On Fri, Nov 22, 2024 at 12:46:49PM +0530, Md Sadre Alam wrote:
> Avoid writing unavailable register in BAM-Lite mode.
> BAM_DESC_CNT_TRSHLD register is unavailable in BAM-Lite
> mode. Its only available in BAM-NDP mode. So avoid writing
> this register for clients who is using BAM-Lite mode.
>
> Signed-off-by: Md Sadre Alam <quic_mdalam@xxxxxxxxxxx>
> ---
> drivers/dma/qcom/bam_dma.c | 22 ++++++++++++++--------
> 1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index d43a881e43b9..13a08c03746b 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -59,6 +59,9 @@ struct bam_desc_hw {
> #define DESC_FLAG_NWD BIT(12)
> #define DESC_FLAG_CMD BIT(11)
>
> +#define BAM_LITE 0x13
> +#define BAM_NDP 0x20
> +
> struct bam_async_desc {
> struct virt_dma_desc vd;
>
> @@ -398,6 +401,7 @@ struct bam_device {
>
> /* dma start transaction tasklet */
> struct tasklet_struct task;
> + u32 bam_revision;
> };
>
> /**
> @@ -441,8 +445,9 @@ static void bam_reset(struct bam_device *bdev)
> writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
>
> /* set descriptor threshold, start with 4 bytes */
> - writel_relaxed(DEFAULT_CNT_THRSHLD,
> - bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
> + if (bdev->bam_revision >= BAM_LITE && bdev->bam_revision < BAM_NDP)
> + writel_relaxed(DEFAULT_CNT_THRSHLD,
> + bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
>
> /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
> writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
> @@ -1000,9 +1005,9 @@ static void bam_apply_new_config(struct bam_chan *bchan,
> maxburst = bchan->slave.src_maxburst;
> else
> maxburst = bchan->slave.dst_maxburst;
> -
> - writel_relaxed(maxburst,
> - bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
> + if (bdev->bam_revision >= BAM_LITE && bdev->bam_revision < BAM_NDP)
> + writel_relaxed(maxburst,
> + bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
> }
>
> bchan->reconfigure = 0;
> @@ -1192,10 +1197,11 @@ static int bam_init(struct bam_device *bdev)
> u32 val;
>
> /* read revision and configuration information */
> - if (!bdev->num_ees) {
> - val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
> + val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
> + if (!bdev->num_ees)
> bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
> - }
> +
> + bdev->bam_revision = val & 0xff;
Use REVISION_MASK instead of 0xff
-Varada
> /* check that configured EE is within range */
> if (bdev->ee >= bdev->num_ees)
> --
> 2.34.1
>
