Add Embedded USB Debugger (EUD) driver

Documentation for Embedded USB Debugger (EUD) device tree bindings.

Signed-off-by Satya Durga Srinivasu Prabhala <[email protected]>

Signed-off-by Prakruthi Deepak Heragu <[email protected]>

---
 .../devicetree/bindings/soc/qcom/qcom,msm-eud.txt  | 43 ++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,msm-eud.txt

Documentation/devicetree/bindings/soc/qcom/qcom,msm-eud.txt new file +43 -0

new file mode 100644
index 0000000..6d339e7
@@ -0,0 +1,43 @@
+* Qualcomm Technologies Inc Embedded USB Debugger (EUD)
+
+The EUD (Embedded USB Debugger) is a mini-USB hub implemented
+on chip to support the USB-based debug and trace capabilities.
+
+Required properties:
+
+ - compatible:  Should be "qcom,msm-eud"
+ - interrupts:  Interrupt number
+ - reg: Should be address and size of EUD register space
+
+EUD notifies clients for VBUS attach/detach and charger enable/disable
+events. The link between client and EUD is established via a directed
+graph. EUD has one endpoint of the graph link mentioning EUD as an
+output link and clients of EUD should have the other endpoint of the
+graph link as an input link.
+
+An example for EUD device node:
+
+	eud: qcom,msm-eud@88e0000 {
+		compatible = "qcom,msm-eud";
+		interrupts = <GIC_SPI 492 IRQ_TYPE_LEVEL_HIGH>;
+		reg = <0x88e0000 0x4000>;
+		usb_con: connector {
+                compatible = "usb-c-connector";
+                label = "USB-C";
+                port {
+                	    eud_usb_output: endpoint {
+                        	    remote-endpoint = <&eud_usb3_input>;
+                        };
+        	    };
+        };
+	};
+
+An example for EUD client:
+
+	usb3 {
+		port {
+                eud_usb3_input: endpoint {
+                        remote-endpoint = <&eud_usb_output>;
+                };
+        };
+	};

Signature · 2 lines

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Quoted 1 line · Prakruthi Deepak Heragu

Documentation for Embedded USB Debugger (EUD) device tree bindings.

I asked questions on v2 which were never answered.

Quoted 61 lines

Signed-off-by Satya Durga Srinivasu Prabhala <[email protected]>

Signed-off-by Prakruthi Deepak Heragu <[email protected]>

---
  .../devicetree/bindings/soc/qcom/qcom,msm-eud.txt  | 43 ++++++++++++++++++++++
  1 file changed, 43 insertions(+)

create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,msm-eud.txt

Documentation/devicetree/bindings/soc/qcom/qcom,msm-eud.txt new file +43 -0

new file mode 100644
index 0000000..6d339e7
@@ -0,0 +1,43 @@
+* Qualcomm Technologies Inc Embedded USB Debugger (EUD)
+
+The EUD (Embedded USB Debugger) is a mini-USB hub implemented
+on chip to support the USB-based debug and trace capabilities.
+
+Required properties:
+
+ - compatible:  Should be "qcom,msm-eud"
+ - interrupts:  Interrupt number
+ - reg: Should be address and size of EUD register space
+
+EUD notifies clients for VBUS attach/detach and charger enable/disable
+events. The link between client and EUD is established via a directed
+graph. EUD has one endpoint of the graph link mentioning EUD as an
+output link and clients of EUD should have the other endpoint of the
+graph link as an input link.
+
+An example for EUD device node:
+
+	eud: qcom,msm-eud@88e0000 {
+		compatible = "qcom,msm-eud";
+		interrupts = <GIC_SPI 492 IRQ_TYPE_LEVEL_HIGH>;
+		reg = <0x88e0000 0x4000>;
+		usb_con: connector {
+                compatible = "usb-c-connector";
+                label = "USB-C";
+                port {
+                	    eud_usb_output: endpoint {
+                        	    remote-endpoint = <&eud_usb3_input>;
+                        };
+        	    };
+        };
+	};
+
+An example for EUD client:
+
+	usb3 {
+		port {
+                eud_usb3_input: endpoint {
+                        remote-endpoint = <&eud_usb_output>;
+                };
+        };
+	};

Signature · 2 lines

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

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

Quoted 4 lines · Prakruthi Deepak Heragu

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

If you add/remove/change a sysfs file, you need to also have a Documentation/ABI/ file update as well. Please do that here.

thanks,

greg k-h

Quoted 8 lines · Greg KH

Quoted 4 lines · Prakruthi Deepak Heragu

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

If you add/remove/change a sysfs file, you need to also have a Documentation/ABI/ file update as well. Please do that here.

Quoted 3 lines

thanks,

greg k-h

Thank you very much Greg for your time to review, Shall i go ahead posting next patch set v4 addressing your comments?

drivers/soc/qcom/eud.c new file +119 -0

+
+static void eud_event_notifier(struct work_struct *eud_work)
+{
+	struct eud_chip *chip = container_of(eud_work, struct eud_chip,
+					eud_work);
+	int ret;
+
+	if (chip->int_status == EUD_INT_VBUS) {
+		ret = extcon_set_state_sync(chip->extcon, chip->extcon_id,
+					chip->usb_attach);
+		if (ret)
+			return;
+	} else if (chip->int_status == EUD_INT_CHGR) {
+		ret = extcon_set_state_sync(chip->extcon, chip->extcon_id,
+					chip->chgr_enable);
+		if (ret)
+			return;
+	}
+}
+
+static void usb_attach_detach(struct eud_chip *chip)
+{
+	u32 reg;
+
+	chip->extcon_id = EXTCON_USB;
+	/* read ctl_out_1[4] to find USB attach or detach event */
+	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
+	if (reg & BIT(4))
+		chip->usb_attach = true;
+	else
+		chip->usb_attach = false;
+
+	schedule_work(&chip->eud_work);
+
+	/* set and clear vbus_int_clr[0] to clear interrupt */
+	writel_relaxed(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+	/* Ensure Register Writes Complete */
+	wmb();
+	writel_relaxed(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
+}
+
+static void chgr_enable_disable(struct eud_chip *chip)
+{
+	u32 reg;
+
+	chip->extcon_id = EXTCON_CHG_USB_SDP;
+	/* read ctl_out_1[6] to find charger enable or disable event */
+	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
+	if (reg & BIT(6))
+		chip->chgr_enable = true;
+	else
+		chip->chgr_enable = false;
+
+	schedule_work(&chip->eud_work);
+
+	/* set and clear chgr_int_clr[0] to clear interrupt */
+	writel_relaxed(BIT(0), chip->eud_reg_base + EUD_REG_CHGR_INT_CLR);
+	/* Ensure Register Writes Complete */
+	wmb();
+	writel_relaxed(0, chip->eud_reg_base + EUD_REG_CHGR_INT_CLR);
+}
+
+static void pet_eud(struct eud_chip *chip)
+{
+	u32 reg;
+
+	/* read sw_attach_det[0] to find attach/detach event */
+	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
+	if (reg & BIT(0)) {
+		/* Detach & Attach pet for EUD */
+		writel_relaxed(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
+		/* Ensure Register Writes Complete */
+		wmb();
+		/* Delay to make sure detach pet is done before attach pet */
+		udelay(100);
+		writel_relaxed(BIT(0), chip->eud_reg_base +
+					EUD_REG_SW_ATTACH_DET);
+		/* Ensure Register Writes Complete */
+		wmb();
+	} else {
+		/* Attach pet for EUD */
+		writel_relaxed(BIT(0), chip->eud_reg_base +
+					EUD_REG_SW_ATTACH_DET);
+		/* Ensure Register Writes Complete */
+		wmb();
+	}
+}
+
+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_relaxed(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);
+		break;
+	case EUD_INT_CHGR:
+		chip->int_status = EUD_INT_CHGR;
+		chgr_enable_disable(chip);
+		break;
+	case EUD_INT_SAFE_MODE:
+		pet_eud(chip);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+	return IRQ_HANDLED;
+}
+
+static int msm_eud_probe(struct platform_device *pdev)
+{
+	struct eud_chip *chip;
+	struct resource *res;
+	int ret;
+