Motivated by a series by Alain Volmat which implements SMBus Host Notify support as a slave backend[1], I wondered how I could actually test it. Then, I picked up my old idea of a "custom remote device" and implemented it as another slave backend. This is the first draft and it works quite well on my Renesas Lager board where I connected two I2C busses where both I2C controllers are master and slave. One slave is the testunit, one slave is the HostNotify listener. While I really like Alain's approach, there is still some more testing needed. So, I already release my testing environment, maybe other people are interested, too. This patch depends on a documentation update. Also, for Renesas R-Car SoCs, some fixes are needed. I suggest you simply pull this branch here: git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git renesas/i2c/slave-testunit As mentioned elsewhere, support for SMBus Alert and I2C_M_RECV_LEN are already planned. But I guess you can do much more. Ideas and comments welcome! Happy hacking, Wolfram [1] http://patchwork.ozlabs.org/project/linux-i2c/list/?series=185718&state=* Wolfram Sang (1): i2c: add slave testunit driver Documentation/i2c/slave-testunit-backend.rst | 48 ++++++ drivers/i2c/Kconfig | 8 + drivers/i2c/Makefile | 1 + drivers/i2c/i2c-slave-testunit.c | 146 +++++++++++++++++++ 4 files changed, 203 insertions(+) create mode 100644 Documentation/i2c/slave-testunit-backend.rst create mode 100644 drivers/i2c/i2c-slave-testunit.c -- 2.20.1
