MLK-17094 dma: fsl-edma-v3: add suspend/resume to restore back channel registers

Add suspend to save channel registers and resume to restore them back since
edmav3 may powered off in suspend.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>

diff --git a/drivers/dma/fsl-edma-v3.c b/drivers/dma/fsl-edma-v3.c
index a049578..6e7c503 100644 (file)
--- a/drivers/dma/fsl-edma-v3.c
+++ b/drivers/dma/fsl-edma-v3.c
@@ -111,6 +111,11 @@
 #define CHAN_PREFIX                    "edma0-chan"
 #define CHAN_POSFIX                    "-tx"
 
+enum fsl_edma3_pm_state {
+       RUNNING = 0,
+       SUSPENDED,
+};
+
 struct fsl_edma3_hw_tcd {
        __le32  saddr;
        __le16  soff;
@@ -142,6 +147,8 @@ struct fsl_edma3_slave_config {
 struct fsl_edma3_chan {
        struct virt_dma_chan            vchan;
        enum dma_status                 status;
+       enum fsl_edma3_pm_state         pm_state;
+       bool                            idle;
        struct fsl_edma3_engine         *edma3;
        struct fsl_edma3_desc           *edesc;
        struct fsl_edma3_slave_config   fsc;
@@ -165,11 +172,18 @@ struct fsl_edma3_desc {
        struct fsl_edma3_sw_tcd         tcd[];
 };
 
+struct fsl_edma3_reg_save {
+       u32 csr;
+       u32 sbr;
+};
+
 struct fsl_edma3_engine {
        struct dma_device       dma_dev;
        struct mutex            fsl_edma3_mutex;
        u32                     n_chans;
        int                     errirq;
+       #define MAX_CHAN_NUM    32
+       struct fsl_edma3_reg_save edma_regs[MAX_CHAN_NUM];
        bool                    swap;   /* remote/local swapped on Audio edma */
        struct fsl_edma3_chan   chans[];
 };
@@ -266,6 +280,7 @@ static int fsl_edma3_terminate_all(struct dma_chan *chan)
        spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
        fsl_edma3_disable_request(fsl_chan);
        fsl_chan->edesc = NULL;
+       fsl_chan->idle = true;
        vchan_get_all_descriptors(&fsl_chan->vchan, &head);
        spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
        vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
@@ -281,6 +296,7 @@ static int fsl_edma3_pause(struct dma_chan *chan)
        if (fsl_chan->edesc) {
                fsl_edma3_disable_request(fsl_chan);
                fsl_chan->status = DMA_PAUSED;
+               fsl_chan->idle = true;
        }
        spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
        return 0;
@@ -295,6 +311,7 @@ static int fsl_edma3_resume(struct dma_chan *chan)
        if (fsl_chan->edesc) {
                fsl_edma3_enable_request(fsl_chan);
                fsl_chan->status = DMA_IN_PROGRESS;
+               fsl_chan->idle = false;
        }
        spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
        return 0;
@@ -664,6 +681,7 @@ static void fsl_edma3_xfer_desc(struct fsl_edma3_chan *fsl_chan)
        fsl_edma3_set_tcd_regs(fsl_chan, fsl_chan->edesc->tcd[0].vtcd);
        fsl_edma3_enable_request(fsl_chan);
        fsl_chan->status = DMA_IN_PROGRESS;
+       fsl_chan->idle = false;
 }
 
 static size_t fsl_edma3_desc_residue(struct fsl_edma3_chan *fsl_chan,
@@ -700,6 +718,7 @@ static irqreturn_t fsl_edma3_tx_handler(int irq, void *dev_id)
                vchan_cookie_complete(&fsl_chan->edesc->vdesc);
                fsl_chan->edesc = NULL;
                fsl_chan->status = DMA_COMPLETE;
+               fsl_chan->idle = true;
        } else {
                vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
        }
@@ -719,6 +738,12 @@ static void fsl_edma3_issue_pending(struct dma_chan *chan)
 
        spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
 
+       if (unlikely(fsl_chan->pm_state != RUNNING)) {
+               spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
+               /* cannot submit due to suspend */
+               return;
+       }
+
        if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
                fsl_edma3_xfer_desc(fsl_chan);
 
@@ -821,6 +846,8 @@ static int fsl_edma3_probe(struct platform_device *pdev)
                unsigned long val;
 
                fsl_chan->edma3 = fsl_edma3;
+               fsl_chan->pm_state = RUNNING;
+               fsl_chan->idle = true;
                /* Get per channel membase */
                res = platform_get_resource(pdev, IORESOURCE_MEM, i);
                fsl_chan->membase = devm_ioremap_resource(&pdev->dev, res);
@@ -932,6 +959,64 @@ static int fsl_edma3_remove(struct platform_device *pdev)
        return 0;
 }
 
+static int fsl_edma3_suspend_late(struct device *dev)
+{
+       struct fsl_edma3_engine *fsl_edma = dev_get_drvdata(dev);
+       struct fsl_edma3_chan *fsl_chan;
+       unsigned long flags;
+       void __iomem *addr;
+       int i;
+
+       for (i = 0; i < fsl_edma->n_chans; i++) {
+               fsl_chan = &fsl_edma->chans[i];
+               addr = fsl_chan->membase;
+
+               spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
+               fsl_edma->edma_regs[i].csr = readl(addr + EDMA_CH_CSR);
+               fsl_edma->edma_regs[i].sbr = readl(addr + EDMA_CH_SBR);
+               /* Make sure chan is idle or will force disable. */
+               if (unlikely(!fsl_chan->idle)) {
+                       dev_warn(dev, "WARN: There is non-idle channel.");
+                       fsl_edma3_disable_request(fsl_chan);
+               }
+               fsl_chan->pm_state = SUSPENDED;
+               spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
+       }
+
+       return 0;
+}
+
+static int fsl_edma3_resume_early(struct device *dev)
+{
+       struct fsl_edma3_engine *fsl_edma = dev_get_drvdata(dev);
+       struct fsl_edma3_chan *fsl_chan;
+       void __iomem *addr;
+       unsigned long flags;
+       int i;
+
+       for (i = 0; i < fsl_edma->n_chans; i++) {
+               fsl_chan = &fsl_edma->chans[i];
+               addr = fsl_chan->membase;
+
+               spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
+               writel(fsl_edma->edma_regs[i].csr, addr + EDMA_CH_CSR);
+               writel(fsl_edma->edma_regs[i].sbr, addr + EDMA_CH_SBR);
+               /* restore tcd if this channel not terminated before suspend */
+               if (fsl_chan->edesc)
+                       fsl_edma3_set_tcd_regs(fsl_chan,
+                                               fsl_chan->edesc->tcd[0].vtcd);
+               fsl_chan->pm_state = RUNNING;
+               spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
+       }
+
+       return 0;
+}
+
+static const struct dev_pm_ops fsl_edma3_pm_ops = {
+       .suspend_late   = fsl_edma3_suspend_late,
+       .resume_early   = fsl_edma3_resume_early,
+};
+
 static const struct of_device_id fsl_edma3_dt_ids[] = {
        { .compatible = "fsl,imx8qm-edma", },
        { .compatible = "fsl,imx8qm-adma", },
@@ -943,6 +1028,7 @@ static struct platform_driver fsl_edma3_driver = {
        .driver         = {
                .name   = "fsl-edma-v3",
                .of_match_table = fsl_edma3_dt_ids,
+               .pm     = &fsl_edma3_pm_ops,
        },
        .probe          = fsl_edma3_probe,
        .remove         = fsl_edma3_remove,