From patchwork Mon Sep 22 09:46:29 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 4946701 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 239EF9F32F for ; Mon, 22 Sep 2014 09:48:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 25D46201FA for ; Mon, 22 Sep 2014 09:48:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABC8B20220 for ; Mon, 22 Sep 2014 09:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752245AbaIVJr4 (ORCPT ); Mon, 22 Sep 2014 05:47:56 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:62961 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753316AbaIVJq7 (ORCPT ); Mon, 22 Sep 2014 05:46:59 -0400 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout1.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NCA00IXSRB3NE60@mailout1.w1.samsung.com>; Mon, 22 Sep 2014 10:49:51 +0100 (BST) X-AuditID: cbfec7f5-b7f776d000003e54-a5-541ff01013de Received: from eusync3.samsung.com ( [203.254.199.213]) by eucpsbgm2.samsung.com (EUCPMTA) with SMTP id 58.69.15956.010FF145; Mon, 22 Sep 2014 10:46:56 +0100 (BST) Received: from AMDC1943.digital.local ([106.116.151.171]) by eusync3.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0NCA006NUR61YU10@eusync3.samsung.com>; Mon, 22 Sep 2014 10:46:56 +0100 (BST) From: Krzysztof Kozlowski To: Russell King , Dan Williams , Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Ulf Hansson , Grant Likely , Lars-Peter Clausen , Michal Simek , "Rafael J. Wysocki" , Len Brown , Pavel Machek , Randy Dunlap , Alan Stern , linux-doc@vger.kernel.org, linux-pm@vger.kernel.org Cc: Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz , Krzysztof Kozlowski Subject: [PATCH v6 4/4] dma: pl330: add Power Management support Date: Mon, 22 Sep 2014 11:46:29 +0200 Message-id: <1411379189-3017-5-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1411379189-3017-1-git-send-email-k.kozlowski@samsung.com> References: <1411379189-3017-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrILMWRmVeSWpSXmKPExsVy+t/xq7oCH+RDDCbs1bPYOGM9q8X0qRcY LVZP/ctqceDPDkaL1y8MLc42vWG3WDJ5PqvFrCl7mSwWti1hsbi8aw6bxefeI4wWty/zWqw9 cpfd4t3LCIu7p46yWby9M53F4szpS6wWE35fYLM4vjbc4mXffhYHEY+W5h42j80rtDwW73nJ 5HHn2h42jyVvDrF6bLnazuIx++4PRo++LasYPVas/s7u8XmTnMfez79ZArijuGxSUnMyy1KL 9O0SuDIOT7zLWnDPsuJPa1ADY4dBFyMnh4SAicSD2aeYIGwxiQv31rN1MXJxCAksZZSY1/4Q yuljknizuo8ZpIpNwFhi8/IlYAkRgSMsEs/uPQFzmAWOMkpM730LNktYwEHiaUM/I4jNIqAq sXD6TbA4r4CbxPbmMywQ++QkTh6bzApicwq4S+x/1sIOYgsB1Rw5NJtpAiPvAkaGVYyiqaXJ BcVJ6blGesWJucWleel6yfm5mxgh0fB1B+PSY1aHGAU4GJV4eH+0yIcIsSaWFVfmHmKU4GBW EuF9+hwoxJuSWFmVWpQfX1Sak1p8iJGJg1OqgdGhsTng7VsHkdN++1TFdgZVPzSq36n6sD7t D6eOdV6pesBpTme9zU8vKM5JzHx/qeGz5szzZXNdbLdv6Ytkuea9p819v3SMl3jhvYbYY88m nChLZF9QlyX3Mf7E55kLri4+3HFyT8Hss0ztAVzlyTcWXfdPzlWqvvuUTWKrS+S5gvAbE1f9 V1RiKc5INNRiLipOBAC2f+WPZAIAAA== Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds both normal PM suspend/resume support and runtime PM support to pl330 DMA engine driver. The runtime power management for pl330 DMA driver allows gating of AMBA clock (PDMA) in FSYS clock domain, when the device is not processing any requests. This is necessary to enter low power modes on Exynos SoCs (e.g. LPA on Exynos4x12 or W-AFTR on Exynos3250). Runtime PM resuming of the device may happen in atomic context (during call device_issue_pending()) so pm_runtime_irq_safe() is used. This will lead only to disabling/enabling of the clock but this is sufficient for gating the clock and for reducing energy usage. During system sleep the AMBA bus clock is also unprepared. Suggested-by: Bartlomiej Zolnierkiewicz Signed-off-by: Krzysztof Kozlowski --- drivers/dma/pl330.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 83 insertions(+), 4 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 4839bfa74a10..43f482811b23 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "dmaengine.h" #define PL330_MAX_CHAN 8 @@ -265,6 +266,9 @@ static unsigned cmd_line; #define NR_DEFAULT_DESC 16 +/* Delay for runtime PM autosuspend, ms */ +#define PL330_AUTOSUSPEND_DELAY 20 + /* Populated by the PL330 core driver for DMA API driver's info */ struct pl330_config { u32 periph_id; @@ -1958,6 +1962,7 @@ static void pl330_tasklet(unsigned long data) struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data; struct dma_pl330_desc *desc, *_dt; unsigned long flags; + bool power_down = false; spin_lock_irqsave(&pch->lock, flags); @@ -1972,10 +1977,17 @@ static void pl330_tasklet(unsigned long data) /* Try to submit a req imm. next to the last completed cookie */ fill_queue(pch); - /* Make sure the PL330 Channel thread is active */ - spin_lock(&pch->thread->dmac->lock); - _start(pch->thread); - spin_unlock(&pch->thread->dmac->lock); + if (list_empty(&pch->work_list)) { + spin_lock(&pch->thread->dmac->lock); + _stop(pch->thread); + spin_unlock(&pch->thread->dmac->lock); + power_down = true; + } else { + /* Make sure the PL330 Channel thread is active */ + spin_lock(&pch->thread->dmac->lock); + _start(pch->thread); + spin_unlock(&pch->thread->dmac->lock); + } while (!list_empty(&pch->completed_list)) { dma_async_tx_callback callback; @@ -1990,6 +2002,12 @@ static void pl330_tasklet(unsigned long data) if (pch->cyclic) { desc->status = PREP; list_move_tail(&desc->node, &pch->work_list); + if (power_down) { + spin_lock(&pch->thread->dmac->lock); + _start(pch->thread); + spin_unlock(&pch->thread->dmac->lock); + power_down = false; + } } else { desc->status = FREE; list_move_tail(&desc->node, &pch->dmac->desc_pool); @@ -2004,6 +2022,12 @@ static void pl330_tasklet(unsigned long data) } } spin_unlock_irqrestore(&pch->lock, flags); + + /* If work list empty, power down */ + if (power_down) { + pm_runtime_mark_last_busy(pch->dmac->ddma.dev); + pm_runtime_put_autosuspend(pch->dmac->ddma.dev); + } } bool pl330_filter(struct dma_chan *chan, void *param) @@ -2073,6 +2097,7 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned switch (cmd) { case DMA_TERMINATE_ALL: + pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); spin_lock(&pl330->lock); @@ -2099,10 +2124,15 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned dma_cookie_complete(&desc->txd); } + if (!list_empty(&pch->work_list)) + pm_runtime_put(pl330->ddma.dev); + list_splice_tail_init(&pch->submitted_list, &pl330->desc_pool); list_splice_tail_init(&pch->work_list, &pl330->desc_pool); list_splice_tail_init(&pch->completed_list, &pl330->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); + pm_runtime_mark_last_busy(pl330->ddma.dev); + pm_runtime_put_autosuspend(pl330->ddma.dev); break; case DMA_SLAVE_CONFIG: slave_config = (struct dma_slave_config *)arg; @@ -2138,6 +2168,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan) tasklet_kill(&pch->task); + pm_runtime_get_sync(pch->dmac->ddma.dev); spin_lock_irqsave(&pch->lock, flags); pl330_release_channel(pch->thread); @@ -2147,6 +2178,8 @@ static void pl330_free_chan_resources(struct dma_chan *chan) list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); + pm_runtime_mark_last_busy(pch->dmac->ddma.dev); + pm_runtime_put_autosuspend(pch->dmac->ddma.dev); } static enum dma_status @@ -2162,6 +2195,15 @@ static void pl330_issue_pending(struct dma_chan *chan) unsigned long flags; spin_lock_irqsave(&pch->lock, flags); + if (list_empty(&pch->work_list)) { + /* + * Warn on nothing pending. Empty submitted_list may + * break our pm_runtime usage counter as it is + * updated on work_list emptiness status. + */ + WARN_ON(list_empty(&pch->submitted_list)); + pm_runtime_get_sync(pch->dmac->ddma.dev); + } list_splice_tail_init(&pch->submitted_list, &pch->work_list); spin_unlock_irqrestore(&pch->lock, flags); @@ -2585,6 +2627,34 @@ static int pl330_dma_device_slave_caps(struct dma_chan *dchan, return 0; } +/* + * Assume that IRQ safe runtime PM is chosen in probe and amba bus driver + * will only disable/enable the clock in runtime PM suspend/resume. + */ +static int __maybe_unused pl330_suspend(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + + if (!pm_runtime_suspended(dev)) + amba_pclk_disable(pcdev); + amba_pclk_unprepare(pcdev); + + return 0; +} + +static int __maybe_unused pl330_resume(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + + amba_pclk_prepare(pcdev); + if (!pm_runtime_suspended(dev)) + return amba_pclk_enable(pcdev); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(pl330_pm, pl330_suspend, pl330_resume); + static int pl330_probe(struct amba_device *adev, const struct amba_id *id) { @@ -2738,6 +2808,12 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) pcfg->data_buf_dep, pcfg->data_bus_width / 8, pcfg->num_chan, pcfg->num_peri, pcfg->num_events); + pm_runtime_irq_safe(&adev->dev); + pm_runtime_use_autosuspend(&adev->dev); + pm_runtime_set_autosuspend_delay(&adev->dev, PL330_AUTOSUSPEND_DELAY); + pm_runtime_mark_last_busy(&adev->dev); + pm_runtime_put_noidle(&adev->dev); + return 0; probe_err3: /* Idle the DMAC */ @@ -2764,6 +2840,8 @@ static int pl330_remove(struct amba_device *adev) struct pl330_dmac *pl330 = amba_get_drvdata(adev); struct dma_pl330_chan *pch, *_p; + pm_runtime_get_noresume(pl330->ddma.dev); + if (adev->dev.of_node) of_dma_controller_free(adev->dev.of_node); @@ -2802,6 +2880,7 @@ static struct amba_driver pl330_driver = { .drv = { .owner = THIS_MODULE, .name = "dma-pl330", + .pm = &pl330_pm, }, .id_table = pl330_ids, .probe = pl330_probe,