Android4.0.3 USB OTG底層插入上報過程分析(1)
下面的兩個宏是PM8058的MMP11（R15），MMP12（P15）管腳。
#define EXT_CHG_VALID_MPP 10
#define EXT_CHG_VALID_MPP_2 11
static struct pm8xxx_mpp_init_info isl_mpp[] = {
PM8058_MPP_INIT(EXT_CHG_VALID_MPP, D_INPUT,
PM8058_MPP_DIG_LEVEL_S3, DIN_TO_INT),
PM8058_MPP_INIT(EXT_CHG_VALID_MPP_2, D_BI_DIR,
PM8058_MPP_DIG_LEVEL_S3, BI_PULLUP_10KOHM),
};
//配置管腳功能函數
#if defined(CONFIG_SMB137B_CHARGER) || defined(CONFIG_SMB137B_CHARGER_MODULE)
static int smb137b_detection_setup(void)
{
int ret = 0, i;
for (i = 0; i < ARRAY_SIZE(isl_mpp); i++) {
ret = pm8xxx_mpp_config(isl_mpp[i].mpp,&isl_mpp[i].config);
}
return ret;
}
static struct smb137b_platform_data smb137b_data __initdata = {
.chg_detection_config = smb137b_detection_setup,
.valid_n_gpio = PM8058_MPP_PM_TO_SYS(10),
.batt_mah_rating = 950,
};
static struct i2c_board_info smb137b_charger_i2c_info[] __initdata = {
{
I2C_BOARD_INFO("smb137b", 0x08),
.irq = PM8058_IRQ_BASE + PM8058_CBLPWR_IRQ,//計算後的irq值＝464
.platform_data = &smb137b_data,
},
};
#endif
static int __devinit smb137b_probe(struct i2c_client *client,const struct i2c_device_id *id)
｛
/*配置usb檢測管腳*/
if (pdata->chg_detection_config)
ret = pdata->chg_detection_config();
/*用該檢測gpio引腳前，申請該GPIO*/
ret = gpio_request(pdata->valid_n_gpio, "smb137b_charger_valid");
/*申請中斷，該中斷號碼爲464*/
ret = request_threaded_irq(client->irq, NULL,smb137b_valid_handler,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"smb137b_charger_valid", client);
/*先讀取一次檢測管腳值*/
ret = gpio_get_value_cansleep(smb137b_chg->valid_n_gpio);
if (!ret) {
/*上報usb的插入狀態*/
msm_charger_notify_event(smb137b_chg->adapter_hw_chg[0],CHG_INSERTED_EVENT);
smb137b_chg->usb_status = SMB137B_PRESENT;
}
｝
/*之後的處理都是在中斷中進行處理*/
static irqreturn_t smb137b_valid_handler(int irq, void *dev_id)
{
struct smb137b_data *smb137b_chg;
smb137b_chg = i2c_get_clientdata(client);
smb137b_chg->current_hw_chg = smb137b_chg->adapter_hw_chg[0];
/*讀出檢測管腳的電平值*/
val = gpio_get_value_cansleep(smb137b_chg->valid_n_gpio);
if (val) {
if (smb137b_chg->usb_status != SMB137B_ABSENT) {
smb137b_chg->usb_status = SMB137B_ABSENT;
/*若是爲高電平，通知usb移出*/
msm_charger_notify_event(smb137b_chg->current_hw_chg,CHG_REMOVED_EVENT);
}
} else if (smb137b_chg->usb_status == SMB137B_ABSENT) {
smb137b_chg->usb_status = SMB137B_PRESENT;
/*若是爲高電平，通知usb插入*/
msm_charger_notify_event(smb137b_chg->current_hw_chg,CHG_INSERTED_EVENT);
}
｝
下面進入發通知流程繼續跟蹤
int msm_charger_notify_event(struct msm_hardware_charger *hw_chg,
enum msm_hardware_charger_event event)
{
/*把該消息加入循環隊列中*/
msm_chg_enqueue_event(hw_chg, event);
/*調度work*/
queue_work(msm_chg.event_wq_thread, &msm_chg.queue_work);
return 0;
}
下面的兩行是在static int __init msm_charger_init(void)函數中進行初始化的：
INIT_WORK(&msm_chg.queue_work, process_events);
msm_chg.event_wq_thread = create_workqueue("msm_charger_eventd");
該work的處理函數以下：
static void process_events(struct work_struct *work)
{
struct msm_charger_event *event;
int rc;
/*循環處理等待隊列中的消息*/
do {
rc = msm_chg_dequeue_event(&event);
if (!rc)
/*對單個的event進行處理*/
handle_event(event->hw_chg, event->event);
} while (!rc);
}
下面進入具體的handle_event函數分析：
static void handle_event(struct msm_hardware_charger *hw_chg, int event)
{
struct msm_hardware_charger_priv *priv = NULL;
if (hw_chg)
priv = hw_chg->charger_private;
switch (event) {
case CHG_INSERTED_EVENT:
if (hw_chg->type == CHG_TYPE_USB) {
.................
priv->hw_chg_state = CHG_PRESENT_STATE;
/*上報usb插入事件*/
notify_usb_of_the_plugin_event(priv, 1);
.........................
break;
case CHG_REMOVED_EVENT:
if (hw_chg->type == CHG_TYPE_USB) {
...............
usb_chg_current = 0;
/*上報usb移出事件*/
notify_usb_of_the_plugin_event(priv, 0);
........................
}
break;
}
/*進入notify_usb_of_the_plugin_event函數繼續跟蹤*/
static void notify_usb_of_the_plugin_event(struct msm_hardware_charger_priv
*hw_chg, int plugin)
{
plugin = !!plugin;
if (plugin == 1 && usb_notified_of_insertion == 0) {
usb_notified_of_insertion = 1;
if (notify_vbus_state_func_ptr) {
/*調用回調函數*/
(*notify_vbus_state_func_ptr) (plugin);
}
if (plugin == 0 && usb_notified_of_insertion == 1) {
if (notify_vbus_state_func_ptr) {
(*notify_vbus_state_func_ptr) (plugin);
}
usb_notified_of_insertion = 0;
}
}
/*下面進入回調函數的跟蹤*/
/*在板級初始化時定義了一個全局函數指針*/
notify_vbus_state notify_vbus_state_func_ptr;
/*該函數指針在該回調函數中賦值*/
static int msm_hsusb_pmic_vbus_notif_init(void (*callback)(int online),
int init)
{
int ret = -ENOTSUPP;
if (machine_is_msm8x60_s9000() || pmic_id_notif_supported)) {
if (init)
ret = msm_charger_register_vbus_sn(callback);
else {
msm_charger_unregister_vbus_sn(callback);
ret = 0;
}
}
}
int msm_charger_register_vbus_sn(void (*callback)(int))
{
notify_vbus_state_func_ptr = callback;
return 0;
}
/*該回調函數註冊的時機以下*/
#if defined(CONFIG_USB_GADGET_MSM_72K) || defined(CONFIG_USB_EHCI_MSM_72K)
static struct msm_otg_platform_data msm_otg_pdata = {
................
#ifdef CONFIG_BATTERY_MSM8X60
.pmic_vbus_notif_init = msm_hsusb_pmic_vbus_notif_init,
#endif
.........................
};
#endif
/*把該平臺數據賦值給平臺設備*/
msm_device_otg.dev.platform_data = &msm_otg_pdata;
/*註冊該平臺設備*/
static struct platform_device *surf_devices[] __initdata = {
#if defined(CONFIG_USB_GADGET_MSM_72K) || defined(CONFIG_USB_EHCI_HCD)
&msm_device_otg,
#endif
｝
static void __init msm8x60_init(struct msm_board_data *board_data)
｛
platform_add_devices(surf_devices,ARRAY_SIZE(surf_devices));
｝
static int __init msm_otg_probe(struct platform_device *pdev)
{
..............
/*初始化work工做隊列*/
INIT_WORK(&dev->sm_work, msm_otg_sm_work);
dev->wq = alloc_workqueue("k_otg", WQ_NON_REENTRANT, 0);
..................
/*調用回調函數，爲全局函數指針賦值*/
if (dev->pdata->pmic_vbus_notif_init) {
ret = dev->pdata->pmic_vbus_notif_init
(&msm_otg_set_vbus_state, 1);
if (!ret) {
dev->pmic_vbus_notif_supp = 1;
}
}
...............
.......................
}
/*而後用該函數上報plug的值*/
void msm_otg_set_vbus_state(int online)
{
struct msm_otg *dev = the_msm_otg;
/*若是上報插入事件，就設置B_SESS_VLD標誌位*/
if (online)
set_bit(B_SESS_VLD, &dev->inputs);
/*若是上報移除事件，就清除B_SESS_VLD標誌位*/
else
clear_bit(B_SESS_VLD, &dev->inputs);
/*得到wakelock鎖*/
wake_lock(&dev->wlock);
/*調度工做隊列中的work*/
queue_work(dev->wq, &dev->sm_work);
}
/*下面進入work繼續跟蹤*/
static void msm_otg_sm_work(struct work_struct *w)
｛
enum usb_otg_state state;
state = dev->otg.state;
switch (state) {
case OTG_STATE_UNDEFINED:
if (!dev->otg.host || !is_host())
{
set_bit(ID, &dev->inputs);
}
if (dev->otg.gadget && is_b_sess_vld())
{
set_bit(B_SESS_VLD, &dev->inputs);
}
if ((test_bit(ID, &dev->inputs)) && !test_bit(ID_A, &dev->inputs)) {
/*改變otg的狀態機狀態爲OTG_STATE_B_IDLE*/
dev->otg.state = OTG_STATE_B_IDLE;
}
work = 1;
break;
case OTG_STATE_B_IDLE:
if (test_bit(B_SESS_VLD, &dev->inputs) && !test_bit(ID_B, &dev->inputs)) {
/*改變otg的狀態機狀態爲OTG_STATE_B_PERIPHERAL*/
dev->otg.state = OTG_STATE_B_PERIPHERAL;
msm_otg_set_power(&dev->otg, 0);
/*啓動外圍設備*/
msm_otg_start_peripheral(&dev->otg, 1);
}
break;
/*若是work爲1，則繼續調度work*/
if (work)
queue_work(dev->wq, &dev->sm_work);
｝
/*上面的work牽涉到兩個函數，經過寄存器的值判斷，設置相應的位域*/
static int is_host(void)
{
struct msm_otg *dev = the_msm_otg;
if (dev->pdata->otg_mode == OTG_ID)
{
/*讀出該寄存器的第8位，若是讀出的爲1，則返回0，即該設備爲B device*/
return (OTGSC_ID & readl(USB_OTGSC)) ? 0 : 1;
}
}
static int is_b_sess_vld(void)
{
struct msm_otg *dev = the_msm_otg;
if (dev->pdata->otg_mode == OTG_ID)
{
/*讀出該寄存器的第11位，若是爲1，則返回1，該寄存器在spec中說明以下：Indicates that the Vbus is above the B session valid threshold.*/
return (OTGSC_BSV & readl(USB_OTGSC)) ? 1 : 0;
}
}
/*下面進入msm_otg_start_peripheral函數進行分析*/
static void msm_otg_start_peripheral(struct otg_transceiver *xceiv, int on)
{
struct msm_otg *dev = container_of(xceiv, struct msm_otg, otg);
if (on) {
usb_gadget_vbus_connect(xceiv->gadget);
}
}
/*設置gadget的vbus*/
static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
{
if (!gadget->ops->vbus_session)
return -EOPNOTSUPP;
return gadget->ops->vbus_session(gadget, 1);
}
/*調用底層gadget的回調函數*/
gadget->ops->vbus_session(gadget, 1);
/*下面是該回調函數的結構體*/
static const struct usb_gadget_ops msm72k_ops = {
.get_frame = msm72k_get_frame,
/*該回調函數*/
.vbus_session = msm72k_udc_vbus_session,
.vbus_draw = msm72k_udc_vbus_draw,
.pullup = msm72k_pullup,
.wakeup = msm72k_wakeup,
.set_selfpowered = msm72k_set_selfpowered,
};
/*回調函數的註冊過程以下*/
static int msm72k_probe(struct platform_device *pdev)
{
ui = kzalloc(sizeof(struct usb_info), GFP_KERNEL);
ui->gadget.ops = &msm72k_ops;
}
/*看下vbus的回調函數*/
static int msm72k_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
{
/*設置vbus的狀態*/
msm_hsusb_set_vbus_state(is_active);
return 0;
}
/*繼續跟蹤設置vbus的狀態*/
void msm_hsusb_set_vbus_state(int online)
{
struct usb_info *ui = the_usb_info;
/*根據傳入的狀態設置usb的狀態位*/
if (online) {
ui->usb_state = USB_STATE_POWERED;
ui->flags |= USB_FLAG_VBUS_ONLINE;
} else {
ui->gadget.speed = USB_SPEED_UNKNOWN;
ui->usb_state = USB_STATE_NOTATTACHED;
ui->flags |= USB_FLAG_VBUS_OFFLINE;
}
/*調度usb的工做隊列*/
if (in_interrupt()) {
schedule_work(&ui->work);
} else {
usb_do_work(&ui->work);
return;
}
}
/*在usb_do_work中會進入一個大的狀態機循環*/
static void usb_do_work(struct work_struct *w)
{
struct usb_info *ui = container_of(w, struct usb_info, work);
struct msm_otg *otg = to_msm_otg(ui->xceiv);
unsigned long iflags;
unsigned flags, _vbus;
for (;;) {
spin_lock_irqsave(&ui->lock, iflags);
flags = ui->flags;
ui->flags = 0;
_vbus = is_usb_online(ui);
spin_unlock_irqrestore(&ui->lock, iflags);
/* give up if we have nothing to do */
if (flags == 0)
break;
switch (ui->state) {
case USB_STATE_IDLE:
if (flags & USB_FLAG_START) {
int ret;
/*重啓設備控制器*/
usb_reset(ui);
/*申請中斷處理函數*/
ret = request_irq(otg->irq, usb_interrupt,IRQF_SHARED,ui->pdev->name, ui);
ui->irq = otg->irq;
/*改變設備狀態*/
ui->state = USB_STATE_ONLINE;
usb_do_work_check_vbus(ui);
/*使能D＋數據線上的上拉電阻*/
msm72k_pullup_internal(&ui->gadget, 1);
break;
case USB_STATE_ONLINE:
if (flags & USB_FLAG_SUSPEND) {
int maxpower = usb_get_max_power(ui);
otg_set_power(ui->xceiv, 0);
break;
}
if (flags & USB_FLAG_CONFIGURED) {
int maxpower = usb_get_max_power(ui);
switch_set_state(&ui->sdev,atomic_read(&ui->configured));
ui->chg_current = maxpower;
otg_set_power(ui->xceiv, maxpower);
break;
}
if (flags & USB_FLAG_RESET) {
msm72k_pullup_internal(&ui->gadget, 0);
usb_reset(ui);
msm72k_pullup_internal(&ui->gadget, 1);
break;
}
break;
case USB_STATE_OFFLINE:
if ((flags & USB_FLAG_VBUS_ONLINE) && _vbus) {
/*重啓設備控制器*/
usb_reset(ui);
/*改變設備狀態*/
ui->state = USB_STATE_ONLINE;
usb_do_work_check_vbus(ui);
/*申請中斷處理函數*/
ret = request_irq(otg->irq, usb_interrupt,IRQF_SHARED,ui->pdev->name, ui);
ui->irq = otg->irq;
/*使能D＋數據線上的上拉電阻*/
msm72k_pullup_internal(&ui->gadget, 1);
}
break;
}
}
}
/*中斷函數的實時處理*/
static irqreturn_t usb_interrupt(int irq, void *data)
{
struct usb_info *ui = data;
unsigned n;
unsigned long flags;
n = readl(USB_USBSTS);
writel(n, USB_USBSTS);
/*端口變化探測*/
if (n & STS_PCI) {
msm_hsusb_set_speed(ui);
if (atomic_read(&ui->configured)) {
ui->usb_state = USB_STATE_CONFIGURED;
ui->flags = USB_FLAG_CONFIGURED;
ui->driver->resume(&ui->gadget);
schedule_work(&ui->work);
} else {
msm_hsusb_set_state(USB_STATE_DEFAULT);
}
}
/*usb重啓*/
if (n & STS_URI) {
dev_dbg(&ui->pdev->dev, "reset\n");
ui->gadget.speed = USB_SPEED_UNKNOWN;
msm_hsusb_set_state(USB_STATE_DEFAULT);
......................
}
/*usb掛起狀態*/
if (n & STS_SLI) {
dev_dbg(&ui->pdev->dev, "suspend\n");
ui->usb_state = USB_STATE_SUSPENDED;
ui->flags = USB_FLAG_SUSPEND;
ui->driver->suspend(&ui->gadget);
schedule_work(&ui->work);
}
/*usb事務傳輸完成中斷*/
if (n & STS_UI) {
n = readl(USB_ENDPTSETUPSTAT);
if (n & EPT_RX(0))
handle_setup(ui);
n = readl(USB_ENDPTCOMPLETE);
writel(n, USB_ENDPTCOMPLETE);
while (n) {
unsigned bit = __ffs(n);
handle_endpoint(ui, bit);
n = n & (~(1 << bit));
}
}
return IRQ_HANDLED;
}
#define EXT_CHG_VALID_MPP 10
#define EXT_CHG_VALID_MPP_2 11
static struct pm8xxx_mpp_init_info isl_mpp[] = {
PM8058_MPP_INIT(EXT_CHG_VALID_MPP, D_INPUT,
PM8058_MPP_DIG_LEVEL_S3, DIN_TO_INT),
PM8058_MPP_INIT(EXT_CHG_VALID_MPP_2, D_BI_DIR,
PM8058_MPP_DIG_LEVEL_S3, BI_PULLUP_10KOHM),
};
//配置管腳功能函數
#if defined(CONFIG_SMB137B_CHARGER) || defined(CONFIG_SMB137B_CHARGER_MODULE)
static int smb137b_detection_setup(void)
{
int ret = 0, i;
for (i = 0; i < ARRAY_SIZE(isl_mpp); i++) {
ret = pm8xxx_mpp_config(isl_mpp[i].mpp,&isl_mpp[i].config);
}
return ret;
}
static struct smb137b_platform_data smb137b_data __initdata = {
.chg_detection_config = smb137b_detection_setup,
.valid_n_gpio = PM8058_MPP_PM_TO_SYS(10),
.batt_mah_rating = 950,
};
static struct i2c_board_info smb137b_charger_i2c_info[] __initdata = {
{
I2C_BOARD_INFO("smb137b", 0x08),
.irq = PM8058_IRQ_BASE + PM8058_CBLPWR_IRQ,//計算後的irq值＝464
.platform_data = &smb137b_data,
},
};
#endif
static int __devinit smb137b_probe(struct i2c_client *client,const struct i2c_device_id *id)
｛
/*配置usb檢測管腳*/
if (pdata->chg_detection_config)
ret = pdata->chg_detection_config();
/*用該檢測gpio引腳前，申請該GPIO*/
ret = gpio_request(pdata->valid_n_gpio, "smb137b_charger_valid");
/*申請中斷，該中斷號碼爲464*/
ret = request_threaded_irq(client->irq, NULL,smb137b_valid_handler,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"smb137b_charger_valid", client);
/*先讀取一次檢測管腳值*/
ret = gpio_get_value_cansleep(smb137b_chg->valid_n_gpio);
if (!ret) {
/*上報usb的插入狀態*/
msm_charger_notify_event(smb137b_chg->adapter_hw_chg[0],CHG_INSERTED_EVENT);
smb137b_chg->usb_status = SMB137B_PRESENT;
}
｝
/*之後的處理都是在中斷中進行處理*/
static irqreturn_t smb137b_valid_handler(int irq, void *dev_id)
{
struct smb137b_data *smb137b_chg;
smb137b_chg = i2c_get_clientdata(client);
smb137b_chg->current_hw_chg = smb137b_chg->adapter_hw_chg[0];
/*讀出檢測管腳的電平值*/
val = gpio_get_value_cansleep(smb137b_chg->valid_n_gpio);
if (val) {
if (smb137b_chg->usb_status != SMB137B_ABSENT) {
smb137b_chg->usb_status = SMB137B_ABSENT;
/*若是爲高電平，通知usb移出*/
msm_charger_notify_event(smb137b_chg->current_hw_chg,CHG_REMOVED_EVENT);
}
} else if (smb137b_chg->usb_status == SMB137B_ABSENT) {
smb137b_chg->usb_status = SMB137B_PRESENT;
/*若是爲高電平，通知usb插入*/
msm_charger_notify_event(smb137b_chg->current_hw_chg,CHG_INSERTED_EVENT);
}
｝
下面進入發通知流程繼續跟蹤
int msm_charger_notify_event(struct msm_hardware_charger *hw_chg,
enum msm_hardware_charger_event event)
{
/*把該消息加入循環隊列中*/
msm_chg_enqueue_event(hw_chg, event);
/*調度work*/
queue_work(msm_chg.event_wq_thread, &msm_chg.queue_work);
return 0;
}
下面的兩行是在static int __init msm_charger_init(void)函數中進行初始化的：
INIT_WORK(&msm_chg.queue_work, process_events);
msm_chg.event_wq_thread = create_workqueue("msm_charger_eventd");
該work的處理函數以下：
static void process_events(struct work_struct *work)
{
struct msm_charger_event *event;
int rc;
/*循環處理等待隊列中的消息*/
do {
rc = msm_chg_dequeue_event(&event);
if (!rc)
/*對單個的event進行處理*/
handle_event(event->hw_chg, event->event);
} while (!rc);
}
下面進入具體的handle_event函數分析：
static void handle_event(struct msm_hardware_charger *hw_chg, int event)
{
struct msm_hardware_charger_priv *priv = NULL;
if (hw_chg)
priv = hw_chg->charger_private;
switch (event) {
case CHG_INSERTED_EVENT:
if (hw_chg->type == CHG_TYPE_USB) {
.................
priv->hw_chg_state = CHG_PRESENT_STATE;
/*上報usb插入事件*/
notify_usb_of_the_plugin_event(priv, 1);
.........................
break;
case CHG_REMOVED_EVENT:
if (hw_chg->type == CHG_TYPE_USB) {
...............
usb_chg_current = 0;
/*上報usb移出事件*/
notify_usb_of_the_plugin_event(priv, 0);
........................
}
break;
}
/*進入notify_usb_of_the_plugin_event函數繼續跟蹤*/
static void notify_usb_of_the_plugin_event(struct msm_hardware_charger_priv
*hw_chg, int plugin)
{
plugin = !!plugin;
if (plugin == 1 && usb_notified_of_insertion == 0) {
usb_notified_of_insertion = 1;
if (notify_vbus_state_func_ptr) {
/*調用回調函數*/
(*notify_vbus_state_func_ptr) (plugin);
}
if (plugin == 0 && usb_notified_of_insertion == 1) {
if (notify_vbus_state_func_ptr) {
(*notify_vbus_state_func_ptr) (plugin);
}
usb_notified_of_insertion = 0;
}
}
/*下面進入回調函數的跟蹤*/
/*在板級初始化時定義了一個全局函數指針*/
notify_vbus_state notify_vbus_state_func_ptr;
/*該函數指針在該回調函數中賦值*/
static int msm_hsusb_pmic_vbus_notif_init(void (*callback)(int online),
int init)
{
int ret = -ENOTSUPP;
if (machine_is_msm8x60_s9000() || pmic_id_notif_supported)) {
if (init)
ret = msm_charger_register_vbus_sn(callback);
else {
msm_charger_unregister_vbus_sn(callback);
ret = 0;
}
}
}
int msm_charger_register_vbus_sn(void (*callback)(int))
{
notify_vbus_state_func_ptr = callback;
return 0;
}
/*該回調函數註冊的時機以下*/
#if defined(CONFIG_USB_GADGET_MSM_72K) || defined(CONFIG_USB_EHCI_MSM_72K)
static struct msm_otg_platform_data msm_otg_pdata = {
................
#ifdef CONFIG_BATTERY_MSM8X60
.pmic_vbus_notif_init = msm_hsusb_pmic_vbus_notif_init,
#endif
.........................
};
#endif
/*把該平臺數據賦值給平臺設備*/
msm_device_otg.dev.platform_data = &msm_otg_pdata;
/*註冊該平臺設備*/
static struct platform_device *surf_devices[] __initdata = {
#if defined(CONFIG_USB_GADGET_MSM_72K) || defined(CONFIG_USB_EHCI_HCD)
&msm_device_otg,
#endif
｝
static void __init msm8x60_init(struct msm_board_data *board_data)
｛
platform_add_devices(surf_devices,ARRAY_SIZE(surf_devices));
｝
static int __init msm_otg_probe(struct platform_device *pdev)
{
..............
/*初始化work工做隊列*/
INIT_WORK(&dev->sm_work, msm_otg_sm_work);
dev->wq = alloc_workqueue("k_otg", WQ_NON_REENTRANT, 0);
..................
/*調用回調函數，爲全局函數指針賦值*/
if (dev->pdata->pmic_vbus_notif_init) {
ret = dev->pdata->pmic_vbus_notif_init
(&msm_otg_set_vbus_state, 1);
if (!ret) {
dev->pmic_vbus_notif_supp = 1;
}
}
...............
.......................
}
/*而後用該函數上報plug的值*/
void msm_otg_set_vbus_state(int online)
{
struct msm_otg *dev = the_msm_otg;
/*若是上報插入事件，就設置B_SESS_VLD標誌位*/
if (online)
set_bit(B_SESS_VLD, &dev->inputs);
/*若是上報移除事件，就清除B_SESS_VLD標誌位*/
else
clear_bit(B_SESS_VLD, &dev->inputs);
/*得到wakelock鎖*/
wake_lock(&dev->wlock);
/*調度工做隊列中的work*/
queue_work(dev->wq, &dev->sm_work);
}
/*下面進入work繼續跟蹤*/
static void msm_otg_sm_work(struct work_struct *w)
｛
enum usb_otg_state state;
state = dev->otg.state;
switch (state) {
case OTG_STATE_UNDEFINED:
if (!dev->otg.host || !is_host())
{
set_bit(ID, &dev->inputs);
}
if (dev->otg.gadget && is_b_sess_vld())
{
set_bit(B_SESS_VLD, &dev->inputs);
}
if ((test_bit(ID, &dev->inputs)) && !test_bit(ID_A, &dev->inputs)) {
/*改變otg的狀態機狀態爲OTG_STATE_B_IDLE*/
dev->otg.state = OTG_STATE_B_IDLE;
}
work = 1;
break;
case OTG_STATE_B_IDLE:
if (test_bit(B_SESS_VLD, &dev->inputs) && !test_bit(ID_B, &dev->inputs)) {
/*改變otg的狀態機狀態爲OTG_STATE_B_PERIPHERAL*/
dev->otg.state = OTG_STATE_B_PERIPHERAL;
msm_otg_set_power(&dev->otg, 0);
/*啓動外圍設備*/
msm_otg_start_peripheral(&dev->otg, 1);
}
break;
/*若是work爲1，則繼續調度work*/
if (work)
queue_work(dev->wq, &dev->sm_work);
｝
/*上面的work牽涉到兩個函數，經過寄存器的值判斷，設置相應的位域*/
static int is_host(void)
{
struct msm_otg *dev = the_msm_otg;
if (dev->pdata->otg_mode == OTG_ID)
{
/*讀出該寄存器的第8位，若是讀出的爲1，則返回0，即該設備爲B device*/
return (OTGSC_ID & readl(USB_OTGSC)) ? 0 : 1;
}
}
static int is_b_sess_vld(void)
{
struct msm_otg *dev = the_msm_otg;
if (dev->pdata->otg_mode == OTG_ID)
{
/*讀出該寄存器的第11位，若是爲1，則返回1，該寄存器在spec中說明以下：Indicates that the Vbus is above the B session valid threshold.*/
return (OTGSC_BSV & readl(USB_OTGSC)) ? 1 : 0;
}
}
/*下面進入msm_otg_start_peripheral函數進行分析*/
static void msm_otg_start_peripheral(struct otg_transceiver *xceiv, int on)
{
struct msm_otg *dev = container_of(xceiv, struct msm_otg, otg);
if (on) {
usb_gadget_vbus_connect(xceiv->gadget);
}
}
/*設置gadget的vbus*/
static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
{
if (!gadget->ops->vbus_session)
return -EOPNOTSUPP;
return gadget->ops->vbus_session(gadget, 1);
}
/*調用底層gadget的回調函數*/
gadget->ops->vbus_session(gadget, 1);
/*下面是該回調函數的結構體*/
static const struct usb_gadget_ops msm72k_ops = {
.get_frame = msm72k_get_frame,
/*該回調函數*/
.vbus_session = msm72k_udc_vbus_session,
.vbus_draw = msm72k_udc_vbus_draw,
.pullup = msm72k_pullup,
.wakeup = msm72k_wakeup,
.set_selfpowered = msm72k_set_selfpowered,
};
/*回調函數的註冊過程以下*/
static int msm72k_probe(struct platform_device *pdev)
{
ui = kzalloc(sizeof(struct usb_info), GFP_KERNEL);
ui->gadget.ops = &msm72k_ops;
}
/*看下vbus的回調函數*/
static int msm72k_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
{
/*設置vbus的狀態*/
msm_hsusb_set_vbus_state(is_active);
return 0;
}
/*繼續跟蹤設置vbus的狀態*/
void msm_hsusb_set_vbus_state(int online)
{
struct usb_info *ui = the_usb_info;
/*根據傳入的狀態設置usb的狀態位*/
if (online) {
ui->usb_state = USB_STATE_POWERED;
ui->flags |= USB_FLAG_VBUS_ONLINE;
} else {
ui->gadget.speed = USB_SPEED_UNKNOWN;
ui->usb_state = USB_STATE_NOTATTACHED;
ui->flags |= USB_FLAG_VBUS_OFFLINE;
}
/*調度usb的工做隊列*/
if (in_interrupt()) {
schedule_work(&ui->work);
} else {
usb_do_work(&ui->work);
return;
}
}
/*在usb_do_work中會進入一個大的狀態機循環*/
static void usb_do_work(struct work_struct *w)
{
struct usb_info *ui = container_of(w, struct usb_info, work);
struct msm_otg *otg = to_msm_otg(ui->xceiv);
unsigned long iflags;
unsigned flags, _vbus;
for (;;) {
spin_lock_irqsave(&ui->lock, iflags);
flags = ui->flags;
ui->flags = 0;
_vbus = is_usb_online(ui);
spin_unlock_irqrestore(&ui->lock, iflags);
/* give up if we have nothing to do */
if (flags == 0)
break;
switch (ui->state) {
case USB_STATE_IDLE:
if (flags & USB_FLAG_START) {
int ret;
/*重啓設備控制器*/
usb_reset(ui);
/*申請中斷處理函數*/
ret = request_irq(otg->irq, usb_interrupt,IRQF_SHARED,ui->pdev->name, ui);
ui->irq = otg->irq;
/*改變設備狀態*/
ui->state = USB_STATE_ONLINE;
usb_do_work_check_vbus(ui);
/*使能D＋數據線上的上拉電阻*/
msm72k_pullup_internal(&ui->gadget, 1);
break;
case USB_STATE_ONLINE:
if (flags & USB_FLAG_SUSPEND) {
int maxpower = usb_get_max_power(ui);
otg_set_power(ui->xceiv, 0);
break;
}
if (flags & USB_FLAG_CONFIGURED) {
int maxpower = usb_get_max_power(ui);
switch_set_state(&ui->sdev,atomic_read(&ui->configured));
ui->chg_current = maxpower;
otg_set_power(ui->xceiv, maxpower);
break;
}
if (flags & USB_FLAG_RESET) {
msm72k_pullup_internal(&ui->gadget, 0);
usb_reset(ui);
msm72k_pullup_internal(&ui->gadget, 1);
break;
}
break;
case USB_STATE_OFFLINE:
if ((flags & USB_FLAG_VBUS_ONLINE) && _vbus) {
/*重啓設備控制器*/
usb_reset(ui);
/*改變設備狀態*/
ui->state = USB_STATE_ONLINE;
usb_do_work_check_vbus(ui);
/*申請中斷處理函數*/
ret = request_irq(otg->irq, usb_interrupt,IRQF_SHARED,ui->pdev->name, ui);
ui->irq = otg->irq;
/*使能D＋數據線上的上拉電阻*/
msm72k_pullup_internal(&ui->gadget, 1);
}
break;
}
}
}
/*中斷函數的實時處理*/
static irqreturn_t usb_interrupt(int irq, void *data)
{
struct usb_info *ui = data;
unsigned n;
unsigned long flags;
n = readl(USB_USBSTS);
writel(n, USB_USBSTS);
/*端口變化探測*/
if (n & STS_PCI) {
msm_hsusb_set_speed(ui);
if (atomic_read(&ui->configured)) {
ui->usb_state = USB_STATE_CONFIGURED;
ui->flags = USB_FLAG_CONFIGURED;
ui->driver->resume(&ui->gadget);
schedule_work(&ui->work);
} else {
msm_hsusb_set_state(USB_STATE_DEFAULT);
}
}
/*usb重啓*/
if (n & STS_URI) {
dev_dbg(&ui->pdev->dev, "reset\n");
ui->gadget.speed = USB_SPEED_UNKNOWN;
msm_hsusb_set_state(USB_STATE_DEFAULT);
......................
}
/*usb掛起狀態*/
if (n & STS_SLI) {
dev_dbg(&ui->pdev->dev, "suspend\n");
ui->usb_state = USB_STATE_SUSPENDED;
ui->flags = USB_FLAG_SUSPEND;
ui->driver->suspend(&ui->gadget);
schedule_work(&ui->work);
}
/*usb事務傳輸完成中斷*/
if (n & STS_UI) {
n = readl(USB_ENDPTSETUPSTAT);
if (n & EPT_RX(0))
handle_setup(ui);
n = readl(USB_ENDPTCOMPLETE);
writel(n, USB_ENDPTCOMPLETE);
while (n) {
unsigned bit = __ffs(n);
handle_endpoint(ui, bit);
n = n & (~(1 << bit));
}
}
return IRQ_HANDLED;
}
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