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Message-ID: <20150717074832.GA4515@shlinux2>
Date: Fri, 17 Jul 2015 15:48:35 +0800
From: Li Jun <b47624@...escale.com>
To: Roger Quadros <rogerq@...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, 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.
> +}
> +
> +/**
> + * 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.
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
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.
> +
> +/**
> + * 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?
> +}
> +
> +/**
> + * 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.
> + 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?
> + } 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.
> +#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.
Li Jun
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