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Message-ID: <55ED6C9F.2000502@ti.com>
Date: Mon, 7 Sep 2015 13:53:19 +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>, <abrestic@...omium.org>,
<linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-omap@...r.kernel.org>
Subject: Re: [PATCH v4 07/13] usb: otg: add OTG core
On 07/09/15 10:40, Li Jun wrote:
> On Mon, Aug 24, 2015 at 04:21:18PM +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 | 1061 ++++++++++++++++++++++++++++++++++++++++++
>> drivers/usb/common/usb-otg.h | 71 +++
>> drivers/usb/core/Kconfig | 11 +-
>> include/linux/usb/otg.h | 189 +++++++-
>> 8 files changed, 1321 insertions(+), 21 deletions(-)
>> create mode 100644 drivers/usb/common/usb-otg.c
>> create mode 100644 drivers/usb/common/usb-otg.h
>>
>
> ... ...
>
>> +
>> +/**
>> + * Get OTG device from host or gadget device.
>> + *
>> + * For non device tree boot, the OTG controller is assumed to be
>> + * the parent of the host/gadget device.
>
> This assumption/restriction maybe a problem, as I pointed in your previous
> version, usb_create_hcd() use the passed dev as its dev, but,
> usb_add_gadget_udc() use the passed dev as its parent dev, so often the
> host and gadget don't share the same parent device, at least it doesn't
> apply to chipidea case.
Let's provide a way for OTG driver to provide the OTG core exactly which is
the related host/gadget device.
>
>> + * For device tree boot, the OTG controller is derived from the
>> + * "otg-controller" property.
>> + */
>> +static struct device *usb_otg_get_device(struct device *hcd_gcd_dev)
>> +{
>> + struct device *otg_dev;
>> +
>> + if (!hcd_gcd_dev)
>> + return NULL;
>> +
>> + if (hcd_gcd_dev->of_node) {
>> + struct device_node *np;
>> + struct platform_device *pdev;
>> +
>> + np = of_parse_phandle(hcd_gcd_dev->of_node, "otg-controller",
>> + 0);
>> + if (!np)
>> + goto legacy; /* continue legacy way */
>> +
>> + pdev = of_find_device_by_node(np);
>> + of_node_put(np);
>> + if (!pdev) {
>> + dev_err(&pdev->dev, "couldn't get otg-controller device\n");
>> + return NULL;
>> + }
>> +
>> + otg_dev = &pdev->dev;
>> + return otg_dev;
>> + }
>> +
>> +legacy:
>> + /* otg device is parent and must be registered */
>> + otg_dev = hcd_gcd_dev->parent;
>> + if (!usb_otg_get_data(otg_dev))
>> + return NULL;
>> +
>> + return otg_dev;
>> +}
>> +
>
> ... ...
>
>> +static void usb_otg_init_timers(struct usb_otg *otgd, unsigned *timeouts)
>> +{
>> + struct otg_fsm *fsm = &otgd->fsm;
>> + unsigned long tmouts[NUM_OTG_FSM_TIMERS];
>> + int i;
>> +
>> + /* set default timeouts */
>> + tmouts[A_WAIT_VRISE] = TA_WAIT_VRISE;
>> + tmouts[A_WAIT_VFALL] = TA_WAIT_VFALL;
>> + tmouts[A_WAIT_BCON] = TA_WAIT_BCON;
>> + tmouts[A_AIDL_BDIS] = TA_AIDL_BDIS;
>> + tmouts[A_BIDL_ADIS] = TA_BIDL_ADIS;
>> + tmouts[B_ASE0_BRST] = TB_ASE0_BRST;
>> + tmouts[B_SE0_SRP] = TB_SE0_SRP;
>> + tmouts[B_SRP_FAIL] = TB_SRP_FAIL;
>> +
>> + /* set controller provided timeouts */
>> + if (timeouts) {
>> + for (i = 0; i < NUM_OTG_FSM_TIMERS; i++) {
>> + if (timeouts[i])
>> + tmouts[i] = timeouts[i];
>> + }
>> + }
>> +
>> + 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);
>> +
>> + /* FIXME: what about A_WAIT_ENUM? */
>
> Either you init it as other timers, or you remove all of it, otherwise
> there will be NULL pointer crash.
I want to initialize it but was not sure about the timeout value.
What timeout value I must use?
>
>> +}
>> +
>> +/**
>> + * OTG FSM ops function to add timer
>> + */
>> +static void usb_otg_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer id)
>> +{
>> + struct usb_otg *otgd = container_of(fsm, struct usb_otg, 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 usb_otg *otgd = container_of(fsm, struct usb_otg, fsm);
>> + struct hrtimer *timer = &otgd->timers[id].timer;
>> +
>> + hrtimer_cancel(timer);
>> +}
>> +
>> +/**
>> + * Helper function to start/stop otg host. For use by otg controller.
>> + */
>> +int usb_otg_start_host(struct otg_fsm *fsm, int on)
>> +{
>> + struct usb_otg *otgd = container_of(fsm, struct usb_otg, 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) {
>> + /* 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);
>> + }
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_start_host);
>> +
>> +/**
>> + * Helper function to start/stop otg gadget. For use by otg controller.
>> + */
>> +int usb_otg_start_gadget(struct otg_fsm *fsm, int on)
>> +{
>> + struct usb_otg *otgd = container_of(fsm, struct usb_otg, 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)
>> + otgd->gadget_ops->start(fsm->otg->gadget);
>> + else
>> + otgd->gadget_ops->stop(fsm->otg->gadget);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_otg_start_gadget);
>> +
>> +/**
>> + * OTG FSM work function
>> + */
>> +static void usb_otg_work(struct work_struct *work)
>> +{
>> + struct usb_otg *otgd = container_of(work, struct usb_otg, work);
>> +
>
> Add runtime pm for it
> pm_runtime_get_sync(otgd->dev);
>> + otg_statemachine(&otgd->fsm);
> pm_runtime_put_sync(otgd->dev);
>
Sorry missed this one. Will add.
> Also as I raised in your previous version, we need successive state machine
> transition, how about:
> if (otg_statemachine(&otgd->fsm))
> usb_otg_sync_inputs(&otgd->fsm);
OK. will add this too.
>> +}
>> +
>> +/**
>> + * usb_otg_register() - Register the OTG device to OTG core
>> + * @dev: OTG controller device.
>> + * @config: OTG configuration.
>> + *
>> + * Register the OTG controller device with the USB OTG core.
>> + * The associated Host and Gadget controllers will be prevented from
>> + * being started till both are available for use.
>> + *
>> + * For non device tree boots, the OTG controller device must be the
>> + * parent node of the Host and Gadget controllers.
>> + *
>> + * For device tree case, the otg-controller property must be present
>> + * in the Host and Gadget controller node and it must point to the
>> + * same OTG controller node.
>> + *
>> + * Return: struct otg_fsm * if success, NULL if error.
>> + */
>> +struct otg_fsm *usb_otg_register(struct device *dev,
>> + struct usb_otg_config *config)
>
> Why not return usb_otg? Since you create usb_otg which contains all stuff
> for otg.
yes, returning usb_otg makes more sense now.
>
>> +{
>> + struct usb_otg *otgd;
>> + struct otg_wait_data *wait;
>> + int ret = 0;
>> +
>> + if (!dev || !config || !config->fsm_ops)
>> + return ERR_PTR(-EINVAL);
>> +
>> + /* already in list? */
>> + mutex_lock(&otg_list_mutex);
>> + if (usb_otg_get_data(dev)) {
>> + dev_err(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 = dev;
>> + otgd->caps = &config->otg_caps;
>
> How about define otgd->caps as a pointer, then don't need copy it.
otgd->caps is a pointer.
>
>> + INIT_WORK(&otgd->work, usb_otg_work);
>> + otgd->wq = create_singlethread_workqueue("usb_otg");
>> + if (!otgd->wq) {
>> + dev_err(dev, "otg: %s: can't create workqueue\n",
>> + __func__);
>> + ret = -ENOMEM;
>> + goto err_wq;
>> + }
>> +
>> + usb_otg_init_timers(otgd, config->otg_timeouts);
>> +
>> + /* create copy of original ops */
>> + otgd->fsm_ops = *config->fsm_ops;
>
> The same, use a pointer is enough?
We are creating a copy because we are overriding timer ops.
>
>> + /* 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;
>> +
>> + mutex_init(&otgd->fsm.lock);
>> +
>> + list_add_tail(&otgd->list, &otg_list);
>> + mutex_unlock(&otg_list_mutex);
>> +
>> + /* were we in wait list? */
>> + mutex_lock(&wait_list_mutex);
>> + wait = usb_otg_get_wait(dev);
>> + mutex_unlock(&wait_list_mutex);
>> + if (wait) {
>> + /* register pending host/gadget and flush from list */
>> + usb_otg_flush_wait(dev);
>> + }
>> +
>> + 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
>> + * @dev: OTG controller device.
>> + *
>> + * Unregister OTG controller device from USB OTG core.
>> + * Prevents unregistering till both the associated Host and Gadget controllers
>> + * have unregistered from the OTG core.
>> + *
>> + * Return: 0 on success, error value otherwise.
>> + */
>> +int usb_otg_unregister(struct device *dev)
>> +{
>> + struct usb_otg *otgd;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_get_data(dev);
>> + if (!otgd) {
>> + dev_err(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(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 usb_otg *otgd = container_of(fsm, struct usb_otg, 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;
>
> So we need register hcd(usb_otg_register_hcd) before start fsm, right?
Right. But you must use the plain old usb_add_hcd().
>
>> + }
>> +
>> + 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 usb_otg *otgd = container_of(fsm, struct usb_otg, 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 usb_otg *otgd = container_of(fsm, struct usb_otg, 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 usb_otg *otgd;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_get_data(usb_otg_get_device(hcd_gcd_device));
>> + mutex_unlock(&otg_list_mutex);
>> + if (!otgd) {
>> + dev_dbg(hcd_gcd_device, "otg: %s: invalid host/gadget device\n",
>> + __func__);
>> + return -ENODEV;
>> + }
>> +
>> + 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.
>
> I am confused on how to use this function.
> - This function should be called before start fsm per usb_otg_start_fsm().
yes.
> - Called by usb_add_hcd(), so we need call usb_add_hcd() before start fsm.
yes.
> - If I want to add hcd when switch to host role, and remove hcd when switch
> to peripheral, with this design, I cannot use this function?
You add hcd only once during the life of the OTG device. If it is linked to the
OTG controller the OTG fsm manages the start/stop of hcd using the otg_hcd_ops.
"usb/core/hcd.c"
static struct otg_hcd_ops otg_hcd_intf = {
.add = usb_otg_add_hcd,
.remove = usb_otg_remove_hcd,
};
Your otg driver must use teh usb_otg_add/remove_hcd to start/stop the controller.
Using usb_remove_hcd() means the hcd resource is no longer available and the
otg fsm will be stopped.
> - How about split it out of usb_add_hcd()?
Adding the HCD and starting/stopping the hcd is split into
usb_add/remove_hcd() and usb_otg_add/remove_hcd() for OTG case.
>
>> + *
>> + * 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 usb_otg *otgd;
>> + struct device *hcd_dev = hcd->self.controller;
>> + struct device *otg_dev = usb_otg_get_device(hcd_dev);
>> +
>> + if (!otg_dev)
>> + return -EINVAL; /* we're definitely not OTG */
>> +
>> + /* we're otg but otg controller might not yet be registered */
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_get_data(otg_dev);
>> + mutex_unlock(&otg_list_mutex);
>> + if (!otgd) {
>> + dev_dbg(hcd_dev,
>> + "otg: controller not yet registered. waiting..\n");
>> + /*
>> + * otg controller might register later. Put the hcd in
>> + * wait list and call us back when ready
>> + */
>> + if (usb_otg_hcd_wait_add(otg_dev, hcd, irqnum, irqflags, ops)) {
>> + dev_dbg(hcd_dev, "otg: failed to add to wait list\n");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> + }
>> +
>> + /* HCD will be started by OTG fsm when needed */
>> + mutex_lock(&otgd->fsm.lock);
>
> If call usb_add_hcd() when start host role, deadlock.
No. You must call usb_otg_add_hcd() to start host role.
>
>> + 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);
>
> otgd->host = hcd_to_bus(hcd);
ok. So we set host at both places. struct usb_otg in struct otg_fsm starts to
feel redundant now. I think we should get rid of it and get the usb_otg struct
using container_of() instead.
>
>> + /* FIXME: set bus->otg_port if this is true OTG port with HNP */
>> +
>> + /* start FSM */
>> + usb_otg_start_fsm(&otgd->fsm);
>> + } 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;
>
> Return non-zero, then if err, do we need call usb_otg_add_hcd() after
> usb_otg_register_hcd() fails?
You should not call usb_otg_register_hcd() but usb_add_hcd().
If that fails then you fail as ususal.
>
>> +}
>> +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 usb_otg *otgd;
>> + struct device *hcd_dev = hcd_to_bus(hcd)->controller;
>> + struct device *otg_dev = usb_otg_get_device(hcd_dev);
>> +
>> + if (!otg_dev)
>> + return -EINVAL; /* we're definitely not OTG */
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_get_data(otg_dev);
>> + mutex_unlock(&otg_list_mutex);
>> + if (!otgd) {
>> + /* are we in wait list? */
>> + if (!usb_otg_hcd_wait_remove(hcd))
>> + return 0;
>> +
>> + dev_dbg(hcd_dev, "otg: host wasn't registered with otg\n");
>> + return -EINVAL;
>> + }
>> +
>> + 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(hcd_dev));
>> + } else if (hcd == otgd->shared_hcd.hcd) {
>> + otgd->shared_hcd.hcd = NULL;
>> + dev_info(otg_dev, "otg: shared host %s unregistered\n",
>> + dev_name(hcd_dev));
>> + } else {
>> + dev_err(otg_dev, "otg: host %s wasn't registered with otg\n",
>> + dev_name(hcd_dev));
>> + 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 usb_otg *otgd;
>> + struct device *gadget_dev = &gadget->dev;
>> + struct device *otg_dev = usb_otg_get_device(gadget_dev);
>> +
>> + if (!otg_dev)
>> + return -EINVAL; /* we're definitely not OTG */
>> +
>> + /* we're otg but otg controller might not yet be registered */
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_get_data(otg_dev);
>> + mutex_unlock(&otg_list_mutex);
>> + if (!otgd) {
>> + dev_dbg(gadget_dev,
>> + "otg: controller not yet registered. waiting..\n");
>> + /*
>> + * otg controller might register later. Put the gadget in
>> + * wait list and call us back when ready
>> + */
>> + if (usb_otg_gadget_wait_add(otg_dev, gadget, ops)) {
>> + dev_dbg(gadget_dev, "otg: failed to add to wait list\n");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> + }
>> +
>> + 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 usb_otg *otgd;
>> + struct device *gadget_dev = &gadget->dev;
>> + struct device *otg_dev = usb_otg_get_device(gadget_dev);
>> +
>> + if (!otg_dev)
>> + return -EINVAL;
>> +
>> + mutex_lock(&otg_list_mutex);
>> + otgd = usb_otg_get_data(otg_dev);
>> + mutex_unlock(&otg_list_mutex);
>> + if (!otgd) {
>> + /* are we in wait list? */
>> + if (!usb_otg_gadget_wait_remove(gadget))
>> + return 0;
>> +
>> + dev_dbg(gadget_dev, "otg: gadget wasn't registered with otg\n");
>> + return -EINVAL;
>> + }
>> +
>> + 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 usb_otg *otgd = container_of(fsm, struct usb_otg, 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)
>> +
>> +#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 bd1dcf8..38cabe0 100644
>> --- a/include/linux/usb/otg.h
>> +++ b/include/linux/usb/otg.h
>> @@ -10,19 +10,100 @@
>> #define __LINUX_USB_OTG_H
>>
>> #include <linux/phy/phy.h>
>> +#include <linux/device.h>
>> +#include <linux/hrtimer.h>
>> +#include <linux/ktime.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 otg_hcd - host controller state and interface
>> + *
>> + * @hcd: host controller
>> + * @irqnum: irq number
>> + * @irqflags: irq flags
>> + * @ops: otg to host controller interface
>> + */
>> +struct otg_hcd {
>> + struct usb_hcd *hcd;
>> + unsigned int irqnum;
>> + unsigned long irqflags;
>> + struct otg_hcd_ops *ops;
>> +};
>> +
>> +struct usb_otg;
>> +
>> +/**
>> + * struct otg_timer - otg timer data
>> + *
>> + * @timer: high resolution timer
>> + * @timeout: timeout value
>> + * @timetout_bit: pointer to variable that is set on timeout
>> + * @otgd: usb otg data
>> + */
>> +struct otg_timer {
>> + struct hrtimer timer;
>> + ktime_t timeout;
>> + /* callback data */
>> + int *timeout_bit;
>> + struct usb_otg *otgd;
>> +};
>> +
>> +/**
>> + * struct usb_otg - usb otg controller state
>> + *
>> + * @default_a: Indicates we are an A device. i.e. Host.
>> + * @phy: USB phy interface
>> + * @usb_phy: old usb_phy interface
>> + * @host: host controller bus
>> + * @gadget: gadget device
>> + * @state: current otg state
>> + * @dev: otg controller device
>> + * @caps: otg capabilities revision, hnp, srp, etc
>> + * @fsm: otg finite state machine
>> + * @fsm_ops: controller hooks for the state machine
>> + * ------- internal use only -------
>> + * @primary_hcd: primary host state and interface
>> + * @shared_hcd: shared host state and interface
>> + * @gadget_ops: gadget interface
>> + * @timers: otg timers for state machine
>> + * @list: list of otg controllers
>> + * @work: otg state machine work
>> + * @wq: otg state machine work queue
>> + * @fsm_running: state machine running/stopped indicator
>> + */
>> struct usb_otg {
>> u8 default_a;
>>
>> struct phy *phy;
>> /* old usb_phy interface */
>> struct usb_phy *usb_phy;
>> +
>
> add a blank line?
>
>> struct usb_bus *host;
>> struct usb_gadget *gadget;
>>
>> enum usb_otg_state state;
>>
>> + struct device *dev;
>> + struct usb_otg_caps *caps;
>> + struct otg_fsm fsm;
>> + struct otg_fsm_ops fsm_ops;
>> +
>> + /* internal use only */
>> + struct otg_hcd primary_hcd;
>> + struct otg_hcd shared_hcd;
>> + struct otg_gadget_ops *gadget_ops;
>> + struct otg_timer timers[NUM_OTG_FSM_TIMERS];
>> + struct list_head list;
>> + struct work_struct work;
>> + struct workqueue_struct *wq;
>> + bool fsm_running;
>
> Should fsm_running be added in otg_fsm struct?
Yes, can be moved there.
>
>> + /* use otg->fsm.lock for serializing access */
>> +
>> +/*------------- deprecated interface -----------------------------*/
>> /* bind/unbind the host controller */
>> int (*set_host)(struct usb_otg *otg, struct usb_bus *host);
>>
>> @@ -38,7 +119,7 @@ struct usb_otg {
>>
>> /* start or continue HNP role switch */
>> int (*start_hnp)(struct usb_otg *otg);
>> -
>> +/*---------------------------------------------------------------*/
>> };
>>
>> /**
>> @@ -56,8 +137,105 @@ struct usb_otg_caps {
>> bool adp_support;
>> };
>>
>> +/**
>> + * struct usb_otg_config - otg controller configuration
>> + * @caps: otg capabilities of the controller
>> + * @ops: otg fsm operations
>> + * @otg_timeouts: override default otg fsm timeouts
>> + */
>> +struct usb_otg_config {
>> + struct usb_otg_caps otg_caps;
>> + struct otg_fsm_ops *fsm_ops;
>> + unsigned otg_timeouts[NUM_OTG_FSM_TIMERS];
>> +};
>> +
>> 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 *dev,
>> + struct usb_otg_config *config);
>> +int usb_otg_unregister(struct device *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);
>> +int usb_otg_start_host(struct otg_fsm *fsm, int on);
>> +int usb_otg_start_gadget(struct otg_fsm *fsm, int on);
>> +
>> +#else /* CONFIG_USB_OTG */
>> +
>> +static inline struct otg_fsm *usb_otg_register(struct device *dev,
>> + struct usb_otg_config *config)
>> +{
>> + return ERR_PTR(-ENOTSUPP);
>> +}
>> +
>> +static inline int usb_otg_unregister(struct device *dev)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
>> + unsigned long irqflags,
>> + struct otg_hcd_ops *ops)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline int usb_otg_unregister_hcd(struct usb_hcd *hcd)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline int usb_otg_register_gadget(struct usb_gadget *gadget,
>> + struct otg_gadget_ops *ops)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline int usb_otg_unregister_gadget(struct usb_gadget *gadget)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline void usb_otg_sync_inputs(struct otg_fsm *fsm)
>> +{
>> +}
>> +
>> +static inline int usb_otg_kick_fsm(struct device *hcd_gcd_device)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline struct device *usb_otg_fsm_to_dev(struct otg_fsm *fsm)
>> +{
>> + return NULL;
>> +}
>> +
>> +static inline int usb_otg_start_host(struct otg_fsm *fsm, int on)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +
>> +static inline int usb_otg_start_gadget(struct otg_fsm *fsm, int on)
>> +{
>> + return -ENOTSUPP;
>> +}
>> +#endif /* CONFIG_USB_OTG */
>> +
>> +/*------------- deprecated interface -----------------------------*/
>> /* Context: can sleep */
>> static inline int
>> otg_start_hnp(struct usb_otg *otg)
>> @@ -109,14 +287,9 @@ 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
>>
--
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