dmaengine: Freescale: add suspend resume functions for DMA driver

This patch adds suspend and resume functions for Freescale DMA driver.

Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index b291e6c650530b16ab440de0259b892861ad94de..465f16dd78e5b5a5a7bab0bbe5aadac1dc8a483b 100644 (file)
--- 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
@@ -1221,6 +1229,9 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
        INIT_LIST_HEAD(&chan->ld_pending);
        INIT_LIST_HEAD(&chan->ld_running);
        chan->idle = true;
+#ifdef CONFIG_PM
+       chan->pm_state = RUNNING;
+#endif
 
        chan->common.device = &fdev->common;
        dma_cookie_init(&chan->common);
@@ -1360,6 +1371,69 @@ static int fsldma_of_remove(struct platform_device *op)
        return 0;
 }
 
+#ifdef CONFIG_PM
+static int fsldma_suspend_late(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 (unlikely(!chan->idle))
+                       goto out;
+               chan->regs_save.mr = get_mr(chan);
+               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_early(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;
+               set_mr(chan, mode);
+               chan->pm_state = RUNNING;
+               spin_unlock_bh(&chan->desc_lock);
+       }
+
+       return 0;
+}
+
+static const struct dev_pm_ops fsldma_pm_ops = {
+       .suspend_late   = fsldma_suspend_late,
+       .resume_early   = fsldma_resume_early,
+};
+#endif
+
 static const struct of_device_id fsldma_of_ids[] = {
        { .compatible = "fsl,elo3-dma", },
        { .compatible = "fsl,eloplus-dma", },
@@ -1372,6 +1446,9 @@ 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 d56e83599825b16666960f78b91ea08620be4cef..f2e0c4dcf901e5c054c8191057ee7c0cdc1d0b0a 100644 (file)
--- a/drivers/dma/fsldma.h
+++ b/drivers/dma/fsldma.h
@@ -134,6 +134,17 @@ 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,
+       SUSPENDED,
+};
+#endif
+
 struct fsldma_chan {
        char name[8];                   /* Channel name */
        struct fsldma_chan_regs __iomem *regs;
@@ -148,6 +159,10 @@ 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);