On 20-12-24, 10:11, Joy Zou wrote:
> Introduce runtime suspend and resume support for FSL eDMA. Enable
> per-channel power domain management to facilitate runtime suspend and
> resume operations.
>
> Implement runtime suspend and resume functions for the eDMA engine and
> individual channels.
>
> Link per-channel power domain device to eDMA per-channel device instead of
> eDMA engine device. So Power Manage framework manage power state of linked
> domain device when per-channel device request runtime resume/suspend.
>
> Trigger the eDMA engine's runtime suspend when all channels are suspended,
> disabling all common clocks through the runtime PM framework.
>
> Signed-off-by: Joy Zou <joy.zou@xxxxxxx>
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> drivers/dma/fsl-edma-common.c | 15 ++---
> drivers/dma/fsl-edma-main.c | 115 ++++++++++++++++++++++++++++++----
> 2 files changed, 110 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
> index b7f15ab96855..fcdb53b21f38 100644
> --- a/drivers/dma/fsl-edma-common.c
> +++ b/drivers/dma/fsl-edma-common.c
> @@ -243,9 +243,6 @@ int fsl_edma_terminate_all(struct dma_chan *chan)
> spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
>
> - if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_PD)
> - pm_runtime_allow(fsl_chan->pd_dev);
> -
> return 0;
> }
>
> @@ -805,8 +802,12 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
> struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> int ret;
>
> - if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
> - clk_prepare_enable(fsl_chan->clk);
> + ret = pm_runtime_get_sync(&fsl_chan->vchan.chan.dev->device);
> + if (ret < 0) {
> + dev_err(&fsl_chan->vchan.chan.dev->device, "pm_runtime_get_sync() failed\n");
> + pm_runtime_disable(&fsl_chan->vchan.chan.dev->device);
> + return ret;
> + }
>
> fsl_chan->tcd_pool = dma_pool_create("tcd_pool", chan->device->dev,
> fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_TCD64 ?
> @@ -819,6 +820,7 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
>
> if (ret) {
> dma_pool_destroy(fsl_chan->tcd_pool);
> + pm_runtime_put_sync_suspend(&fsl_chan->vchan.chan.dev->device);
> return ret;
> }
> }
> @@ -851,8 +853,7 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
> fsl_chan->is_sw = false;
> fsl_chan->srcid = 0;
> fsl_chan->is_remote = false;
> - if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
> - clk_disable_unprepare(fsl_chan->clk);
> + pm_runtime_put_sync_suspend(&fsl_chan->vchan.chan.dev->device);
> }
>
> void fsl_edma_cleanup_vchan(struct dma_device *dmadev)
> diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
> index 60de1003193a..75d6c8984c8e 100644
> --- a/drivers/dma/fsl-edma-main.c
> +++ b/drivers/dma/fsl-edma-main.c
> @@ -420,7 +420,6 @@ MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
> static int fsl_edma3_attach_pd(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
> {
> struct fsl_edma_chan *fsl_chan;
> - struct device_link *link;
> struct device *pd_chan;
> struct device *dev;
> int i;
> @@ -439,24 +438,39 @@ static int fsl_edma3_attach_pd(struct platform_device *pdev, struct fsl_edma_eng
> return -EINVAL;
> }
>
> - link = device_link_add(dev, pd_chan, DL_FLAG_STATELESS |
> - DL_FLAG_PM_RUNTIME |
> - DL_FLAG_RPM_ACTIVE);
> - if (!link) {
> - dev_err(dev, "Failed to add device_link to %d\n", i);
> - return -EINVAL;
> - }
> -
> fsl_chan->pd_dev = pd_chan;
> -
> - pm_runtime_use_autosuspend(fsl_chan->pd_dev);
> - pm_runtime_set_autosuspend_delay(fsl_chan->pd_dev, 200);
> - pm_runtime_set_active(fsl_chan->pd_dev);
> }
>
> return 0;
> }
>
> +/* Per channel dma power domain */
> +static int fsl_edma_chan_runtime_suspend(struct device *dev)
> +{
> + struct fsl_edma_chan *fsl_chan = dev_get_drvdata(dev);
> + int ret = 0;
> +
> + clk_disable_unprepare(fsl_chan->clk);
> +
> + return ret;
Unused ret! drop it
> +}
> +
> +static int fsl_edma_chan_runtime_resume(struct device *dev)
> +{
> + struct fsl_edma_chan *fsl_chan = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = clk_prepare_enable(fsl_chan->clk);
> +
> + return ret;
how about return clk_prepare_enable()
--
~Vinod
