1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
new file mode 100644
index 000000000000..b06929fe1175
--- /dev/null
+++ b/drivers/usb/cdns3/drd.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence USBSS DRD Driver.
+ *
+ * Copyright (C) 2018-2019 Cadence.
+ * Copyright (C) 2019 Texas Instruments
+ *
+ * Author: Pawel Laszczak <pawell@cadence.com>
+ *         Roger Quadros <rogerq@ti.com>
+ *
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/usb/otg.h>
+
+#include "gadget.h"
+#include "drd.h"
+#include "core.h"
+
+/**
+ * cdns3_set_mode - change mode of OTG Core
+ * @cdns: pointer to context structure
+ * @mode: selected mode from cdns_role
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode)
+{
+	int ret = 0;
+	u32 reg;
+
+	cdns->current_dr_mode = mode;
+
+	switch (mode) {
+	case USB_DR_MODE_PERIPHERAL:
+		break;
+	case USB_DR_MODE_HOST:
+		break;
+	case USB_DR_MODE_OTG:
+		dev_dbg(cdns->dev, "Set controller to OTG mode\n");
+		if (cdns->version == CDNS3_CONTROLLER_V1) {
+			reg = readl(&cdns->otg_v1_regs->override);
+			reg |= OVERRIDE_IDPULLUP;
+			writel(reg, &cdns->otg_v1_regs->override);
+		} else {
+			reg = readl(&cdns->otg_v0_regs->ctrl1);
+			reg |= OVERRIDE_IDPULLUP_V0;
+			writel(reg, &cdns->otg_v0_regs->ctrl1);
+		}
+
+		/*
+		 * Hardware specification says: "ID_VALUE must be valid within
+		 * 50ms after idpullup is set to '1" so driver must wait
+		 * 50ms before reading this pin.
+		 */
+		usleep_range(50000, 60000);
+		break;
+	default:
+		cdns->current_dr_mode = USB_DR_MODE_UNKNOWN;
+		dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+int cdns3_get_id(struct cdns3 *cdns)
+{
+	int id;
+
+	id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
+	dev_dbg(cdns->dev, "OTG ID: %d", id);
+
+	return id;
+}
+
+int cdns3_get_vbus(struct cdns3 *cdns)
+{
+	int vbus;
+
+	vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
+	dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
+	return vbus;
+}
+
+int cdns3_is_host(struct cdns3 *cdns)
+{
+	if (cdns->current_dr_mode == USB_DR_MODE_HOST)
+		return 1;
+	else if (!cdns3_get_id(cdns))
+		return 1;
+
+	return 0;
+}
+
+int cdns3_is_device(struct cdns3 *cdns)
+{
+	if (cdns->current_dr_mode == USB_DR_MODE_PERIPHERAL)
+		return 1;
+	else if (cdns->current_dr_mode == USB_DR_MODE_OTG)
+		if (cdns3_get_id(cdns))
+			return 1;
+
+	return 0;
+}
+
+/**
+ * cdns3_otg_disable_irq - Disable all OTG interrupts
+ * @cdns: Pointer to controller context structure
+ */
+static void cdns3_otg_disable_irq(struct cdns3 *cdns)
+{
+	writel(0, &cdns->otg_regs->ien);
+}
+
+/**
+ * cdns3_otg_enable_irq - enable id and sess_valid interrupts
+ * @cdns: Pointer to controller context structure
+ */
+static void cdns3_otg_enable_irq(struct cdns3 *cdns)
+{
+	writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT |
+	       OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_regs->ien);
+}
+
+/**
+ * cdns3_drd_switch_host - start/stop host
+ * @cdns: Pointer to controller context structure
+ * @on: 1 for start, 0 for stop
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
+{
+	int ret;
+	u32 reg = OTGCMD_OTG_DIS;
+
+	/* switch OTG core */
+	if (on) {
+		writel(OTGCMD_HOST_BUS_REQ | reg, &cdns->otg_regs->cmd);
+
+		dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
+		ret = cdns3_handshake(&cdns->otg_regs->sts, OTGSTS_XHCI_READY,
+				      OTGSTS_XHCI_READY, 100000);
+
+		if (ret) {
+			dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
+			return ret;
+		}
+	} else {
+		writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
+		       OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
+		       &cdns->otg_regs->cmd);
+		/* Waiting till H_IDLE state.*/
+		cdns3_handshake(&cdns->otg_regs->state,
+				OTGSTATE_HOST_STATE_MASK,
+				0, 2000000);
+	}
+
+	return 0;
+}
+
+/**
+ * cdns3_drd_switch_gadget - start/stop gadget
+ * @cdns: Pointer to controller context structure
+ * @on: 1 for start, 0 for stop
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
+{
+	int ret;
+	u32 reg = OTGCMD_OTG_DIS;
+
+	/* switch OTG core */
+	if (on) {
+		writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
+
+		dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
+
+		ret = cdns3_handshake(&cdns->otg_regs->sts, OTGSTS_DEV_READY,
+				      OTGSTS_DEV_READY, 100000);
+
+		if (ret) {
+			dev_err(cdns->dev, "timeout waiting for dev_ready\n");
+			return ret;
+		}
+	} else {
+		/*
+		 * driver should wait at least 10us after disabling Device
+		 * before turning-off Device (DEV_BUS_DROP)
+		 */
+		usleep_range(20, 30);
+		writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
+		       OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
+		       &cdns->otg_regs->cmd);
+		/* Waiting till DEV_IDLE state.*/
+		cdns3_handshake(&cdns->otg_regs->state, OTGSTATE_DEV_STATE_MASK,
+				0, 2000000);
+	}
+
+	return 0;
+}
+
+/**
+ * cdns3_init_otg_mode - initialize drd controller
+ * @cdns: Pointer to controller context structure
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+static int cdns3_init_otg_mode(struct cdns3 *cdns)
+{
+	int ret = 0;
+
+	cdns3_otg_disable_irq(cdns);
+	/* clear all interrupts */
+	writel(~0, &cdns->otg_regs->ivect);
+
+	ret = cdns3_set_mode(cdns, USB_DR_MODE_OTG);
+	if (ret)
+		return ret;
+
+	cdns3_otg_enable_irq(cdns);
+	return ret;
+}
+
+/**
+ * cdns3_drd_update_mode - initialize mode of operation
+ * @cdns: Pointer to controller context structure
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+int cdns3_drd_update_mode(struct cdns3 *cdns)
+{
+	int ret = 0;
+
+	if (cdns->desired_dr_mode == cdns->current_dr_mode)
+		return ret;
+
+	switch (cdns->desired_dr_mode) {
+	case USB_DR_MODE_PERIPHERAL:
+		ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
+		break;
+	case USB_DR_MODE_HOST:
+		ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
+		break;
+	case USB_DR_MODE_OTG:
+		ret = cdns3_init_otg_mode(cdns);
+		break;
+	default:
+		dev_err(cdns->dev, "Unsupported mode of operation %d\n",
+			cdns->dr_mode);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+/**
+ * cdns3_drd_irq - interrupt handler for OTG events
+ *
+ * @irq: irq number for cdns3 core device
+ * @data: structure of cdns3
+ *
+ * Returns IRQ_HANDLED or IRQ_NONE
+ */
+static irqreturn_t cdns3_drd_irq(int irq, void *data)
+{
+	irqreturn_t ret = IRQ_NONE;
+	struct cdns3 *cdns = data;
+	u32 reg;
+
+	if (cdns->dr_mode != USB_DR_MODE_OTG)
+		return ret;
+
+	reg = readl(&cdns->otg_regs->ivect);
+
+	if (!reg)
+		return ret;
+
+	if (reg & OTGIEN_ID_CHANGE_INT) {
+		dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
+			cdns3_get_id(cdns));
+
+		ret = IRQ_HANDLED;
+	}
+
+	if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) {
+		dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
+			cdns3_get_vbus(cdns));
+
+		ret = IRQ_HANDLED;
+	}
+
+	if (ret == IRQ_HANDLED)
+		queue_work(system_freezable_wq, &cdns->role_switch_wq);
+
+	writel(~0, &cdns->otg_regs->ivect);
+	return ret;
+}
+
+int cdns3_drd_init(struct cdns3 *cdns)
+{
+	void __iomem *regs;
+	int ret = 0;
+	u32 state;
+
+	regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	/* Detection of DRD version. Controller has been released
+	 * in two versions. Both are similar, but they have same changes
+	 * in register maps.
+	 * The first register in old version is command register and it's read
+	 * only, so driver should read 0 from it. On the other hand, in v1
+	 * the first register contains device ID number which is not set to 0.
+	 * Driver uses this fact to detect the proper version of
+	 * controller.
+	 */
+	cdns->otg_v0_regs = regs;
+	if (!readl(&cdns->otg_v0_regs->cmd)) {
+		cdns->version  = CDNS3_CONTROLLER_V0;
+		cdns->otg_v1_regs = NULL;
+		cdns->otg_regs = regs;
+		writel(1, &cdns->otg_v0_regs->simulate);
+		dev_info(cdns->dev, "DRD version v0 (%08x)\n",
+			 readl(&cdns->otg_v0_regs->version));
+	} else {
+		cdns->otg_v0_regs = NULL;
+		cdns->otg_v1_regs = regs;
+		cdns->otg_regs = (void *)&cdns->otg_v1_regs->cmd;
+		cdns->version  = CDNS3_CONTROLLER_V1;
+		writel(1, &cdns->otg_v1_regs->simulate);
+		dev_info(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
+			 readl(&cdns->otg_v1_regs->did),
+			 readl(&cdns->otg_v1_regs->rid));
+	}
+
+	state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));
+
+	/* Update dr_mode according to STRAP configuration. */
+	cdns->dr_mode = USB_DR_MODE_OTG;
+	if (state == OTGSTS_STRAP_HOST) {
+		dev_dbg(cdns->dev, "Controller strapped to HOST\n");
+		cdns->dr_mode = USB_DR_MODE_HOST;
+	} else if (state == OTGSTS_STRAP_GADGET) {
+		dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
+		cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
+	}
+
+	cdns->desired_dr_mode = cdns->dr_mode;
+	cdns->current_dr_mode = USB_DR_MODE_UNKNOWN;
+
+	ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
+					cdns3_drd_irq,
+					NULL, IRQF_SHARED,
+					dev_name(cdns->dev), cdns);
+
+	if (ret) {
+		dev_err(cdns->dev, "couldn't get otg_irq\n");
+		return ret;
+	}
+
+	state = readl(&cdns->otg_regs->sts);
+	if (OTGSTS_OTG_NRDY(state) != 0) {
+		dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
+		return -ENODEV;
+	}
+
+	return ret;
+}
+
+int cdns3_drd_exit(struct cdns3 *cdns)
+{
+	return 0;
+}