[PATCHv3 2/8] mailbox/omap: add support for parsing dt devices

[Kumar Gala]

On Aug 6, 2013, at 4:40 PM, Suman Anna wrote:

> Logic has been added to the OMAP2+ mailbox code to
> parse the mailbox dt nodes and construct the different
> mailboxes associated with the instance. The design is
> based on gathering the same information that was being
> passed previously through the platform data, except for
> the interrupt type configuration information.
> 
> Signed-off-by: Suman Anna <s-anna at ti.com>
> ---
> .../devicetree/bindings/mailbox/omap-mailbox.txt   |  43 +++++++
> drivers/mailbox/mailbox-omap2.c                    | 130 ++++++++++++++++++---
> 2 files changed, 158 insertions(+), 15 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/mailbox/omap-mailbox.txt
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/omap-mailbox.txt b/Documentation/devicetree/bindings/mailbox/omap-mailbox.txt
> new file mode 100644
> index 0000000..8ffb08a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/omap-mailbox.txt
> @@ -0,0 +1,43 @@
> +OMAP2+ Mailbox Driver
> +
> +Required properties:
> +- compatible:		Should be one of the following,
> +			    "ti,omap2-mailbox" for
> +				OMAP2420, OMAP2430, OMAP3430, OMAP3630 SoCs
> +			    "ti,omap4-mailbox" for
> +				OMAP44xx, OMAP54xx, AM33xx, AM43xx, DRA7xx SoCs
> +- reg:			Contains the mailbox register address range (base address
> +			and length)
> +- interrupts: 		Contains the interrupt information for the mailbox
> +			device. The format is dependent on which interrupt
> +			controller the OMAP device uses
> +- ti,hwmods:		Name of the hwmod associated with the mailbox
> +- ti,mbox-num-users:	Number of targets (processor devices) that the mailbox device
> +			can interrupt
> +- ti,mbox-num-fifos:	Number of h/w fifos within the mailbox device

Isn't "ti,mbox-num-users", "ti,mbox-num-fifos" this SoC specific, why do we need to encode in the device tree.  Can we not have a more SoC specific compatiable and encode such info in the driver as part of the .data field in of_device_id ?

> +- ti,mbox-names:	Array of the names of the mailboxes
> +- ti,mbox-data:		Mailbox descriptor data private to each mailbox. The 4
> +			cells represent the following data,
> +			  Cell #1 (tx_id) - mailbox fifo id used for
> +						transmitting messages
> +			  Cell #2 (rx_id) - mailbox fifo id on which messages
> +						are received
> +			  Cell #3 (irq_id) - irq identifier index number to use
> +						from the interrupts data
> +			  Cell #4 (usr_id) - mailbox user id for identifying the
> +						interrupt into the MPU interrupt
> +						controller.
> +

ti,mbox-data really seems like it should be encoded in the driver and not in the device tree.  Is it specific to the SoC?

> +Example:
> +
> +/* OMAP4 */
> +mailbox: mailbox at 4a0f4000 {
> +	compatible = "ti,omap4-mailbox";
> +	reg = <0x4a0f4000 0x200>;
> +	interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>;
> +	ti,hwmods = "mailbox";
> +	ti,mbox-num-users = <3>;
> +	ti,mbox-num-fifos = <8>;
> +	ti,mbox-names = "mbox-ipu", "mbox-dsp";
> +	ti,mbox-data = <0 1 0 0>, <3 2 0 0>;
> +};

[snip]

- k

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