From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH v7 2/7] mailbox: arm_mhu: add driver for ARM MHU controller Date: Thu, 26 Mar 2015 11:43:21 +0000 Message-ID: <5513F0D9.5080807@arm.com> References: <1425466367-30556-1-git-send-email-vincent.yang@socionext.com> <1425466884-30648-1-git-send-email-vincent.yang@socionext.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1425466884-30648-1-git-send-email-vincent.yang@socionext.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "jaswinder.singh@linaro.org" Cc: Mark Rutland , "andy.green@linaro.org" , "linux@arm.linux.org.uk" , Pawel Moll , "arnd@arndb.de" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "robh+dt@kernel.org" , Tetsuya Nuriya , "arm@kernel.org" , "patches@linaro.org" , Vincent Yang , Sudeep Holla , "olof@lixom.net" , Vincent Yang List-Id: devicetree@vger.kernel.org On 04/03/15 11:01, Vincent Yang wrote: > From: Jassi Brar > > Add driver for the ARM Primecell Message-Handling-Unit(MHU) controller. > > Signed-off-by: Jassi Brar > Signed-off-by: Andy Green > Signed-off-by: Vincent Yang > Signed-off-by: Tetsuya Nuriya > --- > .../devicetree/bindings/mailbox/arm-mhu.txt | 43 +++++ > drivers/mailbox/Kconfig | 9 + > drivers/mailbox/Makefile | 2 + > drivers/mailbox/arm_mhu.c | 195 +++++++++++++++++++++ > 4 files changed, 249 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mailbox/arm-mhu.txt > create mode 100644 drivers/mailbox/arm_mhu.c > > diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt > new file mode 100644 > index 0000000..4971f03 > --- /dev/null > +++ b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt > @@ -0,0 +1,43 @@ > +ARM MHU Mailbox Driver > +====================== > + > +The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has > +3 independent channels/links to communicate with remote processor(s). > + MHU links are hardwired on a platform. A link raises interrupt for any > +received data. However, there is no specified way of knowing if the sent > +data has been read by the remote. This driver assumes the sender polls > +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. > + > +Mailbox Device Node: > +==================== > + > +Required properties: > +-------------------- > +- compatible: Shall be "arm,mhu" & "arm,primecell" > +- reg: Contains the mailbox register address range (base > + address and length) > +- #mbox-cells Shall be 1 - the index of the channel needed. > +- interrupts: Contains the interrupt information corresponding to > + each of the 3 links of MHU. > + I tried using this driver and found that AMBA driver expects apb_clk without which probe fails. Though your example have it, it's not explicit from the binding. Also AMBA binding expects the primecell id in the binding. Regards, Sudeep