On Mon, Feb 27, 2017 at 06:48:01PM +0800, Icenowy Zheng wrote:
>
>
> 27.02.2017, 15:50, "Maxime Ripard" <maxime.ripard@xxxxxxxxxxxxxxxxxx>:
> > On Sat, Feb 25, 2017 at 08:30:25PM +0800, Icenowy Zheng wrote:
> >> Allwinner V3s has a DMA engine similar to the ones from A31, but with
> >> fewer channels and DRQs.
> >>
> >> Add support for it.
> >>
> >> As it also needs the special gate bit, make the gate bit generic.
> >
> > That should be part of a separate patch.
>
> OK.
>
> >
> >> According to BSP source code, SUN8IW6 (A83T) also needs the bit, so it
> >> have also been specified gate_needed property.
> >>
> >> Signed-off-by: Icenowy Zheng <icenowy@xxxxxxxx>
> >> ---
> >> Documentation/devicetree/bindings/dma/sun6i-dma.txt | 1 +
> >> drivers/dma/sun6i-dma.c | 17 ++++++++++++++---
> >> 2 files changed, 15 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/Documentation/devicetree/bindings/dma/sun6i-dma.txt b/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> >> index 6b267045f522..98fbe1a5c6dd 100644
> >> --- a/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> >> +++ b/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> >> @@ -9,6 +9,7 @@ Required properties:
> >> "allwinner,sun8i-a23-dma"
> >> "allwinner,sun8i-a83t-dma"
> >> "allwinner,sun8i-h3-dma"
> >> + "allwinner,sun8i-v3s-dma"
> >> - reg: Should contain the registers base address and length
> >> - interrupts: Should contain a reference to the interrupt used by this device
> >> - clocks: Should contain a reference to the parent AHB clock
> >> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> >> index a2358780ab2c..1f38424c1b14 100644
> >> --- a/drivers/dma/sun6i-dma.c
> >> +++ b/drivers/dma/sun6i-dma.c
> >> @@ -101,6 +101,7 @@ struct sun6i_dma_config {
> >> u32 nr_max_channels;
> >> u32 nr_max_requests;
> >> u32 nr_max_vchans;
> >> + bool gate_needed;
> >> };
> >>
> >> /*
> >> @@ -1009,12 +1010,14 @@ static struct sun6i_dma_config sun8i_a23_dma_cfg = {
> >> .nr_max_channels = 8,
> >> .nr_max_requests = 24,
> >> .nr_max_vchans = 37,
> >> + .gate_needed = true,
> >> };
> >>
> >> static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
> >> .nr_max_channels = 8,
> >> .nr_max_requests = 28,
> >> .nr_max_vchans = 39,
> >> + .gate_needed = true,
> >> };
> >>
> >> /*
> >> @@ -1028,11 +1031,19 @@ static struct sun6i_dma_config sun8i_h3_dma_cfg = {
> >> .nr_max_vchans = 34,
> >> };
> >>
> >> +static struct sun6i_dma_config sun8i_v3s_dma_cfg = {
> >> + .nr_max_channels = 8,
> >> + .nr_max_requests = 23,
> >> + .nr_max_vchans = 24,
> >
> > This one is suspicious. There's just a single endpoint that can be
> > used in both directions?
>
> nr_max_vchans is the endpoint number. nr_max_requests is the
> maximum DRQ number, for V3s, according to the datasheet, it's
> 23: SPI0_{R,T}X.
There's not a lot of endpoints indeed, but you need 28 vchans (2 *
14).
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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