| Message ID | ee7439aea0c2076aab5dab26d8266d5faab01b6b.1599632119.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [V2] dt-bindings: mailbox: add doorbell support to ARM MHU | expand |
On Wed, Sep 9, 2020 at 12:19 AM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > From: Sudeep Holla <sudeep.holla@arm.com> > > The ARM MHU's reference manual states following: > > "The MHU drives the signal using a 32-bit register, with all 32 bits > logically ORed together. The MHU provides a set of registers to enable > software to set, clear, and check the status of each of the bits of this > register independently. The use of 32 bits for each interrupt line > enables software to provide more information about the source of the > interrupt. For example, each bit of the register can be associated with > a type of event that can contribute to raising the interrupt." > > This patch thus extends the MHU controller's DT binding to add support > for doorbell mode. > > Though the same MHU hardware controller is used in the two modes, A new > compatible string is added here to represent the combination of the MHU > hardware and the firmware sitting on the other side (which expects each > bit to represent a different signal now). > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > Co-developed-by: Viresh Kumar <viresh.kumar@linaro.org> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > V2: > - New compatible string and minor reformatting. Fine with me despite whatever I may have said in the past. Whatever puts this to rest finally. > - Not sending as RFC anymore. > > .../devicetree/bindings/mailbox/arm-mhu.txt | 44 +++++++++++++++++-- > 1 file changed, 41 insertions(+), 3 deletions(-) I'd really like this converted to schema first given it's more than a minor change, but I don't want to hold things up. (Though, where's the new driver?) > diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt > index 4971f03f0b33..1adc441a2c63 100644 > --- a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt > +++ b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt > @@ -10,21 +10,41 @@ STAT register and the remote clears it after having read the data. > The last channel is specified to be a 'Secure' resource, hence can't be > used by Linux running NS. > > +Doorbell mode: The MHU drives the interrupt signal using a 32-bit > +register, with all 32-bits logically ORed together. It provides a set of > +registers to enable software to set, clear and check the status of each > +of the bits of this register independently. The use of 32 bits per > +interrupt line enables software to provide more information about the > +source of the interrupt. For example, each bit of the register can be > +associated with a type of event that can contribute to raising the > +interrupt. Each of the 32-bits can be used as "doorbell" to alert the > +remote processor. > + > Mailbox Device Node: > ==================== > > Required properties: > -------------------- > -- compatible: Shall be "arm,mhu" & "arm,primecell" > +- compatible: Shall be "arm,mhu" (in data transfer mode) or > + "arm,mhu-doorbell" (in doorbell mode) and > + "arm,primecell". > - reg: Contains the mailbox register address range (base > address and length) > -- #mbox-cells Shall be 1 - the index of the channel needed. > +- #mbox-cells Shall be 1 - the index of the channel needed, > + when used in data transfer mode. > + Shall be 2 - the index of the channel needed, and > + the index of the doorbell bit within the > + channel, when used in doorbell mode. > - interrupts: Contains the interrupt information corresponding to > - each of the 3 links of MHU. > + each of the 3 physical channels of MHU namely low > + priority non-secure, high priority non-secure and > + secure channels. > > Example: > -------- > > +1. In data transfer mode > + > mhu: mailbox@2b1f0000 { > #mbox-cells = <1>; > compatible = "arm,mhu", "arm,primecell"; > @@ -41,3 +61,21 @@ used by Linux running NS. > reg = <0 0x2e000000 0x4000>; > mboxes = <&mhu 1>; /* HP-NonSecure */ > }; > + > +2. In doorbell mode > + > + mhu: mailbox@2b1f0000 { > + #mbox-cells = <2>; > + compatible = "arm,mhu-doorbell", "arm,primecell"; > + reg = <0 0x2b1f0000 0x1000>; > + interrupts = <0 36 4>, /* LP-NonSecure */ > + <0 35 4>; /* HP-NonSecure */ The binding says there are 3 interrupts. > + clocks = <&clock 0 2 1>; > + clock-names = "apb_pclk"; > + }; > + > + mhu_client: scb@2e000000 { > + compatible = "arm,scpi"; > + reg = <0 0x2e000000 0x200>; > + mboxes = <&mhu 1 4>; /* HP-NonSecure 5th doorbell bit */ > + }; > -- > 2.25.0.rc1.19.g042ed3e048af >
On 09-09-20, 13:35, Rob Herring wrote: > I'd really like this converted to schema first given it's more than a > minor change, but I don't want to hold things up. (Though, where's the > new driver?) Sudeep will re-work his older patches to get the separate driver ready for inclusion. We were blocked on this idea for ever and so I didn't try playing with it until now :) -- viresh
diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt index 4971f03f0b33..1adc441a2c63 100644 --- a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt +++ b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt @@ -10,21 +10,41 @@ STAT register and the remote clears it after having read the data. The last channel is specified to be a 'Secure' resource, hence can't be used by Linux running NS. +Doorbell mode: The MHU drives the interrupt signal using a 32-bit +register, with all 32-bits logically ORed together. It provides a set of +registers to enable software to set, clear and check the status of each +of the bits of this register independently. The use of 32 bits per +interrupt line enables software to provide more information about the +source of the interrupt. For example, each bit of the register can be +associated with a type of event that can contribute to raising the +interrupt. Each of the 32-bits can be used as "doorbell" to alert the +remote processor. + Mailbox Device Node: ==================== Required properties: -------------------- -- compatible: Shall be "arm,mhu" & "arm,primecell" +- compatible: Shall be "arm,mhu" (in data transfer mode) or + "arm,mhu-doorbell" (in doorbell mode) and + "arm,primecell". - reg: Contains the mailbox register address range (base address and length) -- #mbox-cells Shall be 1 - the index of the channel needed. +- #mbox-cells Shall be 1 - the index of the channel needed, + when used in data transfer mode. + Shall be 2 - the index of the channel needed, and + the index of the doorbell bit within the + channel, when used in doorbell mode. - interrupts: Contains the interrupt information corresponding to - each of the 3 links of MHU. + each of the 3 physical channels of MHU namely low + priority non-secure, high priority non-secure and + secure channels. Example: -------- +1. In data transfer mode + mhu: mailbox@2b1f0000 { #mbox-cells = <1>; compatible = "arm,mhu", "arm,primecell"; @@ -41,3 +61,21 @@ used by Linux running NS. reg = <0 0x2e000000 0x4000>; mboxes = <&mhu 1>; /* HP-NonSecure */ }; + +2. In doorbell mode + + mhu: mailbox@2b1f0000 { + #mbox-cells = <2>; + compatible = "arm,mhu-doorbell", "arm,primecell"; + reg = <0 0x2b1f0000 0x1000>; + interrupts = <0 36 4>, /* LP-NonSecure */ + <0 35 4>; /* HP-NonSecure */ + clocks = <&clock 0 2 1>; + clock-names = "apb_pclk"; + }; + + mhu_client: scb@2e000000 { + compatible = "arm,scpi"; + reg = <0 0x2e000000 0x200>; + mboxes = <&mhu 1 4>; /* HP-NonSecure 5th doorbell bit */ + };