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usb: gadget: mv_udc: add clock gating support
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This patch is going to support clock gating when vbus detection is
posible. Clock and phy will be on only when usb gadget is used(vbus valid).

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
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Neil Zhang authored and Felipe Balbi committed Oct 13, 2011
1 parent fb22cba commit 1aec033
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Showing 2 changed files with 185 additions and 11 deletions.
7 changes: 6 additions & 1 deletion drivers/usb/gadget/mv_udc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -209,7 +209,12 @@ struct mv_udc {
vbus_active:1,
remote_wakeup:1,
softconnected:1,
force_fs:1;
force_fs:1,
clock_gating:1,
active:1;

struct work_struct vbus_work;
struct workqueue_struct *qwork;

struct mv_usb_platform_data *pdata;

Expand Down
189 changes: 179 additions & 10 deletions drivers/usb/gadget/mv_udc_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,7 @@ static struct mv_udc *the_controller;
int mv_usb_otgsc;

static void nuke(struct mv_ep *ep, int status);
static void stop_activity(struct mv_udc *udc, struct usb_gadget_driver *driver);

/* for endpoint 0 operations */
static const struct usb_endpoint_descriptor mv_ep0_desc = {
Expand Down Expand Up @@ -1133,6 +1134,40 @@ static int udc_reset(struct mv_udc *udc)
return 0;
}

static int mv_udc_enable(struct mv_udc *udc)
{
int retval;

if (udc->clock_gating == 0 || udc->active)
return 0;

dev_dbg(&udc->dev->dev, "enable udc\n");
udc_clock_enable(udc);
if (udc->pdata->phy_init) {
retval = udc->pdata->phy_init(udc->phy_regs);
if (retval) {
dev_err(&udc->dev->dev,
"init phy error %d\n", retval);
udc_clock_disable(udc);
return retval;
}
}
udc->active = 1;

return 0;
}

static void mv_udc_disable(struct mv_udc *udc)
{
if (udc->clock_gating && udc->active) {
dev_dbg(&udc->dev->dev, "disable udc\n");
if (udc->pdata->phy_deinit)
udc->pdata->phy_deinit(udc->phy_regs);
udc_clock_disable(udc);
udc->active = 0;
}
}

static int mv_udc_get_frame(struct usb_gadget *gadget)
{
struct mv_udc *udc;
Expand Down Expand Up @@ -1168,22 +1203,68 @@ static int mv_udc_wakeup(struct usb_gadget *gadget)
return 0;
}

static int mv_udc_vbus_session(struct usb_gadget *gadget, int is_active)
{
struct mv_udc *udc;
unsigned long flags;
int retval = 0;

udc = container_of(gadget, struct mv_udc, gadget);
spin_lock_irqsave(&udc->lock, flags);

dev_dbg(&udc->dev->dev, "%s: softconnect %d, vbus_active %d\n",
__func__, udc->softconnect, udc->vbus_active);

udc->vbus_active = (is_active != 0);
if (udc->driver && udc->softconnect && udc->vbus_active) {
retval = mv_udc_enable(udc);
if (retval == 0) {
/* Clock is disabled, need re-init registers */
udc_reset(udc);
ep0_reset(udc);
udc_start(udc);
}
} else if (udc->driver && udc->softconnect) {
/* stop all the transfer in queue*/
stop_activity(udc, udc->driver);
udc_stop(udc);
mv_udc_disable(udc);
}

spin_unlock_irqrestore(&udc->lock, flags);
return retval;
}

static int mv_udc_pullup(struct usb_gadget *gadget, int is_on)
{
struct mv_udc *udc;
unsigned long flags;
int retval = 0;

udc = container_of(gadget, struct mv_udc, gadget);
spin_lock_irqsave(&udc->lock, flags);

dev_dbg(&udc->dev->dev, "%s: softconnect %d, vbus_active %d\n",
__func__, udc->softconnect, udc->vbus_active);

udc->softconnect = (is_on != 0);
if (udc->driver && udc->softconnect)
udc_start(udc);
else
if (udc->driver && udc->softconnect && udc->vbus_active) {
retval = mv_udc_enable(udc);
if (retval == 0) {
/* Clock is disabled, need re-init registers */
udc_reset(udc);
ep0_reset(udc);
udc_start(udc);
}
} else if (udc->driver && udc->vbus_active) {
/* stop all the transfer in queue*/
stop_activity(udc, udc->driver);
udc_stop(udc);
mv_udc_disable(udc);
}

spin_unlock_irqrestore(&udc->lock, flags);
return 0;
return retval;
}

static int mv_udc_start(struct usb_gadget_driver *driver,
Expand All @@ -1198,6 +1279,9 @@ static const struct usb_gadget_ops mv_ops = {
/* tries to wake up the host connected to this gadget */
.wakeup = mv_udc_wakeup,

/* notify controller that VBUS is powered or not */
.vbus_session = mv_udc_vbus_session,

/* D+ pullup, software-controlled connect/disconnect to USB host */
.pullup = mv_udc_pullup,
.start = mv_udc_start,
Expand Down Expand Up @@ -1310,7 +1394,7 @@ static int mv_udc_start(struct usb_gadget_driver *driver,

udc->usb_state = USB_STATE_ATTACHED;
udc->ep0_state = WAIT_FOR_SETUP;
udc->ep0_dir = USB_DIR_OUT;
udc->ep0_dir = EP_DIR_OUT;

spin_unlock_irqrestore(&udc->lock, flags);

Expand All @@ -1322,9 +1406,13 @@ static int mv_udc_start(struct usb_gadget_driver *driver,
udc->gadget.dev.driver = NULL;
return retval;
}
udc_reset(udc);
ep0_reset(udc);
udc_start(udc);

/* pullup is always on */
mv_udc_pullup(&udc->gadget, 1);

/* When boot with cable attached, there will be no vbus irq occurred */
if (udc->qwork)
queue_work(udc->qwork, &udc->vbus_work);

return 0;
}
Expand All @@ -1337,13 +1425,16 @@ static int mv_udc_stop(struct usb_gadget_driver *driver)
if (!udc)
return -ENODEV;

udc_stop(udc);

spin_lock_irqsave(&udc->lock, flags);

mv_udc_enable(udc);
udc_stop(udc);

/* stop all usb activities */
udc->gadget.speed = USB_SPEED_UNKNOWN;
stop_activity(udc, driver);
mv_udc_disable(udc);

spin_unlock_irqrestore(&udc->lock, flags);

/* unbind gadget driver */
Expand Down Expand Up @@ -1969,6 +2060,35 @@ static irqreturn_t mv_udc_irq(int irq, void *dev)
return IRQ_HANDLED;
}

static irqreturn_t mv_udc_vbus_irq(int irq, void *dev)
{
struct mv_udc *udc = (struct mv_udc *)dev;

/* polling VBUS and init phy may cause too much time*/
if (udc->qwork)
queue_work(udc->qwork, &udc->vbus_work);

return IRQ_HANDLED;
}

static void mv_udc_vbus_work(struct work_struct *work)
{
struct mv_udc *udc;
unsigned int vbus;

udc = container_of(work, struct mv_udc, vbus_work);
if (!udc->pdata->vbus)
return;

vbus = udc->pdata->vbus->poll();
dev_info(&udc->dev->dev, "vbus is %d\n", vbus);

if (vbus == VBUS_HIGH)
mv_udc_vbus_session(&udc->gadget, 1);
else if (vbus == VBUS_LOW)
mv_udc_vbus_session(&udc->gadget, 0);
}

/* release device structure */
static void gadget_release(struct device *_dev)
{
Expand All @@ -1984,6 +2104,14 @@ static int __devexit mv_udc_remove(struct platform_device *dev)

usb_del_gadget_udc(&udc->gadget);

if (udc->qwork) {
flush_workqueue(udc->qwork);
destroy_workqueue(udc->qwork);
}

if (udc->pdata && udc->pdata->vbus && udc->clock_gating)
free_irq(udc->pdata->vbus->irq, &dev->dev);

/* free memory allocated in probe */
if (udc->dtd_pool)
dma_pool_destroy(udc->dtd_pool);
Expand All @@ -1997,6 +2125,8 @@ static int __devexit mv_udc_remove(struct platform_device *dev)
if (udc->irq)
free_irq(udc->irq, &dev->dev);

mv_udc_disable(udc);

if (udc->cap_regs)
iounmap(udc->cap_regs);
udc->cap_regs = NULL;
Expand Down Expand Up @@ -2197,13 +2327,52 @@ static int __devinit mv_udc_probe(struct platform_device *dev)

eps_init(udc);

/* VBUS detect: we can disable/enable clock on demand.*/
if (pdata->vbus) {
udc->clock_gating = 1;
retval = request_threaded_irq(pdata->vbus->irq, NULL,
mv_udc_vbus_irq, IRQF_ONESHOT, "vbus", udc);
if (retval) {
dev_info(&dev->dev,
"Can not request irq for VBUS, "
"disable clock gating\n");
udc->clock_gating = 0;
}

udc->qwork = create_singlethread_workqueue("mv_udc_queue");
if (!udc->qwork) {
dev_err(&dev->dev, "cannot create workqueue\n");
retval = -ENOMEM;
goto err_unregister;
}

INIT_WORK(&udc->vbus_work, mv_udc_vbus_work);
}

/*
* When clock gating is supported, we can disable clk and phy.
* If not, it means that VBUS detection is not supported, we
* have to enable vbus active all the time to let controller work.
*/
if (udc->clock_gating) {
if (udc->pdata->phy_deinit)
udc->pdata->phy_deinit(udc->phy_regs);
udc_clock_disable(udc);
} else
udc->vbus_active = 1;

retval = usb_add_gadget_udc(&dev->dev, &udc->gadget);
if (retval)
goto err_unregister;

dev_info(&dev->dev, "successful probe UDC device %s clock gating.\n",
udc->clock_gating ? "with" : "without");

return 0;

err_unregister:
if (udc->pdata && udc->pdata->vbus && udc->clock_gating)
free_irq(pdata->vbus->irq, &dev->dev);
device_unregister(&udc->gadget.dev);
err_free_irq:
free_irq(udc->irq, &dev->dev);
Expand Down

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