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[PATCH v5 0/4] mailbox: hisilicon: add Hi6220 mailbox driver

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  [PATCH v5 0/4] mailbox: hisilicon: add Hi6220 mailbox driver Leo Yan <leo.yan@linaro.org> - 2016-02-01 14:40 +0100
    [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver Leo Yan <leo.yan@linaro.org> - 2016-02-01 14:40 +0100
      Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox  driver Rob Herring <robh@kernel.org> - 2016-02-01 15:10 +0100
        Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox  driver Leo Yan <leo.yan@linaro.org> - 2016-02-01 16:30 +0100
          Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver Jassi Brar <jassisinghbrar@gmail.com> - 2016-02-01 17:20 +0100
            Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox  driver Leo Yan <leo.yan@linaro.org> - 2016-02-02 10:30 +0100

#1323114 — [PATCH v5 0/4] mailbox: hisilicon: add Hi6220 mailbox driver

Hi6220 mailbox supports up to 32 channels. Each channel is unidirectional
with a maximum message size of 8 words. I/O is performed using register
access (there is no DMA) and the cell raises an interrupt when messages
are received.

This patch series is to implement Hi6220 mailbox driver. It registers
two channels into framework for communication with MCU, one is tx channel
and another is rx channel. Now mailbox driver is used to send message to
MCU to control dynamic voltage and frequency scaling for CPU, GPU and DDR.

Changes from v4:
* According to Jassi's suggestion, using DT binding to register channels
* Change to use operating-points-v2 to register operating points

Changes from v3:
* The patch series for enabling idle state for Hi6220 has reserved memory
  regions, so this series will not include it anymore
* Refined mailbox driver according to Jassi's suggestion;
  Removed kfifo from mailbox driver;
  Removed spinlock for ipc registers accessing, due every channel has its
  own dedicated bit in ipc register and readl/writel will introduce memory
  barrier, so don't need spinlock to protect ipc registers accessing
* After mailbox driver is ready, can use patch 4 to enable CPU's OPPs and
  stub clock driver; finally can enable CPUFreq driver for CPU frequency
  scaling

Changes from v2:
* Get rid of unused memory regions from memory node in DT, and don't use
  reserved-memory node according to Mark and Leif's suggestion; Haojian also
  has updated UEFI for efi memory info

Changes from v1:
* Correct lock usage for SMP scenario

Changes from RFC:
* According to Jassi's review, totally remove the abstract common driver
  layer and only commit driver dedicated for Hi6220
* According to Paul Bolle's review, fix typo issue for Kconfig and remove
  unnecessary dependency with OF and fix minor for mailbox driver
* Refine a little for dts nodes


Leo Yan (4):
  dt-bindings: mailbox: Document Hi6220 mailbox driver
  mailbox: Hi6220: add mailbox driver
  arm64: dts: add mailbox node for Hi6220
  arm64: dts: add Hi6220's stub clock node

 .../bindings/mailbox/hisilicon,hi6220-mailbox.txt  |  90 +++++
 arch/arm64/boot/dts/hisilicon/hi6220.dtsi          |  67 ++++
 drivers/mailbox/Kconfig                            |   8 +
 drivers/mailbox/Makefile                           |   2 +
 drivers/mailbox/hi6220-mailbox.c                   | 407 +++++++++++++++++++++
 5 files changed, 574 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
 create mode 100644 drivers/mailbox/hi6220-mailbox.c

-- 
1.9.1

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#1323121 — [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

Document DT binding for Hisilicon Hi6220 mailbox driver.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 .../bindings/mailbox/hisilicon,hi6220-mailbox.txt  | 90 ++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt

diff --git a/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
new file mode 100644
index 0000000..96e6acc
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
@@ -0,0 +1,90 @@
+Hisilicon Hi6220 Mailbox Driver
+===============================
+
+Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
+is unidirectional with a maximum message size of 8 words. I/O is
+performed using register access (there is no DMA) and the cell
+raises an interrupt when messages are received.
+
+Mailbox Device Node:
+====================
+
+Required properties:
+--------------------
+- compatible:		Shall be "hisilicon,hi6220-mbox"
+- reg:			Contains the mailbox register address range (base
+			address and length); the first item is for IPC
+			registers, the second item is shared buffer for
+			slots.
+- #mbox-cells		Common mailbox binding property to identify the number
+			of cells required for the mailbox specifier. Should be 1.
+- interrupts:		Contains the interrupt information for the mailbox
+			device. The format is dependent on which interrupt
+			controller the SoCs use.
+
+Optional Properties:
+--------------------
+- hi6220,mbox-tx-noirq: Flag to allow the client user of this mailbox driver
+			to send messages without triggering a TX completion
+			interrupt.
+
+Child Nodes:
+============
+A child node is used for representing the actual sub-mailbox device that is
+used for the communication between the host processor and a remote processor.
+Each child node should have a unique node name across all the different
+mailbox device nodes.
+
+Required properties:
+--------------------
+- hi6220,mbox-tx:	sub-mailbox descriptor property defining Tx channel
+- hi6220,mbox-rx:	sub-mailbox descriptor property defining Rx channel
+
+Sub-mailbox Descriptor Data
+---------------------------
+Each of the above hi6220,mbox-tx and hi6220,mbox-rx properties should have 3
+cells of data that represent the following:
+    Cell #1 (slot_id) - mailbox slot id used either for transmitting
+                        (hi6220,mbox-tx) or for receiving (hi6220,mbox-rx)
+    Cell #2 (dst_irq) - irq identifier index number which used by MCU.
+    Cell #3 (ack_irq) - irq identifier index number with generating a tx/rx
+                        interrupt to application processor, mailbox driver
+                        used this id to acknowledge interrupt.
+
+Example:
+--------
+
+	mailbox: mailbox@F7510000 {
+		#mbox-cells = <1>;
+		compatible = "hisilicon,hi6220-mbox";
+		reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
+		      <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
+		mbox_stub_clock: mbox_stub_clock {
+			hi6220,mbox-rx = <0 1 10>;
+			hi6220,mbox-tx = <1 0 11>;
+		};
+	};
+
+
+Mailbox client
+===============
+
+"mboxes" and the optional "mbox-names" (please see
+Documentation/devicetree/bindings/mailbox/mailbox.txt for details). Each value
+of the mboxes property should contain a phandle to the mailbox controller
+device node and second argument is the channel index. It must be 0 (hardware
+support only one channel). The equivalent "mbox-names" property value can be
+used to give a name to the communication channel to be used by the client user.
+
+Example:
+--------
+
+	stub_clock: stub_clock {
+		compatible = "hisilicon,hi6220-stub-clk";
+		hisilicon,hi6220-clk-sram = <&sram>;
+		#clock-cells = <1>;
+		mbox-names = "mbox-tx";
+		mboxes = <&mailbox 1>;
+	};
-- 
1.9.1

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#1323147 — Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

On Mon, Feb 01, 2016 at 09:34:44PM +0800, Leo Yan wrote:
> Document DT binding for Hisilicon Hi6220 mailbox driver.
> 
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
>  .../bindings/mailbox/hisilicon,hi6220-mailbox.txt  | 90 ++++++++++++++++++++++
>  1 file changed, 90 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> new file mode 100644
> index 0000000..96e6acc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> @@ -0,0 +1,90 @@
> +Hisilicon Hi6220 Mailbox Driver
> +===============================
> +
> +Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
> +is unidirectional with a maximum message size of 8 words. I/O is
> +performed using register access (there is no DMA) and the cell
> +raises an interrupt when messages are received.
> +
> +Mailbox Device Node:
> +====================
> +
> +Required properties:
> +--------------------
> +- compatible:		Shall be "hisilicon,hi6220-mbox"
> +- reg:			Contains the mailbox register address range (base
> +			address and length); the first item is for IPC
> +			registers, the second item is shared buffer for
> +			slots.
> +- #mbox-cells		Common mailbox binding property to identify the number
> +			of cells required for the mailbox specifier. Should be 1.
> +- interrupts:		Contains the interrupt information for the mailbox
> +			device. The format is dependent on which interrupt
> +			controller the SoCs use.
> +
> +Optional Properties:
> +--------------------
> +- hi6220,mbox-tx-noirq: Flag to allow the client user of this mailbox driver
> +			to send messages without triggering a TX completion
> +			interrupt.

I don't think this belongs in DT. This should be a flag the client 
driver sets when it sends messages.

> +
> +Child Nodes:
> +============
> +A child node is used for representing the actual sub-mailbox device that is
> +used for the communication between the host processor and a remote processor.
> +Each child node should have a unique node name across all the different
> +mailbox device nodes.
> +
> +Required properties:
> +--------------------
> +- hi6220,mbox-tx:	sub-mailbox descriptor property defining Tx channel
> +- hi6220,mbox-rx:	sub-mailbox descriptor property defining Rx channel
> +
> +Sub-mailbox Descriptor Data
> +---------------------------
> +Each of the above hi6220,mbox-tx and hi6220,mbox-rx properties should have 3
> +cells of data that represent the following:
> +    Cell #1 (slot_id) - mailbox slot id used either for transmitting
> +                        (hi6220,mbox-tx) or for receiving (hi6220,mbox-rx)
> +    Cell #2 (dst_irq) - irq identifier index number which used by MCU.
> +    Cell #3 (ack_irq) - irq identifier index number with generating a tx/rx
> +                        interrupt to application processor, mailbox driver
> +                        used this id to acknowledge interrupt.
> +
> +Example:
> +--------
> +
> +	mailbox: mailbox@F7510000 {
> +		#mbox-cells = <1>;
> +		compatible = "hisilicon,hi6220-mbox";
> +		reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
> +		      <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
> +		interrupt-parent = <&gic>;
> +		interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
> +		mbox_stub_clock: mbox_stub_clock {
> +			hi6220,mbox-rx = <0 1 10>;
> +			hi6220,mbox-tx = <1 0 11>;
> +		};
> +	};
> +
> +
> +Mailbox client
> +===============
> +
> +"mboxes" and the optional "mbox-names" (please see
> +Documentation/devicetree/bindings/mailbox/mailbox.txt for details). Each value
> +of the mboxes property should contain a phandle to the mailbox controller
> +device node and second argument is the channel index. It must be 0 (hardware

0? But the example has 1.

> +support only one channel). The equivalent "mbox-names" property value can be
> +used to give a name to the communication channel to be used by the client user.
> +
> +Example:
> +--------
> +
> +	stub_clock: stub_clock {
> +		compatible = "hisilicon,hi6220-stub-clk";
> +		hisilicon,hi6220-clk-sram = <&sram>;
> +		#clock-cells = <1>;
> +		mbox-names = "mbox-tx";
> +		mboxes = <&mailbox 1>;
> +	};
> -- 
> 1.9.1
> 

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#1323232 — Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

Hi Rob,

Thanks for reviewing, please see below inline comments.

On Mon, Feb 01, 2016 at 08:08:28AM -0600, Rob Herring wrote:
> On Mon, Feb 01, 2016 at 09:34:44PM +0800, Leo Yan wrote:
> > Document DT binding for Hisilicon Hi6220 mailbox driver.
> > 
> > Signed-off-by: Leo Yan <leo.yan@linaro.org>
> > ---
> >  .../bindings/mailbox/hisilicon,hi6220-mailbox.txt  | 90 ++++++++++++++++++++++
> >  1 file changed, 90 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> > new file mode 100644
> > index 0000000..96e6acc
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> > @@ -0,0 +1,90 @@
> > +Hisilicon Hi6220 Mailbox Driver
> > +===============================
> > +
> > +Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
> > +is unidirectional with a maximum message size of 8 words. I/O is
> > +performed using register access (there is no DMA) and the cell
> > +raises an interrupt when messages are received.
> > +
> > +Mailbox Device Node:
> > +====================
> > +
> > +Required properties:
> > +--------------------
> > +- compatible:		Shall be "hisilicon,hi6220-mbox"
> > +- reg:			Contains the mailbox register address range (base
> > +			address and length); the first item is for IPC
> > +			registers, the second item is shared buffer for
> > +			slots.
> > +- #mbox-cells		Common mailbox binding property to identify the number
> > +			of cells required for the mailbox specifier. Should be 1.
> > +- interrupts:		Contains the interrupt information for the mailbox
> > +			device. The format is dependent on which interrupt
> > +			controller the SoCs use.
> > +
> > +Optional Properties:
> > +--------------------
> > +- hi6220,mbox-tx-noirq: Flag to allow the client user of this mailbox driver
> > +			to send messages without triggering a TX completion
> > +			interrupt.
> 
> I don't think this belongs in DT. This should be a flag the client 
> driver sets when it sends messages.

The client driver can set "tx_block = true" so use this flag indicates
the client thread should be blocked until data is transmitted.

But low level mailbox driver can use two method to support "tx_block"
mode:
- One method is to avoid using interrupt and mailbox framework will
  poll with mailbox's idle flag which is set by remote processor
  automatically;
- Another method is to use interrupt to notify data has been
  transmitted and interrupt handler will call completion function to
  wake up blocked client thread;

So this flag is to distinguish these two different hardware mechanism.
Do you think this is make sense or have other suggestion?

> > +
> > +Child Nodes:
> > +============
> > +A child node is used for representing the actual sub-mailbox device that is
> > +used for the communication between the host processor and a remote processor.
> > +Each child node should have a unique node name across all the different
> > +mailbox device nodes.
> > +
> > +Required properties:
> > +--------------------
> > +- hi6220,mbox-tx:	sub-mailbox descriptor property defining Tx channel
> > +- hi6220,mbox-rx:	sub-mailbox descriptor property defining Rx channel
> > +
> > +Sub-mailbox Descriptor Data
> > +---------------------------
> > +Each of the above hi6220,mbox-tx and hi6220,mbox-rx properties should have 3
> > +cells of data that represent the following:
> > +    Cell #1 (slot_id) - mailbox slot id used either for transmitting
> > +                        (hi6220,mbox-tx) or for receiving (hi6220,mbox-rx)
> > +    Cell #2 (dst_irq) - irq identifier index number which used by MCU.
> > +    Cell #3 (ack_irq) - irq identifier index number with generating a tx/rx
> > +                        interrupt to application processor, mailbox driver
> > +                        used this id to acknowledge interrupt.
> > +
> > +Example:
> > +--------
> > +
> > +	mailbox: mailbox@F7510000 {
> > +		#mbox-cells = <1>;
> > +		compatible = "hisilicon,hi6220-mbox";
> > +		reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
> > +		      <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
> > +		mbox_stub_clock: mbox_stub_clock {
> > +			hi6220,mbox-rx = <0 1 10>;
> > +			hi6220,mbox-tx = <1 0 11>;
> > +		};
> > +	};
> > +
> > +
> > +Mailbox client
> > +===============
> > +
> > +"mboxes" and the optional "mbox-names" (please see
> > +Documentation/devicetree/bindings/mailbox/mailbox.txt for details). Each value
> > +of the mboxes property should contain a phandle to the mailbox controller
> > +device node and second argument is the channel index. It must be 0 (hardware
> 
> 0? But the example has 1.

Will fix.

Thanks,
Leo Yan

> > +support only one channel). The equivalent "mbox-names" property value can be
> > +used to give a name to the communication channel to be used by the client user.
> > +
> > +Example:
> > +--------
> > +
> > +	stub_clock: stub_clock {
> > +		compatible = "hisilicon,hi6220-stub-clk";
> > +		hisilicon,hi6220-clk-sram = <&sram>;
> > +		#clock-cells = <1>;
> > +		mbox-names = "mbox-tx";
> > +		mboxes = <&mailbox 1>;
> > +	};
> > -- 
> > 1.9.1
> > 

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#1323291 — Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

On Mon, Feb 1, 2016 at 8:53 PM, Leo Yan <leo.yan@linaro.org> wrote:
> Hi Rob,
>
> Thanks for reviewing, please see below inline comments.
>
> On Mon, Feb 01, 2016 at 08:08:28AM -0600, Rob Herring wrote:
>> On Mon, Feb 01, 2016 at 09:34:44PM +0800, Leo Yan wrote:
>> > Document DT binding for Hisilicon Hi6220 mailbox driver.
>> >
>> > Signed-off-by: Leo Yan <leo.yan@linaro.org>
>> > ---
>> >  .../bindings/mailbox/hisilicon,hi6220-mailbox.txt  | 90 ++++++++++++++++++++++
>> >  1 file changed, 90 insertions(+)
>> >  create mode 100644 Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
>> > new file mode 100644
>> > index 0000000..96e6acc
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
>> > @@ -0,0 +1,90 @@
>> > +Hisilicon Hi6220 Mailbox Driver
>> > +===============================
>> > +
>> > +Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
>> > +is unidirectional with a maximum message size of 8 words. I/O is
>> > +performed using register access (there is no DMA) and the cell
>> > +raises an interrupt when messages are received.
>> > +
>> > +Mailbox Device Node:
>> > +====================
>> > +
>> > +Required properties:
>> > +--------------------
>> > +- compatible:              Shall be "hisilicon,hi6220-mbox"
>> > +- reg:                     Contains the mailbox register address range (base
>> > +                   address and length); the first item is for IPC
>> > +                   registers, the second item is shared buffer for
>> > +                   slots.
>> > +- #mbox-cells              Common mailbox binding property to identify the number
>> > +                   of cells required for the mailbox specifier. Should be 1.
>> > +- interrupts:              Contains the interrupt information for the mailbox
>> > +                   device. The format is dependent on which interrupt
>> > +                   controller the SoCs use.
>> > +
>> > +Optional Properties:
>> > +--------------------
>> > +- hi6220,mbox-tx-noirq: Flag to allow the client user of this mailbox driver
>> > +                   to send messages without triggering a TX completion
>> > +                   interrupt.
>>
>> I don't think this belongs in DT. This should be a flag the client
>> driver sets when it sends messages.
>
> The client driver can set "tx_block = true" so use this flag indicates
> the client thread should be blocked until data is transmitted.
>
Yes, but the 'tx_block' feature is provided by the core. The
controller driver should not need to know how the client works.

> But low level mailbox driver can use two method to support "tx_block"
> mode:
>
No, as I said, provider shouldn't care about consumers..

> - One method is to avoid using interrupt and mailbox framework will
>   poll with mailbox's idle flag which is set by remote processor
>   automatically;
> - Another method is to use interrupt to notify data has been
>   transmitted and interrupt handler will call completion function to
>   wake up blocked client thread;
>
If it is possible to have either 'idle flag set' or irq generated (not
both) by the remote, then you may sell the hi6220,mbox-tx-noirq
property as a "f/w feature" ... but still not for the sake of
tx_block.


>> > +
>> > +Child Nodes:
>> > +============
>> > +A child node is used for representing the actual sub-mailbox device that is
>> > +used for the communication between the host processor and a remote processor.
>> > +Each child node should have a unique node name across all the different
>> > +mailbox device nodes.
>> > +
>> > +Required properties:
>> > +--------------------
>> > +- hi6220,mbox-tx:  sub-mailbox descriptor property defining Tx channel
>> > +- hi6220,mbox-rx:  sub-mailbox descriptor property defining Rx channel
>> > +
>> > +Sub-mailbox Descriptor Data
>> > +---------------------------
>> > +Each of the above hi6220,mbox-tx and hi6220,mbox-rx properties should have 3
>> > +cells of data that represent the following:
>> > +    Cell #1 (slot_id) - mailbox slot id used either for transmitting
>> > +                        (hi6220,mbox-tx) or for receiving (hi6220,mbox-rx)
>> > +    Cell #2 (dst_irq) - irq identifier index number which used by MCU.
>> > +    Cell #3 (ack_irq) - irq identifier index number with generating a tx/rx
>> > +                        interrupt to application processor, mailbox driver
>> > +                        used this id to acknowledge interrupt.
>> > +
>> > +Example:
>> > +--------
>> > +
>> > +   mailbox: mailbox@F7510000 {
>> > +           #mbox-cells = <1>;
>> > +           compatible = "hisilicon,hi6220-mbox";
>> > +           reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
>> > +                 <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
>> > +           interrupt-parent = <&gic>;
>> > +           interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
>> > +           mbox_stub_clock: mbox_stub_clock {
>> > +                   hi6220,mbox-rx = <0 1 10>;
>> > +                   hi6220,mbox-tx = <1 0 11>;
>
This looks like meant for the client node...
         mbox-names = "mbox-tx", "mbox-rx";
         mboxes = <&mailbox 1 0 11>, <&mailbox 0 1 10>;

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#1323907 — Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

On Mon, Feb 01, 2016 at 09:46:39PM +0530, Jassi Brar wrote:
> On Mon, Feb 1, 2016 at 8:53 PM, Leo Yan <leo.yan@linaro.org> wrote:
> > On Mon, Feb 01, 2016 at 08:08:28AM -0600, Rob Herring wrote:
> >> On Mon, Feb 01, 2016 at 09:34:44PM +0800, Leo Yan wrote:

[...]

> >> > +Optional Properties:
> >> > +--------------------
> >> > +- hi6220,mbox-tx-noirq: Flag to allow the client user of this mailbox driver
> >> > +                   to send messages without triggering a TX completion
> >> > +                   interrupt.
> >>
> >> I don't think this belongs in DT. This should be a flag the client
> >> driver sets when it sends messages.
> >
> > The client driver can set "tx_block = true" so use this flag indicates
> > the client thread should be blocked until data is transmitted.
> >
> Yes, but the 'tx_block' feature is provided by the core. The
> controller driver should not need to know how the client works.
> 
> > But low level mailbox driver can use two method to support "tx_block"
> > mode:
> >
> No, as I said, provider shouldn't care about consumers..
> 
> > - One method is to avoid using interrupt and mailbox framework will
> >   poll with mailbox's idle flag which is set by remote processor
> >   automatically;
> > - Another method is to use interrupt to notify data has been
> >   transmitted and interrupt handler will call completion function to
> >   wake up blocked client thread;
> >
> If it is possible to have either 'idle flag set' or irq generated (not
> both) by the remote, then you may sell the hi6220,mbox-tx-noirq
> property as a "f/w feature" ... but still not for the sake of
> tx_block.

Indeed and totally agree. MCU can support two modes for "automatic idle
flag" or IRQ generated mode, so we can take "hi6220,mbox-tx-noirq" as a
firmware's property.

> >> > +
> >> > +Child Nodes:
> >> > +============
> >> > +A child node is used for representing the actual sub-mailbox device that is
> >> > +used for the communication between the host processor and a remote processor.
> >> > +Each child node should have a unique node name across all the different
> >> > +mailbox device nodes.
> >> > +
> >> > +Required properties:
> >> > +--------------------
> >> > +- hi6220,mbox-tx:  sub-mailbox descriptor property defining Tx channel
> >> > +- hi6220,mbox-rx:  sub-mailbox descriptor property defining Rx channel
> >> > +
> >> > +Sub-mailbox Descriptor Data
> >> > +---------------------------
> >> > +Each of the above hi6220,mbox-tx and hi6220,mbox-rx properties should have 3
> >> > +cells of data that represent the following:
> >> > +    Cell #1 (slot_id) - mailbox slot id used either for transmitting
> >> > +                        (hi6220,mbox-tx) or for receiving (hi6220,mbox-rx)
> >> > +    Cell #2 (dst_irq) - irq identifier index number which used by MCU.
> >> > +    Cell #3 (ack_irq) - irq identifier index number with generating a tx/rx
> >> > +                        interrupt to application processor, mailbox driver
> >> > +                        used this id to acknowledge interrupt.
> >> > +
> >> > +Example:
> >> > +--------
> >> > +
> >> > +   mailbox: mailbox@F7510000 {
> >> > +           #mbox-cells = <1>;
> >> > +           compatible = "hisilicon,hi6220-mbox";
> >> > +           reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
> >> > +                 <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
> >> > +           interrupt-parent = <&gic>;
> >> > +           interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
> >> > +           mbox_stub_clock: mbox_stub_clock {
> >> > +                   hi6220,mbox-rx = <0 1 10>;
> >> > +                   hi6220,mbox-tx = <1 0 11>;
> >
> This looks like meant for the client node...
>          mbox-names = "mbox-tx", "mbox-rx";
>          mboxes = <&mailbox 1 0 11>, <&mailbox 0 1 10>;

Good suggestion. Will refine with this way.

Thanks,
Leo Yan

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