Re: [PATCH v12 1/1] Add support for IPMB driver
From: Randy Dunlap
Date: Tue Jun 11 2019 - 12:18:29 EST
On 6/11/19 6:28 AM, Asmaa Mnebhi wrote:
> Hello Randy,
> Please refer to the slave-interface linux documentation:
> -----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
>> 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
>> +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.