[PATCH 05/15] Introduce Cadence USBSSP DRD Driver - added gadget-port.c file.

[Pawel Laszczak]

Signed-off-by: Laszczak Pawel <pawell@xxxxxxxxxxx>
---
 drivers/usb/usbssp/gadget-port.c | 284 +++++++++++++++++++++++++++++++
 1 file changed, 284 insertions(+)
 create mode 100644 drivers/usb/usbssp/gadget-port.c

diff --git a/drivers/usb/usbssp/gadget-port.c b/drivers/usb/usbssp/gadget-port.c
new file mode 100644
index 000000000000..8335bc31ad09
--- /dev/null
+++ b/drivers/usb/usbssp/gadget-port.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USBSSP device controller driver
+ *
+ * Copyright (C) 2018 Cadence.
+ *
+ * Author: Pawel Laszczak
+ * Some code borrowed from the Linux XHCI driver.
+ */
+
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#include "gadget-trace.h"
+#include "gadget.h"
+
+unsigned int usbssp_port_speed(unsigned int port_status)
+{
+	/*Detect gadget speed*/
+	if (DEV_SUPERSPEEDPLUS(port_status))
+		return USB_SPEED_SUPER_PLUS;
+	else if (DEV_SUPERSPEED(port_status))
+		return USB_SPEED_SUPER;
+	else if (DEV_HIGHSPEED(port_status))
+		return USB_SPEED_HIGH;
+	else if (DEV_FULLSPEED(port_status))
+		return USB_SPEED_FULL;
+	else if (DEV_LOWSPEED(port_status))
+		return USB_SPEED_LOW;
+
+	/*if device is detached  then speed will be USB_SPEED_UNKNOWN*/
+	return USB_SPEED_UNKNOWN;
+}
+
+/*
+ * These bits are Read Only (RO) and should be saved and written to the
+ * registers: 0, 3, 10:13, 30
+ * connect status, over-current status and port speed.
+ * connect status and port speed are also sticky - meaning they're in
+ * the AUX well and they aren't changed by a hot and warm.
+ */
+#define	USBSSP_PORT_RO	(PORT_CONNECT | PORT_OC | DEV_SPEED_MASK)
+
+/*
+ * These bits are RW; writing a 0 clears the bit, writing a 1 sets the bit:
+ * bits 5:8, 9, 14:15, 25:27
+ * link state, port power, port indicator state, "wake on" enable state
+ */
+#define USBSSP_PORT_RWS	(PORT_PLS_MASK | PORT_POWER | PORT_WKCONN_E | \
+			PORT_WKDISC_E | PORT_WKOC_E)
+
+/*
+ * Given a port state, this function returns a value that would result in the
+ * port being in the same state, if the value was written to the port status
+ * control register.
+ * Save Read Only (RO) bits and save read/write bits where
+ * writing a 0 clears the bit and writing a 1 sets the bit (RWS).
+ * For all other types (RW1S, RW1CS, RW, and RZ), writing a '0' has no effect.
+ */
+u32 usbssp_port_state_to_neutral(u32 state)
+{
+	/* Save read-only status and port state */
+	return (state & USBSSP_PORT_RO) | (state & USBSSP_PORT_RWS);
+}
+
+/*
+ * Stop device
+ * It issues stop endpoint command for EP 0 to 30. And wait the last command
+ * to complete.
+ */
+int usbssp_stop_device(struct usbssp_udc *usbssp_data, int suspend)
+{
+	struct usbssp_device *priv_dev;
+	struct usbssp_ep_ctx *ep_ctx;
+	int ret = 0;
+	int i;
+
+	ret = 0;
+	priv_dev = &usbssp_data->devs;
+
+	trace_usbssp_stop_device(priv_dev);
+
+	if (usbssp_data->gadget.state < USB_STATE_ADDRESS) {
+		usbssp_dbg(usbssp_data,
+			"Device is not yet in  USB_STATE_ADDRESS state\n");
+		goto stop_ep0;
+	}
+
+	for (i = LAST_EP_INDEX; i > 0; i--) {
+		if (priv_dev->eps[i].ring && priv_dev->eps[i].ring->dequeue) {
+			struct usbssp_command *command;
+
+			if (priv_dev->eps[i].ep_state & EP_HALTED) {
+				usbssp_dbg(usbssp_data,
+					"ep_index %d is in halted state "
+					"- ep state: %x\n",
+					i, priv_dev->eps[i].ep_state);
+				usbssp_halt_endpoint(usbssp_data,
+						&priv_dev->eps[i], 0);
+			}
+
+			ep_ctx = usbssp_get_ep_ctx(usbssp_data,
+					priv_dev->out_ctx, i);
+
+			/* Check ep is running, required by AMD SNPS 3.1 xHC */
+			if (GET_EP_CTX_STATE(ep_ctx) != EP_STATE_RUNNING) {
+				usbssp_dbg(usbssp_data,
+					"ep_index %d is already stopped.\n", i);
+				continue;
+			}
+
+			if (priv_dev->eps[i].ep_state & EP_STOP_CMD_PENDING) {
+				usbssp_dbg(usbssp_data,
+					"Stop endpoint command is pending "
+					"for ep_index %d.\n", i);
+				continue;
+			}
+
+			/*device was disconnected so endpoint should be disabled
+			 * and transfer ring stopped.
+			 */
+			priv_dev->eps[i].ep_state |= EP_STOP_CMD_PENDING |
+					USBSSP_EP_DISABLE_PENDING;
+
+			command = usbssp_alloc_command(usbssp_data, false,
+					GFP_ATOMIC);
+			if (!command)
+				return -ENOMEM;
+
+			ret = usbssp_queue_stop_endpoint(usbssp_data,
+					command, i, suspend);
+			if (ret) {
+				usbssp_free_command(usbssp_data, command);
+				return ret;
+			}
+		}
+	}
+
+stop_ep0:
+	if (priv_dev->eps[0].ep_state & EP_HALTED) {
+		usbssp_dbg(usbssp_data,
+			"ep_index 0 is in halted state - ep state: %x\n",
+			priv_dev->eps[i].ep_state);
+		ret = usbssp_halt_endpoint(usbssp_data, &priv_dev->eps[0], 0);
+	} else {
+		/*device was disconnected so endpoint should be disabled
+		 * and transfer ring stopped.
+		 */
+		priv_dev->eps[0].ep_state &= ~USBSSP_EP_ENABLED;
+		ret = usbssp_cmd_stop_ep(usbssp_data, &usbssp_data->gadget,
+				&priv_dev->eps[0]);
+	}
+
+	return ret;
+}
+
+__le32 __iomem *usbssp_get_port_io_addr(struct usbssp_udc *usbssp_data)
+{
+	if (usbssp_data->port_major_revision == 0x03)
+		return usbssp_data->usb3_ports;
+	else
+		return usbssp_data->usb2_ports;
+}
+
+
+void usbssp_set_link_state(struct usbssp_udc *usbssp_data,
+			   __le32 __iomem *port_regs,
+			   u32 link_state)
+{
+	u32 temp;
+
+	temp = readl(port_regs);
+	temp = usbssp_port_state_to_neutral(temp);
+	temp &= ~PORT_PLS_MASK;
+	temp |= PORT_LINK_STROBE | link_state;
+	writel(temp, port_regs);
+}
+
+/* Test and clear port RWC bit */
+void usbssp_test_and_clear_bit(struct usbssp_udc *usbssp_data,
+			       __le32 __iomem *port_regs,
+			       u32 port_bit)
+{
+	u32 temp;
+
+	temp = readl(port_regs);
+	if (temp & port_bit) {
+		temp = usbssp_port_state_to_neutral(temp);
+		temp |= port_bit;
+		writel(temp, port_regs);
+	}
+}
+
+static void usbssp_set_port_power(struct usbssp_udc *usbssp_data,
+				  bool on, unsigned long *flags)
+{
+	__le32 __iomem *addr;
+	u32 temp;
+
+	addr = usbssp_get_port_io_addr(usbssp_data);
+	temp = readl(addr);
+	temp = usbssp_port_state_to_neutral(temp);
+	if (on) {
+		/* Power on */
+		writel(temp | PORT_POWER, addr);
+		temp = readl(addr);
+		usbssp_dbg(usbssp_data,
+			"set port power, actual port status  = 0x%x\n",
+			temp);
+	} else {
+		/* Power off */
+		writel(temp & ~PORT_POWER, addr);
+		usbssp_dbg(usbssp_data,
+			"clear port power, actual port status  = 0x%x\n",
+			 temp);
+	}
+}
+
+static void usbssp_port_set_test_mode(struct usbssp_udc *usbssp_data,
+	u16 test_mode)
+{
+	u32 temp;
+	__le32 __iomem *addr;
+
+	/* USBSSP only supports test mode for usb2 ports, */
+	addr = usbssp_get_port_io_addr(usbssp_data);
+	temp = readl(addr + PORTPMSC);
+	temp |= test_mode << PORT_TEST_MODE_SHIFT;
+	writel(temp, addr + PORTPMSC);
+	usbssp_data->test_mode = test_mode;
+	if (test_mode == TEST_FORCE_EN)
+		usbssp_start(usbssp_data);
+}
+
+int usbssp_enter_test_mode(struct usbssp_udc *usbssp_data,
+			   u16 test_mode, unsigned long *flags)
+{
+	int retval;
+
+	retval = usbssp_disable_slot(usbssp_data);
+	if (retval) {
+		usbssp_err(usbssp_data,
+			"Failed to disable slot %d, %d. Enter test mode anyway\n",
+			usbssp_data->slot_id, retval);
+		return retval;
+	}
+	/* Put port to the Disable state by clear PP */
+	usbssp_set_port_power(usbssp_data, false, flags);
+
+	/* Stop the controller */
+	retval = usbssp_halt(usbssp_data);
+	if (retval)
+		return retval;
+
+	/* Disable runtime PM for test mode */
+	pm_runtime_forbid(usbssp_data->dev);
+	/* Set PORTPMSC.PTC field to enter selected test mode */
+	/* Port is selected by wIndex. port_id = wIndex + 1 */
+	usbssp_dbg(usbssp_data, "Enter Test Mode: _id=%d\n",
+			test_mode);
+	usbssp_port_set_test_mode(usbssp_data, test_mode);
+
+	return retval;
+}
+
+int usbssp_exit_test_mode(struct usbssp_udc *usbssp_data)
+{
+	int retval;
+
+	if (!usbssp_data->test_mode) {
+		usbssp_err(usbssp_data, "Not in test mode, do nothing.\n");
+		return 0;
+	}
+	if (usbssp_data->test_mode == TEST_FORCE_EN &&
+		!(usbssp_data->usbssp_state & USBSSP_STATE_HALTED)) {
+		retval = usbssp_halt(usbssp_data);
+		if (retval)
+			return retval;
+	}
+	pm_runtime_allow(usbssp_data->dev);
+	usbssp_data->test_mode = 0;
+	return usbssp_reset(usbssp_data);
+}
+
-- 
2.17.1