From patchwork Tue Nov 4 12:52:49 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 5227471 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AE173C11AC for ; Tue, 4 Nov 2014 12:54:26 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 75C6F20145 for ; Tue, 4 Nov 2014 12:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 361922012E for ; Tue, 4 Nov 2014 12:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753481AbaKDMyH (ORCPT ); Tue, 4 Nov 2014 07:54:07 -0500 Received: from mailout3.w1.samsung.com ([210.118.77.13]:46565 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300AbaKDMxJ (ORCPT ); Tue, 4 Nov 2014 07:53:09 -0500 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NEI00HMTML9DAA0@mailout3.w1.samsung.com>; Tue, 04 Nov 2014 12:55:57 +0000 (GMT) X-AuditID: cbfec7f5-b7f956d000005ed7-d9-5458cc31e1df Received: from eusync3.samsung.com ( [203.254.199.213]) by eucpsbgm2.samsung.com (EUCPMTA) with SMTP id 6B.B2.24279.13CC8545; Tue, 04 Nov 2014 12:53:05 +0000 (GMT) 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 <0NEI00F5DMGAFJ30@eusync3.samsung.com>; Tue, 04 Nov 2014 12:53:05 +0000 (GMT) From: Krzysztof Kozlowski To: "Rafael J. Wysocki" , Len Brown , Pavel Machek , Jonathan Corbet , Russell King , Dan Williams , Vinod Koul , Ulf Hansson , Alan Stern , Krzysztof Kozlowski , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Lars-Peter Clausen , Michal Simek Cc: Kevin Hilman , Laurent Pinchart , Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz Subject: [PATCH v9 3/4] dma: pl330: add Power Management support Date: Tue, 04 Nov 2014 13:52:49 +0100 Message-id: <1415105570-7871-4-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1415105570-7871-1-git-send-email-k.kozlowski@samsung.com> References: <1415105570-7871-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrDLMWRmVeSWpSXmKPExsVy+t/xq7qGZyJCDHrnSFhsnLGe1eLJgXZG i+lTLzBarJ76l9Xi9QtDi6ebHzNZnG16w26xZPJ8VovOiUvYLWZN2ctkcXnXHDaLz71HGC1u X+a1WHvkLrvFu5cRFndPHWWzOHP6EqvFhN8X2CyOrw23eNm3n8VBxKOluYfNY3bHTFaPxXte MnlsWtXJ5nHn2h42j8V9k1k9lrw5xOqx5Wo7i8fsuz8YPfq2rGL0WLH6O7vH501yHns//2YJ 4I3isklJzcksSy3St0vgyvj+/gRbQatNxbJ595kaGF8YdjFyckgImEgcPb+TDcIWk7hwbz2Q zcUhJLCUUeLS+mcsIAkhgT4miUXzIkFsNgFjic3Ll4AViQisYpF4tec6mMMs8JFR4ubqjcwg VcICDhKnV71lBbFZBFQl7r89BTaJV8BNYuuZG+wQ6+QkTh6bDFbDKeAusXXjPjaIbW4Sbx69 YZvAyLuAkWEVo2hqaXJBcVJ6rpFecWJucWleul5yfu4mRkiMfN3BuPSY1SFGAQ5GJR7eFfER IUKsiWXFlbmHGCU4mJVEeLedBgrxpiRWVqUW5ccXleakFh9iZOLglGpglPlx+Dv7JbW5RpuP RjtsXCCzc5v2D5HSHXERoee335X/ahi0wOTYBa/vs9dNeZm0pO+uwe7Lr3OkahqFk2Ztnfry cqqYGmdsmafCn4iVj1YEBfIclDf44Fm0NDXql2LOl3eWvCfrz669WXDIduXmhiOvkjk63mjF ykl87T/7uuRUhThrYv05AyWW4oxEQy3mouJEAOldEA9vAgAA Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.5 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 Reviewed-by: Ulf Hansson --- drivers/dma/pl330.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 90 insertions(+), 4 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 4839bfa74a10..b123431e62ed 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 +2627,41 @@ 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); + int ret; + + ret = pm_runtime_force_suspend(dev); + if (ret) + return ret; + + 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); + + /* + * TODO: Idea for future. The device should not be woken up after + * system resume if it is not needed. It could stay runtime suspended + * waiting for DMA requests. However for safe suspend and resume we + * forcibly resume the device here. + */ + return pm_runtime_force_resume(dev); +} + +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 +2815,12 @@ 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_autosuspend(&adev->dev); + return 0; probe_err3: /* Idle the DMAC */ @@ -2764,6 +2847,8 @@ 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 +2887,7 @@ static struct amba_driver pl330_driver = { .drv = { .owner = THIS_MODULE, .name = "dma-pl330", + .pm = &pl330_pm, }, .id_table = pl330_ids, .probe = pl330_probe,