usb: gadget: atmel_usba_udc: condition clocks to vbus state
If USB PLL is not necessary for other USB drivers (e.g. OHCI and EHCI)
we will reduce power consumption by switching off the USB PLL if no USB
Host is currently connected to this USB Device.
We are using Vbus GPIO signal to detect Host presence. If Vbus signal is
not available then the device stays continuously clocked.
Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index bbbd5f11..999e2f2 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -1739,7 +1739,72 @@
return IRQ_HANDLED;
}
-static irqreturn_t usba_vbus_irq(int irq, void *devid)
+static int start_clock(struct usba_udc *udc)
+{
+ int ret;
+
+ if (udc->clocked)
+ return 0;
+
+ ret = clk_prepare_enable(udc->pclk);
+ if (ret)
+ return ret;
+ ret = clk_prepare_enable(udc->hclk);
+ if (ret) {
+ clk_disable_unprepare(udc->pclk);
+ return ret;
+ }
+
+ udc->clocked = true;
+ return 0;
+}
+
+static void stop_clock(struct usba_udc *udc)
+{
+ if (!udc->clocked)
+ return;
+
+ clk_disable_unprepare(udc->hclk);
+ clk_disable_unprepare(udc->pclk);
+
+ udc->clocked = false;
+}
+
+static int usba_start(struct usba_udc *udc)
+{
+ unsigned long flags;
+ int ret;
+
+ ret = start_clock(udc);
+ if (ret)
+ return ret;
+
+ spin_lock_irqsave(&udc->lock, flags);
+ toggle_bias(udc, 1);
+ usba_writel(udc, CTRL, USBA_ENABLE_MASK);
+ usba_int_enb_set(udc, USBA_END_OF_RESET);
+ spin_unlock_irqrestore(&udc->lock, flags);
+
+ return 0;
+}
+
+static void usba_stop(struct usba_udc *udc)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&udc->lock, flags);
+ udc->gadget.speed = USB_SPEED_UNKNOWN;
+ reset_all_endpoints(udc);
+
+ /* This will also disable the DP pullup */
+ toggle_bias(udc, 0);
+ usba_writel(udc, CTRL, USBA_DISABLE_MASK);
+ spin_unlock_irqrestore(&udc->lock, flags);
+
+ stop_clock(udc);
+}
+
+static irqreturn_t usba_vbus_irq_thread(int irq, void *devid)
{
struct usba_udc *udc = devid;
int vbus;
@@ -1747,30 +1812,22 @@
/* debounce */
udelay(10);
- spin_lock(&udc->lock);
+ mutex_lock(&udc->vbus_mutex);
vbus = vbus_is_present(udc);
if (vbus != udc->vbus_prev) {
if (vbus) {
- toggle_bias(udc, 1);
- usba_writel(udc, CTRL, USBA_ENABLE_MASK);
- usba_int_enb_set(udc, USBA_END_OF_RESET);
+ usba_start(udc);
} else {
- udc->gadget.speed = USB_SPEED_UNKNOWN;
- reset_all_endpoints(udc);
- toggle_bias(udc, 0);
- usba_writel(udc, CTRL, USBA_DISABLE_MASK);
- if (udc->driver->disconnect) {
- spin_unlock(&udc->lock);
+ usba_stop(udc);
+
+ if (udc->driver->disconnect)
udc->driver->disconnect(&udc->gadget);
- spin_lock(&udc->lock);
- }
}
udc->vbus_prev = vbus;
}
- spin_unlock(&udc->lock);
-
+ mutex_unlock(&udc->vbus_mutex);
return IRQ_HANDLED;
}
@@ -1782,57 +1839,47 @@
unsigned long flags;
spin_lock_irqsave(&udc->lock, flags);
-
udc->devstatus = 1 << USB_DEVICE_SELF_POWERED;
udc->driver = driver;
spin_unlock_irqrestore(&udc->lock, flags);
- ret = clk_prepare_enable(udc->pclk);
- if (ret)
- return ret;
- ret = clk_prepare_enable(udc->hclk);
- if (ret) {
- clk_disable_unprepare(udc->pclk);
- return ret;
- }
+ mutex_lock(&udc->vbus_mutex);
- udc->vbus_prev = 0;
if (gpio_is_valid(udc->vbus_pin))
enable_irq(gpio_to_irq(udc->vbus_pin));
/* If Vbus is present, enable the controller and wait for reset */
- spin_lock_irqsave(&udc->lock, flags);
- if (vbus_is_present(udc) && udc->vbus_prev == 0) {
- toggle_bias(udc, 1);
- usba_writel(udc, CTRL, USBA_ENABLE_MASK);
- usba_int_enb_set(udc, USBA_END_OF_RESET);
-
- udc->vbus_prev = 1;
+ udc->vbus_prev = vbus_is_present(udc);
+ if (udc->vbus_prev) {
+ ret = usba_start(udc);
+ if (ret)
+ goto err;
}
- spin_unlock_irqrestore(&udc->lock, flags);
+ mutex_unlock(&udc->vbus_mutex);
return 0;
+
+err:
+ if (gpio_is_valid(udc->vbus_pin))
+ disable_irq(gpio_to_irq(udc->vbus_pin));
+
+ mutex_unlock(&udc->vbus_mutex);
+
+ spin_lock_irqsave(&udc->lock, flags);
+ udc->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
+ udc->driver = NULL;
+ spin_unlock_irqrestore(&udc->lock, flags);
+ return ret;
}
static int atmel_usba_stop(struct usb_gadget *gadget)
{
struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget);
- unsigned long flags;
if (gpio_is_valid(udc->vbus_pin))
disable_irq(gpio_to_irq(udc->vbus_pin));
- spin_lock_irqsave(&udc->lock, flags);
- udc->gadget.speed = USB_SPEED_UNKNOWN;
- reset_all_endpoints(udc);
- spin_unlock_irqrestore(&udc->lock, flags);
-
- /* This will also disable the DP pullup */
- toggle_bias(udc, 0);
- usba_writel(udc, CTRL, USBA_DISABLE_MASK);
-
- clk_disable_unprepare(udc->hclk);
- clk_disable_unprepare(udc->pclk);
+ usba_stop(udc);
udc->driver = NULL;
@@ -2054,6 +2101,7 @@
return PTR_ERR(hclk);
spin_lock_init(&udc->lock);
+ mutex_init(&udc->vbus_mutex);
udc->pdev = pdev;
udc->pclk = pclk;
udc->hclk = hclk;
@@ -2110,9 +2158,9 @@
if (!devm_gpio_request(&pdev->dev, udc->vbus_pin, "atmel_usba_udc")) {
irq_set_status_flags(gpio_to_irq(udc->vbus_pin),
IRQ_NOAUTOEN);
- ret = devm_request_irq(&pdev->dev,
- gpio_to_irq(udc->vbus_pin),
- usba_vbus_irq, 0,
+ ret = devm_request_threaded_irq(&pdev->dev,
+ gpio_to_irq(udc->vbus_pin), NULL,
+ usba_vbus_irq_thread, IRQF_ONESHOT,
"atmel_usba_udc", udc);
if (ret) {
udc->vbus_pin = -ENODEV;