From patchwork Wed Jan 21 19:31:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sylvain Rochet X-Patchwork-Id: 5680181 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id F33DCC058D for ; Wed, 21 Jan 2015 19:34:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 85BA8204CF for ; Wed, 21 Jan 2015 19:34:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C52752026F for ; Wed, 21 Jan 2015 19:34:54 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YE11A-0000ne-3g; Wed, 21 Jan 2015 19:32:44 +0000 Received: from mx-guillaumet.finsecur.com ([91.217.234.131] helo=guillaumet.finsecur.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YE10C-00009i-BF for linux-arm-kernel@lists.infradead.org; Wed, 21 Jan 2015 19:31:48 +0000 Received: from [172.16.8.13] (helo=spice.lan) by guillaumet.finsecur.com with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1YE0zl-000AbP-Ez; Wed, 21 Jan 2015 20:31:19 +0100 Received: from gradator by spice.lan with local (Exim 4.84) (envelope-from ) id 1YE0zl-0008E0-71; Wed, 21 Jan 2015 20:31:17 +0100 From: Sylvain Rochet To: Boris Brezillon , Alexandre Belloni , plagnioj@jcrosoft.com, nicolas.ferre@atmel.com, linux-arm-kernel@lists.infradead.org, voice.shen@atmel.com, Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Wenyou Yang Date: Wed, 21 Jan 2015 20:31:13 +0100 Message-Id: <1421868674-30757-4-git-send-email-sylvain.rochet@finsecur.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1421868674-30757-1-git-send-email-sylvain.rochet@finsecur.com> References: <1421868674-30757-1-git-send-email-sylvain.rochet@finsecur.com> X-SA-Exim-Connect-IP: 172.16.8.13 X-SA-Exim-Mail-From: sylvain.rochet@finsecur.com X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Subject: [PATCHv5 3/4] USB: gadget: atmel_usba_udc: Start clocks on rising edge of the Vbus signal, stop clocks on falling edge of the Vbus signal X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on guillaumet.finsecur.com) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150121_113144_610384_F6119A7C X-CRM114-Status: GOOD ( 17.95 ) X-Spam-Score: -0.7 (/) Cc: Sylvain Rochet X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Acked-by: Nicolas Ferre --- drivers/usb/gadget/udc/atmel_usba_udc.c | 149 +++++++++++++++++++++----------- drivers/usb/gadget/udc/atmel_usba_udc.h | 4 + 2 files changed, 104 insertions(+), 49 deletions(-) diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c index d369ae0..963e398 100644 --- a/drivers/usb/gadget/udc/atmel_usba_udc.c +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c @@ -1719,38 +1719,98 @@ static irqreturn_t usba_udc_irq(int irq, void *devid) 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(1); + usba_writel(udc, CTRL, USBA_ENABLE_MASK); + usba_writel(udc, INT_ENB, 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(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; + int ret; /* debounce */ udelay(10); - spin_lock(&udc->lock); + mutex_lock(&udc->vbus_mutex); vbus = vbus_is_present(udc); if (vbus != udc->vbus_prev) { + udc->vbus_prev = vbus; if (vbus) { - toggle_bias(1); - usba_writel(udc, CTRL, USBA_ENABLE_MASK); - usba_writel(udc, INT_ENB, USBA_END_OF_RESET); + ret = usba_start(udc); + if (ret) + goto out; } else { - 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); + usba_stop(udc); + + if (udc->driver->disconnect) udc->driver->disconnect(&udc->gadget); - spin_lock(&udc->lock); - } } - udc->vbus_prev = vbus; } - spin_unlock(&udc->lock); - +out: + mutex_unlock(&udc->vbus_mutex); return IRQ_HANDLED; } @@ -1762,57 +1822,47 @@ static int atmel_usba_start(struct usb_gadget *gadget, 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(1); - usba_writel(udc, CTRL, USBA_ENABLE_MASK); - usba_writel(udc, INT_ENB, 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(0); - usba_writel(udc, CTRL, USBA_DISABLE_MASK); - - clk_disable_unprepare(udc->hclk); - clk_disable_unprepare(udc->pclk); + usba_stop(udc); udc->driver = NULL; @@ -1992,6 +2042,7 @@ 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; @@ -2045,9 +2096,9 @@ 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")) { 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; 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;