[PATCH v8 2/4] dt-bindings: mailbox: imx-mu: add generic MU channel support
flat view
From: jassisinghbrar@gmail.com (Jassi Brar)
Date: 2018-07-31 15:58:09
Also in:
linux-devicetree
On Tue, Jul 31, 2018 at 7:41 PM, Oleksij Rempel [off-list ref] wrote:
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Each MU has four pairs of rx/tx data register with four rx/tx interrupts which can also be used as a separate channel. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- .../devicetree/bindings/mailbox/fsl,mu.txt | 28 +++++++++++++++++-- 1 file changed, 25 insertions(+), 3 deletions(-)diff --git a/Documentation/devicetree/bindings/mailbox/fsl,mu.txt b/Documentation/devicetree/bindings/mailbox/fsl,mu.txt index 90e4905dfc69..9efd3a9ade44 100644 --- a/Documentation/devicetree/bindings/mailbox/fsl,mu.txt +++ b/Documentation/devicetree/bindings/mailbox/fsl,mu.txt@@ -18,11 +18,33 @@ Messaging Unit Device Node: Required properties: ------------------- - compatible : should be "fsl,<chip>-mu", the supported chips include - imx8qxp, imx8qm. + imx6sx, imx7s, imx8qxp, imx8qm. + The "fsl,imx6sx-mu" compatible is seen as generic and should + be included together with SoC specific compatible. - reg : Should contain the registers location and length - interrupts : Interrupt number. The interrupt specifier format depends on the interrupt controller parent. -- #mbox-cells: Must be 0. Number of cells in a mailbox +- #mbox-cells: Must be 2.
This seems like modifying the bindings. But since nothing exists yet, maybe we should merge patch 1 and 2 ?
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+ <&phandle type channel> + phandle : Label name of controller + type : Channel type + channel : Channel number + + This MU support 4 type of unidirectional channels, each type + has 4 channels. A total of 16 channels. Following types are + supported: + 0 - TX channel with 32bit transmit register and IRQ transmit + acknowledgment support. + 1 - RX channel with 32bit receive register and IRQ support + 2 - TX doorbell channel. Without own register and no ACK support. + 3 - RX doorbell channel.
Thanks. This is great.
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+ The doorbell channels should be used with shared memory and protocol + level acknowledgment if needed. +
I would avoid this. People might get notions that they have to use shmem with doorbell -- a trivial protocol might mean doing some fixed action (like reset) whenever the doorbell rings.
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+Optional properties: +------------------- +- clocks : phandle to the input clock. +- fsl,mu-side-b : Should be set for side B MU.
Nit: can we call this 'fsl,no-init' ?