From: nicolas.ferre@atmel•com (Nicolas Ferre)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv3 2/2] USB: gadget: atmel_usba_udc: Enable/disable USB PLL on Vbus change
Date: Mon, 19 Jan 2015 17:55:18 +0100 [thread overview]
Message-ID: <54BD36F6.8030408@atmel.com> (raw)
In-Reply-To: <1421601875-9436-3-git-send-email-sylvain.rochet@finsecur.com>
Le 18/01/2015 18:24, Sylvain Rochet a ?crit :
> Prepare_enable on rising edge, disable_unprepare on falling edge. Reduce
Please re-write which "edge" we are talking about: "... falling edge of
the Vbus signal" for example.
> power consumption if USB PLL is not already necessary for OHCI or EHCI.
Is a verb missing in the previous sentence?
> If USB host is not connected we can sleep with USB PLL stopped.
>
> This driver does not support suspend/resume yet, not suspending if we
> are still attached to an USB host is fine for what I need, this patch
> allow suspending with USB PLL stopped when USB device is not currently
> used.
Can you please make it more clear. Several separated sentences seem
necessary here.
> Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur•com>
> ---
> drivers/usb/gadget/udc/atmel_usba_udc.c | 96 ++++++++++++++++++++++++---------
> drivers/usb/gadget/udc/atmel_usba_udc.h | 4 ++
> 2 files changed, 74 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
> index e207d75..9cce50a 100644
> --- a/drivers/usb/gadget/udc/atmel_usba_udc.c
> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
> @@ -315,6 +315,38 @@ static inline void usba_cleanup_debugfs(struct usba_udc *udc)
> }
> #endif
>
> +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 ret;
> +}
> +
> +static int stop_clock(struct usba_udc *udc)
> +{
> + if (!udc->clocked)
> + return 0;
> +
> + clk_disable_unprepare(udc->hclk);
> + clk_disable_unprepare(udc->pclk);
> +
> + udc->clocked = false;
> + return 0;
> +}
> +
> static int vbus_is_present(struct usba_udc *udc)
> {
> if (gpio_is_valid(udc->vbus_pin))
> @@ -1719,42 +1751,56 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
> return IRQ_HANDLED;
> }
>
> -static irqreturn_t usba_vbus_irq(int irq, void *devid)
> +static irqreturn_t usba_vbus_irq_thread(int irq, void *devid)
> {
> struct usba_udc *udc = devid;
> int vbus;
> + int ret;
> + unsigned long flags;
>
> /* debounce */
> udelay(10);
>
> - spin_lock(&udc->lock);
> + mutex_lock(&udc->vbus_mutex);
>
> /* May happen if Vbus pin toggles during probe() */
> - if (!udc->driver)
> + spin_lock_irqsave(&udc->lock, flags);
> + if (!udc->driver) {
> + spin_unlock_irqrestore(&udc->lock, flags);
> goto out;
> + }
> + spin_unlock_irqrestore(&udc->lock, flags);
I'm not sure that the protection by spin_lock is needed above.
>
> vbus = vbus_is_present(udc);
> if (vbus != udc->vbus_prev) {
> if (vbus) {
> + ret = start_clock(udc);
> + if (ret)
> + goto out;
> +
> + spin_lock_irqsave(&udc->lock, flags);
> toggle_bias(1);
> usba_writel(udc, CTRL, USBA_ENABLE_MASK);
> usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
> + spin_unlock_irqrestore(&udc->lock, flags);
> } else {
> + spin_lock_irqsave(&udc->lock, flags);
> udc->gadget.speed = USB_SPEED_UNKNOWN;
> reset_all_endpoints(udc);
> toggle_bias(0);
> usba_writel(udc, CTRL, USBA_DISABLE_MASK);
> - if (udc->driver->disconnect) {
> - spin_unlock(&udc->lock);
> + spin_unlock_irqrestore(&udc->lock, flags);
> +
> + stop_clock(udc);
> +
> + if (udc->driver->disconnect)
> udc->driver->disconnect(&udc->gadget);
> - spin_lock(&udc->lock);
> - }
> }
> udc->vbus_prev = vbus;
> }
>
> out:
> - spin_unlock(&udc->lock);
> + mutex_unlock(&udc->vbus_mutex);
>
> return IRQ_HANDLED;
> }
> @@ -1762,7 +1808,7 @@ out:
> static int atmel_usba_start(struct usb_gadget *gadget,
> struct usb_gadget_driver *driver)
> {
> - int ret;
> + int ret = 0;
> struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget);
> unsigned long flags;
>
> @@ -1772,31 +1818,29 @@ static int atmel_usba_start(struct usb_gadget *gadget,
> 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) {
> + ret = start_clock(udc);
> + if (ret)
> + goto out;
> +
> + spin_lock_irqsave(&udc->lock, flags);
> toggle_bias(1);
> usba_writel(udc, CTRL, USBA_ENABLE_MASK);
> usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
> + spin_unlock_irqrestore(&udc->lock, flags);
>
> udc->vbus_prev = 1;
> }
> - spin_unlock_irqrestore(&udc->lock, flags);
>
> - return 0;
> +out:
> + mutex_unlock(&udc->vbus_mutex);
> + return ret;
> }
>
> static int atmel_usba_stop(struct usb_gadget *gadget)
> @@ -1816,8 +1860,7 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
> toggle_bias(0);
> usba_writel(udc, CTRL, USBA_DISABLE_MASK);
>
> - clk_disable_unprepare(udc->hclk);
> - clk_disable_unprepare(udc->pclk);
> + stop_clock(udc);
>
> udc->driver = NULL;
>
> @@ -1997,6 +2040,7 @@ static int usba_udc_probe(struct platform_device *pdev)
> return PTR_ERR(hclk);
>
> spin_lock_init(&udc->lock);
> + mutex_init(&udc->vbus_mutex);
> udc->pdev = pdev;
> udc->pclk = pclk;
> udc->hclk = hclk;
> @@ -2049,9 +2093,9 @@ static int usba_udc_probe(struct platform_device *pdev)
>
> if (gpio_is_valid(udc->vbus_pin)) {
> if (!devm_gpio_request(&pdev->dev, udc->vbus_pin, "atmel_usba_udc")) {
> - 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;
> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
> index a70706e..3ceed76 100644
> --- a/drivers/usb/gadget/udc/atmel_usba_udc.h
> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
> @@ -308,6 +308,9 @@ struct usba_udc {
> /* Protect hw registers from concurrent modifications */
> spinlock_t lock;
>
> + /* Mutex to prevent concurrent start or stop */
> + struct mutex vbus_mutex;
> +
> void __iomem *regs;
> void __iomem *fifo;
>
> @@ -321,6 +324,7 @@ struct usba_udc {
> struct clk *pclk;
> struct clk *hclk;
> struct usba_ep *usba_ep;
> + bool clocked;
>
> u16 devstatus;
Otherwise, it looks okay, so once little corrections done, you can add my:
Acked-by: Nicolas Ferre <nicolas.ferre@atmel•com>
Thanks, bye,
--
Nicolas Ferre
next prev parent reply other threads:[~2015-01-19 16:55 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-16 22:21 [PATCH] USB: gadget: atmel_usba_udc: Enable/disable USB PLL on Vbus change Sylvain Rochet
2015-01-17 1:42 ` Alexandre Belloni
2015-01-17 9:43 ` Boris Brezillon
2015-01-17 11:07 ` Sylvain Rochet
2015-01-18 14:51 ` [PATCHv2 0/2] " Sylvain Rochet
2015-01-18 14:51 ` [PATCHv2 1/2] USB: gadget: atmel_usba_udc: Fixed vbus_prev initial state Sylvain Rochet
2015-01-18 14:51 ` [PATCH 2/2] USB: gadget: atmel_usba_udc: Enable/disable USB PLL on Vbus change Sylvain Rochet
2015-01-18 16:56 ` Boris Brezillon
2015-01-18 17:24 ` [PATCHv3 0/2] " Sylvain Rochet
2015-01-18 17:24 ` [PATCHv3 1/2] USB: gadget: atmel_usba_udc: Fixed vbus_prev initial state Sylvain Rochet
2015-01-19 14:09 ` Nicolas Ferre
2015-01-19 18:55 ` Felipe Balbi
2015-01-20 11:02 ` Sylvain Rochet
2015-01-20 11:11 ` Nicolas Ferre
2015-01-18 17:24 ` [PATCHv3 2/2] USB: gadget: atmel_usba_udc: Enable/disable USB PLL on Vbus change Sylvain Rochet
2015-01-19 16:55 ` Nicolas Ferre [this message]
2015-01-19 17:46 ` Sylvain Rochet
2015-01-19 20:15 ` Boris Brezillon
2015-01-20 9:02 ` Nicolas Ferre
2015-01-18 17:34 ` [PATCH " Boris Brezillon
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