Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Masahiro Yamada]

(+CC Rob, DT, LKML)

I forgot to CC this to DT community...


2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
> Pro4, and sLD8 SoCs.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
>  .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>
> diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> new file mode 100644
> index 0000000..a9e969e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> @@ -0,0 +1,28 @@
> +UniPhier Media IO DMA controller
> +
> +This works as an external DMA engine for SD/eMMC controllers etc.
> +found in UniPhier LD4, Pro4, sLD8 SoCs.
> +
> +Required properties:
> +- compatible: should be "socionext,uniphier-mio-dmac".
> +- reg: offset and length of the register set for the device.
> +- interrupts: a list of interrupt specifiers associated with the DMA channels.
> +- clocks: a single clock specifier
> +- #dma-cells: should be <1>. The single cell represents the channel number.
> +- dma-channels: specify the number of the DMA channels. This should match to
> +  the number of tuples in the interrupts property.
> +
> +Example:
> +       dmac: dmac@5a000000 {
> +               compatible = "socionext,uniphier-mio-dmac";
> +               reg = <0x5a000000 0x1000>;
> +               interrupts = <0 68 4>, <0 68 4>, <0 69 4>, <0 70 4>,
> +                            <0 71 4>, <0 72 4>, <0 73 4>, <0 74 4>;
> +               clocks = <&mio_clk 7>;
> +               #dma-cells = <1>;
> +               dma-channels = <8>;
> +       };
> +
> +Note:
> +In the example above, "interrupts = <0 68 4>, <0 68 4>, ..." is not a typo.
> +The first two channels share a single interrupt line.
> --
> 2.7.4
>



-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Jassi Brar]

On 21 August 2018 at 15:17, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> (+CC Rob, DT, LKML)
>
> I forgot to CC this to DT community...
>
>
> 2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
>> The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
>> Pro4, and sLD8 SoCs.
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> ---
>>
>>  .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
>>  1 file changed, 28 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>
>> diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>> new file mode 100644
>> index 0000000..a9e969e
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>> @@ -0,0 +1,28 @@
>> +UniPhier Media IO DMA controller
>> +
>> +This works as an external DMA engine for SD/eMMC controllers etc.
>> +found in UniPhier LD4, Pro4, sLD8 SoCs.
>> +
>> +Required properties:
>> +- compatible: should be "socionext,uniphier-mio-dmac".
>> +- reg: offset and length of the register set for the device.
>> +- interrupts: a list of interrupt specifiers associated with the DMA channels.
>> +- clocks: a single clock specifier
>> +- #dma-cells: should be <1>. The single cell represents the channel number.
>> +- dma-channels: specify the number of the DMA channels. This should match to
>> +  the number of tuples in the interrupts property.
>> +
Can we not infer the number of channels from interrupt tuples? After
all the driver assumes they are same.

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Masahiro Yamada]

Hi Jassi,


2018-08-21 19:44 GMT+09:00 Jassi Brar <jaswinder.singh@linaro.org>:
> On 21 August 2018 at 15:17, Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
>> (+CC Rob, DT, LKML)
>>
>> I forgot to CC this to DT community...
>>
>>
>> 2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
>>> The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
>>> Pro4, and sLD8 SoCs.
>>>
>>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>>> ---
>>>
>>>  .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
>>>  1 file changed, 28 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>>
>>> diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>> new file mode 100644
>>> index 0000000..a9e969e
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>> @@ -0,0 +1,28 @@
>>> +UniPhier Media IO DMA controller
>>> +
>>> +This works as an external DMA engine for SD/eMMC controllers etc.
>>> +found in UniPhier LD4, Pro4, sLD8 SoCs.
>>> +
>>> +Required properties:
>>> +- compatible: should be "socionext,uniphier-mio-dmac".
>>> +- reg: offset and length of the register set for the device.
>>> +- interrupts: a list of interrupt specifiers associated with the DMA channels.
>>> +- clocks: a single clock specifier
>>> +- #dma-cells: should be <1>. The single cell represents the channel number.
>>> +- dma-channels: specify the number of the DMA channels. This should match to
>>> +  the number of tuples in the interrupts property.
>>> +
> Can we not infer the number of channels from interrupt tuples? After
> all the driver assumes they are same.


It would be possible to count the number of tuples
in "interrupts".



I know of_irq_count(), but I do not see any driver
in drivers/dma/ that calls it.


I guess the reason is that of_irq_count() is not exported,
so tristate drivers like this cannot use it.


I checked Documentation/devicetree/bindings/dma/,
and some controllers specify _redundant_ dma-channels property.

fsl-mxs-dma.txt
renesas,rcar-dmac.txt
renesas,usb-dmac.txt



I also see counter-implementation.


bcm2835-dma.c hard-codes the number of channels in the driver.
tegra210-adma.c associates nr_channels with compatible string.



I will wait for comments from the maintainers.

If desired, I will export of_irq_count()
and use it from my driver.



Thanks.

-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Jassi Brar]

On 23 August 2018 at 10:48, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> Hi Jassi,
>
>
> 2018-08-21 19:44 GMT+09:00 Jassi Brar <jaswinder.singh@linaro.org>:
>> On 21 August 2018 at 15:17, Masahiro Yamada
>> <yamada.masahiro@socionext.com> wrote:
>>> (+CC Rob, DT, LKML)
>>>
>>> I forgot to CC this to DT community...
>>>
>>>
>>> 2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
>>>> The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
>>>> Pro4, and sLD8 SoCs.
>>>>
>>>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>>>> ---
>>>>
>>>>  .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
>>>>  1 file changed, 28 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>>> new file mode 100644
>>>> index 0000000..a9e969e
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
>>>> @@ -0,0 +1,28 @@
>>>> +UniPhier Media IO DMA controller
>>>> +
>>>> +This works as an external DMA engine for SD/eMMC controllers etc.
>>>> +found in UniPhier LD4, Pro4, sLD8 SoCs.
>>>> +
>>>> +Required properties:
>>>> +- compatible: should be "socionext,uniphier-mio-dmac".
>>>> +- reg: offset and length of the register set for the device.
>>>> +- interrupts: a list of interrupt specifiers associated with the DMA channels.
>>>> +- clocks: a single clock specifier
>>>> +- #dma-cells: should be <1>. The single cell represents the channel number.
>>>> +- dma-channels: specify the number of the DMA channels. This should match to
>>>> +  the number of tuples in the interrupts property.
>>>> +
>> Can we not infer the number of channels from interrupt tuples? After
>> all the driver assumes they are same.
>
>
> It would be possible to count the number of tuples
> in "interrupts".
>
>
>
> I know of_irq_count(), but I do not see any driver
> in drivers/dma/ that calls it.
>
>
> I guess the reason is that of_irq_count() is not exported,
> so tristate drivers like this cannot use it.
>
>
> I checked Documentation/devicetree/bindings/dma/,
> and some controllers specify _redundant_ dma-channels property.
>
> fsl-mxs-dma.txt
> renesas,rcar-dmac.txt
> renesas,usb-dmac.txt
>
:) I am not sure "because others are doing it" is a good reason to
introduce redundancy.


> I also see counter-implementation.
>
>
> bcm2835-dma.c hard-codes the number of channels in the driver.
> tegra210-adma.c associates nr_channels with compatible string.
>
>
>
> I will wait for comments from the maintainers.
>
> If desired, I will export of_irq_count()
> and use it from my driver.
>
If you don't want to leave too much footprint, you could do

  count = 0;
  while (of_irq_parse_one(dev, count, &irq) == 0) count++

of_irq_parse_one() is already exported.

A good side-effect is you wouldn't have to hardcode the count in the
driver (like bcm and tegra examples you quote).

Having said that, I wouldn't lose sleep over it. So ....

Cheers!

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Rob Herring]

On Thu, Aug 23, 2018 at 12:38 AM Jassi Brar <jaswinder.singh@linaro.org> wrote:
>
> On 23 August 2018 at 10:48, Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> > Hi Jassi,
> >
> >
> > 2018-08-21 19:44 GMT+09:00 Jassi Brar <jaswinder.singh@linaro.org>:
> >> On 21 August 2018 at 15:17, Masahiro Yamada
> >> <yamada.masahiro@socionext.com> wrote:
> >>> (+CC Rob, DT, LKML)
> >>>
> >>> I forgot to CC this to DT community...
> >>>
> >>>
> >>> 2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> >>>> The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
> >>>> Pro4, and sLD8 SoCs.
> >>>>
> >>>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> >>>> ---
> >>>>
> >>>>  .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
> >>>>  1 file changed, 28 insertions(+)
> >>>>  create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> >>>>
> >>>> diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> >>>> new file mode 100644
> >>>> index 0000000..a9e969e
> >>>> --- /dev/null
> >>>> +++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> >>>> @@ -0,0 +1,28 @@
> >>>> +UniPhier Media IO DMA controller
> >>>> +
> >>>> +This works as an external DMA engine for SD/eMMC controllers etc.
> >>>> +found in UniPhier LD4, Pro4, sLD8 SoCs.
> >>>> +
> >>>> +Required properties:
> >>>> +- compatible: should be "socionext,uniphier-mio-dmac".
> >>>> +- reg: offset and length of the register set for the device.
> >>>> +- interrupts: a list of interrupt specifiers associated with the DMA channels.
> >>>> +- clocks: a single clock specifier
> >>>> +- #dma-cells: should be <1>. The single cell represents the channel number.
> >>>> +- dma-channels: specify the number of the DMA channels. This should match to
> >>>> +  the number of tuples in the interrupts property.
> >>>> +
> >> Can we not infer the number of channels from interrupt tuples? After
> >> all the driver assumes they are same.
> >
> >
> > It would be possible to count the number of tuples
> > in "interrupts".
> >
> >
> >
> > I know of_irq_count(), but I do not see any driver
> > in drivers/dma/ that calls it.
> >
> >
> > I guess the reason is that of_irq_count() is not exported,
> > so tristate drivers like this cannot use it.
> >
> >
> > I checked Documentation/devicetree/bindings/dma/,
> > and some controllers specify _redundant_ dma-channels property.
> >
> > fsl-mxs-dma.txt
> > renesas,rcar-dmac.txt
> > renesas,usb-dmac.txt
> >
> :) I am not sure "because others are doing it" is a good reason to
> introduce redundancy.
>
>
> > I also see counter-implementation.
> >
> >
> > bcm2835-dma.c hard-codes the number of channels in the driver.
> > tegra210-adma.c associates nr_channels with compatible string.
> >
> >
> >
> > I will wait for comments from the maintainers.
> >
> > If desired, I will export of_irq_count()
> > and use it from my driver.
> >
> If you don't want to leave too much footprint, you could do
>
>   count = 0;
>   while (of_irq_parse_one(dev, count, &irq) == 0) count++
>
> of_irq_parse_one() is already exported.

Yes, but we really don't more users and drivers shouldn't be using it.
Grepping DT functions and when the only users are pretty much powerpc,
that's a good indication not to use the function.

And you don't want to use of_irq_count either. platform_irq_count is
what should be used here. It's already exported.

Rob

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Jassi Brar]

On 23 August 2018 at 18:51, Rob Herring <robh+dt@kernel.org> wrote:
> On Thu, Aug 23, 2018 at 12:38 AM Jassi Brar <jaswinder.singh@linaro.org> wrote:
>> On 23 August 2018 at 10:48, Masahiro Yamada

>> >
>> > If desired, I will export of_irq_count()
>> > and use it from my driver.
>> >
>> If you don't want to leave too much footprint, you could do
>>
>>   count = 0;
>>   while (of_irq_parse_one(dev, count, &irq) == 0) count++
>>
>> of_irq_parse_one() is already exported.
>
> Yes, but we really don't more users and drivers shouldn't be using it.
> Grepping DT functions and when the only users are pretty much powerpc,
> that's a good indication not to use the function.
>
> And you don't want to use of_irq_count either. platform_irq_count is
> what should be used here. It's already exported.
>
Thanks, platform_irq_count() is definitely better.

Yamada-san, for example, gpio-tegra.c infers the number of banks from
platform_irq_count() rather than the 'gpio-banks' property.

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Masahiro Yamada]

Hi Rob, Jassi,


2018-08-23 23:12 GMT+09:00 Jassi Brar <jaswinder.singh@linaro.org>:
> On 23 August 2018 at 18:51, Rob Herring <robh+dt@kernel.org> wrote:
>> On Thu, Aug 23, 2018 at 12:38 AM Jassi Brar <jaswinder.singh@linaro.org> wrote:
>>> On 23 August 2018 at 10:48, Masahiro Yamada
>
>>> >
>>> > If desired, I will export of_irq_count()
>>> > and use it from my driver.
>>> >
>>> If you don't want to leave too much footprint, you could do
>>>
>>>   count = 0;
>>>   while (of_irq_parse_one(dev, count, &irq) == 0) count++
>>>
>>> of_irq_parse_one() is already exported.
>>
>> Yes, but we really don't more users and drivers shouldn't be using it.
>> Grepping DT functions and when the only users are pretty much powerpc,
>> that's a good indication not to use the function.
>>
>> And you don't want to use of_irq_count either. platform_irq_count is
>> what should be used here. It's already exported.
>>
> Thanks, platform_irq_count() is definitely better.
>
> Yamada-san, for example, gpio-tegra.c infers the number of banks from
> platform_irq_count() rather than the 'gpio-banks' property.


I did not platform_irq_count().  I will send v2 with it.

Thanks.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/2] dt-bindings: dmaengine: add DT binding for UniPhier MIO DMAC

[Rob Herring]

On Tue, Aug 21, 2018 at 4:48 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> (+CC Rob, DT, LKML)
>
> I forgot to CC this to DT community...

You really need to resend so that patchwork will pick it up and I'll
see it for sure.

>
>
> 2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> > The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
> > Pro4, and sLD8 SoCs.
> >
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> > ---
> >
> >  .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
> >  1 file changed, 28 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> >
> > diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> > new file mode 100644
> > index 0000000..a9e969e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
> > @@ -0,0 +1,28 @@
> > +UniPhier Media IO DMA controller
> > +
> > +This works as an external DMA engine for SD/eMMC controllers etc.
> > +found in UniPhier LD4, Pro4, sLD8 SoCs.
> > +
> > +Required properties:
> > +- compatible: should be "socionext,uniphier-mio-dmac".
> > +- reg: offset and length of the register set for the device.
> > +- interrupts: a list of interrupt specifiers associated with the DMA channels.
> > +- clocks: a single clock specifier
> > +- #dma-cells: should be <1>. The single cell represents the channel number.
> > +- dma-channels: specify the number of the DMA channels. This should match to
> > +  the number of tuples in the interrupts property.
> > +
> > +Example:
> > +       dmac: dmac@5a000000 {

dma-controller@...

> > +               compatible = "socionext,uniphier-mio-dmac";
> > +               reg = <0x5a000000 0x1000>;
> > +               interrupts = <0 68 4>, <0 68 4>, <0 69 4>, <0 70 4>,
> > +                            <0 71 4>, <0 72 4>, <0 73 4>, <0 74 4>;
> > +               clocks = <&mio_clk 7>;
> > +               #dma-cells = <1>;
> > +               dma-channels = <8>;
> > +       };
> > +
> > +Note:
> > +In the example above, "interrupts = <0 68 4>, <0 68 4>, ..." is not a typo.
> > +The first two channels share a single interrupt line.
> > --
> > 2.7.4
> >
>
>
>
> --
> Best Regards
> Masahiro Yamada

Re: [PATCH 2/2] dmaengine: uniphier-mdmac: add UniPhier MIO DMAC driver

[Masahiro Yamada]

(+CC LKML just in case)

2018-08-21 18:30 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
> Pro4, and sLD8 SoCs.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
>  MAINTAINERS                  |   1 +
>  drivers/dma/Kconfig          |  11 +
>  drivers/dma/Makefile         |   1 +
>  drivers/dma/uniphier-mdmac.c | 484 +++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 497 insertions(+)
>  create mode 100644 drivers/dma/uniphier-mdmac.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8838bf1..c15a024 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2171,6 +2171,7 @@ F:        arch/arm/mm/cache-uniphier.c
>  F:     arch/arm64/boot/dts/socionext/uniphier*
>  F:     drivers/bus/uniphier-system-bus.c
>  F:     drivers/clk/uniphier/
> +F:     drivers/dmaengine/uniphier-mdmac.c
>  F:     drivers/gpio/gpio-uniphier.c
>  F:     drivers/i2c/busses/i2c-uniphier*
>  F:     drivers/irqchip/irq-uniphier-aidet.c
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index dacf3f4..8b8c7f0 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -576,6 +576,17 @@ config TIMB_DMA
>         help
>           Enable support for the Timberdale FPGA DMA engine.
>
> +config UNIPHIER_MDMAC
> +       tristate "UniPhier MIO DMAC"
> +       depends on ARCH_UNIPHIER || COMPILE_TEST
> +       depends on OF
> +       select DMA_ENGINE
> +       select DMA_VIRTUAL_CHANNELS
> +       help
> +         Enable support for the MIO DMAC (Media I/O DMA controller) on the
> +         UniPhier platform.  This DMA controller is used as the external
> +         DMA engine of the SD/eMMC controllers of the LD4, Pro4, sLD8 SoCs.
> +
>  config XGENE_DMA
>         tristate "APM X-Gene DMA support"
>         depends on ARCH_XGENE || COMPILE_TEST
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index c91702d..973a170 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
>  obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
>  obj-$(CONFIG_TEGRA210_ADMA) += tegra210-adma.o
>  obj-$(CONFIG_TIMB_DMA) += timb_dma.o
> +obj-$(CONFIG_UNIPHIER_MDMAC) += uniphier-mdmac.o
>  obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
>  obj-$(CONFIG_ZX_DMA) += zx_dma.o
>  obj-$(CONFIG_ST_FDMA) += st_fdma.o
> diff --git a/drivers/dma/uniphier-mdmac.c b/drivers/dma/uniphier-mdmac.c
> new file mode 100644
> index 0000000..d558851
> --- /dev/null
> +++ b/drivers/dma/uniphier-mdmac.c
> @@ -0,0 +1,484 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2018 Socionext Inc.
> +//   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
> +
> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dmaengine.h>
> +#include <linux/interrupt.h>
> +#include <linux/iopoll.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_dma.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +
> +#include "virt-dma.h"
> +
> +/* registers common for all channels */
> +#define UNIPHIER_MDMAC_CMD             0x000   // issue DMA start/abort
> +#define   UNIPHIER_MDMAC_CMD_ABORT             BIT(31) // 1: abort, 0: start
> +
> +/* per-channel registers */
> +#define UNIPHIER_MDMAC_CH_OFFSET       0x100
> +#define UNIPHIER_MDMAC_CH_STRIDE       0x040
> +
> +#define UNIPHIER_MDMAC_CH_IRQ_STAT     0x010   // current hw status (RO)
> +#define UNIPHIER_MDMAC_CH_IRQ_REQ      0x014   // latched STAT (WOC)
> +#define UNIPHIER_MDMAC_CH_IRQ_EN       0x018   // IRQ enable mask
> +#define UNIPHIER_MDMAC_CH_IRQ_DET      0x01c   // REQ & EN (RO)
> +#define   UNIPHIER_MDMAC_CH_IRQ__ABORT         BIT(13)
> +#define   UNIPHIER_MDMAC_CH_IRQ__DONE          BIT(1)
> +#define UNIPHIER_MDMAC_CH_SRC_MODE     0x020   // mode of source
> +#define UNIPHIER_MDMAC_CH_DEST_MODE    0x024   // mode of destination
> +#define   UNIPHIER_MDMAC_CH_MODE__ADDR_INC     (0 << 4)
> +#define   UNIPHIER_MDMAC_CH_MODE__ADDR_DEC     (1 << 4)
> +#define   UNIPHIER_MDMAC_CH_MODE__ADDR_FIXED   (2 << 4)
> +#define UNIPHIER_MDMAC_CH_SRC_ADDR     0x028   // source address
> +#define UNIPHIER_MDMAC_CH_DEST_ADDR    0x02c   // destination address
> +#define UNIPHIER_MDMAC_CH_SIZE         0x030   // transfer bytes
> +
> +struct uniphier_mdmac_desc {
> +       struct virt_dma_desc vd;
> +       struct scatterlist *sgl;
> +       unsigned int sg_len;
> +       unsigned int sg_cur;
> +       enum dma_transfer_direction dir;
> +};
> +
> +struct uniphier_mdmac_chan {
> +       struct virt_dma_chan vc;
> +       struct uniphier_mdmac_device *mdev;
> +       struct uniphier_mdmac_desc *md;
> +       void __iomem *reg_ch_base;
> +       unsigned int chan_id;
> +};
> +
> +struct uniphier_mdmac_device {
> +       struct dma_device ddev;
> +       struct clk *clk;
> +       void __iomem *reg_base;
> +       struct uniphier_mdmac_chan channels[0];
> +};
> +
> +static struct uniphier_mdmac_chan *to_uniphier_mdmac_chan(
> +                                               struct virt_dma_chan *vc)
> +{
> +       return container_of(vc, struct uniphier_mdmac_chan, vc);
> +}
> +
> +static struct uniphier_mdmac_desc *to_uniphier_mdmac_desc(
> +                                               struct virt_dma_desc *vd)
> +{
> +       return container_of(vd, struct uniphier_mdmac_desc, vd);
> +}
> +
> +/* mc->vc.lock must be held by caller */
> +static struct uniphier_mdmac_desc *__uniphier_mdmac_next_desc(
> +                                               struct uniphier_mdmac_chan *mc)
> +{
> +       struct virt_dma_desc *vd;
> +
> +       vd = vchan_next_desc(&mc->vc);
> +       if (!vd) {
> +               mc->md = NULL;
> +               return NULL;
> +       }
> +
> +       list_del(&vd->node);
> +
> +       mc->md = to_uniphier_mdmac_desc(vd);
> +
> +       return mc->md;
> +}
> +
> +/* mc->vc.lock must be held by caller */
> +static void __uniphier_mdmac_handle(struct uniphier_mdmac_chan *mc,
> +                                   struct uniphier_mdmac_desc *md)
> +{
> +       struct uniphier_mdmac_device *mdev = mc->mdev;
> +       struct scatterlist *sg;
> +       u32 irq_flag = UNIPHIER_MDMAC_CH_IRQ__DONE;
> +       u32 src_mode, src_addr, dest_mode, dest_addr, chunk_size;
> +
> +       sg = &md->sgl[md->sg_cur];
> +
> +       if (md->dir == DMA_MEM_TO_DEV) {
> +               src_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_INC;
> +               src_addr = sg_dma_address(sg);
> +               dest_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_FIXED;
> +               dest_addr = 0;
> +       } else {
> +               src_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_FIXED;
> +               src_addr = 0;
> +               dest_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_INC;
> +               dest_addr = sg_dma_address(sg);
> +       }
> +
> +       chunk_size = sg_dma_len(sg);
> +
> +       writel(src_mode, mc->reg_ch_base + UNIPHIER_MDMAC_CH_SRC_MODE);
> +       writel(dest_mode, mc->reg_ch_base + UNIPHIER_MDMAC_CH_DEST_MODE);
> +       writel(src_addr, mc->reg_ch_base + UNIPHIER_MDMAC_CH_SRC_ADDR);
> +       writel(dest_addr, mc->reg_ch_base + UNIPHIER_MDMAC_CH_DEST_ADDR);
> +       writel(chunk_size, mc->reg_ch_base + UNIPHIER_MDMAC_CH_SIZE);
> +
> +       /* write 1 to clear */
> +       writel(irq_flag, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ);
> +
> +       writel(irq_flag, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_EN);
> +
> +       writel(BIT(mc->chan_id), mdev->reg_base + UNIPHIER_MDMAC_CMD);
> +}
> +
> +/* mc->vc.lock must be held by caller */
> +static void __uniphier_mdmac_start(struct uniphier_mdmac_chan *mc)
> +{
> +       struct uniphier_mdmac_desc *md;
> +
> +       md = __uniphier_mdmac_next_desc(mc);
> +       if (md)
> +               __uniphier_mdmac_handle(mc, md);
> +}
> +
> +/* mc->vc.lock must be held by caller */
> +static int __uniphier_mdmac_abort(struct uniphier_mdmac_chan *mc)
> +{
> +       struct uniphier_mdmac_device *mdev = mc->mdev;
> +       u32 irq_flag = UNIPHIER_MDMAC_CH_IRQ__ABORT;
> +       u32 val;
> +
> +       /* write 1 to clear */
> +       writel(irq_flag, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ);
> +
> +       writel(UNIPHIER_MDMAC_CMD_ABORT | BIT(mc->chan_id),
> +              mdev->reg_base + UNIPHIER_MDMAC_CMD);
> +
> +       /*
> +        * Abort should be accepted soon. We poll the bit here instead of
> +        * waiting for the interrupt.
> +        */
> +       return readl_poll_timeout(mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ,
> +                                 val, val & irq_flag, 0, 20);
> +}
> +
> +/* mc->vc.lock must be held by caller */
> +static u32 __uniphier_mdmac_get_residue(struct uniphier_mdmac_desc *md)
> +{
> +       u32 residue = 0;
> +       int i;
> +
> +       for (i = md->sg_cur; i < md->sg_len; i++)
> +               residue += sg_dma_len(&md->sgl[i]);
> +
> +       return residue;
> +}
> +
> +static irqreturn_t uniphier_mdmac_interrupt(int irq, void *dev_id)
> +{
> +       struct uniphier_mdmac_chan *mc = dev_id;
> +       struct uniphier_mdmac_desc *md;
> +       irqreturn_t ret = IRQ_HANDLED;
> +       u32 irq_stat;
> +
> +       spin_lock(&mc->vc.lock);
> +
> +       irq_stat = readl(mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_DET);
> +
> +       /*
> +        * Some channels share a single interrupt line. If the IRQ status is 0,
> +        * this is probably triggered by a different channel.
> +        */
> +       if (!irq_stat) {
> +               ret = IRQ_NONE;
> +               goto out;
> +       }
> +
> +       /* write 1 to clear */
> +       writel(irq_stat, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ);
> +
> +       /*
> +        * UNIPHIER_MDMAC_CH_IRQ__DONE interrupt is asserted even when the DMA
> +        * is aborted.  To distinguish the normal completion and the abort,
> +        * check mc->md.  If it is NULL, we are aborting.
> +        */
> +       md = mc->md;
> +       if (!md)
> +               goto out;
> +
> +       md->sg_cur++;
> +
> +       if (md->sg_cur >= md->sg_len) {
> +               vchan_cookie_complete(&md->vd);
> +               md = __uniphier_mdmac_next_desc(mc);
> +               if (!md)
> +                       goto out;
> +       }
> +
> +       __uniphier_mdmac_handle(mc, md);
> +
> +out:
> +       spin_unlock(&mc->vc.lock);
> +
> +       return ret;
> +}
> +
> +static struct dma_async_tx_descriptor *uniphier_mdmac_prep_slave_sg(
> +                                       struct dma_chan *chan,
> +                                       struct scatterlist *sgl,
> +                                       unsigned int sg_len,
> +                                       enum dma_transfer_direction direction,
> +                                       unsigned long flags, void *context)
> +{
> +       struct virt_dma_chan *vc = to_virt_chan(chan);
> +       struct uniphier_mdmac_desc *md;
> +
> +       if (!is_slave_direction(direction))
> +               return NULL;
> +
> +       md = kzalloc(sizeof(*md), GFP_KERNEL);
> +       if (!md)
> +               return NULL;
> +
> +       md->sgl = sgl;
> +       md->sg_len = sg_len;
> +       md->dir = direction;
> +
> +       return vchan_tx_prep(vc, &md->vd, flags);
> +}
> +
> +static int uniphier_mdmac_terminate_all(struct dma_chan *chan)
> +{
> +       struct virt_dma_chan *vc = to_virt_chan(chan);
> +       struct uniphier_mdmac_chan *mc = to_uniphier_mdmac_chan(vc);
> +       unsigned long flags;
> +       int ret = 0;
> +       LIST_HEAD(head);
> +
> +       spin_lock_irqsave(&vc->lock, flags);
> +
> +       if (mc->md) {
> +               vchan_terminate_vdesc(&mc->md->vd);
> +               mc->md = NULL;
> +               ret = __uniphier_mdmac_abort(mc);
> +       }
> +       vchan_get_all_descriptors(vc, &head);
> +
> +       spin_unlock_irqrestore(&vc->lock, flags);
> +
> +       vchan_dma_desc_free_list(vc, &head);
> +
> +       return ret;
> +}
> +
> +static void uniphier_mdmac_synchronize(struct dma_chan *chan)
> +{
> +       vchan_synchronize(to_virt_chan(chan));
> +}
> +
> +static enum dma_status uniphier_mdmac_tx_status(struct dma_chan *chan,
> +                                               dma_cookie_t cookie,
> +                                               struct dma_tx_state *txstate)
> +{
> +       struct virt_dma_chan *vc;
> +       struct virt_dma_desc *vd;
> +       struct uniphier_mdmac_chan *mc;
> +       struct uniphier_mdmac_desc *md = NULL;
> +       enum dma_status stat;
> +       unsigned long flags;
> +
> +       stat = dma_cookie_status(chan, cookie, txstate);
> +       if (stat == DMA_COMPLETE)
> +               return stat;
> +
> +       vc = to_virt_chan(chan);
> +
> +       spin_lock_irqsave(&vc->lock, flags);
> +
> +       mc = to_uniphier_mdmac_chan(vc);
> +
> +       if (mc->md && mc->md->vd.tx.cookie == cookie)
> +               md = mc->md;
> +
> +       if (!md) {
> +               vd = vchan_find_desc(vc, cookie);
> +               if (vd)
> +                       md = to_uniphier_mdmac_desc(vd);
> +       }
> +
> +       if (md)
> +               txstate->residue = __uniphier_mdmac_get_residue(md);
> +
> +       spin_unlock_irqrestore(&vc->lock, flags);
> +
> +       return stat;
> +}
> +
> +static void uniphier_mdmac_issue_pending(struct dma_chan *chan)
> +{
> +       struct virt_dma_chan *vc = to_virt_chan(chan);
> +       struct uniphier_mdmac_chan *mc = to_uniphier_mdmac_chan(vc);
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&vc->lock, flags);
> +
> +       if (vchan_issue_pending(vc) && !mc->md)
> +               __uniphier_mdmac_start(mc);
> +
> +       spin_unlock_irqrestore(&vc->lock, flags);
> +}
> +
> +static void uniphier_mdmac_desc_free(struct virt_dma_desc *vd)
> +{
> +       kfree(to_uniphier_mdmac_desc(vd));
> +}
> +
> +static int uniphier_mdmac_chan_init(struct platform_device *pdev,
> +                                   struct uniphier_mdmac_device *mdev,
> +                                   int chan_id)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct uniphier_mdmac_chan *mc = &mdev->channels[chan_id];
> +       char *irq_name;
> +       int irq, ret;
> +
> +       irq = platform_get_irq(pdev, chan_id);
> +       if (irq < 0) {
> +               dev_err(&pdev->dev, "failed to get IRQ number for ch%d\n",
> +                       chan_id);
> +               return irq;
> +       }
> +
> +       irq_name = devm_kasprintf(dev, GFP_KERNEL, "uniphier-mio-dmac-ch%d",
> +                                 chan_id);
> +       if (!irq_name)
> +               return -ENOMEM;
> +
> +       ret = devm_request_irq(dev, irq, uniphier_mdmac_interrupt,
> +                              IRQF_SHARED, irq_name, mc);
> +       if (ret)
> +               return ret;
> +
> +       mc->mdev = mdev;
> +       mc->reg_ch_base = mdev->reg_base + UNIPHIER_MDMAC_CH_OFFSET +
> +                                       UNIPHIER_MDMAC_CH_STRIDE * chan_id;
> +       mc->chan_id = chan_id;
> +       mc->vc.desc_free = uniphier_mdmac_desc_free;
> +       vchan_init(&mc->vc, &mdev->ddev);
> +
> +       return 0;
> +}
> +
> +static int uniphier_mdmac_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct uniphier_mdmac_device *mdev;
> +       struct dma_device *ddev;
> +       struct resource *res;
> +       u32 nr_chans;
> +       int ret, i;
> +
> +       ret = of_property_read_u32(dev->of_node, "dma-channels", &nr_chans);
> +       if (ret) {
> +               dev_err(dev, "failed to read dma-channels property\n");
> +               return ret;
> +       }
> +
> +       ret = dma_set_mask(dev, DMA_BIT_MASK(32));
> +       if (ret)
> +               return ret;
> +
> +       mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
> +                           GFP_KERNEL);
> +       if (!mdev)
> +               return -ENOMEM;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       mdev->reg_base = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(mdev->reg_base))
> +               return PTR_ERR(mdev->reg_base);
> +
> +       mdev->clk = devm_clk_get(dev, NULL);
> +       if (IS_ERR(mdev->clk)) {
> +               dev_err(dev, "failed to get clock\n");
> +               return PTR_ERR(mdev->clk);
> +       }
> +
> +       ret = clk_prepare_enable(mdev->clk);
> +       if (ret)
> +               return ret;
> +
> +       ddev = &mdev->ddev;
> +       ddev->dev = dev;
> +       dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
> +       ddev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
> +       ddev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
> +       ddev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
> +       ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
> +       ddev->device_prep_slave_sg = uniphier_mdmac_prep_slave_sg;
> +       ddev->device_terminate_all = uniphier_mdmac_terminate_all;
> +       ddev->device_synchronize = uniphier_mdmac_synchronize;
> +       ddev->device_tx_status = uniphier_mdmac_tx_status;
> +       ddev->device_issue_pending = uniphier_mdmac_issue_pending;
> +       INIT_LIST_HEAD(&ddev->channels);
> +
> +       for (i = 0; i < nr_chans; i++) {
> +               ret = uniphier_mdmac_chan_init(pdev, mdev, i);
> +               if (ret)
> +                       goto disable_clk;
> +       }
> +
> +       ret = dma_async_device_register(ddev);
> +       if (ret)
> +               goto disable_clk;
> +
> +       ret = of_dma_controller_register(dev->of_node, of_dma_xlate_by_chan_id,
> +                                        ddev);
> +       if (ret)
> +               goto unregister_dmac;
> +
> +       platform_set_drvdata(pdev, mdev);
> +
> +       return 0;
> +
> +unregister_dmac:
> +       dma_async_device_unregister(ddev);
> +disable_clk:
> +       clk_disable_unprepare(mdev->clk);
> +
> +       return ret;
> +}
> +
> +static int uniphier_mdmac_remove(struct platform_device *pdev)
> +{
> +       struct uniphier_mdmac_device *mdev = platform_get_drvdata(pdev);
> +
> +       of_dma_controller_free(pdev->dev.of_node);
> +       dma_async_device_unregister(&mdev->ddev);
> +       clk_disable_unprepare(mdev->clk);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id uniphier_mdmac_match[] = {
> +       { .compatible = "socionext,uniphier-mio-dmac" },
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, uniphier_mdmac_match);
> +
> +static struct platform_driver uniphier_mdmac_driver = {
> +       .probe = uniphier_mdmac_probe,
> +       .remove = uniphier_mdmac_remove,
> +       .driver = {
> +               .name = "uniphier-mio-dmac",
> +               .of_match_table = uniphier_mdmac_match,
> +       },
> +};
> +module_platform_driver(uniphier_mdmac_driver);
> +
> +MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
> +MODULE_DESCRIPTION("UniPhier MIO DMAC driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>



-- 
Best Regards
Masahiro Yamada