[PATCH v3 1/3] ipmi: add an Aspeed BT IPMI BMC driver

[Rob Herring]

On Tue, Sep 20, 2016 at 09:01:38AM +0200, Cédric Le Goater wrote:
> From: Alistair Popple <alistair at popple.id.au>
> 
> This patch adds a simple device driver to expose the iBT interface on
> Aspeed SOCs (AST2400 and AST2500) as a character device. Such SOCs are
> commonly used as BMCs (BaseBoard Management Controllers) and this
> driver implements the BMC side of the BT interface.
> 
> The BT (Block Transfer) interface is used to perform in-band IPMI
> communication between a host and its BMC. Entire messages are buffered
> before sending a notification to the other end, host or BMC, that
> there is data to be read. Usually, the host emits requests and the BMC
> responses but the specification provides a mean for the BMC to send
> SMS Attention (BMC-to-Host attention or System Management Software
> attention) messages.
> 
> For this purpose, the driver introduces a specific ioctl on the
> device: 'BT_BMC_IOCTL_SMS_ATN' that can be used by the system running
> on the BMC to signal the host of such an event.
> 
> The device name defaults to '/dev/ipmi-bt-host'
> 
> Signed-off-by: Alistair Popple <alistair at popple.id.au>
> Signed-off-by: Jeremy Kerr <jk at ozlabs.org>
> Signed-off-by: Joel Stanley <joel at jms.id.au>
> [clg: - checkpatch fixes
>       - added a devicetree binding documentation
>       - replace 'bt_host' by 'bt_bmc' to reflect that the driver is
>         the BMC side of the IPMI BT interface
>       - renamed the device to 'ipmi-bt-host'
>       - introduced a temporary buffer to copy_{to,from}_user
>       - used platform_get_irq()
>       - moved the driver under drivers/char/ipmi/ but kept it as a misc
>         device
>       - changed the compatible cell to "aspeed,ast2400-bt-bmc"
> ]
> Signed-off-by: Cédric Le Goater <clg at kaod.org>
> Acked-by: Arnd Bergmann <arnd at arndb.de>
> [clg: - checkpatch --strict fixes
>       - removed the use of devm_iounmap, devm_kfree in cleanup paths
>       - introduced an atomic-t to limit opens to 1
>       - introduced a mutex to protect write/read operations]
> Signed-off-by: Cédric Le Goater <clg at kaod.org>
> 
> ---
> 
>  Changes since v2:
> 
>  - fixed checkpatch --strict issues
>  - cleanup'ed includes
>  - limit to one opener
>  - protect write/read operations with a mutex.
>  - removed the use of devm_iounmap, devm_kfree in cleanup paths
> 
>  Changes since v1:
> 
>  - replace 'bt_host' by 'bt_bmc' to reflect that the driver is
>    the BMC side of the IPMI BT interface
>  - renamed the device to 'ipmi-bt-host'
>  - introduced a temporary buffer to copy_{to,from}_user
>  - used platform_get_irq()
>  - moved the driver under drivers/char/ipmi/ but kept it as a misc
>    device
>  - changed the compatible cell to "aspeed,ast2400-bt-bmc"
> 
>  .../bindings/char/ipmi/aspeed,ast2400-bt-bmc.txt   |  23 +

While similar, this is not the kernel directory structure. Just make 
this bindings/ipmi/

With that,

Acked-by: Rob Herring <robh at kernel.org>

>  drivers/Makefile                                   |   2 +-
>  drivers/char/ipmi/Kconfig                          |   7 +
>  drivers/char/ipmi/Makefile                         |   1 +
>  drivers/char/ipmi/bt-bmc.c                         | 510 +++++++++++++++++++++
>  include/uapi/linux/Kbuild                          |   1 +
>  include/uapi/linux/bt-bmc.h                        |  18 +
>  7 files changed, 561 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/char/ipmi/aspeed,ast2400-bt-bmc.txt
>  create mode 100644 drivers/char/ipmi/bt-bmc.c
>  create mode 100644 include/uapi/linux/bt-bmc.h