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usb: dwc3: implement runtime PM
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this patch implements the most basic pm_runtime
support for dwc3. Whenever USB cable is dettached,
then we will allow core to runtime_suspend.

Runtime suspending will involve completely tearing
down event buffers and require a full soft-reset of
the IP.

Note that a further optimization could be
implemented once we decide to support hibernation,
which is to allow runtime_suspend with cable
connected when bus is in U3. That's subject to a
separate patch, however.

Tested-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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Felipe Balbi committed Jun 20, 2016
1 parent 4cb4221 commit fc8bb91
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Showing 3 changed files with 174 additions and 15 deletions.
148 changes: 134 additions & 14 deletions drivers/usb/dwc3/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,7 +48,7 @@

#include "debug.h"

/* -------------------------------------------------------------------------- */
#define DWC3_DEFAULT_AUTOSUSPEND_DELAY 5000 /* ms */

void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
{
Expand Down Expand Up @@ -996,6 +996,9 @@ static int dwc3_probe(struct platform_device *pdev)
dma_set_coherent_mask(dev, dev->parent->coherent_dma_mask);
}

pm_runtime_set_active(dev);
pm_runtime_use_autosuspend(dev);
pm_runtime_set_autosuspend_delay(dev, DWC3_DEFAULT_AUTOSUSPEND_DELAY);
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
pm_runtime_forbid(dev);
Expand Down Expand Up @@ -1057,7 +1060,7 @@ static int dwc3_probe(struct platform_device *pdev)
goto err3;

dwc3_debugfs_init(dwc);
pm_runtime_allow(dev);
pm_runtime_put(dev);

return 0;

Expand Down Expand Up @@ -1087,6 +1090,7 @@ static int dwc3_remove(struct platform_device *pdev)
struct dwc3 *dwc = platform_get_drvdata(pdev);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

pm_runtime_get_sync(&pdev->dev);
/*
* restore res->start back to its original value so that, in case the
* probe is deferred, we don't end up getting error in request the
Expand All @@ -1100,24 +1104,27 @@ static int dwc3_remove(struct platform_device *pdev)
dwc3_core_exit(dwc);
dwc3_ulpi_exit(dwc);

dwc3_free_event_buffers(dwc);
dwc3_free_scratch_buffers(dwc);

pm_runtime_put_sync(&pdev->dev);
pm_runtime_allow(&pdev->dev);
pm_runtime_disable(&pdev->dev);

dwc3_free_event_buffers(dwc);
dwc3_free_scratch_buffers(dwc);

return 0;
}

#ifdef CONFIG_PM_SLEEP
static int dwc3_suspend(struct device *dev)
#ifdef CONFIG_PM
static int dwc3_suspend_common(struct dwc3 *dwc)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
unsigned long flags;

switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_suspend(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
break;
case USB_DR_MODE_HOST:
default:
Expand All @@ -1127,33 +1134,144 @@ static int dwc3_suspend(struct device *dev)

dwc3_core_exit(dwc);

pinctrl_pm_select_sleep_state(dev);

return 0;
}

static int dwc3_resume(struct device *dev)
static int dwc3_resume_common(struct dwc3 *dwc)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
unsigned long flags;
int ret;

pinctrl_pm_select_default_state(dev);

ret = dwc3_core_init(dwc);
if (ret)
return ret;

switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_resume(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
/* FALLTHROUGH */
case USB_DR_MODE_HOST:
default:
/* do nothing */
break;
}

return 0;
}

static int dwc3_runtime_checks(struct dwc3 *dwc)
{
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
if (dwc->connected)
return -EBUSY;
break;
case USB_DR_MODE_HOST:
default:
/* do nothing */
break;
}

return 0;
}

static int dwc3_runtime_suspend(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
int ret;

if (dwc3_runtime_checks(dwc))
return -EBUSY;

ret = dwc3_suspend_common(dwc);
if (ret)
return ret;

device_init_wakeup(dev, true);

return 0;
}

static int dwc3_runtime_resume(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
int ret;

device_init_wakeup(dev, false);

ret = dwc3_resume_common(dwc);
if (ret)
return ret;

switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
dwc3_gadget_process_pending_events(dwc);
break;
case USB_DR_MODE_HOST:
default:
/* do nothing */
break;
}

pm_runtime_mark_last_busy(dev);

return 0;
}

static int dwc3_runtime_idle(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);

switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
if (dwc3_runtime_checks(dwc))
return -EBUSY;
break;
case USB_DR_MODE_HOST:
default:
/* do nothing */
break;
}

pm_runtime_mark_last_busy(dev);
pm_runtime_autosuspend(dev);

return 0;
}
#endif /* CONFIG_PM */

#ifdef CONFIG_PM_SLEEP
static int dwc3_suspend(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
int ret;

ret = dwc3_suspend_common(dwc);
if (ret)
return ret;

pinctrl_pm_select_sleep_state(dev);

return 0;
}

static int dwc3_resume(struct device *dev)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
int ret;

pinctrl_pm_select_default_state(dev);

ret = dwc3_resume_common(dwc);
if (ret)
return ret;

pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
Expand All @@ -1164,6 +1282,8 @@ static int dwc3_resume(struct device *dev)

static const struct dev_pm_ops dwc3_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
SET_RUNTIME_PM_OPS(dwc3_runtime_suspend, dwc3_runtime_resume,
dwc3_runtime_idle)
};

#ifdef CONFIG_OF
Expand Down
9 changes: 9 additions & 0 deletions drivers/usb/dwc3/core.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -763,6 +763,7 @@ struct dwc3_scratchpad_array {
* @lpm_nyet_threshold: LPM NYET response threshold
* @hird_threshold: HIRD threshold
* @hsphy_interface: "utmi" or "ulpi"
* @connected: true when we're connected to a host, false otherwise
* @delayed_status: true when gadget driver asks for delayed status
* @ep0_bounced: true when we used bounce buffer
* @ep0_expect_in: true when we expect a DATA IN transfer
Expand All @@ -773,6 +774,7 @@ struct dwc3_scratchpad_array {
* 0 - utmi_sleep_n
* 1 - utmi_l1_suspend_n
* @is_fpga: true when we are using the FPGA board
* @pending_events: true when we have pending IRQs to be handled
* @pullups_connected: true when Run/Stop bit is set
* @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
* @start_config_issued: true when StartConfig command has been issued
Expand Down Expand Up @@ -907,13 +909,15 @@ struct dwc3 {

const char *hsphy_interface;

unsigned connected:1;
unsigned delayed_status:1;
unsigned ep0_bounced:1;
unsigned ep0_expect_in:1;
unsigned has_hibernation:1;
unsigned has_lpm_erratum:1;
unsigned is_utmi_l1_suspend:1;
unsigned is_fpga:1;
unsigned pending_events:1;
unsigned pullups_connected:1;
unsigned setup_packet_pending:1;
unsigned three_stage_setup:1;
Expand Down Expand Up @@ -1139,6 +1143,7 @@ static inline int dwc3_send_gadget_generic_command(struct dwc3 *dwc,
#if !IS_ENABLED(CONFIG_USB_DWC3_HOST)
int dwc3_gadget_suspend(struct dwc3 *dwc);
int dwc3_gadget_resume(struct dwc3 *dwc);
void dwc3_gadget_process_pending_events(struct dwc3 *dwc);
#else
static inline int dwc3_gadget_suspend(struct dwc3 *dwc)
{
Expand All @@ -1149,6 +1154,10 @@ static inline int dwc3_gadget_resume(struct dwc3 *dwc)
{
return 0;
}

static inline void dwc3_gadget_process_pending_events(struct dwc3 *dwc)
{
}
#endif /* !IS_ENABLED(CONFIG_USB_DWC3_HOST) */

#if IS_ENABLED(CONFIG_USB_DWC3_ULPI)
Expand Down
32 changes: 31 additions & 1 deletion drivers/usb/dwc3/gadget.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -199,6 +199,9 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
spin_unlock(&dwc->lock);
usb_gadget_giveback_request(&dep->endpoint, &req->request);
spin_lock(&dwc->lock);

if (dep->number > 1)
pm_runtime_put(dwc->dev);
}

int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
Expand Down Expand Up @@ -1081,6 +1084,8 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
return -EINVAL;
}

pm_runtime_get(dwc->dev);

req->request.actual = 0;
req->request.status = -EINPROGRESS;
req->direction = dep->direction;
Expand Down Expand Up @@ -1509,6 +1514,9 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
u32 reg;
u32 timeout = 500;

if (pm_runtime_suspended(dwc->dev))
return 0;

reg = dwc3_readl(dwc->regs, DWC3_DCTL);
if (is_on) {
if (dwc->revision <= DWC3_REVISION_187A) {
Expand Down Expand Up @@ -1766,7 +1774,9 @@ static int dwc3_gadget_start(struct usb_gadget *g,

dwc->gadget_driver = driver;

__dwc3_gadget_start(dwc);
if (pm_runtime_active(dwc->dev))
__dwc3_gadget_start(dwc);

spin_unlock_irqrestore(&dwc->lock, flags);

return 0;
Expand Down Expand Up @@ -2355,12 +2365,16 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
dwc->gadget.speed = USB_SPEED_UNKNOWN;
dwc->setup_packet_pending = false;
usb_gadget_set_state(&dwc->gadget, USB_STATE_NOTATTACHED);

dwc->connected = false;
}

static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
{
u32 reg;

dwc->connected = true;

/*
* WORKAROUND: DWC3 revisions <1.88a have an issue which
* would cause a missing Disconnect Event if there's a
Expand Down Expand Up @@ -2822,6 +2836,13 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
u32 count;
u32 reg;

if (pm_runtime_suspended(dwc->dev)) {
pm_runtime_get(dwc->dev);
disable_irq_nosync(dwc->irq_gadget);
dwc->pending_events = true;
return IRQ_HANDLED;
}

count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
count &= DWC3_GEVNTCOUNT_MASK;
if (!count)
Expand Down Expand Up @@ -3028,3 +3049,12 @@ int dwc3_gadget_resume(struct dwc3 *dwc)
err0:
return ret;
}

void dwc3_gadget_process_pending_events(struct dwc3 *dwc)
{
if (dwc->pending_events) {
dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
dwc->pending_events = false;
enable_irq(dwc->irq_gadget);
}
}

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