Kumar,
>> 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 <[email protected]>
>> ---
>> .../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 ?
They are IP design parameters for the number of h/w fifos and interrupts
coming out of the IP block, with the functionality identical. This
information could not be read from any registers. Until OMAP5, we always
had a single IP in the SoC and so these could been encoded in the
driver. But in DRA7xx, a new SoC, we have 13 mailboxes which have
differing number of these properties even though the functional IP block
is same.
>
>> +- 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?
The mbox-data represents the assignment of h/w fifos between a pair of
processors on an SoC, so it is specific to a mailbox IP instance in an
SoC. Also, this assignment makes it flexible for anyone wishing to use
their own firmware/stack on the remote processor side if using different
h/w fifo combination.
So, a single SoC-specific compatible string would not be enough to
identify either of the above data in the driver.
regards
Suman
>
>> +Example:
>> +
>> +/* OMAP4 */
>> +mailbox: mailbox@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
>
> --
> Employee of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by
> The Linux Foundation
>
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