Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965309AbaDJHLq (ORCPT ); Thu, 10 Apr 2014 03:11:46 -0400 Received: from co9ehsobe004.messaging.microsoft.com ([207.46.163.27]:5491 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965205AbaDJHLL (ORCPT ); Thu, 10 Apr 2014 03:11:11 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzd799hzz1f42h1ee6h1de0h1fdah2073h2146h1202h1e76h2189h1d1ah1d2ah21bch21a7h1fc6h208chzdchz1de098h8275bh1de097hz2dh2a8h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh2222h224fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e23h1fe8h1ff5h2218h2216h226dh22d0h24afh2327h2336h2438h2461h2487h24d7h2516h2545h255eh25cch25f6h2605h268bh26d3h1155h) From: To: , , CC: , , , , Hongbo Zhang Subject: [PATCH v3 8/8] DMA: Freescale: add suspend resume functions for DMA driver Date: Thu, 10 Apr 2014 15:10:05 +0800 Message-ID: <1397113805-24171-9-git-send-email-hongbo.zhang@freescale.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1397113805-24171-1-git-send-email-hongbo.zhang@freescale.com> References: <1397113805-24171-1-git-send-email-hongbo.zhang@freescale.com> MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% X-FOPE-CONNECTOR: Id%0$Dn%FREESCALE.MAIL.ONMICROSOFT.COM$RO%1$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hongbo Zhang This patch adds suspend resume functions for Freescale DMA driver. .prepare callback is used to stop further descriptors from being added into the pending queue, and also issue pending queues into execution if there is any. .suspend callback makes sure all the pending jobs are cleaned up and all the channels are idle, and save the mode registers. .resume callback re-initializes the channels by restore the mode registers. Signed-off-by: Hongbo Zhang --- drivers/dma/fsldma.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/dma/fsldma.h | 16 ++++++++ 2 files changed, 116 insertions(+) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index c9bf54a..d6da222 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -400,6 +400,14 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) spin_lock_bh(&chan->desc_lock); +#ifdef CONFIG_PM + if (unlikely(chan->pm_state != RUNNING)) { + chan_dbg(chan, "cannot submit due to suspend\n"); + spin_unlock_bh(&chan->desc_lock); + return -1; + } +#endif + /* * assign cookies to all of the software descriptors * that make up this transaction @@ -1311,6 +1319,9 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev, INIT_LIST_HEAD(&chan->ld_running); INIT_LIST_HEAD(&chan->ld_completed); chan->idle = true; +#ifdef CONFIG_PM + chan->pm_state = RUNNING; +#endif chan->common.device = &fdev->common; dma_cookie_init(&chan->common); @@ -1450,6 +1461,92 @@ static int fsldma_of_remove(struct platform_device *op) return 0; } +#ifdef CONFIG_PM +static int fsldma_prepare(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct fsldma_device *fdev = platform_get_drvdata(pdev); + struct fsldma_chan *chan; + int i; + + for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { + chan = fdev->chan[i]; + if (!chan) + continue; + + spin_lock_bh(&chan->desc_lock); + chan->pm_state = SUSPENDING; + if (!list_empty(&chan->ld_pending)) + fsl_chan_xfer_ld_queue(chan); + spin_unlock_bh(&chan->desc_lock); + } + + return 0; +} + +static int fsldma_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct fsldma_device *fdev = platform_get_drvdata(pdev); + struct fsldma_chan *chan; + int i; + + for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { + chan = fdev->chan[i]; + if (!chan) + continue; + + spin_lock_bh(&chan->desc_lock); + if (!chan->idle) + goto out; + chan->regs_save.mr = DMA_IN(chan, &chan->regs->mr, 32); + chan->pm_state = SUSPENDED; + spin_unlock_bh(&chan->desc_lock); + } + return 0; + +out: + for (; i >= 0; i--) { + chan = fdev->chan[i]; + if (!chan) + continue; + chan->pm_state = RUNNING; + spin_unlock_bh(&chan->desc_lock); + } + return -EBUSY; +} + +static int fsldma_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct fsldma_device *fdev = platform_get_drvdata(pdev); + struct fsldma_chan *chan; + u32 mode; + int i; + + for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { + chan = fdev->chan[i]; + if (!chan) + continue; + + spin_lock_bh(&chan->desc_lock); + mode = chan->regs_save.mr + & ~FSL_DMA_MR_CS & ~FSL_DMA_MR_CC & ~FSL_DMA_MR_CA; + DMA_OUT(chan, &chan->regs->mr, mode, 32); + chan->pm_state = RUNNING; + spin_unlock_bh(&chan->desc_lock); + } + + return 0; +} + +static const struct dev_pm_ops fsldma_pm_ops = { + .prepare = fsldma_prepare, + .suspend = fsldma_suspend, + .resume = fsldma_resume, +}; +#endif + static const struct of_device_id fsldma_of_ids[] = { { .compatible = "fsl,elo3-dma", }, { .compatible = "fsl,eloplus-dma", }, @@ -1462,6 +1559,9 @@ static struct platform_driver fsldma_of_driver = { .name = "fsl-elo-dma", .owner = THIS_MODULE, .of_match_table = fsldma_of_ids, +#ifdef CONFIG_PM + .pm = &fsldma_pm_ops, +#endif }, .probe = fsldma_of_probe, .remove = fsldma_of_remove, diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h index ec19517..eecaf9e 100644 --- a/drivers/dma/fsldma.h +++ b/drivers/dma/fsldma.h @@ -134,6 +134,18 @@ struct fsldma_device { #define FSL_DMA_CHAN_PAUSE_EXT 0x00001000 #define FSL_DMA_CHAN_START_EXT 0x00002000 +#ifdef CONFIG_PM +struct fsldma_chan_regs_save { + u32 mr; +}; + +enum fsldma_pm_state { + RUNNING = 0, + SUSPENDING, + SUSPENDED, +}; +#endif + struct fsldma_chan { char name[8]; /* Channel name */ struct fsldma_chan_regs __iomem *regs; @@ -161,6 +173,10 @@ struct fsldma_chan { struct tasklet_struct tasklet; u32 feature; bool idle; /* DMA controller is idle */ +#ifdef CONFIG_PM + struct fsldma_chan_regs_save regs_save; + enum fsldma_pm_state pm_state; +#endif void (*toggle_ext_pause)(struct fsldma_chan *fsl_chan, int enable); void (*toggle_ext_start)(struct fsldma_chan *fsl_chan, int enable); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/