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Date: Mon, 19 Aug 2019 10:30:02 +0000
From: Pawel Laszczak <pawell@...ence.com>
To: Roger Quadros <rogerq@...com>,
"felipe.balbi@...ux.intel.com" <felipe.balbi@...ux.intel.com>
CC: "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"jbergsagel@...com" <jbergsagel@...com>,
"nsekhar@...com" <nsekhar@...com>, "nm@...com" <nm@...com>,
Suresh Punnoose <sureshp@...ence.com>,
Jayshri Dajiram Pawar <jpawar@...ence.com>,
Rahul Kumar <kurahul@...ence.com>,
Anil Joy Varughese <aniljoy@...ence.com>
Subject: RE: [PATCH v10 5/6] usb:cdns3 Add Cadence USB3 DRD Driver
Hi,
>
>On 21/07/2019 21:32, Pawel Laszczak wrote:
>> This patch introduce new Cadence USBSS DRD driver to Linux kernel.
>>
>> The Cadence USBSS DRD Controller is a highly configurable IP Core which
>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
>> Host Only (XHCI)configurations.
>>
>> The current driver has been validated with FPGA platform. We have
>> support for PCIe bus, which is used on FPGA prototyping.
>>
>> The host side of USBSS-DRD controller is compliant with XHCI
>> specification, so it works with standard XHCI Linux driver.
>>
>> Signed-off-by: Pawel Laszczak <pawell@...ence.com>
>> ---
>> drivers/usb/Kconfig | 2 +
>> drivers/usb/Makefile | 2 +
>> drivers/usb/cdns3/Kconfig | 46 +
>> drivers/usb/cdns3/Makefile | 17 +
>> drivers/usb/cdns3/cdns3-pci-wrap.c | 203 +++
>> drivers/usb/cdns3/core.c | 554 +++++++
>> drivers/usb/cdns3/core.h | 109 ++
>> drivers/usb/cdns3/debug.h | 171 ++
>> drivers/usb/cdns3/debugfs.c | 87 ++
>> drivers/usb/cdns3/drd.c | 390 +++++
>> drivers/usb/cdns3/drd.h | 166 ++
>> drivers/usb/cdns3/ep0.c | 914 +++++++++++
>> drivers/usb/cdns3/gadget-export.h | 28 +
>> drivers/usb/cdns3/gadget.c | 2338 ++++++++++++++++++++++++++++
>> drivers/usb/cdns3/gadget.h | 1321 ++++++++++++++++
>> drivers/usb/cdns3/host-export.h | 28 +
>> drivers/usb/cdns3/host.c | 71 +
>> drivers/usb/cdns3/trace.c | 11 +
>> drivers/usb/cdns3/trace.h | 493 ++++++
>> 19 files changed, 6951 insertions(+)
>> create mode 100644 drivers/usb/cdns3/Kconfig
>> create mode 100644 drivers/usb/cdns3/Makefile
>> create mode 100644 drivers/usb/cdns3/cdns3-pci-wrap.c
>> create mode 100644 drivers/usb/cdns3/core.c
>> create mode 100644 drivers/usb/cdns3/core.h
>> create mode 100644 drivers/usb/cdns3/debug.h
>> create mode 100644 drivers/usb/cdns3/debugfs.c
>> create mode 100644 drivers/usb/cdns3/drd.c
>> create mode 100644 drivers/usb/cdns3/drd.h
>> create mode 100644 drivers/usb/cdns3/ep0.c
>> create mode 100644 drivers/usb/cdns3/gadget-export.h
>> create mode 100644 drivers/usb/cdns3/gadget.c
>> create mode 100644 drivers/usb/cdns3/gadget.h
>> create mode 100644 drivers/usb/cdns3/host-export.h
>> create mode 100644 drivers/usb/cdns3/host.c
>> create mode 100644 drivers/usb/cdns3/trace.c
>> create mode 100644 drivers/usb/cdns3/trace.h
>>
>
><snip>
>
>> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
>> new file mode 100644
>> index 000000000000..900b2ce08162
>> --- /dev/null
>> +++ b/drivers/usb/cdns3/core.c
>> @@ -0,0 +1,554 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Cadence USBSS DRD Driver.
>> + *
>> + * Copyright (C) 2018-2019 Cadence.
>> + * Copyright (C) 2017-2018 NXP
>> + * Copyright (C) 2019 Texas Instruments
>> + *
>> + * Author: Peter Chen <peter.chen@....com>
>> + * Pawel Laszczak <pawell@...ence.com>
>> + * Roger Quadros <rogerq@...com>
>> + */
>> +
>> +#include <linux/dma-mapping.h>
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/pm_runtime.h>
>> +
>> +#include "gadget.h"
>> +#include "core.h"
>> +#include "host-export.h"
>> +#include "gadget-export.h"
>> +#include "drd.h"
>> +#include "debug.h"
>> +
>> +static inline
>> +struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
>> +{
>> + WARN_ON(!cdns->roles[cdns->role]);
>> + return cdns->roles[cdns->role];
>> +}
>> +
>> +static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
>> +{
>> + int ret;
>> +
>> + if (WARN_ON(role > USB_ROLE_DEVICE))
>> + return 0;
>> +
>> + mutex_lock(&cdns->mutex);
>> + cdns->role = role;
>> + mutex_unlock(&cdns->mutex);
>> +
>> + if (role == USB_ROLE_NONE)
>> + return 0;
>
>We will need to have a role driver for NONE case so we can deal with
>type-C cable swap case. I will post a patch at the end about this.
>You can squash the patches and use them in the next revision.
>
>> +
>> + if (!cdns->roles[role])
>> + return -ENXIO;
>> +
>> + if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
>> + return 0;
>> +
>> + mutex_lock(&cdns->mutex);
>> + if (role == USB_ROLE_HOST)
>> + cdns3_drd_switch_host(cdns, 1);
>> + else
>> + cdns3_drd_switch_gadget(cdns, 1);
>
>Please don't do this here. You can call them from the respective role
>drivers at the start. i.e. __cdns3_host_init(), __cdns3_gadget_init()
Why it can't do this here?
Do we really want to mix drd code with gadget/host ?
>> +
>> + ret = cdns->roles[role]->start(cdns);
>> + if (!ret)
>> + cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
>> + mutex_unlock(&cdns->mutex);
>> +
>> + return ret;
>> +}
>> +
>> +static void cdns3_role_stop(struct cdns3 *cdns)
>> +{
>> + enum usb_role role = cdns->role;
>> +
>> + if (WARN_ON(role > USB_ROLE_DEVICE))
>> + return;
>> +
>> + if (role == USB_ROLE_NONE)
>> + return;
>> +
>> + if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
>> + return;
>> +
>> + mutex_lock(&cdns->mutex);
>> + cdns->roles[role]->stop(cdns);
>> + if (role == USB_ROLE_HOST)
>> + cdns3_drd_switch_host(cdns, 0);
>> + else
>> + cdns3_drd_switch_gadget(cdns, 0);
>
>No need to do this here. They can be done at the respective role
>drivers at the end. i.e. cdns3_host_exit(), cdns3_gadget_exit()
>
>> +
>> + cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
>> + mutex_unlock(&cdns->mutex);
>> +}
>> +
>> +static void cdns3_exit_roles(struct cdns3 *cdns)
>> +{
>> + cdns3_role_stop(cdns);
>> + cdns3_drd_exit(cdns);
>> +}
>> +
>> +enum usb_role cdsn3_real_role_switch_get(struct device *dev);
>> +
>> +/**
>> + * cdns3_core_init_role - initialize role of operation
>> + * @cdns: Pointer to cdns3 structure
>> + *
>> + * Returns 0 on success otherwise negative errno
>> + */
>> +static int cdns3_core_init_role(struct cdns3 *cdns)
>> +{
>> + struct device *dev = cdns->dev;
>> + enum usb_dr_mode best_dr_mode;
>> + enum usb_dr_mode dr_mode;
>> + int ret = 0;
>> +
>> + dr_mode = usb_get_dr_mode(dev);
>> + cdns->role = USB_ROLE_NONE;
>> +
>> + /*
>> + * If driver can't read mode by means of usb_get_dr_mode function then
>> + * chooses mode according with Kernel configuration. This setting
>> + * can be restricted later depending on strap pin configuration.
>> + */
>> + if (dr_mode == USB_DR_MODE_UNKNOWN) {
>> + if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
>> + IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
>> + dr_mode = USB_DR_MODE_OTG;
>> + else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
>> + dr_mode = USB_DR_MODE_HOST;
>> + else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
>> + dr_mode = USB_DR_MODE_PERIPHERAL;
>> + }
>> +
>> + /*
>> + * At this point cdns->dr_mode contains strap configuration.
>> + * Driver try update this setting considering kernel configuration
>> + */
>> + best_dr_mode = cdns->dr_mode;
>> +
>> + if (dr_mode == USB_DR_MODE_OTG) {
>> + best_dr_mode = cdns->dr_mode;
>> + } else if (cdns->dr_mode == USB_DR_MODE_OTG) {
>> + best_dr_mode = dr_mode;
>> + } else if (cdns->dr_mode != dr_mode) {
>> + dev_err(dev, "Incorrect DRD configuration\n");
>> + return -EINVAL;
>> + }
>> +
>> + dr_mode = best_dr_mode;
>> +
>> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
>> + ret = cdns3_host_init(cdns);
>> + if (ret) {
>> + dev_err(dev, "Host initialization failed with %d\n",
>> + ret);
>> + goto err;
>> + }
>> + }
>> +
>> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
>> + ret = cdns3_gadget_init(cdns);
>> + if (ret) {
>> + dev_err(dev, "Device initialization failed with %d\n",
>> + ret);
>> + goto err;
>> + }
>> + }
>> +
>> + cdns->desired_dr_mode = dr_mode;
>> + cdns->dr_mode = dr_mode;
>> +
>> + /*
>> + * desired_dr_mode might have changed so we need to update
>> + * the controller configuration"?
>> + */
>> + ret = cdns3_drd_update_mode(cdns);
>> + if (ret)
>> + goto err;
>> +
>> + cdns->role = cdsn3_real_role_switch_get(cdns->dev);
>> +
>> + ret = cdns3_role_start(cdns, cdns->role);
>> + if (ret) {
>> + dev_err(dev, "can't start %s role\n",
>> + cdns3_get_current_role_driver(cdns)->name);
>> + goto err;
>> + }
>> +
>> + return ret;
>> +err:
>> + cdns3_exit_roles(cdns);
>> + return ret;
>> +}
>> +
>> +/**
>> + * cdsn3_real_role_switch_get - get real role of controller based on hardware
>> + * settings.
>> + * @dev: Pointer to device structure
>> + *
>> + * Returns role
>> + */
>> +enum usb_role cdsn3_real_role_switch_get(struct device *dev)
>
>let's not mix user space role_switch and HW based role swith.
>
>This function is really the HW based state machine. Let's rename it to
>
> * cdsn3_hw_role_state_machine - role switch state machine based on hw events
> *
> * @cdns: Pointer to controller structure
> *
> * Returns next role to be entered based on hw events.
> */
>static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
>
>> +{
>> + struct cdns3 *cdns = dev_get_drvdata(dev);
>> + enum usb_role role;
>> + int id, vbus;
>> +
>> + if (cdns->current_dr_mode != USB_DR_MODE_OTG)
>> + goto not_otg;
>> +
>> + id = cdns3_get_id(cdns);
>> + vbus = cdns3_get_vbus(cdns);
>> +
>> + /*
>> + * Role change state machine
>> + * Inputs: ID, VBUS
>> + * Previous state: cdns->role
>> + * Next state: role
>> + */
>> + role = cdns->role;
>> +
>> + switch (role) {
>> + case USB_ROLE_NONE:
>> + /*
>> + * Driver treat USB_ROLE_NONE synonymous to IDLE state from
>
>s/treat/treats
>
>> + * controller specification.
>> + */
>> + if (!id)
>> + role = USB_ROLE_HOST;
>> + else if (vbus)
>> + role = USB_ROLE_DEVICE;
>> + break;
>> + case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
>> + if (id)
>> + role = USB_ROLE_NONE;
>> + break;
>> + case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
>> + if (!vbus)
>> + role = USB_ROLE_NONE;
>> + break;
>> + }
>> +
>> + dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);
>> +
>> + return role;
>> +
>> +not_otg:
>> + if (cdns3_is_host(cdns))
>> + role = USB_ROLE_HOST;
>> + if (cdns3_is_device(cdns))
>> + role = USB_ROLE_DEVICE;
>> +
>> + return role;
>> +}
>> +
>> +/**
>> + * cdns3_role_switch_set - work queue handler for role switch
>> + *
>> + * @dev: pointer to device object
>> + * @role - the previous role
>> + * Handles below events:
>> + * - Role switch for dual-role devices
>> + * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
>> + */
>> +static int cdns3_role_switch_set(struct device *dev, enum usb_role role)
>
>Let's not use this for user space role switch but just for HW based switching
>How about calling it
>
>int cdns3_hw_role_switch(struct cdns3 *cdns)
Ok, I will change name.
>
>> +{
>> + struct cdns3 *cdns = dev_get_drvdata(dev);
>> + enum usb_role real_role = USB_ROLE_NONE;
>> + enum usb_role current_role;
>
>enum usb_role real_role, current_role;
>
>> + int ret = 0;
>> +
>> + /* Check if dr_mode was changed.*/
>> + ret = cdns3_drd_update_mode(cdns);
>
After removing debugfs it's not longer needed.
>Why is this check required? Who is going to change dr_mode?
>
>> + if (ret)
>> + return ret;
>
>I think here we need to check if user overrides the role
>using role switch sysfs. If yes then we ned ignore HW events
>and just return here.
Should I add some extra flags for detecting this in CDNS3 driver
or we should assume that it will be added in role switch framework ?
>
>> +
>> + pm_runtime_get_sync(cdns->dev);
>> +
>> + real_role = cdsn3_real_role_switch_get(cdns->dev);
>
> current_role = cdns->role;
> real_role = cdsn3_hw_role_state_machine(cdns);
>
>> +
>> + /* Do nothing if nothing changed */
>> + if (cdns->role == real_role)
>
> if (current_role == real_role)
>
>> + goto exit;
>> +
>> + cdns3_role_stop(cdns);
>> +
>> + real_role = cdsn3_real_role_switch_get(cdns->dev);
>> +
>> + current_role = role;
>
>Remove above 2 lines. Don't need to get real role again
>here as it will break the state machine.
>If HW state changes, we will deal with it in next interrupt
>not here.
>
>> + dev_dbg(cdns->dev, "Switching role");
>
> dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
>
>> +
>> + ret = cdns3_role_start(cdns, real_role);
>> + if (ret) {
>> + /* Back to current role */
>> + dev_err(cdns->dev, "set %d has failed, back to %d\n",
>> + role, current_role);
>
> real_role, current_role
>
>> + ret = cdns3_role_start(cdns, current_role);
>> + if (ret)
>> + dev_err(cdns->dev, "back to %d failed too\n",
>> + current_role);
>> + }
>> +exit:
>> + pm_runtime_put_sync(cdns->dev);
>> + return ret;
>> +}
>
>How about the below 2 functions for user space role switch handling.
>
>+/**
>+ * cdsn3_role_get - get current role of controller.
>+ *
>+ * @dev: Pointer to device structure
>+ *
>+ * Returns role
>+ */
>+static enum usb_role cdns3_role_get(struct device *dev)
>+{
>+ struct cdns3 *cdns = dev_get_drvdata(dev);
>+
>+ return cdns->role;
>+}
>+
>+/**
>+ * cdns3_role_set - set current role of controller.
>+ *
>+ * @dev: pointer to device object
>+ * @role - the previous role
>+ * Handles below events:
>+ * - Role switch for dual-role devices
>+ * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
>+ */
>+static int cdns3_role_set(struct device *dev, enum usb_role role)
>+{
>+ /* FIXME: doing nothing for now */
>
>Here we need to implement the user space switching logic.
>
>1) If called change to desired role and set a userspace override flag
>2) How do we clear the userspace override flag so HW based switching can
>continue? Need new API hook in struct usb_role_switch_desc?
>
>+ return -EPERM;
>+}
>+
But Felipe will complain for this empty function :).
>> +
>> +static const struct usb_role_switch_desc cdns3_switch_desc = {
>> + .set = cdns3_role_switch_set,
>> + .get = cdsn3_real_role_switch_get,
>
> .set = cdns3_role_set,
> .get = cdns3_role_get,
>
>> + .allow_userspace_control = true,
>> +};
>> +
>
><snip>
>
>> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
>> new file mode 100644
>> index 000000000000..77f8a1516140
>> --- /dev/null
>> +++ b/drivers/usb/cdns3/drd.c
>> @@ -0,0 +1,390 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Cadence USBSS DRD Driver.
>> + *
>> + * Copyright (C) 2018-2019 Cadence.
>> + * Copyright (C) 2019 Texas Instruments
>> + *
>> + * Author: Pawel Laszczak <pawell@...ence.com>
>> + * Roger Quadros <rogerq@...com>
>> + *
>> + *
>> + */
>> +#include <linux/kernel.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/delay.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/usb/otg.h>
>> +
>> +#include "gadget.h"
>> +#include "drd.h"
>> +#include "core.h"
>> +
>
><snip>
>
>> +/**
>> + * 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;
>> +}
>> +
>> +static irqreturn_t cdns3_drd_thread_irq(int irq, void *data)
>> +{
>> + struct cdns3 *cdns = data;
>> +
>> + usb_role_switch_set_role(cdns->role_sw, cdns->role);
>> +
> This is HW based event. Don't mix this with user space role switch.
> So,
>
> cdns3_hw_role_switch(cdns);
>
>> + return IRQ_HANDLED;
>> +}
>> +
>
><snip>
>
>The below 2 patches address the above comments and introduce
>a IDLE role driver so we can deal with Type-C lane swap.
>
>Please squash them into this patch, if they look OK. Thanks.
>
>cheers,
>-roger
>--
>
>From 228da29ea47d0000f2bab49377fce8f3f0e97b63 Mon Sep 17 00:00:00 2001
>From: Roger Quadros <rogerq@...com>
>Date: Thu, 15 Aug 2019 11:11:02 +0300
>Subject: [PATCH 1/2] usb: cdns3: Fix hw based role switch
>
>Signed-off-by: Roger Quadros <rogerq@...com>
>---
> drivers/usb/cdns3/core.c | 76 ++++++++++++++++++++++++++--------------
> drivers/usb/cdns3/core.h | 2 ++
> drivers/usb/cdns3/drd.c | 2 +-
> 3 files changed, 52 insertions(+), 28 deletions(-)
>
>diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
>index b132acca60f1..07f8d8f23930 100644
>--- a/drivers/usb/cdns3/core.c
>+++ b/drivers/usb/cdns3/core.c
>@@ -97,7 +97,7 @@ static void cdns3_exit_roles(struct cdns3 *cdns)
> cdns3_drd_exit(cdns);
> }
>
>-enum usb_role cdsn3_real_role_switch_get(struct device *dev);
>+static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns);
>
> /**
> * cdns3_core_init_role - initialize role of operation
>@@ -176,7 +176,7 @@ static int cdns3_core_init_role(struct cdns3 *cdns)
> if (ret)
> goto err;
>
>- cdns->role = cdsn3_real_role_switch_get(cdns->dev);
>+ cdns->role = cdsn3_hw_role_state_machine(cdns);
>
> ret = cdns3_role_start(cdns, cdns->role);
> if (ret) {
>@@ -192,15 +192,14 @@ static int cdns3_core_init_role(struct cdns3 *cdns)
> }
>
> /**
>- * cdsn3_real_role_switch_get - get real role of controller based on hardware
>- * settings.
>- * @dev: Pointer to device structure
>+ * cdsn3_hw_role_state_machine - role switch state machine based on hw events
> *
>- * Returns role
>+ * @cdns: Pointer to controller structure
>+ *
>+ * Returns next role to be entered based on hw events.
> */
>-enum usb_role cdsn3_real_role_switch_get(struct device *dev)
>+static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
> {
>- struct cdns3 *cdns = dev_get_drvdata(dev);
> enum usb_role role;
> int id, vbus;
>
>@@ -253,46 +252,40 @@ enum usb_role cdsn3_real_role_switch_get(struct device *dev)
> }
>
> /**
>- * cdns3_role_switch_set - work queue handler for role switch
>+ * cdns3_hw_role_switch - switch roles based on HW state
> *
>- * @dev: pointer to device object
>- * @role - the previous role
>- * Handles below events:
>- * - Role switch for dual-role devices
>- * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
>+ * @cdns: controller
> */
>-static int cdns3_role_switch_set(struct device *dev, enum usb_role role)
>+int cdns3_hw_role_switch(struct cdns3 *cdns)
> {
>- struct cdns3 *cdns = dev_get_drvdata(dev);
>- enum usb_role real_role = USB_ROLE_NONE;
>- enum usb_role current_role;
>+ enum usb_role real_role, current_role;
> int ret = 0;
>
> /* Check if dr_mode was changed.*/
>+ /* FIXME: why do we need this call? */
> ret = cdns3_drd_update_mode(cdns);
> if (ret)
> return ret;
>
>+ /* FIXME: don't do anything if userspace role switch has override */
> pm_runtime_get_sync(cdns->dev);
>
>- real_role = cdsn3_real_role_switch_get(cdns->dev);
>+ current_role = cdns->role;
>+ real_role = cdsn3_hw_role_state_machine(cdns);
>
> /* Do nothing if nothing changed */
>- if (cdns->role == real_role)
>+ if (current_role == real_role)
> goto exit;
>
> cdns3_role_stop(cdns);
>
>- real_role = cdsn3_real_role_switch_get(cdns->dev);
>-
>- current_role = role;
>- dev_dbg(cdns->dev, "Switching role");
>+ dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
>
> ret = cdns3_role_start(cdns, real_role);
> if (ret) {
> /* Back to current role */
> dev_err(cdns->dev, "set %d has failed, back to %d\n",
>- role, current_role);
>+ real_role, current_role);
> ret = cdns3_role_start(cdns, current_role);
> if (ret)
> dev_err(cdns->dev, "back to %d failed too\n",
>@@ -303,9 +296,38 @@ static int cdns3_role_switch_set(struct device *dev, enum usb_role role)
> return ret;
> }
>
>+/**
>+ * cdsn3_role_get - get current role of controller.
>+ *
>+ * @dev: Pointer to device structure
>+ *
>+ * Returns role
>+ */
>+static enum usb_role cdns3_role_get(struct device *dev)
>+{
>+ struct cdns3 *cdns = dev_get_drvdata(dev);
>+
>+ return cdns->role;
>+}
>+
>+/**
>+ * cdns3_role_set - set current role of controller.
>+ *
>+ * @dev: pointer to device object
>+ * @role - the previous role
>+ * Handles below events:
>+ * - Role switch for dual-role devices
>+ * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
>+ */
>+static int cdns3_role_set(struct device *dev, enum usb_role role)
>+{
>+ /* FIXME: doing nothing for now */
>+ return -EPERM;
>+}
>+
> static const struct usb_role_switch_desc cdns3_switch_desc = {
>- .set = cdns3_role_switch_set,
>- .get = cdsn3_real_role_switch_get,
>+ .set = cdns3_role_set,
>+ .get = cdns3_role_get,
> .allow_userspace_control = true,
> };
>
>diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h
>index 2a35f025b0a5..e0d23f2934bb 100644
>--- a/drivers/usb/cdns3/core.h
>+++ b/drivers/usb/cdns3/core.h
>@@ -103,4 +103,6 @@ struct cdns3 {
> struct usb_role_switch *role_sw;
> };
>
>+int cdns3_hw_role_switch(struct cdns3 *cdns);
>+
> #endif /* __LINUX_CDNS3_CORE_H */
>diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
>index 77f8a1516140..780fc7d59932 100644
>--- a/drivers/usb/cdns3/drd.c
>+++ b/drivers/usb/cdns3/drd.c
>@@ -265,7 +265,7 @@ static irqreturn_t cdns3_drd_thread_irq(int irq, void *data)
> {
> struct cdns3 *cdns = data;
>
>- usb_role_switch_set_role(cdns->role_sw, cdns->role);
>+ cdns3_hw_role_switch(cdns);
>
> return IRQ_HANDLED;
> }
>
>
>From 701277afb2c1087d327be5387b239d507f0abf6e Mon Sep 17 00:00:00 2001
>From: Roger Quadros <rogerq@...com>
>Date: Thu, 15 Aug 2019 11:39:38 +0300
>Subject: [PATCH 2/2] usb: cdns3: fix type-c lane swap
>
>We need to have a discrete IDLE state so that
>we know type-C cable is disconnected.
>
>On exting IDLE state we can program lane swap
>via a PHY reset.
>
>Signed-off-by: Roger Quadros <rogerq@...com>
>---
> drivers/usb/cdns3/core.c | 49 +++++++++++++++++++++++++++-----------
> drivers/usb/cdns3/gadget.c | 2 ++
> drivers/usb/cdns3/host.c | 3 +++
> 3 files changed, 40 insertions(+), 14 deletions(-)
>
>diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
>index 07f8d8f23930..3c42ee347836 100644
>--- a/drivers/usb/cdns3/core.c
>+++ b/drivers/usb/cdns3/core.c
>@@ -44,9 +44,6 @@ static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
> cdns->role = role;
> mutex_unlock(&cdns->mutex);
>
>- if (role == USB_ROLE_NONE)
>- return 0;
>-
> if (!cdns->roles[role])
> return -ENXIO;
>
>@@ -54,10 +51,6 @@ static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
> return 0;
>
> mutex_lock(&cdns->mutex);
>- if (role == USB_ROLE_HOST)
>- cdns3_drd_switch_host(cdns, 1);
>- else
>- cdns3_drd_switch_gadget(cdns, 1);
>
> ret = cdns->roles[role]->start(cdns);
> if (!ret)
>@@ -74,18 +67,11 @@ static void cdns3_role_stop(struct cdns3 *cdns)
> if (WARN_ON(role > USB_ROLE_DEVICE))
> return;
>
>- if (role == USB_ROLE_NONE)
>- return;
>-
> if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
> return;
>
> mutex_lock(&cdns->mutex);
> cdns->roles[role]->stop(cdns);
>- if (role == USB_ROLE_HOST)
>- cdns3_drd_switch_host(cdns, 0);
>- else
>- cdns3_drd_switch_gadget(cdns, 0);
>
> cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
> mutex_unlock(&cdns->mutex);
>@@ -99,6 +85,37 @@ static void cdns3_exit_roles(struct cdns3 *cdns)
>
> static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns);
>
>+static int cdns3_idle_role_start(struct cdns3 *cdns)
>+{
>+ return 0;
>+}
>+
>+static void cdns3_idle_role_stop(struct cdns3 *cdns)
>+{
>+ /* Program Lane swap and bring PHY out of RESET */
>+ phy_reset(cdns->usb3_phy);
>+}
>+
>+static int cdns3_idle_init(struct cdns3 *cdns)
>+{
>+ struct cdns3_role_driver *rdrv;
>+
>+ rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
>+ if (!rdrv)
>+ return -ENOMEM;
>+
>+ rdrv->start = cdns3_idle_role_start;
>+ rdrv->stop = cdns3_idle_role_stop;
>+ rdrv->state = CDNS3_ROLE_STATE_INACTIVE;
>+ rdrv->suspend = NULL;
>+ rdrv->resume = NULL;
>+ rdrv->name = "idle";
>+
>+ cdns->roles[USB_ROLE_NONE] = rdrv;
>+
>+ return 0;
>+}
>+
> /**
> * cdns3_core_init_role - initialize role of operation
> * @cdns: Pointer to cdns3 structure
>@@ -136,6 +153,10 @@ static int cdns3_core_init_role(struct cdns3 *cdns)
> */
> best_dr_mode = cdns->dr_mode;
>
>+ ret = cdns3_idle_init(cdns);
>+ if (ret)
>+ return ret;
>+
> if (dr_mode == USB_DR_MODE_OTG) {
> best_dr_mode = cdns->dr_mode;
> } else if (cdns->dr_mode == USB_DR_MODE_OTG) {
>diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>index a42e832b3c6a..2ac2eba284c7 100644
>--- a/drivers/usb/cdns3/gadget.c
>+++ b/drivers/usb/cdns3/gadget.c
>@@ -2475,6 +2475,7 @@ void cdns3_gadget_exit(struct cdns3 *cdns)
> kfree(priv_dev->zlp_buf);
> kfree(priv_dev);
> cdns->gadget_dev = NULL;
>+ cdns3_drd_switch_gadget(cdns, 0);
> }
>
> static int cdns3_gadget_start(struct cdns3 *cdns)
>@@ -2594,6 +2595,7 @@ static int __cdns3_gadget_init(struct cdns3 *cdns)
> struct cdns3_device *priv_dev;
> int ret = 0;
>
>+ cdns3_drd_switch_gadget(cdns, 1);
> pm_runtime_get_sync(cdns->dev);
>
> ret = cdns3_gadget_start(cdns);
>diff --git a/drivers/usb/cdns3/host.c b/drivers/usb/cdns3/host.c
>index a7629ab2c20c..2733a8f71fcd 100644
>--- a/drivers/usb/cdns3/host.c
>+++ b/drivers/usb/cdns3/host.c
>@@ -18,6 +18,8 @@ static int __cdns3_host_init(struct cdns3 *cdns)
> struct platform_device *xhci;
> int ret;
>
>+ cdns3_drd_switch_host(cdns, 1);
>+
> xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
> if (!xhci) {
> dev_err(cdns->dev, "couldn't allocate xHCI device\n");
>@@ -50,6 +52,7 @@ static void cdns3_host_exit(struct cdns3 *cdns)
> {
> platform_device_unregister(cdns->host_dev);
> cdns->host_dev = NULL;
>+ cdns3_drd_switch_host(cdns, 0);
> }
>
> int cdns3_host_init(struct cdns3 *cdns)
>
--
Cheers,
pawell
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