Hello Randy, Please refer to the slave-interface linux documentation: https://www.kernel.org/doc/Documentation/i2c/slave-interface Thanks. Asmaa -----Original Message----- From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Sent: Monday, June 10, 2019 5:56 PM To: Asmaa Mnebhi <Asmaa@xxxxxxxxxxxx>; minyard@xxxxxxx; wsa@xxxxxxxxxxxxx; Vadim Pasternak <vadimp@xxxxxxxxxxxx>; Michael Shych <michaelsh@xxxxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx Subject: Re: [PATCH v12 1/1] Add support for IPMB driver On 6/10/19 11:57 AM, Asmaa Mnebhi wrote: > Support receiving IPMB requests on a Satellite MC from the BMC. > Once a response is ready, this driver will send back a response to the > BMC via the IPMB channel. > > Signed-off-by: Asmaa Mnebhi <Asmaa@xxxxxxxxxxxx> > Acked-by: vadimp@xxxxxxxxxxxx > --- > Documentation/IPMB.txt | 103 +++++++++++ > drivers/char/ipmi/Kconfig | 8 + > drivers/char/ipmi/Makefile | 1 + > drivers/char/ipmi/ipmb_dev_int.c | 364 > +++++++++++++++++++++++++++++++++++++++ > 4 files changed, 476 insertions(+) > create mode 100644 Documentation/IPMB.txt create mode 100644 > drivers/char/ipmi/ipmb_dev_int.c > > diff --git a/Documentation/IPMB.txt b/Documentation/IPMB.txt new file > mode 100644 index 0000000..7160d53 > --- /dev/null > +++ b/Documentation/IPMB.txt > @@ -0,0 +1,103 @@ [...] > +Instantiate the device > +---------------------- > + > +After loading the driver, you can instantiate the device as described > +in 'Documentation/i2c/instantiating-devices'. > +If you have multiple BMCs, each connected to your Satellite MC via a > +different I2C bus, you can instantiate a device for each of those > +BMCs. > +The name of the instantiated device contains the I2C bus number > +associated with it as follows: > + > +BMC1 ------ IPMB/I2C bus 1 ---------| /dev/ipmb-1 > + Satellite MC > +BMC1 ------ IPMB/I2C bus 2 ---------| /dev/ipmb-2 > + > +For instance, you can instantiate the ipmb-dev-int device from user > +space at the 7 bit address 0x10 on bus 2: > + > + # echo ipmb-dev 0x1010 > /sys/bus/i2c/devices/i2c-2/new_device This is confusing. Can you clarify how the 7-bit address is extracted from that hex number? Is the 7-bit address repeated (duplicated)? Is the 7-bit address the low order (low bits) 0x10 or the 0x10 at bits 15-8 (or 14-8)? > +This will create the device file /dev/ipmb-2, which can be accessed > +by the user space program. The device needs to be instantiated before > +running the user space program. thanks. -- ~Randy
