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 <rog...@ti.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.
> + * 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.
> +}
> +
> +/**
> + * 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);
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);
> +}
> +
> +/**
> + * 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.
> +{
> + 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.
> + 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?
> + /* 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?
> + }
> +
> + 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().
- Called by usb_add_hcd(), so we need call usb_add_hcd() before start fsm.
- 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?
- How about split it out of usb_add_hcd()?
> + *
> + * 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.
> + 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);
> + /* 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?
> +}
> +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 <rog...@ti.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?
> + /* 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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