On 24-01-19, 12:24, John Stultz wrote:
> From: Li Yu <[email protected]>
> 
> Add dma-channel-mask as a property for k3dma, it defines
> available dma channels which a non-secure mode driver can use.
> 
> One sample usage of this is in Hi3660 SoC. DMA channel 0 is
> reserved to lpm3, which is a coprocessor for power management. So
> as a result, any request in kernel (which runs on main processor
> and in non-secure mode) should start from at least channel 1.
> 
> Cc: Dan Williams <[email protected]>
> Cc: Vinod Koul <[email protected]>
> Cc: Tanglei Han <[email protected]>
> Cc: Zhuangluan Su <[email protected]>
> Cc: Ryan Grachek <[email protected]>
> Cc: Manivannan Sadhasivam <[email protected]>
> Cc: Guodong Xu <[email protected]>
> Cc: [email protected]
> Signed-off-by: Li Yu <[email protected]>
> [jstultz: Reworked to use a channel mask]
> Signed-off-by: John Stultz <[email protected]>
> ---
> v3: Rename to hisi-dma-avail-chan
> v4: Rename to dma-channel-mask
> v5: Use BIT(i) instead of (1<<i)
> ---
>  drivers/dma/k3dma.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c
> index e415c85..294ec64 100644
> --- a/drivers/dma/k3dma.c
> +++ b/drivers/dma/k3dma.c
> @@ -111,6 +111,7 @@ struct k3_dma_dev {
>       struct dma_pool         *pool;
>       u32                     dma_channels;
>       u32                     dma_requests;
> +     u32                     dma_channel_mask;
>       unsigned int            irq;
>  };
>  
> @@ -319,6 +320,9 @@ static void k3_dma_tasklet(unsigned long arg)
>       /* check new channel request in d->chan_pending */
>       spin_lock_irq(&d->lock);
>       for (pch = 0; pch < d->dma_channels; pch++) {
> +             if (!(d->dma_channel_mask & (1<<pch)))

spaces around <<

> +                     continue;
> +
>               p = &d->phy[pch];
>  
>               if (p->vchan == NULL && !list_empty(&d->chan_pending)) {
> @@ -336,6 +340,9 @@ static void k3_dma_tasklet(unsigned long arg)
>       spin_unlock_irq(&d->lock);
>  
>       for (pch = 0; pch < d->dma_channels; pch++) {
> +             if (!(d->dma_channel_mask & (1<<pch)))

and here :(

> +                     continue;
> +
>               if (pch_alloc & (1 << pch)) {
>                       p = &d->phy[pch];
>                       c = p->vchan;
> @@ -856,6 +863,13 @@ static int k3_dma_probe(struct platform_device *op)
>                               "dma-channels", &d->dma_channels);
>               of_property_read_u32((&op->dev)->of_node,
>                               "dma-requests", &d->dma_requests);
> +             ret = of_property_read_u32((&op->dev)->of_node,
> +                             "dma-channel-mask", &d->dma_channel_mask);
> +             if (ret) {
> +                     dev_warn(&op->dev,
> +                              "dma-channel-mask doesn't exist, considering 
> all as available.\n");
> +                     d->dma_channel_mask = (u32)~0UL;
> +             }
>       }
>  
>       if (!(soc_data->flags & K3_FLAG_NOCLK)) {
> @@ -887,8 +901,12 @@ static int k3_dma_probe(struct platform_device *op)
>               return -ENOMEM;
>  
>       for (i = 0; i < d->dma_channels; i++) {
> -             struct k3_dma_phy *p = &d->phy[i];
> +             struct k3_dma_phy *p;
> +
> +             if (!(d->dma_channel_mask & BIT(i)))
> +                     continue;
>  
> +             p = &d->phy[i];
>               p->idx = i;
>               p->base = d->base + i * 0x40;
>       }
> -- 
> 2.7.4

-- 
~Vinod

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