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authorJonas Bonn <jonas@norrbonn.se>2019-02-20 15:20:00 +0300
committerFelipe Balbi <felipe.balbi@linux.intel.com>2019-05-03 09:13:49 +0300
commit70a7f8be85986a3c2ffc7274c41b89552dfe2ad0 (patch)
tree89b24f17ae5d68c4f7b3843b03f8475b1246cf0c /drivers/usb
parent66b61e27a98c8d5772dae543ca3581da0c2137a1 (diff)
downloadlinux-70a7f8be85986a3c2ffc7274c41b89552dfe2ad0.tar.xz
usb: gadget: atmel: support USB suspend
This patch adds support for USB suspend to the Atmel UDC. When suspended, the UDC clock can be stopped, resulting in some power savings. The "wake up" interrupt will fire irregardless of whether the clock is running or not, allowing the UDC clock to be restarted when the USB master wants to wake the device again. The IRQ state of this device is somewhat fiddly. The "wake up" IRQ seems to actually be a "bus activity" indicator; the IRQ is almost continuously asserted so enabling this IRQ should only be done after a suspend when the wake IRQ becomes relevant. Similarly, the "suspend" IRQ detects "bus inactivity" and may therefore fire together with a "wake" if the two types of activity coincide during the period between two IRQ handler invocations; therefore, it's important to ignore the "suspend" IRQ while waiting for a wake-up. This has been tested on a SAMA5D2 board. Signed-off-by: Jonas Bonn <jonas@norrbonn.se> CC: Cristian Birsan <cristian.birsan@microchip.com> CC: Felipe Balbi <balbi@kernel.org> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Nicolas Ferre <nicolas.ferre@microchip.com> CC: Alexandre Belloni <alexandre.belloni@bootlin.com> CC: Ludovic Desroches <ludovic.desroches@microchip.com> CC: linux-arm-kernel@lists.infradead.org CC: linux-usb@vger.kernel.org Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/gadget/udc/atmel_usba_udc.c55
-rw-r--r--drivers/usb/gadget/udc/atmel_usba_udc.h1
2 files changed, 50 insertions, 6 deletions
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 9a7901c579a2..7972aabe46ae 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -1703,6 +1703,9 @@ static void usba_dma_irq(struct usba_udc *udc, struct usba_ep *ep)
}
}
+static int start_clock(struct usba_udc *udc);
+static void stop_clock(struct usba_udc *udc);
+
static irqreturn_t usba_udc_irq(int irq, void *devid)
{
struct usba_udc *udc = devid;
@@ -1717,10 +1720,13 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
DBG(DBG_INT, "irq, status=%#08x\n", status);
if (status & USBA_DET_SUSPEND) {
- toggle_bias(udc, 0);
- usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
+ usba_writel(udc, INT_CLR, USBA_DET_SUSPEND|USBA_WAKE_UP);
usba_int_enb_set(udc, USBA_WAKE_UP);
+ usba_int_enb_clear(udc, USBA_DET_SUSPEND);
+ udc->suspended = true;
+ toggle_bias(udc, 0);
udc->bias_pulse_needed = true;
+ stop_clock(udc);
DBG(DBG_BUS, "Suspend detected\n");
if (udc->gadget.speed != USB_SPEED_UNKNOWN
&& udc->driver && udc->driver->suspend) {
@@ -1731,14 +1737,17 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
}
if (status & USBA_WAKE_UP) {
+ start_clock(udc);
toggle_bias(udc, 1);
usba_writel(udc, INT_CLR, USBA_WAKE_UP);
- usba_int_enb_clear(udc, USBA_WAKE_UP);
DBG(DBG_BUS, "Wake Up CPU detected\n");
}
if (status & USBA_END_OF_RESUME) {
+ udc->suspended = false;
usba_writel(udc, INT_CLR, USBA_END_OF_RESUME);
+ usba_int_enb_clear(udc, USBA_WAKE_UP);
+ usba_int_enb_set(udc, USBA_DET_SUSPEND);
generate_bias_pulse(udc);
DBG(DBG_BUS, "Resume detected\n");
if (udc->gadget.speed != USB_SPEED_UNKNOWN
@@ -1753,6 +1762,8 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
if (dma_status) {
int i;
+ usba_int_enb_set(udc, USBA_DET_SUSPEND);
+
for (i = 1; i <= USBA_NR_DMAS; i++)
if (dma_status & (1 << i))
usba_dma_irq(udc, &udc->usba_ep[i]);
@@ -1762,6 +1773,8 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
if (ep_status) {
int i;
+ usba_int_enb_set(udc, USBA_DET_SUSPEND);
+
for (i = 0; i < udc->num_ep; i++)
if (ep_status & (1 << i)) {
if (ep_is_control(&udc->usba_ep[i]))
@@ -1775,7 +1788,9 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
struct usba_ep *ep0, *ep;
int i, n;
- usba_writel(udc, INT_CLR, USBA_END_OF_RESET);
+ usba_writel(udc, INT_CLR,
+ USBA_END_OF_RESET|USBA_END_OF_RESUME
+ |USBA_DET_SUSPEND|USBA_WAKE_UP);
generate_bias_pulse(udc);
reset_all_endpoints(udc);
@@ -1802,6 +1817,11 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
| USBA_BF(BK_NUMBER, USBA_BK_NUMBER_ONE)));
usba_ep_writel(ep0, CTL_ENB,
USBA_EPT_ENABLE | USBA_RX_SETUP);
+
+ /* If we get reset while suspended... */
+ udc->suspended = false;
+ usba_int_enb_clear(udc, USBA_WAKE_UP);
+
usba_int_enb_set(udc, USBA_BF(EPT_INT, 1) |
USBA_DET_SUSPEND | USBA_END_OF_RESUME);
@@ -1869,9 +1889,19 @@ static int usba_start(struct usba_udc *udc)
if (ret)
return ret;
+ if (udc->suspended)
+ return 0;
+
spin_lock_irqsave(&udc->lock, flags);
toggle_bias(udc, 1);
usba_writel(udc, CTRL, USBA_ENABLE_MASK);
+ /* Clear all requested and pending interrupts... */
+ usba_writel(udc, INT_ENB, 0);
+ udc->int_enb_cache = 0;
+ usba_writel(udc, INT_CLR,
+ USBA_END_OF_RESET|USBA_END_OF_RESUME
+ |USBA_DET_SUSPEND|USBA_WAKE_UP);
+ /* ...and enable just 'reset' IRQ to get us started */
usba_int_enb_set(udc, USBA_END_OF_RESET);
spin_unlock_irqrestore(&udc->lock, flags);
@@ -1882,6 +1912,9 @@ static void usba_stop(struct usba_udc *udc)
{
unsigned long flags;
+ if (udc->suspended)
+ return;
+
spin_lock_irqsave(&udc->lock, flags);
udc->gadget.speed = USB_SPEED_UNKNOWN;
reset_all_endpoints(udc);
@@ -1909,6 +1942,7 @@ static irqreturn_t usba_vbus_irq_thread(int irq, void *devid)
if (vbus) {
usba_start(udc);
} else {
+ udc->suspended = false;
usba_stop(udc);
if (udc->driver->disconnect)
@@ -1972,6 +2006,7 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
if (fifo_mode == 0)
udc->configured_ep = 1;
+ udc->suspended = false;
usba_stop(udc);
udc->driver = NULL;
@@ -2285,6 +2320,7 @@ static int usba_udc_suspend(struct device *dev)
mutex_lock(&udc->vbus_mutex);
if (!device_may_wakeup(dev)) {
+ udc->suspended = false;
usba_stop(udc);
goto out;
}
@@ -2294,10 +2330,13 @@ static int usba_udc_suspend(struct device *dev)
* to request vbus irq, assuming always on.
*/
if (udc->vbus_pin) {
+ /* FIXME: right to stop here...??? */
usba_stop(udc);
enable_irq_wake(gpiod_to_irq(udc->vbus_pin));
}
+ enable_irq_wake(udc->irq);
+
out:
mutex_unlock(&udc->vbus_mutex);
return 0;
@@ -2311,8 +2350,12 @@ static int usba_udc_resume(struct device *dev)
if (!udc->driver)
return 0;
- if (device_may_wakeup(dev) && udc->vbus_pin)
- disable_irq_wake(gpiod_to_irq(udc->vbus_pin));
+ if (device_may_wakeup(dev)) {
+ if (udc->vbus_pin)
+ disable_irq_wake(gpiod_to_irq(udc->vbus_pin));
+
+ disable_irq_wake(udc->irq);
+ }
/* If Vbus is present, enable the controller and wait for reset */
mutex_lock(&udc->vbus_mutex);
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
index 030bf797cd25..a0225e4543d4 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.h
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
@@ -331,6 +331,7 @@ struct usba_udc {
struct usba_ep *usba_ep;
bool bias_pulse_needed;
bool clocked;
+ bool suspended;
u16 devstatus;