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Date: Fri, 17 Jul 2015 15:06:18 +0300
From: Roger Quadros <rogerq@...com>
To: Li Jun <b47624@...escale.com>
CC: <stern@...land.harvard.edu>, <balbi@...com>,
<gregkh@...uxfoundation.org>, <peter.chen@...escale.com>,
<dan.j.williams@...el.com>, <jun.li@...escale.com>,
<mathias.nyman@...ux.intel.com>, <tony@...mide.com>,
<Joao.Pinto@...opsys.com>, <linux-usb@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>
Subject: Re: [PATCH v3 07/11] usb: otg: add OTG core
Hi Li,
On 17/07/15 10:48, Li Jun wrote:
> Hi, Roger
>
> On Wed, Jul 08, 2015 at 01:19:33PM +0300, Roger Quadros wrote:
>> The OTG core instantiates the OTG Finite State Machine
>> per OTG controller and manages starting/stopping the
>> host and gadget controllers based on the bus state.
>>
>> It provides APIs for the following tasks
>>
>> - Registering an OTG capable controller
>> - Registering Host and Gadget controllers to OTG core
>> - Providing inputs to and kicking the OTG state machine
>>
>> Signed-off-by: Roger Quadros <rogerq@...com>
>> ---
>> MAINTAINERS | 4 +-
>> drivers/usb/Kconfig | 2 +-
>> drivers/usb/Makefile | 1 +
>> drivers/usb/common/Makefile | 3 +-
>> drivers/usb/common/usb-otg.c | 768 +++++++++++++++++++++++++++++++++++++++++++
>> drivers/usb/common/usb-otg.h | 71 ++++
>> drivers/usb/core/Kconfig | 11 +-
>> include/linux/usb/otg.h | 91 ++++-
>> 8 files changed, 930 insertions(+), 21 deletions(-)
>> create mode 100644 drivers/usb/common/usb-otg.c
>> create mode 100644 drivers/usb/common/usb-otg.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 8133cef..b21278e 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10640,12 +10640,14 @@ S: Maintained
>> F: Documentation/usb/ohci.txt
>> F: drivers/usb/host/ohci*
>>
>> -USB OTG FSM (Finite State Machine)
>> +USB OTG/DRD core and FSM (Finite State Machine)
>> M: Peter Chen <Peter.Chen@...escale.com>
>> +M: Roger Quadros <rogerq@...com>
>> T: git git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git
>> L: linux-usb@...r.kernel.org
>> S: Maintained
>> F: drivers/usb/common/usb-otg-fsm.c
>> +F: drivers/usb/common/usb-otg.c
>>
>> USB OVER IP DRIVER
>> M: Valentina Manea <valentina.manea.m@...il.com>
>> diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
>> index 8ed451d..5b625e2 100644
>> --- a/drivers/usb/Kconfig
>> +++ b/drivers/usb/Kconfig
>> @@ -32,7 +32,7 @@ if USB_SUPPORT
>> config USB_COMMON
>> tristate
>> default y
>> - depends on USB || USB_GADGET
>> + depends on USB || USB_GADGET || USB_OTG
>>
>> config USB_ARCH_HAS_HCD
>> def_bool y
>> diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
>> index d8926c6..769d13b 100644
>> --- a/drivers/usb/Makefile
>> +++ b/drivers/usb/Makefile
>> @@ -60,5 +60,6 @@ obj-$(CONFIG_USB_RENESAS_USBHS) += renesas_usbhs/
>> obj-$(CONFIG_USB_GADGET) += gadget/
>>
>> obj-$(CONFIG_USB_COMMON) += common/
>> +obj-$(CONFIG_USB_OTG) += common/
>>
>> obj-$(CONFIG_USBIP_CORE) += usbip/
>> diff --git a/drivers/usb/common/Makefile b/drivers/usb/common/Makefile
>> index 6bbb3ec..730d928 100644
>> --- a/drivers/usb/common/Makefile
>> +++ b/drivers/usb/common/Makefile
>> @@ -6,5 +6,6 @@ obj-$(CONFIG_USB_COMMON) += usb-common.o
>> usb-common-y += common.o
>> usb-common-$(CONFIG_USB_LED_TRIG) += led.o
>>
>> -obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o
>> obj-$(CONFIG_USB_ULPI_BUS) += ulpi.o
>> +usbotg-y := usb-otg.o usb-otg-fsm.o
>> +obj-$(CONFIG_USB_OTG) += usbotg.o
>> diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
>> new file mode 100644
>> index 0000000..0379034
>> --- /dev/null
>> +++ b/drivers/usb/common/usb-otg.c
>> @@ -0,0 +1,768 @@
>> +/**
>> + * drivers/usb/common/usb-otg.c - USB OTG core
>> + *
>> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
>> + * Author: Roger Quadros <rogerq@...com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/ktime.h>
>> +#include <linux/hrtimer.h>
>> +#include <linux/list.h>
>> +#include <linux/usb/otg.h>
>> +#include <linux/usb/phy.h> /* enum usb_otg_state */
>> +#include <linux/usb/gadget.h>
>> +#include <linux/workqueue.h>
>> +
>> +#include "usb-otg.h"
>> +
>> +/* to link timer with callback data */
>> +struct otg_timer {
>> + struct hrtimer timer;
>> + ktime_t timeout;
>> + /* callback data */
>> + int *timeout_bit;
>> + struct otg_data *otgd;
>> +};
>> +
>> +struct otg_hcd {
>> + struct usb_hcd *hcd;
>> + unsigned int irqnum;
>> + unsigned long irqflags;
>> + struct otg_hcd_ops *ops;
>> +};
>> +
>> +struct otg_data {
>> + struct device *dev; /* HCD & GCD's parent device */
>> +
>> + struct otg_fsm fsm;
>> + /* HCD, GCD and usb_otg_state are present in otg_fsm->otg
>> + * HCD is bus_to_hcd(fsm->otg->host)
>> + * GCD is fsm->otg->gadget
>> + */
>> + struct otg_fsm_ops fsm_ops; /* private copy for override */
>> + struct usb_otg otg; /* allocator for fsm->otg */
>> +
>> + struct otg_hcd primary_hcd;
>> + struct otg_hcd shared_hcd;
>> +
>> + struct otg_gadget_ops *gadget_ops; /* interface to gadget f/w */
>> +
>> + /* saved hooks to OTG device */
>> + int (*start_host)(struct otg_fsm *fsm, int on);
>> + int (*start_gadget)(struct otg_fsm *fsm, int on);
>> +
>> + struct list_head list;
>> +
>> + struct work_struct work; /* OTG FSM work */
>> + struct workqueue_struct *wq;
>> +
>> + struct otg_timer timers[NUM_OTG_FSM_TIMERS];
>> +
>> + bool fsm_running;
>> + /* use otg->fsm.lock for serializing access */
>> +};
>> +
>> +/* OTG device list */
>> +LIST_HEAD(otg_list);
>> +static DEFINE_MUTEX(otg_list_mutex);
>> +
>> +static int usb_otg_hcd_is_primary_hcd(struct usb_hcd *hcd)
>> +{
>> + if (!hcd->primary_hcd)
>> + return 1;
>> + return hcd == hcd->primary_hcd;
>> +}
>> +
>> +/**
>> + * check if device is in our OTG list and return
>> + * otg_data, else NULL.
>> + *
>> + * otg_list_mutex must be held.
>> + */
>> +static struct otg_data *usb_otg_device_get_otgd(struct device *parent_dev)
>> +{
>> + struct otg_data *otgd;
>> +
>> + list_for_each_entry(otgd, &otg_list, list) {
>> + if (otgd->dev == parent_dev)
>> + return otgd;
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> +/**
>> + * timer callback to set timeout bit and kick FSM
>> + */
>> +static enum hrtimer_restart set_tmout(struct hrtimer *data)
>> +{
>> + struct otg_timer *otgtimer;
>> +
>> + otgtimer = container_of(data, struct otg_timer, timer);
>> + if (otgtimer->timeout_bit)
>> + *otgtimer->timeout_bit = 1;
>> +
>> + usb_otg_sync_inputs(&otgtimer->otgd->fsm);
>> +
>> + return HRTIMER_NORESTART;
>> +}
>> +
>> +/**
>> + * Initialize one OTG timer with callback, timeout and timeout bit
>> + */
>> +static void otg_timer_init(enum otg_fsm_timer id, struct otg_data *otgd,
>> + enum hrtimer_restart (*callback)(struct hrtimer *),
>> + unsigned long expires_ms,
>> + int *timeout_bit)
>> +{
>> + struct otg_timer *otgtimer = &otgd->timers[id];
>> + struct hrtimer *timer = &otgtimer->timer;
>> +
>> + otgtimer->timeout = ms_to_ktime(expires_ms);
>> + hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>> + timer->function = callback;
>> +
>> + otgtimer->timeout_bit = timeout_bit;
>> + otgtimer->otgd = otgd;
>> +}
>> +
>> +/**
>> + * Initialize standard OTG timers
>> + */
>> +static void usb_otg_init_timers(struct otg_data *otgd)
>> +{
>> + struct otg_fsm *fsm = &otgd->fsm;
>> +
>> + otg_timer_init(A_WAIT_VRISE, otgd, set_tmout, TA_WAIT_VRISE,
>> + &fsm->a_wait_vrise_tmout);
>> + otg_timer_init(A_WAIT_VFALL, otgd, set_tmout, TA_WAIT_VFALL,
>> + &fsm->a_wait_vfall_tmout);
>> + otg_timer_init(A_WAIT_BCON, otgd, set_tmout, TA_WAIT_BCON,
>> + &fsm->a_wait_bcon_tmout);
>> + otg_timer_init(A_AIDL_BDIS, otgd, set_tmout, TA_AIDL_BDIS,
>> + &fsm->a_aidl_bdis_tmout);
>> + otg_timer_init(A_BIDL_ADIS, otgd, set_tmout, TA_BIDL_ADIS,
>> + &fsm->a_bidl_adis_tmout);
>> + otg_timer_init(B_ASE0_BRST, otgd, set_tmout, TB_ASE0_BRST,
>> + &fsm->b_ase0_brst_tmout);
>> +
>> + otg_timer_init(B_SE0_SRP, otgd, set_tmout, TB_SE0_SRP, &fsm->b_se0_srp);
>> + otg_timer_init(B_SRP_FAIL, otgd, set_tmout, TB_SRP_FAIL,
>> + &fsm->b_srp_done);
>> +
>> + otg_timer_init(A_WAIT_ENUM, otgd, set_tmout, TB_SRP_FAIL, NULL);
>
> 2 timers are missing: B_DATA_PLS, B_SSEND_SRP.
Those 2 are not used by usb-otg-fsm.c. We can add it when usb-otg-fsm.c is updated.
>
>> +}
>> +
>> +/**
>> + * OTG FSM ops function to add timer
>> + */
>> +static void usb_otg_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer id)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> + struct otg_timer *otgtimer = &otgd->timers[id];
>> + struct hrtimer *timer = &otgtimer->timer;
>> +
>> + if (!otgd->fsm_running)
>> + return;
>> +
>> + /* if timer is already active, exit */
>> + if (hrtimer_active(timer)) {
>> + dev_err(otgd->dev, "otg: timer %d is already running\n", id);
>> + return;
>> + }
>> +
>> + hrtimer_start(timer, otgtimer->timeout, HRTIMER_MODE_REL);
>> +}
>> +
>> +/**
>> + * OTG FSM ops function to delete timer
>> + */
>> +static void usb_otg_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer id)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> + struct hrtimer *timer = &otgd->timers[id].timer;
>> +
>> + hrtimer_cancel(timer);
>> +}
>> +
>> +/**
>> + * OTG FSM ops function to start/stop host
>> + */
>> +static int usb_otg_start_host(struct otg_fsm *fsm, int on)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> + struct otg_hcd_ops *hcd_ops;
>> +
>> + dev_dbg(otgd->dev, "otg: %s %d\n", __func__, on);
>> + if (!fsm->otg->host) {
>> + WARN_ONCE(1, "otg: fsm running without host\n");
>> + return 0;
>> + }
>> +
>> + if (on) {
>> + /* OTG device operations */
>> + if (otgd->start_host)
>> + otgd->start_host(fsm, on);
>> +
>> + /* start host */
>> + hcd_ops = otgd->primary_hcd.ops;
>> + hcd_ops->add(otgd->primary_hcd.hcd, otgd->primary_hcd.irqnum,
>> + otgd->primary_hcd.irqflags);
>> + if (otgd->shared_hcd.hcd) {
>> + hcd_ops = otgd->shared_hcd.ops;
>> + hcd_ops->add(otgd->shared_hcd.hcd,
>> + otgd->shared_hcd.irqnum,
>> + otgd->shared_hcd.irqflags);
>> + }
>> + } else {
>> + /* stop host */
>> + if (otgd->shared_hcd.hcd) {
>> + hcd_ops = otgd->shared_hcd.ops;
>> + hcd_ops->remove(otgd->shared_hcd.hcd);
>> + }
>> + hcd_ops = otgd->primary_hcd.ops;
>> + hcd_ops->remove(otgd->primary_hcd.hcd);
>> +
>> + /* OTG device operations */
>> + if (otgd->start_host)
>> + otgd->start_host(fsm, on);
>> + }
>> +
>> + return 0;
>> +}
>
> I do not see much benefit by this override function, usb_add/remove_hcd
> can be simply included by controller's start_host function, also there
> maybe some additional operations after usb_add_hcd, but this override
> function limit usb_add_hcd() is the last step.
I had tried host start/stop way before but Alan's suggestion was to use
bind/unbind the host controller completely as that is much simpler
[1] http://article.gmane.org/gmane.linux.usb.general/123842
>
> Maybe your intention is to make usb_add_hcd is the only operation required
> to start host, so ideally controller driver need not define its start_host
> routine for this otg ops, I am not sure if this can work for different otg
Yes that was the intention.
> platforms. If the shared code is only usb_add/remove_hcd(), maybe leave this
> ops defined by controller driver can make core code simple and give flexibility
> to controller drivers.
We don't completely override start/stop_host(). The flexibility is still there.
We call controllers start_host(1) before starting the controller and controllers
start_host(0) after stopping the controller.
So the the controller can still do what they want in otg_fsm_ops.start_host/gadget().
The OTG core only takes care of actually starting/stopping the host controller.
If we don't do that then the code in usb_otg_start_host() has to be pasted
in every OTG controller driver. This is code duplication.
>
>> +
>> +/**
>> + * OTG FSM ops function to start/stop gadget
>> + */
>> +static int usb_otg_start_gadget(struct otg_fsm *fsm, int on)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> + struct usb_gadget *gadget = fsm->otg->gadget;
>> +
>> + dev_dbg(otgd->dev, "otg: %s %d\n", __func__, on);
>> + if (!gadget) {
>> + WARN_ONCE(1, "otg: fsm running without gadget\n");
>> + return 0;
>> + }
>> +
>> + if (on) {
>> + /* OTG device operations */
>> + if (otgd->start_gadget)
>> + otgd->start_gadget(fsm, on);
>> +
>> + otgd->gadget_ops->start(fsm->otg->gadget);
>> + } else {
>> + otgd->gadget_ops->stop(fsm->otg->gadget);
>> +
>> + /* OTG device operations */
>> + if (otgd->start_gadget)
>> + otgd->start_gadget(fsm, on);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * OTG FSM work function
>> + */
>> +static void usb_otg_work(struct work_struct *work)
>> +{
>> + struct otg_data *otgd = container_of(work, struct otg_data, work);
>> +
>> + otg_statemachine(&otgd->fsm);
>
> Need consider runtime pm, or you want to rely on controller driver take
> care of it?
For simplicity let's say that controller driver takes care of it.
>
>> +}
>> +
>> +/**
>> + * usb_otg_register() - Register the OTG device to OTG core
>> + * @parent_device: parent device of Host & Gadget controllers.
>> + * @otg_fsm_ops: otg state machine ops.
>> + *
>> + * Register parent device that contains both HCD and GCD into
>> + * the USB OTG core. HCD and GCD will be prevented from starting
>> + * till both are available for use.
>> + *
>> + * Return: struct otg_fsm * if success, NULL if error.
>> + */
>> +struct otg_fsm *usb_otg_register(struct device *parent_dev,
>> + struct otg_fsm_ops *fsm_ops)
>> +{
>> + struct otg_data *otgd;
>> + int ret = 0;
>> +
>> + if (!parent_dev || !fsm_ops)
>> + return ERR_PTR(-EINVAL);
>> +
>> + /* already in list? */
>> + mutex_lock(&otg_list_mutex);
>> + if (usb_otg_device_get_otgd(parent_dev)) {
>> + dev_err(parent_dev, "otg: %s: device already in otg list\n",
>> + __func__);
>> + ret = -EINVAL;
>> + goto unlock;
>> + }
>> +
>> + /* allocate and add to list */
>> + otgd = kzalloc(sizeof(*otgd), GFP_KERNEL);
>> + if (!otgd) {
>> + ret = -ENOMEM;
>> + goto unlock;
>> + }
>> +
>> + otgd->dev = parent_dev;
>> + INIT_WORK(&otgd->work, usb_otg_work);
>> + otgd->wq = create_singlethread_workqueue("usb_otg");
>> + if (!otgd->wq) {
>> + dev_err(parent_dev, "otg: %s: can't create workqueue\n",
>> + __func__);
>> + ret = -ENODEV;
>> + goto err_wq;
>> + }
>> +
>> + usb_otg_init_timers(otgd);
>> +
>> + /* save original start host/gadget ops */
>> + otgd->start_host = fsm_ops->start_host;
>> + otgd->start_gadget = fsm_ops->start_gadget;
>> + /* create copy of original ops */
>> + otgd->fsm_ops = *fsm_ops;
>> + /* override ops */
>> + otgd->fsm_ops.start_host = usb_otg_start_host;
>> + otgd->fsm_ops.start_gadget = usb_otg_start_gadget;
>> + /* FIXME: we ignore caller's timer ops */
>> + otgd->fsm_ops.add_timer = usb_otg_add_timer;
>> + otgd->fsm_ops.del_timer = usb_otg_del_timer;
>> + /* set otg ops */
>> + otgd->fsm.ops = &otgd->fsm_ops;
>> + otgd->fsm.otg = &otgd->otg;
>> +
>> + mutex_init(&otgd->fsm.lock);
>> +
>> + list_add_tail(&otgd->list, &otg_list);
>> + mutex_unlock(&otg_list_mutex);
>> + return &otgd->fsm;
>> +
>> +err_wq:
>> + kfree(otgd);
>> +unlock:
>> + mutex_unlock(&otg_list_mutex);
>> + return ERR_PTR(ret);
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_register);
>> +
>> +/**
>> + * usb_otg_unregister() - Unregister the OTG device from USB OTG core
>> + * @parent_device: parent device of Host & Gadget controllers.
>> + *
>> + * Unregister parent OTG deviced from USB OTG core.
>> + * Prevents unregistering till both Host and Gadget controllers
>> + * have unregistered from the OTG core.
>> + *
>> + * Return: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_unregister(struct device *parent_dev)
>> +{
>> + struct otg_data *otgd;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_device_get_otgd(parent_dev);
>> + if (!otgd) {
>> + dev_err(parent_dev, "otg: %s: device not in otg list\n",
>> + __func__);
>> + mutex_unlock(&otg_list_mutex);
>> + return -EINVAL;
>> + }
>> +
>> + /* prevent unregister till both host & gadget have unregistered */
>> + if (otgd->fsm.otg->host || otgd->fsm.otg->gadget) {
>> + dev_err(parent_dev, "otg: %s: host/gadget still registered\n",
>> + __func__);
>> + return -EBUSY;
>> + }
>> +
>> + /* OTG FSM is halted when host/gadget unregistered */
>> + destroy_workqueue(otgd->wq);
>> +
>> + /* remove from otg list */
>> + list_del(&otgd->list);
>> + kfree(otgd);
>> + mutex_unlock(&otg_list_mutex);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_unregister);
>> +
>> +/**
>> + * start/kick the OTG FSM if we can
>> + * fsm->lock must be held
>> + */
>> +static void usb_otg_start_fsm(struct otg_fsm *fsm)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> +
>> + if (otgd->fsm_running)
>> + goto kick_fsm;
>> +
>> + if (!fsm->otg->host) {
>> + dev_info(otgd->dev, "otg: can't start till host registers\n");
>> + return;
>> + }
>> +
>
> This cannot work, fsm->otg->host is set in usb_otg_register_hcd(), which is
> called by usb_add_hcd(), but usb_add_hcd() should be called only if otg fsm
> already started to some A-device state, deadlock.
I've changed usb_add_hcd() behaviour. Now usb_otg_add_hcd() does the real work of adding
the hcd. usb_add_hcd() prevents the add if it is an otg hcd and just registers
with OTG core.
>
>> + if (!fsm->otg->gadget) {
>> + dev_info(otgd->dev, "otg: can't start till gadget registers\n");
>> + return;
>> + }
>> +
>> + otgd->fsm_running = true;
>> +kick_fsm:
>> + queue_work(otgd->wq, &otgd->work);
>> +}
>> +
>> +/**
>> + * stop the OTG FSM. Stops Host & Gadget controllers as well.
>> + * fsm->lock must be held
>> + */
>> +static void usb_otg_stop_fsm(struct otg_fsm *fsm)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> + int i;
>> +
>> + if (!otgd->fsm_running)
>> + return;
>> +
>> + /* no more new events queued */
>> + otgd->fsm_running = false;
>> +
>> + /* Stop state machine / timers */
>> + for (i = 0; i < ARRAY_SIZE(otgd->timers); i++)
>> + hrtimer_cancel(&otgd->timers[i].timer);
>> +
>> + flush_workqueue(otgd->wq);
>> + fsm->otg->state = OTG_STATE_UNDEFINED;
>> +
>> + /* stop host/gadget immediately */
>> + if (fsm->protocol == PROTO_HOST)
>> + otg_start_host(fsm, 0);
>> + else if (fsm->protocol == PROTO_GADGET)
>> + otg_start_gadget(fsm, 0);
>> + fsm->protocol = PROTO_UNDEF;
>> +}
>> +
>> +/**
>> + * usb_otg_sync_inputs - Sync OTG inputs with the OTG state machine
>> + * @fsm: OTG FSM instance
>> + *
>> + * Used by the OTG driver to update the inputs to the OTG
>> + * state machine.
>> + *
>> + * Can be called in IRQ context.
>> + */
>> +void usb_otg_sync_inputs(struct otg_fsm *fsm)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> +
>> + /* Don't kick FSM till it has started */
>> + if (!otgd->fsm_running)
>> + return;
>> +
>> + /* Kick FSM */
>> + queue_work(otgd->wq, &otgd->work);
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_sync_inputs);
>> +
>> +/**
>> + * usb_otg_kick_fsm - Kick the OTG state machine
>> + * @hcd_gcd_device: Host/Gadget controller device
>> + *
>> + * Used by USB host/device stack to sync OTG related
>> + * events to the OTG state machine.
>> + * e.g. change in host_bus->b_hnp_enable, gadget->b_hnp_enable
>> + *
>> + * Returns: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_kick_fsm(struct device *hcd_gcd_device)
>> +{
>> + struct otg_data *otgd;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_device_get_otgd(hcd_gcd_device->parent);
>> + if (!otgd) {
>> + dev_err(hcd_gcd_device, "otg: %s: invalid host/gadget device\n",
>> + __func__);
>> + mutex_unlock(&otg_list_mutex);
>> + return -ENODEV;
>> + }
>> +
>> + mutex_unlock(&otg_list_mutex);
>> + usb_otg_sync_inputs(&otgd->fsm);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_kick_fsm);
>> +
>> +/**
>> + * usb_otg_register_hcd - Register Host controller to OTG core
>> + * @hcd: Host controller device
>> + * @irqnum: interrupt number
>> + * @irqflags: interrupt flags
>> + * @ops: HCD ops to add/remove the HCD
>> + *
>> + * This is used by the USB Host stack to register the Host controller
>> + * to the OTG core. Host controller must not be started by the
>> + * caller as it is left upto the OTG state machine to do so.
>> + *
>> + * Returns: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
>> + unsigned long irqflags, struct otg_hcd_ops *ops)
>> +{
>> + struct otg_data *otgd;
>> + struct device *otg_dev = hcd->self.controller->parent;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_device_get_otgd(otg_dev);
>> + if (!otgd) {
>> + dev_dbg(otg_dev, "otg: %s: device not registered to otg core\n",
>> + __func__);
>> + mutex_unlock(&otg_list_mutex);
>> + return -EINVAL;
>> + }
>> +
>> + mutex_unlock(&otg_list_mutex);
>> + /* HCD will be started by OTG fsm when needed */
>> + mutex_lock(&otgd->fsm.lock);
>> + if (otgd->primary_hcd.hcd) {
>> + /* probably a shared HCD ? */
>> + if (usb_otg_hcd_is_primary_hcd(hcd)) {
>> + dev_err(otg_dev, "otg: primary host already registered\n");
>> + goto err;
>> + }
>> +
>> + if (hcd->shared_hcd == otgd->primary_hcd.hcd) {
>> + if (otgd->shared_hcd.hcd) {
>> + dev_err(otg_dev, "otg: shared host already registered\n");
>> + goto err;
>> + }
>> +
>> + otgd->shared_hcd.hcd = hcd;
>> + otgd->shared_hcd.irqnum = irqnum;
>> + otgd->shared_hcd.irqflags = irqflags;
>> + otgd->shared_hcd.ops = ops;
>> + dev_info(otg_dev, "otg: shared host %s registered\n",
>> + dev_name(hcd->self.controller));
>> + } else {
>> + dev_err(otg_dev, "otg: invalid shared host %s\n",
>> + dev_name(hcd->self.controller));
>> + goto err;
>> + }
>> + } else {
>> + if (!usb_otg_hcd_is_primary_hcd(hcd)) {
>> + dev_err(otg_dev, "otg: primary host must be registered first\n");
>> + goto err;
>> + }
>> +
>> + otgd->primary_hcd.hcd = hcd;
>> + otgd->primary_hcd.irqnum = irqnum;
>> + otgd->primary_hcd.irqflags = irqflags;
>> + otgd->primary_hcd.ops = ops;
>> + dev_info(otg_dev, "otg: primary host %s registered\n",
>> + dev_name(hcd->self.controller));
>> + }
>> +
>> + /*
>> + * we're ready only if we have shared HCD
>> + * or we don't need shared HCD.
>> + */
>> + if (otgd->shared_hcd.hcd || !otgd->primary_hcd.hcd->shared_hcd) {
>> + otgd->fsm.otg->host = hcd_to_bus(hcd);
>> + /* FIXME: set bus->otg_port if this is true OTG port with HNP */
>> +
>> + /* start FSM */
>> + usb_otg_start_fsm(&otgd->fsm);
>
> usb_otg_register_hcd() is called before usb_otg_add_hcd(), start fsm on
> this point can make sense since hcd has not been added?
for OTG/DRD HCD case:
- usb_add_hcd() does not really ADD (or START) the HCD. It just registers with OTG core.
- FSM takes care of ADDing (or STARTing) the HCD when it wants using the
usb_otg_add_hcd() call.
- FSM does not need HCD to be already added. It just needs it to be registered.
It takes care of strting it when it wants to.
>
>> + } else {
>> + dev_dbg(otg_dev, "otg: can't start till shared host registers\n");
>> + }
>> +
>> + mutex_unlock(&otgd->fsm.lock);
>> +
>> + return 0;
>> +
>> +err:
>> + mutex_unlock(&otgd->fsm.lock);
>> + return -EINVAL;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_register_hcd);
>> +
>> +/**
>> + * usb_otg_unregister_hcd - Unregister Host controller from OTG core
>> + * @hcd: Host controller device
>> + *
>> + * This is used by the USB Host stack to unregister the Host controller
>> + * from the OTG core. Ensures that Host controller is not running
>> + * on successful return.
>> + *
>> + * Returns: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_unregister_hcd(struct usb_hcd *hcd)
>> +{
>> + struct otg_data *otgd;
>> + struct usb_bus *bus = hcd_to_bus(hcd);
>> + struct device *otg_dev = bus->controller->parent;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_device_get_otgd(otg_dev);
>> + if (!otgd) {
>> + dev_err(otg_dev, "otg: %s: device not registered to otg core\n",
>> + __func__);
>> + mutex_unlock(&otg_list_mutex);
>> + return -EINVAL;
>> + }
>> +
>> + mutex_unlock(&otg_list_mutex);
>> +
>> + mutex_lock(&otgd->fsm.lock);
>> + if (hcd == otgd->primary_hcd.hcd) {
>> + otgd->primary_hcd.hcd = NULL;
>> + dev_info(otg_dev, "otg: primary host %s unregistered\n",
>> + dev_name(bus->controller));
>> + } else if (hcd == otgd->shared_hcd.hcd) {
>> + otgd->shared_hcd.hcd = NULL;
>> + dev_info(otg_dev, "otg: shared host %s unregistered\n",
>> + dev_name(bus->controller));
>> + } else {
>> + dev_err(otg_dev, "otg: host %s wasn't registered with otg\n",
>> + dev_name(bus->controller));
>> + mutex_unlock(&otgd->fsm.lock);
>> + return -EINVAL;
>> + }
>> +
>> + /* stop FSM & Host */
>> + usb_otg_stop_fsm(&otgd->fsm);
>> + otgd->fsm.otg->host = NULL;
>> +
>> + mutex_unlock(&otgd->fsm.lock);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_unregister_hcd);
>> +
>> +/**
>> + * usb_otg_register_gadget - Register Gadget controller to OTG core
>> + * @gadget: Gadget controller
>> + *
>> + * This is used by the USB Gadget stack to register the Gadget controller
>> + * to the OTG core. Gadget controller must not be started by the
>> + * caller as it is left upto the OTG state machine to do so.
>> + *
>> + * Gadget core must call this only when all resources required for
>> + * gadget controller to run are available.
>> + * i.e. gadget function driver is available.
>> + *
>> + * Returns: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_register_gadget(struct usb_gadget *gadget,
>> + struct otg_gadget_ops *ops)
>> +{
>> + struct otg_data *otgd;
>> + struct device *otg_dev = gadget->dev.parent;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_device_get_otgd(otg_dev);
>> + if (!otgd) {
>> + dev_err(otg_dev, "otg: %s: device not registered to otg core\n",
>> + __func__);
>> + mutex_unlock(&otg_list_mutex);
>> + return -EINVAL;
>> + }
>> +
>> + mutex_unlock(&otg_list_mutex);
>> +
>> + mutex_lock(&otgd->fsm.lock);
>> + if (otgd->fsm.otg->gadget) {
>> + dev_err(otg_dev, "otg: gadget already registered with otg\n");
>> + mutex_unlock(&otgd->fsm.lock);
>> + return -EINVAL;
>> + }
>> +
>> + otgd->fsm.otg->gadget = gadget;
>> + otgd->gadget_ops = ops;
>> + dev_info(otg_dev, "otg: gadget %s registered\n",
>> + dev_name(&gadget->dev));
>> +
>> + /* start FSM */
>> + usb_otg_start_fsm(&otgd->fsm);
>> + mutex_unlock(&otgd->fsm.lock);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_register_gadget);
>> +
>> +/**
>> + * usb_otg_unregister_gadget - Unregister Gadget controller from OTG core
>> + * @gadget: Gadget controller
>> + *
>> + * This is used by the USB Gadget stack to unregister the Gadget controller
>> + * from the OTG core. Ensures that Gadget controller is not running
>> + * on successful return.
>> + *
>> + * Returns: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_unregister_gadget(struct usb_gadget *gadget)
>> +{
>> + struct otg_data *otgd;
>> + struct device *otg_dev = gadget->dev.parent;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_device_get_otgd(otg_dev);
>> + if (!otgd) {
>> + dev_err(otg_dev, "otg: %s: device not registered to otg core\n",
>> + __func__);
>> + mutex_unlock(&otg_list_mutex);
>> + return -EINVAL;
>> + }
>> +
>> + mutex_unlock(&otg_list_mutex);
>> +
>> + mutex_lock(&otgd->fsm.lock);
>> + if (otgd->fsm.otg->gadget != gadget) {
>> + dev_err(otg_dev, "otg: gadget %s wasn't registered with otg\n",
>> + dev_name(&gadget->dev));
>> + mutex_unlock(&otgd->fsm.lock);
>> + return -EINVAL;
>> + }
>> +
>> + /* Stop FSM & gadget */
>> + usb_otg_stop_fsm(&otgd->fsm);
>> + otgd->fsm.otg->gadget = NULL;
>> + mutex_unlock(&otgd->fsm.lock);
>> +
>> + dev_info(otg_dev, "otg: gadget %s unregistered\n",
>> + dev_name(&gadget->dev));
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_unregister_gadget);
>> +
>> +/**
>> + * usb_otg_fsm_to_dev - Get OTG controller device from struct otg_fsm
>> + * @fsm: otg_fsm data structure
>> + *
>> + * This is used by the OTG controller driver to get it's device node
>> + * from any of the otg_fsm->ops.
>> + */
>> +struct device *usb_otg_fsm_to_dev(struct otg_fsm *fsm)
>> +{
>> + struct otg_data *otgd = container_of(fsm, struct otg_data, fsm);
>> +
>> + return otgd->dev;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_fsm_to_dev);
>> diff --git a/drivers/usb/common/usb-otg.h b/drivers/usb/common/usb-otg.h
>> new file mode 100644
>> index 0000000..05331f0
>> --- /dev/null
>> +++ b/drivers/usb/common/usb-otg.h
>> @@ -0,0 +1,71 @@
>> +/**
>> + * drivers/usb/common/usb-otg.h - USB OTG core local header
>> + *
>> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
>> + * Author: Roger Quadros <rogerq@...com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#ifndef __DRIVERS_USB_COMMON_USB_OTG_H
>> +#define __DRIVERS_USB_COMMON_USB_OTG_H
>> +
>> +/*
>> + * A-DEVICE timing constants
>> + */
>> +
>> +/* Wait for VBUS Rise */
>> +#define TA_WAIT_VRISE (100) /* a_wait_vrise: section 7.1.2
>> + * a_wait_vrise_tmr: section 7.4.5.1
>> + * TA_VBUS_RISE <= 100ms, section 4.4
>> + * Table 4-1: Electrical Characteristics
>> + * ->DC Electrical Timing
>> + */
>> +/* Wait for VBUS Fall */
>> +#define TA_WAIT_VFALL (1000) /* a_wait_vfall: section 7.1.7
>> + * a_wait_vfall_tmr: section: 7.4.5.2
>> + */
>> +/* Wait for B-Connect */
>> +#define TA_WAIT_BCON (10000) /* a_wait_bcon: section 7.1.3
>> + * TA_WAIT_BCON: should be between 1100
>> + * and 30000 ms, section 5.5, Table 5-1
>> + */
>> +/* A-Idle to B-Disconnect */
>> +#define TA_AIDL_BDIS (5000) /* a_suspend min 200 ms, section 5.2.1
>> + * TA_AIDL_BDIS: section 5.5, Table 5-1
>> + */
>> +/* B-Idle to A-Disconnect */
>> +#define TA_BIDL_ADIS (500) /* TA_BIDL_ADIS: section 5.2.1
>> + * 500ms is used for B switch to host
>> + * for safe
>> + */
>> +
>> +/*
>> + * B-device timing constants
>> + */
>> +
>> +/* Data-Line Pulse Time*/
>> +#define TB_DATA_PLS (10) /* b_srp_init,continue 5~10ms
>> + * section:5.1.3
>> + */
>> +/* SRP Fail Time */
>> +#define TB_SRP_FAIL (6000) /* b_srp_init,fail time 5~6s
>> + * section:5.1.6
>> + */
>> +/* A-SE0 to B-Reset */
>> +#define TB_ASE0_BRST (155) /* minimum 155 ms, section:5.3.1 */
>> +/* SE0 Time Before SRP */
>> +#define TB_SE0_SRP (1000) /* b_idle,minimum 1s, section:5.1.2 */
>> +/* SSEND time before SRP */
>> +#define TB_SSEND_SRP (1500) /* minimum 1.5 sec, section:5.1.2 */
>> +
>> +#define TB_SESS_VLD (1000)
>> +
>
> All otg timer timeout value should be in some *range* defined by otg spec,
> not some specific value, I don't think one specific value can meet all otg
> platforms, so we need find a way to make those value can be configured by
> controller drivers.
OK. How about introducing 'struct usb_otg_config' which must be passed
to usb_otg_register().
/* otg controller configuration */
struct usb_otg_config {
/* OTG caps */
struct usb_otg_caps otg_caps;
/* OTG Timer timeouts in ms. If 0, sane default will be used */
int ta_wait_vrise;
...
};
>
>> +#endif /* __DRIVERS_USB_COMMON_USB_OTG_H */
>> diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
>> index a99c89e..b468a9f 100644
>> --- a/drivers/usb/core/Kconfig
>> +++ b/drivers/usb/core/Kconfig
>> @@ -42,7 +42,7 @@ config USB_DYNAMIC_MINORS
>> If you are unsure about this, say N here.
>>
>> config USB_OTG
>> - bool "OTG support"
>> + bool "OTG/Dual-role support"
>> depends on PM
>> default n
>> help
>> @@ -75,15 +75,6 @@ config USB_OTG_BLACKLIST_HUB
>> and software costs by not supporting external hubs. So
>> are "Embedded Hosts" that don't offer OTG support.
>>
>> -config USB_OTG_FSM
>> - tristate "USB 2.0 OTG FSM implementation"
>> - depends on USB
>> - select USB_OTG
>> - select USB_PHY
>> - help
>> - Implements OTG Finite State Machine as specified in On-The-Go
>> - and Embedded Host Supplement to the USB Revision 2.0 Specification.
>> -
>> config USB_ULPI_BUS
>> tristate "USB ULPI PHY interface support"
>> depends on USB_SUPPORT
>> diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
>> index 52661c5..ce6f8d8 100644
>> --- a/include/linux/usb/otg.h
>> +++ b/include/linux/usb/otg.h
>> @@ -10,6 +10,11 @@
>> #define __LINUX_USB_OTG_H
>>
>> #include <linux/phy/phy.h>
>> +#include <linux/device.h>
>> +#include <linux/usb.h>
>> +#include <linux/usb/hcd.h>
>> +#include <linux/usb/gadget.h>
>> +#include <linux/usb/otg-fsm.h>
>> #include <linux/usb/phy.h>
>>
>> struct usb_otg {
>> @@ -23,6 +28,7 @@ struct usb_otg {
>>
>> enum usb_otg_state state;
>>
>> +/*------------- deprecated interface -----------------------------*/
>> /* bind/unbind the host controller */
>> int (*set_host)(struct usb_otg *otg, struct usb_bus *host);
>>
>> @@ -38,11 +44,85 @@ struct usb_otg {
>>
>> /* start or continue HNP role switch */
>> int (*start_hnp)(struct usb_otg *otg);
>> -
>> +/*---------------------------------------------------------------*/
>> };
>>
>> extern const char *usb_otg_state_string(enum usb_otg_state state);
>>
>> +enum usb_dr_mode {
>> + USB_DR_MODE_UNKNOWN,
>> + USB_DR_MODE_HOST,
>> + USB_DR_MODE_PERIPHERAL,
>> + USB_DR_MODE_OTG,
>> +};
>> +
>> +#if IS_ENABLED(CONFIG_USB_OTG)
>> +struct otg_fsm *usb_otg_register(struct device *parent_dev,
>> + struct otg_fsm_ops *fsm_ops);
>> +int usb_otg_unregister(struct device *parent_dev);
>> +int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
>> + unsigned long irqflags, struct otg_hcd_ops *ops);
>> +int usb_otg_unregister_hcd(struct usb_hcd *hcd);
>> +int usb_otg_register_gadget(struct usb_gadget *gadget,
>> + struct otg_gadget_ops *ops);
>> +int usb_otg_unregister_gadget(struct usb_gadget *gadget);
>> +void usb_otg_sync_inputs(struct otg_fsm *fsm);
>> +int usb_otg_kick_fsm(struct device *hcd_gcd_device);
>> +struct device *usb_otg_fsm_to_dev(struct otg_fsm *fsm);
>> +
>> +#else /* CONFIG_USB_OTG */
>> +
>> +static inline struct otg_fsm *usb_otg_register(struct device *parent_dev,
>> + struct otg_fsm_ops *fsm_ops)
>> +{
>> + return ERR_PTR(-ENOSYS);
>> +}
>> +
>> +static inline int usb_otg_unregister(struct device *parent_dev)
>> +{
>> + return -ENOSYS;
>> +}
>> +
>> +static inline int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
>> + unsigned long irqflags,
>> + struct otg_hcd_ops *ops)
>> +{
>> + return -ENOSYS;
>> +}
>> +
>> +static inline int usb_otg_unregister_hcd(struct usb_hcd *hcd)
>> +{
>> + return -ENOSYS;
>> +}
>> +
>> +static inline int usb_otg_register_gadget(struct usb_gadget *gadget,
>> + struct otg_gadget_ops *ops)
>> +{
>> + return -ENOSYS;
>> +}
>> +
>> +static inline int usb_otg_unregister_gadget(struct usb_gadget *gadget)
>> +{
>> + return -ENOSYS;
>> +}
>> +
>> +static inline void usb_otg_sync_inputs(struct otg_fsm *fsm)
>> +{
>> +}
>> +
>> +static inline int usb_otg_kick_fsm(struct device *hcd_gcd_device)
>> +{
>> + return -ENOSYS;
>> +}
>> +
>> +static inline struct device *usb_otg_fsm_to_dev(struct otg_fsm *fsm)
>> +{
>> + return NULL;
>> +}
>> +
>> +#endif /* CONFIG_USB_OTG */
>> +
>> +/*------------- deprecated interface -----------------------------*/
>> /* Context: can sleep */
>> static inline int
>> otg_start_hnp(struct usb_otg *otg)
>> @@ -94,14 +174,9 @@ otg_start_srp(struct usb_otg *otg)
>> return -ENOTSUPP;
>> }
>>
>> +/*---------------------------------------------------------------*/
>> +
>> /* for OTG controller drivers (and maybe other stuff) */
>> extern int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num);
>>
>> -enum usb_dr_mode {
>> - USB_DR_MODE_UNKNOWN,
>> - USB_DR_MODE_HOST,
>> - USB_DR_MODE_PERIPHERAL,
>> - USB_DR_MODE_OTG,
>> -};
>> -
>> #endif /* __LINUX_USB_OTG_H */
>> --
>> 2.1.4
>>
>
> I assume I will have more comments after try more.
Sure, no worries :)
cheers,
-roger
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