:
     description: Symbolic name for the connector.
 

Signature · 2 lines

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

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 |   7 +
 drivers/usb/common/Kconfig                 |   9 +
 drivers/usb/common/Makefile                |   1 +
 drivers/usb/common/qcom_eud.c              | 256 +++++++++++++++++++++++++++++
 4 files changed, 273 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-eud
 create mode 100644 drivers/usb/common/qcom_eud.c

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

new file mode 100644
index 0000000..14a02da
@@ -0,0 +1,7 @@
+What:		/sys/bus/platform/.../enable
+Date:           October 2021
+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.

drivers/usb/common/Kconfig +9 -0

index 5e8a04e..669b3fe 100644
@@ -50,3 +50,12 @@ config USB_CONN_GPIO
 
 	  To compile the driver as a module, choose M here: the module will
 	  be called usb-conn-gpio.ko
+
+config USB_QCOM_EUD
+	tristate "USB 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.

drivers/usb/common/Makefile +1 -0

index 8ac4d21..eb66045 100644
@@ -11,3 +11,4 @@ usb-common-$(CONFIG_USB_LED_TRIG) += led.o
 obj-$(CONFIG_USB_CONN_GPIO)	+= usb-conn-gpio.o
 obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o
 obj-$(CONFIG_USB_ULPI_BUS)	+= ulpi.o
+obj-$(CONFIG_USB_QCOM_EUD)      += qcom_eud.o

drivers/usb/common/qcom_eud.c new file +164 -0

new file mode 100644
index 0000000..7a92fff
@@ -0,0 +1,256 @@
+// 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				enable;
+	int				eud_irq;
+	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 sprintf(buf, "%d", 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);
+	unsigned long enable;
+	int ret;
+
+	if (kstrtoul(buf, 16, &enable))
+		return -EINVAL;
+
+	if (enable == 1) {
+		ret = enable_eud(chip);
+		if (!ret)
+			chip->enable = enable;
+	} else if (enable == 0) {
+		disable_eud(chip);
+	} else {
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(enable);
+
+static const struct device_attribute *eud_attrs[] = {
+	&dev_attr_enable,
+	NULL,
+};
+
+static void usb_attach_detach(struct eud_chip *chip)
+{
+	u32 reg;
+
+	/* read ctl_out_1[4] to find USB attach or detach event */
+	reg = readl(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
+	if (reg & EUD_INT_SAFE_MODE)
+		chip->usb_attach = true;
+	else
+		chip->usb_attach = false;
+
+	/* set and clear vbus_int_clr[0] to clear interrupt */
+	writel(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+	writel(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+}
+
+static void pet_eud(struct eud_chip *chip)
+{
+	u32 reg;
+	int ret;
+
+	/* read sw_attach_det[0] to find attach/detach event */
+	reg = readl(chip->eud_reg_base +  EUD_REG_SW_ATTACH_DET);
+	if (reg & EUD_INT_PET_EUD) {
+		/* Detach & Attach pet for EUD */
+		writel(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
+		/* Delay to make sure detach pet is done before attach pet */
+		ret = readl_poll_timeout(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET,
+					reg, (reg == 0), 1, 100);
+		if (ret) {
+			dev_err(chip->dev, "Detach pet failed\n");
+			return;
+		}
+
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	} else {
+		/* Attach pet for EUD */
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	}
+}
+
+static irqreturn_t handle_eud_irq(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	u32 reg;
+
+	/* read status register and find out which interrupt triggered */
+	reg = readl(chip->eud_reg_base +  EUD_REG_INT_STATUS_1);
+	switch (reg & EUD_INT_ALL) {
+	case EUD_INT_VBUS:
+		chip->int_status = EUD_INT_VBUS;
+		usb_attach_detach(chip);
+		return IRQ_WAKE_THREAD;
+	case EUD_INT_SAFE_MODE:
+		pet_eud(chip);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+	return IRQ_HANDLED;
+}
+

drivers/usb/common/qcom_eud.c new file +14 -0

+		if (ret)
+			dev_err(chip->dev, "failed to set role switch\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int eud_probe(struct platform_device *pdev)
+{
+	struct eud_chip *chip;
+	int ret;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)

drivers/usb/common/qcom_eud.c new file +4 -0

+	}
+
+	chip->eud_reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(chip->eud_reg_base))

drivers/usb/common/qcom_eud.c new file +44 -1

+		return ret;
+
+	device_init_wakeup(&pdev->dev, true);
+	enable_irq_wake(chip->eud_irq);
+
+	platform_set_drvdata(pdev, chip);
+
+	ret = device_create_file(&pdev->dev, eud_attrs[0]);
+
+	return ret;
+}
+
+static int eud_remove(struct platform_device *pdev)
+{
+	struct eud_chip *chip = platform_get_drvdata(pdev);
+
+	if (chip->enable)
+		disable_eud(chip);
+
+	device_remove_file(&pdev->dev, eud_attrs[0]);
+	device_init_wakeup(&pdev->dev, false);
+	disable_irq_wake(chip->eud_irq);
+
+	return 0;
+}
+
+static const struct of_device_id eud_dt_match[] = {
+	{ .compatible = "qcom,usb-connector-eud" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, eud_dt_match);
+
+static struct platform_driver eud_driver = {
+	.probe		= eud_probe,
+	.remove		= eud_remove,
+	.driver		= {
+		.name		= "eud",
+		.of_match_table = eud_dt_match,
+	},
+};
+module_platform_driver(eud_driver);
+
+MODULE_DESCRIPTION("QTI EUD driver");
+MODULE_LICENSE("GPL v2");
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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 |   7 +
  drivers/usb/common/Kconfig                 |   9 +
  drivers/usb/common/Makefile                |   1 +
  drivers/usb/common/qcom_eud.c              | 256 +++++++++++++++++++++++++++++
  4 files changed, 273 insertions(+)

create mode 100644 Documentation/ABI/testing/sysfs-driver-eud create mode 100644 drivers/usb/common/qcom_eud.c

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

new file mode 100644
index 0000000..14a02da

Documentation/ABI/testing/sysfs-driver-eud new file +1 -0

+		EUD based on a 1 or a 0 value.

Quoted 4 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.

drivers/usb/common/qcom_eud.c

Quoted 1 line

drivers/usb/common/qcom_eud.c +0 -0

drivers/usb/common/qcom_eud.c line 67

Quoted 6 lines

drivers/usb/common/qcom_eud.c +6 -0

+static ssize_t enable_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d", chip->enable);

Quoted 28 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 |   7 +
 drivers/usb/common/Kconfig                 |   9 +
 drivers/usb/common/Makefile                |   1 +
 drivers/usb/common/qcom_eud.c              | 256 
+++++++++++++++++++++++++++++
 4 files changed, 273 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-eud
 create mode 100644 drivers/usb/common/qcom_eud.c

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

new file mode 100644
index 0000000..14a02da

Documentation/ABI/testing/sysfs-driver-eud line 1

Quoted 1 line

Documentation/ABI/testing/sysfs-driver-eud new file +1 -0

@@ -0,0 +1,7 @@
+What:		/sys/bus/platform/.../enable

Um, that's a _very_ generic regex, you just matched with any platform device that might have a "enable" sysfs entry :(

Please use the dwc's name in here to help out with figuring this out.

Documentation/ABI/testing/sysfs-driver-eud line 3

Quoted 3 lines

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

+Date:           October 2021
+Contact:        Souradeep Chowdhury <[email protected]>

No tabs?

Documentation/ABI/testing/sysfs-driver-eud line 7

Quoted 4 lines

Documentation/ABI/testing/sysfs-driver-eud new file +4 -0

+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.

What does enabling or disabling actually do?

And please use a ' ' after a '.'.

Quoted 7 lines

drivers/usb/common/Kconfig +0 -0

index 5e8a04e..669b3fe 100644
@@ -50,3 +50,12 @@ config USB_CONN_GPIO
 

drivers/usb/common/Kconfig config USB_CONN_GPIO · line 61

Quoted 11 lines

drivers/usb/common/Kconfig +9 -0

 	  To compile the driver as a module, choose M here: the module will
 	  be called usb-conn-gpio.ko
+
+config USB_QCOM_EUD
+	tristate "USB 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.

What is the module name if this is built?

Quoted 51 lines

drivers/usb/common/Makefile +1 -0

index 8ac4d21..eb66045 100644
@@ -11,3 +11,4 @@ usb-common-$(CONFIG_USB_LED_TRIG) += led.o
 obj-$(CONFIG_USB_CONN_GPIO)	+= usb-conn-gpio.o
 obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o
 obj-$(CONFIG_USB_ULPI_BUS)	+= ulpi.o
+obj-$(CONFIG_USB_QCOM_EUD)      += qcom_eud.o

drivers/usb/common/qcom_eud.c new file +3 -0

new file mode 100644
index 0000000..7a92fff
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights 

reserved.
+ */

drivers/usb/common/qcom_eud.c new file +30 -0

+
+#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 {

drivers/usb/common/qcom_eud.c line 40

Quoted 6 lines

drivers/usb/common/qcom_eud.c new file +6 -0

+	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				enable;

bool?

drivers/usb/common/qcom_eud.c line 43

Quoted 4 lines

drivers/usb/common/qcom_eud.c new file +3 -0

+	int				eud_irq;
+	bool				usb_attach;
+

No need for a blank line.

Quoted 19 lines

drivers/usb/common/qcom_eud.c new file +18 -0

+};
+
+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);
+}
+

drivers/usb/common/qcom_eud.c line 67

Quoted 6 lines

drivers/usb/common/qcom_eud.c new file +6 -0

+static ssize_t enable_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d", chip->enable);

sysfs_emit() please.

drivers/usb/common/qcom_eud.c line 79

Quoted 13 lines

drivers/usb/common/qcom_eud.c new file +12 -0

+}
+
+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);
+	unsigned long enable;
+	int ret;
+
+	if (kstrtoul(buf, 16, &enable))
+		return -EINVAL;

Use the default sysfs function to parse 0/1/y/n/Y/N please.

Quoted 11 lines

drivers/usb/common/qcom_eud.c new file +10 -0

+
+	if (enable == 1) {
+		ret = enable_eud(chip);
+		if (!ret)
+			chip->enable = enable;
+	} else if (enable == 0) {
+		disable_eud(chip);
+	} else {
+		return -EINVAL;
+	}

drivers/usb/common/qcom_eud.c line 99

Quoted 10 lines

drivers/usb/common/qcom_eud.c new file +10 -0

+
+	return count;
+}
+
+static DEVICE_ATTR_RW(enable);
+
+static const struct device_attribute *eud_attrs[] = {
+	&dev_attr_enable,
+	NULL,
+};

You create a list of attributes and then never use it?

Who reviewed this thing?

You were so close in getting this right, see below...

Quoted 115 lines

drivers/usb/common/qcom_eud.c new file +29 -0

+
+static void usb_attach_detach(struct eud_chip *chip)
+{
+	u32 reg;
+
+	/* read ctl_out_1[4] to find USB attach or detach event */
+	reg = readl(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
+	if (reg & EUD_INT_SAFE_MODE)
+		chip->usb_attach = true;
+	else
+		chip->usb_attach = false;
+
+	/* set and clear vbus_int_clr[0] to clear interrupt */
+	writel(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+	writel(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+}
+
+static void pet_eud(struct eud_chip *chip)
+{
+	u32 reg;
+	int ret;
+
+	/* read sw_attach_det[0] to find attach/detach event */
+	reg = readl(chip->eud_reg_base +  EUD_REG_SW_ATTACH_DET);
+	if (reg & EUD_INT_PET_EUD) {
+		/* Detach & Attach pet for EUD */
+		writel(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
+		/* Delay to make sure detach pet is done before attach pet */
+		ret = readl_poll_timeout(chip->eud_reg_base + 

EUD_REG_SW_ATTACH_DET,

drivers/usb/common/qcom_eud.c new file +77 -0

+					reg, (reg == 0), 1, 100);
+		if (ret) {
+			dev_err(chip->dev, "Detach pet failed\n");
+			return;
+		}
+
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	} else {
+		/* Attach pet for EUD */
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	}
+}
+
+static irqreturn_t handle_eud_irq(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	u32 reg;
+
+	/* read status register and find out which interrupt triggered */
+	reg = readl(chip->eud_reg_base +  EUD_REG_INT_STATUS_1);
+	switch (reg & EUD_INT_ALL) {
+	case EUD_INT_VBUS:
+		chip->int_status = EUD_INT_VBUS;
+		usb_attach_detach(chip);
+		return IRQ_WAKE_THREAD;
+	case EUD_INT_SAFE_MODE:
+		pet_eud(chip);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t handle_eud_irq_thread(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	int ret;
+
+	if (chip->int_status == EUD_INT_VBUS) {
+		if (chip->usb_attach)
+			ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE);
+		else
+			ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST);
+		if (ret)
+			dev_err(chip->dev, "failed to set role switch\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int eud_probe(struct platform_device *pdev)
+{
+	struct eud_chip *chip;
+	int ret;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &pdev->dev;
+
+	chip->role_sw = usb_role_switch_get(chip->dev);
+	if (IS_ERR(chip->role_sw)) {
+		if (PTR_ERR(chip->role_sw) != -EPROBE_DEFER)
+			dev_err(chip->dev, "failed to get role switch\n");
+
+		return PTR_ERR(chip->role_sw);
+	}
+
+	chip->eud_reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(chip->eud_reg_base))
+		return PTR_ERR(chip->eud_reg_base);
+
+	chip->eud_mode_mgr2_phys_base = devm_platform_ioremap_resource(pdev, 

1);

drivers/usb/common/qcom_eud.c new file +5 -0

+	if (IS_ERR(chip->eud_mode_mgr2_phys_base))
+		return PTR_ERR(chip->eud_mode_mgr2_phys_base);
+
+	chip->eud_irq = platform_get_irq(pdev, 0);
+	ret = devm_request_threaded_irq(&pdev->dev, chip->eud_irq, 

handle_eud_irq,

drivers/usb/common/qcom_eud.c line 220

Quoted 10 lines

drivers/usb/common/qcom_eud.c new file +10 -0

+			handle_eud_irq_thread, IRQF_ONESHOT, NULL, chip);
+	if (ret)
+		return ret;
+
+	device_init_wakeup(&pdev->dev, true);
+	enable_irq_wake(chip->eud_irq);
+
+	platform_set_drvdata(pdev, chip);
+
+	ret = device_create_file(&pdev->dev, eud_attrs[0]);

You raced with userspace and lost :(

Please properly attach the sysfs file to the platform driver to have the driver core register this correctly.

drivers/usb/common/qcom_eud.c line 232

Quoted 13 lines

drivers/usb/common/qcom_eud.c new file +12 -0

+
+	return ret;
+}
+
+static int eud_remove(struct platform_device *pdev)
+{
+	struct eud_chip *chip = platform_get_drvdata(pdev);
+
+	if (chip->enable)
+		disable_eud(chip);
+
+	device_remove_file(&pdev->dev, eud_attrs[0]);

No need for this if you do the above correctly.

drivers/usb/common/qcom_eud.c line 233

Quoted 2 lines

drivers/usb/common/qcom_eud.c new file +1 -0

+	device_init_wakeup(&pdev->dev, false);

Why is this needed?

thanks,

greg k-h

Quoted 3 lines · Souradeep Chowdhury

Adding the address size,cell size and ranges property for EUD connector. Adding the connector property for EUD which is child of dwc3 node.

When we have a Type-C controller involved, the connector is described using of_graph, so will we not then have two different connectors described, in two different ways?

Regards,
Bjorn

Quoted 46 lines

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

---
 Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 15 
+++++++++++++++
 1 file changed, 15 insertions(+)

Documentation/devicetree/bindings/usb/snps,dwc3.yaml +8 -0

index 078fb78..3e71205 100644
@@ -36,6 +36,14 @@ properties:
         - const: synopsys,dwc3
           deprecated: true
 
+  "#address-cells":
+    enum: [ 1, 2 ]
+
+  "#size-cells":
+    enum: [ 1, 2 ]
+
+  ranges: true
+
   interrupts:
     description:
       It's either a single common DWC3 interrupt (dwc_usb3) or 

individual

Documentation/devicetree/bindings/usb/snps,dwc3.yaml +5 -0

@@ -318,6 +326,13 @@ properties:
     items:
       enum: [1, 4, 8, 16, 32, 64, 128, 256]
 
+  connector:
+    type: object
+    $ref: /connector/usb-connector.yaml#
+    description:
+      Connector for dual role switch, especially for 

"eud-usb-c-connector"

Documentation/devicetree/bindings/usb/snps,dwc3.yaml +2 -1

+
+
 unevaluatedProperties: false
 
 required:
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Quoted 233 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 |   7 +
 drivers/usb/common/Kconfig                 |   9 +
 drivers/usb/common/Makefile                |   1 +
 drivers/usb/common/qcom_eud.c              | 256 
+++++++++++++++++++++++++++++
 4 files changed, 273 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-eud
 create mode 100644 drivers/usb/common/qcom_eud.c

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

new file mode 100644
index 0000000..14a02da
@@ -0,0 +1,7 @@
+What:		/sys/bus/platform/.../enable
+Date:           October 2021
+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.

drivers/usb/common/Kconfig +9 -0

index 5e8a04e..669b3fe 100644
@@ -50,3 +50,12 @@ config USB_CONN_GPIO
 
 	  To compile the driver as a module, choose M here: the module will
 	  be called usb-conn-gpio.ko
+
+config USB_QCOM_EUD
+	tristate "USB 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.

drivers/usb/common/Makefile +1 -0

index 8ac4d21..eb66045 100644
@@ -11,3 +11,4 @@ usb-common-$(CONFIG_USB_LED_TRIG) += led.o
 obj-$(CONFIG_USB_CONN_GPIO)	+= usb-conn-gpio.o
 obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o
 obj-$(CONFIG_USB_ULPI_BUS)	+= ulpi.o
+obj-$(CONFIG_USB_QCOM_EUD)      += qcom_eud.o

drivers/usb/common/qcom_eud.c new file +3 -0

new file mode 100644
index 0000000..7a92fff
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights 

reserved.
+ */

drivers/usb/common/qcom_eud.c new file +124 -0

+
+#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				enable;
+	int				eud_irq;
+	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 sprintf(buf, "%d", 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);
+	unsigned long enable;
+	int ret;
+
+	if (kstrtoul(buf, 16, &enable))
+		return -EINVAL;
+
+	if (enable == 1) {
+		ret = enable_eud(chip);
+		if (!ret)
+			chip->enable = enable;
+	} else if (enable == 0) {
+		disable_eud(chip);
+	} else {
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(enable);
+
+static const struct device_attribute *eud_attrs[] = {
+	&dev_attr_enable,
+	NULL,
+};
+
+static void usb_attach_detach(struct eud_chip *chip)
+{
+	u32 reg;
+
+	/* read ctl_out_1[4] to find USB attach or detach event */
+	reg = readl(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
+	if (reg & EUD_INT_SAFE_MODE)
+		chip->usb_attach = true;
+	else
+		chip->usb_attach = false;
+
+	/* set and clear vbus_int_clr[0] to clear interrupt */
+	writel(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+	writel(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+}
+
+static void pet_eud(struct eud_chip *chip)
+{
+	u32 reg;
+	int ret;
+
+	/* read sw_attach_det[0] to find attach/detach event */
+	reg = readl(chip->eud_reg_base +  EUD_REG_SW_ATTACH_DET);
+	if (reg & EUD_INT_PET_EUD) {
+		/* Detach & Attach pet for EUD */
+		writel(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
+		/* Delay to make sure detach pet is done before attach pet */
+		ret = readl_poll_timeout(chip->eud_reg_base + 

EUD_REG_SW_ATTACH_DET,

drivers/usb/common/qcom_eud.c new file +36 -0

+					reg, (reg == 0), 1, 100);
+		if (ret) {
+			dev_err(chip->dev, "Detach pet failed\n");
+			return;
+		}
+
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	} else {
+		/* Attach pet for EUD */
+		writel(EUD_INT_PET_EUD, chip->eud_reg_base +
+				EUD_REG_SW_ATTACH_DET);
+	}
+}
+
+static irqreturn_t handle_eud_irq(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	u32 reg;
+
+	/* read status register and find out which interrupt triggered */
+	reg = readl(chip->eud_reg_base +  EUD_REG_INT_STATUS_1);
+	switch (reg & EUD_INT_ALL) {
+	case EUD_INT_VBUS:
+		chip->int_status = EUD_INT_VBUS;
+		usb_attach_detach(chip);
+		return IRQ_WAKE_THREAD;
+	case EUD_INT_SAFE_MODE:
+		pet_eud(chip);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+	return IRQ_HANDLED;
+}
+

drivers/usb/common/qcom_eud.c line 174

Quoted 10 lines

drivers/usb/common/qcom_eud.c new file +10 -0

+static irqreturn_t handle_eud_irq_thread(int irq, void *data)
+{
+	struct eud_chip *chip = data;
+	int ret;
+
+	if (chip->int_status == EUD_INT_VBUS) {
+		if (chip->usb_attach)
+			ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE);
+		else
+			ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST);

How does this work if I have a Type-C controller wired up to the dwc3 and it has negotiated that we're supposed to be in device mode?

Shouldn't this driver somehow work as an override only when EUD is enabled, but otherwise let the Type-C controller deal with things?

Or is this interrupt simply not delivered when EUD is disabled, so that it happens to work as expected?

Quoted 15 lines

drivers/usb/common/qcom_eud.c new file +14 -0

+		if (ret)
+			dev_err(chip->dev, "failed to set role switch\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int eud_probe(struct platform_device *pdev)
+{
+	struct eud_chip *chip;
+	int ret;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)

drivers/usb/common/qcom_eud.c line 198

Quoted 10 lines

drivers/usb/common/qcom_eud.c new file +10 -0

+		return -ENOMEM;
+
+	chip->dev = &pdev->dev;
+
+	chip->role_sw = usb_role_switch_get(chip->dev);
+	if (IS_ERR(chip->role_sw)) {
+		if (PTR_ERR(chip->role_sw) != -EPROBE_DEFER)
+			dev_err(chip->dev, "failed to get role switch\n");
+
+		return PTR_ERR(chip->role_sw);

Please use

		dev_err_probe(chip->dev, PTR_ERR(chip->role_sw), "failed to...\n");

Quoted 11 lines

drivers/usb/common/qcom_eud.c new file +7 -0

+	}
+
+	chip->eud_reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(chip->eud_reg_base))
+		return PTR_ERR(chip->eud_reg_base);
+
+	chip->eud_mode_mgr2_phys_base = devm_platform_ioremap_resource(pdev, 

1);

drivers/usb/common/qcom_eud.c new file +2 -0

+	if (IS_ERR(chip->eud_mode_mgr2_phys_base))
+		return PTR_ERR(chip->eud_mode_mgr2_phys_base);

drivers/usb/common/qcom_eud.c line 212

Quoted 6 lines

drivers/usb/common/qcom_eud.c new file +3 -0

+
+	chip->eud_irq = platform_get_irq(pdev, 0);
+	ret = devm_request_threaded_irq(&pdev->dev, chip->eud_irq, 

handle_eud_irq,

drivers/usb/common/qcom_eud.c new file +2 -0

+			handle_eud_irq_thread, IRQF_ONESHOT, NULL, chip);
+	if (ret)

This deserved another dev_err_probe()

Thanks,
Bjorn

Quoted 48 lines

drivers/usb/common/qcom_eud.c new file +44 -1

+		return ret;
+
+	device_init_wakeup(&pdev->dev, true);
+	enable_irq_wake(chip->eud_irq);
+
+	platform_set_drvdata(pdev, chip);
+
+	ret = device_create_file(&pdev->dev, eud_attrs[0]);
+
+	return ret;
+}
+
+static int eud_remove(struct platform_device *pdev)
+{
+	struct eud_chip *chip = platform_get_drvdata(pdev);
+
+	if (chip->enable)
+		disable_eud(chip);
+
+	device_remove_file(&pdev->dev, eud_attrs[0]);
+	device_init_wakeup(&pdev->dev, false);
+	disable_irq_wake(chip->eud_irq);
+
+	return 0;
+}
+
+static const struct of_device_id eud_dt_match[] = {
+	{ .compatible = "qcom,usb-connector-eud" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, eud_dt_match);
+
+static struct platform_driver eud_driver = {
+	.probe		= eud_probe,
+	.remove		= eud_remove,
+	.driver		= {
+		.name		= "eud",
+		.of_match_table = eud_dt_match,
+	},
+};
+module_platform_driver(eud_driver);
+
+MODULE_DESCRIPTION("QTI EUD driver");
+MODULE_LICENSE("GPL v2");
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Quoted 2 lines · Souradeep Chowdhury

Added the property for EUD(Embedded USB Debug) connector.Added the "reg" and "interrupts" property which is needed for EUD.

You are going to need a better explanation of this h/w.

Quoted 16 lines

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

---
 .../devicetree/bindings/connector/usb-connector.yaml      | 15 
+++++++++++++++
 1 file changed, 15 insertions(+)

Documentation/devicetree/bindings/connector/usb-connector.yaml +0 -0

index 7eb8659..908129f 100644
@@ -30,6 +30,21 @@ properties:
           - const: samsung,usb-connector-11pin
           - const: usb-b-connector
 

Documentation/devicetree/bindings/connector/usb-connector.yaml properties: · line 42

Quoted 10 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +10 -0

+      - items:
+          - enum:
+              - qcom,sc7280-usb-connector-eud
+          - const: qcom,usb-connector-eud
+          - const: usb-c-connector
+
+  reg:
+    items:
+      - description: EUD Base Register Region
+      - description: EUD Mode Manager Region

A connector node represents the physical connector on a board. That can't really be an MMIO peripheral. Maybe you need a node for EUD and then it should have a connector child node? Don't really know without understanding this h/w.

Quoted 14 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +5 -1

+
+  interrupts:
+    description:
+      EUD interrupt
+
   label:
     description: Symbolic name for the connector.
 
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Quoted 2 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

I don't quite understand: what pets the EUD? how does it do that?

Quoted 2 lines

is functional.Reusing the platform device kobj, sysfs entry 'enable' is

functional. Reusing

Quoted 20 lines

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 |   7 +
  drivers/usb/common/Kconfig                 |   9 +
  drivers/usb/common/Makefile                |   1 +
  drivers/usb/common/qcom_eud.c              | 256 
+++++++++++++++++++++++++++++
  4 files changed, 273 insertions(+)

create mode 100644 Documentation/ABI/testing/sysfs-driver-eud create mode 100644 drivers/usb/common/qcom_eud.c

Documentation/ABI/testing/sysfs-driver-eud line 6

Quoted 12 lines

Documentation/ABI/testing/sysfs-driver-eud new file +6 -0

new file mode 100644
index 0000000..14a02da
@@ -0,0 +1,7 @@
+What:		/sys/bus/platform/.../enable
+Date:           October 2021
+Contact:        Souradeep Chowdhury<[email protected]>
+Description:
+		The Enable/Disable sysfs interface for Embedded
+		USB Debugger(EUD).This enables and disables the

Debugger (EUD). This enables

Quoted 2 lines

Documentation/ABI/testing/sysfs-driver-eud new file +1 -0

+		EUD based on a 1 or a 0 value.

Quoted 6 lines · Bjorn Andersson

Quoted 4 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.

[]

Quoted 1 line

drivers/usb/common/qcom_eud.c

Quoted 1 line

drivers/usb/common/qcom_eud.c +0 -0

[]

Quoted 6 lines

drivers/usb/common/qcom_eud.c line 67

Quoted 6 lines

drivers/usb/common/qcom_eud.c +6 -0

+static ssize_t enable_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct eud_chip *chip = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d", chip->enable);

trivia:

should probably use sysfs_emit and have a trailing '\n' in the format.

Quoted 5 lines · Rob Herring

Quoted 2 lines · Souradeep Chowdhury

Added the property for EUD(Embedded USB Debug) connector.Added the "reg" and "interrupts" property which is needed for EUD.

You are going to need a better explanation of this h/w.

Ack. Will update this with the detailed hardware description in the next version.

Quoted 18 lines

Quoted 18 lines

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

---
 .../devicetree/bindings/connector/usb-connector.yaml      | 15
+++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml index 7eb8659..908129f 100644

Documentation/devicetree/bindings/connector/usb-connector.yaml +0 -0

@@ -30,6 +30,21 @@ properties:
           - const: samsung,usb-connector-11pin
           - const: usb-b-connector
 

Quoted 15 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml properties: · line 42

Quoted 10 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +10 -0

+      - items:
+          - enum:
+              - qcom,sc7280-usb-connector-eud
+          - const: qcom,usb-connector-eud
+          - const: usb-c-connector
+
+  reg:
+    items:
+      - description: EUD Base Register Region
+      - description: EUD Mode Manager Region

A connector node represents the physical connector on a board. That can't really be an MMIO peripheral. Maybe you need a node for EUD and then it should have a connector child node? Don't really know without understanding this h/w.

As per the previous discussion on the EUD, it was agreed upon to map EUD as a type C connector and use Role-Switch to change the USB role instead of extcon interface that was being used previously. The link for the same is as follows:-

https://lore.kernel.org/lkml/[email protected]/

Quoted 15 lines

Quoted 15 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +5 -1

+
+  interrupts:
+    description:
+      EUD interrupt
+
   label:
     description: Symbolic name for the connector.
 
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Quoted 44 lines · On Tue 05 Oct 06:11 PDT 2021, [email protected] wrote:

Quoted 5 lines · Rob Herring

Quoted 2 lines · Souradeep Chowdhury

Added the property for EUD(Embedded USB Debug) connector.Added the "reg" and "interrupts" property which is needed for EUD.

You are going to need a better explanation of this h/w.

Ack. Will update this with the detailed hardware description in the next version.

Quoted 18 lines

Quoted 18 lines

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

---
 .../devicetree/bindings/connector/usb-connector.yaml      | 15
+++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml index 7eb8659..908129f 100644

Documentation/devicetree/bindings/connector/usb-connector.yaml +0 -0

@@ -30,6 +30,21 @@ properties:
           - const: samsung,usb-connector-11pin
           - const: usb-b-connector
 

Quoted 15 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml properties: · line 42

Quoted 10 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +10 -0

+      - items:
+          - enum:
+              - qcom,sc7280-usb-connector-eud
+          - const: qcom,usb-connector-eud
+          - const: usb-c-connector
+
+  reg:
+    items:
+      - description: EUD Base Register Region
+      - description: EUD Mode Manager Region

A connector node represents the physical connector on a board. That can't really be an MMIO peripheral. Maybe you need a node for EUD and then it should have a connector child node? Don't really know without understanding this h/w.

Quoted 7 lines

As per the previous discussion on the EUD, it was agreed upon to map EUD as a type C connector and use Role-Switch to change the USB role instead of extcon interface that was being used previously. The link for the same is as follows:-

https://lore.kernel.org/lkml/[email protected]/

Not using extcon is the right thing, but perhaps we should make the EUD a role_switch provider and client, so that we can describe how it sits inbetween the connector and the controller.

That way it has the power to pass through or override requests from the upstream role-switcher, based on the status of EUD.

That said, I'm still curious to what happens if I renegotiate the roles dynamically in a Type-C environment, while enabling EUD. How would the device on the other end of the cable know that it's supposed to be a host? Or there's simply a reset of the link when this happens?

Thanks,
Bjorn

Quoted 16 lines

Quoted 16 lines

Quoted 16 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +5 -1

+
+  interrupts:
+    description:
+      EUD interrupt
+
   label:
     description: Symbolic name for the connector.
 
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Quoted 70 lines · Bjorn Andersson

Quoted 52 lines · On Tue 05 Oct 06:11 PDT 2021, [email protected] wrote:

Quoted 5 lines · Rob Herring

Quoted 2 lines · Souradeep Chowdhury

Added the property for EUD(Embedded USB Debug) connector.Added the "reg" and "interrupts" property which is needed for EUD.

You are going to need a better explanation of this h/w.

Ack. Will update this with the detailed hardware description in the next version.

Quoted 18 lines

Quoted 18 lines

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

---
 .../devicetree/bindings/connector/usb-connector.yaml      | 15
+++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml index 7eb8659..908129f 100644

Documentation/devicetree/bindings/connector/usb-connector.yaml +0 -0

@@ -30,6 +30,21 @@ properties:
           - const: samsung,usb-connector-11pin
           - const: usb-b-connector
 

Quoted 15 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml properties: · line 42

Quoted 10 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +10 -0

+      - items:
+          - enum:
+              - qcom,sc7280-usb-connector-eud
+          - const: qcom,usb-connector-eud
+          - const: usb-c-connector
+
+  reg:
+    items:
+      - description: EUD Base Register Region
+      - description: EUD Mode Manager Region

A connector node represents the physical connector on a board. That can't really be an MMIO peripheral. Maybe you need a node for EUD and then it should have a connector child node? Don't really know without understanding this h/w.

As per the previous discussion on the EUD, it was agreed upon to map EUD
as a type C connector and use Role-Switch to change the USB role instead
of extcon interface that was being used previously. The link for the same
is as follows:-

Quoted 2 lines

https://lore.kernel.org/lkml/[email protected]/

Not using extcon is the right thing, but perhaps we should make the EUD a role_switch provider and client, so that we can describe how it sits inbetween the connector and the controller.

That way it has the power to pass through or override requests from the upstream role-switcher, based on the status of EUD.

That said, I'm still curious to what happens if I renegotiate the roles dynamically in a Type-C environment, while enabling EUD. How would the device on the other end of the cable know that it's supposed to be a host? Or there's simply a reset of the link when this happens?

Quoted 2 lines

Thanks,
Bjorn

Hi Bjorn,

By making EUD Role-Switch provider and client do you mean that we should have a EUD node which will have a connector node as child and this connector node will have a port that points towards the drd role-switch?

So that my device tree node will look like the following in that case

eud@88e0000 {
        compatible = "qcom,usb-connector-eud";
        reg = <0 0x88e0000 0 0x2000>,
              <0 0x88e2000 0 0x1000>;
        interrupt-parent = <&pdc>;
        interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
        usb_con: connector {
                compatible = "usb-c-connector";
                label = "USB-C";
                port {
                      eud_usb_output: endpoint {
                      remote-endpoint = <&eud_usb3_input>;
                 };
        };

};

@usb2 {
    dwc3 {
       usb-role-switch;
       port {
             eud_usb3_input: endpoint {
                   remote-endpoint = <&eud_usb_output>;
             };
     };
};

Also EUD functions only in device mode, so when the role-switch is done by the controller
to set the device mode, the PC on the other end becomes the host.

Thanks,
Souradeep

Quoted 16 lines

Quoted 16 lines

Quoted 16 lines

Quoted 16 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +5 -1

+
+  interrupts:
+    description:
+      EUD interrupt
+
   label:
     description: Symbolic name for the connector.
 
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Quoted 71 lines · On Thu 07 Oct 04:25 CDT 2021, [email protected] wrote:

Quoted 70 lines · Bjorn Andersson

Quoted 52 lines · On Tue 05 Oct 06:11 PDT 2021, [email protected] wrote:

Quoted 5 lines · Rob Herring

Quoted 2 lines · Souradeep Chowdhury

Added the property for EUD(Embedded USB Debug) connector.Added the "reg" and "interrupts" property which is needed for EUD.

You are going to need a better explanation of this h/w.

Ack. Will update this with the detailed hardware description in the next version.

Quoted 18 lines

Quoted 18 lines

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

---
 .../devicetree/bindings/connector/usb-connector.yaml      | 15
+++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml index 7eb8659..908129f 100644

Documentation/devicetree/bindings/connector/usb-connector.yaml +0 -0

@@ -30,6 +30,21 @@ properties:
           - const: samsung,usb-connector-11pin
           - const: usb-b-connector
 

Quoted 15 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml properties: · line 42

Quoted 10 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +10 -0

+      - items:
+          - enum:
+              - qcom,sc7280-usb-connector-eud
+          - const: qcom,usb-connector-eud
+          - const: usb-c-connector
+
+  reg:
+    items:
+      - description: EUD Base Register Region
+      - description: EUD Mode Manager Region

A connector node represents the physical connector on a board. That can't really be an MMIO peripheral. Maybe you need a node for EUD and then it should have a connector child node? Don't really know without understanding this h/w.

As per the previous discussion on the EUD, it was agreed upon to map EUD
as a type C connector and use Role-Switch to change the USB role instead
of extcon interface that was being used previously. The link for the same
is as follows:-

Quoted 2 lines

https://lore.kernel.org/lkml/[email protected]/

Not using extcon is the right thing, but perhaps we should make the EUD a role_switch provider and client, so that we can describe how it sits inbetween the connector and the controller.

That way it has the power to pass through or override requests from the upstream role-switcher, based on the status of EUD.

That said, I'm still curious to what happens if I renegotiate the roles dynamically in a Type-C environment, while enabling EUD. How would the device on the other end of the cable know that it's supposed to be a host? Or there's simply a reset of the link when this happens?

Quoted 5 lines

Quoted 2 lines

Thanks,
Bjorn

Hi Bjorn,

Hi Souradeep

Quoted 25 lines

By making EUD Role-Switch provider and client do you mean that we should have a EUD node which will have a connector node as child and this connector node will have a port that points towards the drd role-switch?

So that my device tree node will look like the following in that case

eud@88e0000 {
        compatible = "qcom,usb-connector-eud";
        reg = <0 0x88e0000 0 0x2000>,
              <0 0x88e2000 0 0x1000>;
        interrupt-parent = <&pdc>;
        interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
        usb_con: connector {
                compatible = "usb-c-connector";
                label = "USB-C";
                port {
                      eud_usb_output: endpoint {
                      remote-endpoint = <&eud_usb3_input>;
                 };
        };

};

Quoted 9 lines

@usb2 {
    dwc3 {
       usb-role-switch;
       port {
             eud_usb3_input: endpoint {
                   remote-endpoint = <&eud_usb_output>;
             };
     };
};

While your "output" and "input" matches the direction of the role switching, I think the connection should be describe in the other direction.

Also my suggestion was that EUD is both connector for the dwc3 and has a reference to the connector described in the TypeC controller - to properly describe the relationship:

DWC -> EUD -> connector

With the role switching request going from the connector (pmic_glink driver) to DWC through the EUD, which can override the vote.

That said, this is just my suggestion. You need to ensure that Rob understands the hardware design well enough to approve your proposed binding.

E.g. The connector in the EUD isn't a usb-c-connector, it's some type of internal connection, the next step in that chain is the actual usb-c-connector.

Regards,
Bjorn

Quoted 7 lines

Also EUD functions only in device mode, so when the role-switch is done by the controller
to set the device mode, the PC on the other end becomes the host.

Thanks,
Souradeep

Quoted 17 lines

Quoted 17 lines

Quoted 17 lines

Quoted 17 lines

Quoted 17 lines

Documentation/devicetree/bindings/connector/usb-connector.yaml +5 -1

+
+  interrupts:
+    description:
+      EUD interrupt
+
   label:
     description: Symbolic name for the connector.
 
--

QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation