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From: Stephen Warren <swarren@wwwdotorg.org>
To: Jassi Brar <jassisinghbrar@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Joseph Lo <josephl@nvidia.com>
Subject: Using the mailbox subsystem for plain doorbells?
Date: Mon, 9 May 2016 17:45:14 -0600	[thread overview]
Message-ID: <5731210A.4000401@wwwdotorg.org> (raw)

Jassi,

Does the HW described below sound like something that should be 
represented using the Linux kernel's mailbox subsystem, and related DT 
bindings? I think the existing drivers/mailbox/pcc.c is similar, but 
wanted to double-check.

We have some HW that literally just allows a SW-generated interrupt to 
be generated by our main CPU complex to an auxiliary CPU, and likewise a 
different interrupt can be generated in the opposite direction. There's 
no ability to transfer any data; just an IRQ is generated. Our current 
mailbox implementation just handles IRQ generation/reception so struct 
mbox_chan_ops.send_data completely ignores the data parameter, and our 
IRQ handler "receives" hard-coded NULL messages when the IRQ fires. 
Higher level protocol code (using shared memory along with the plain-IRQ 
mbox channels) is outside the mailbox driver.

Does that fit the mailbox subsystem?

             reply	other threads:[~2016-05-09 23:45 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-09 23:45 Stephen Warren [this message]
2016-05-10  3:29 ` Using the mailbox subsystem for plain doorbells? Jassi Brar
2016-05-10 15:56   ` Stephen Warren
2016-05-10 16:10     ` Jassi Brar

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