[v5,1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

Message ID 1454333687-20421-2-git-send-email-leo.yan@linaro.org
State New
Headers show

Commit Message

Leo Yan Feb. 1, 2016, 1:34 p.m.
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

-- 
1.9.1

Comments

Leo Yan Feb. 1, 2016, 3:23 p.m. | #1
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

> >

Patch

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>;
+	};