On 21-09-22, 08:36, Bhupesh Sharma wrote:
> From: Thara Gopinath <thara.gopinath@xxxxxxxxx>
>
> BAM dma engine associated with certain hardware blocks could require
> relevant interconnect pieces be initialized prior to the dma engine
> initialization. For e.g. crypto bam dma engine on sm8250. Such requirement
> is passed on to the bam dma driver from dt via the "interconnects"
> property. Add support in bam_dma driver to check whether the interconnect
> path is accessible/enabled prior to attempting driver intializations.
>
> If interconnects are not yet setup, defer the BAM DMA driver probe().
>
> Cc: Bjorn Andersson <andersson@xxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxx>
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
> [Bhupesh: Make header file inclusion alphabetical and use 'devm_of_icc_get()']
> ---
> drivers/dma/qcom/bam_dma.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index 2ff787df513e..a5b0cf28ffb7 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -26,6 +26,7 @@
> #include <linux/kernel.h>
> #include <linux/io.h>
> #include <linux/init.h>
> +#include <linux/interconnect.h>
> #include <linux/slab.h>
> #include <linux/module.h>
> #include <linux/interrupt.h>
> @@ -394,6 +395,7 @@ struct bam_device {
> const struct reg_offset_data *layout;
>
> struct clk *bamclk;
> + struct icc_path *mem_path;
> int irq;
>
> /* dma start transaction tasklet */
> @@ -1294,6 +1296,14 @@ static int bam_dma_probe(struct platform_device *pdev)
> if (IS_ERR(bdev->bamclk))
> return PTR_ERR(bdev->bamclk);
>
> + /* Ensure that interconnects are initialized */
> + bdev->mem_path = devm_of_icc_get(bdev->dev, "memory");
> + if (IS_ERR(bdev->mem_path)) {
> + ret = dev_err_probe(bdev->dev, PTR_ERR(bdev->mem_path),
> + "failed to acquire icc path\n");
> + return ret;
> + }
So this makes us fail on older DT where icc path may not be present.
Should this not be an optional thing?
> +
> ret = clk_prepare_enable(bdev->bamclk);
> if (ret) {
> dev_err(bdev->dev, "failed to prepare/enable clock\n");
> --
> 2.37.1
--
~Vinod
