[PATCH v5 1/2] i2c: aspeed: added driver for Aspeed I2C

Brendan Higgins brendanhiggins at google.com
Tue Mar 28 16:23:29 AEDT 2017

>> >>  + /* Switch from master mode to slave mode. */
>> >>  + func_ctrl_reg_val = aspeed_i2c_read(bus, ASPEED_I2C_FUN_CTRL_REG);
>> >>  + func_ctrl_reg_val &= ~ASPEED_I2CD_MASTER_EN;
>> >>  + func_ctrl_reg_val |= ASPEED_I2CD_SLAVE_EN;
>> >>  + aspeed_i2c_write(bus, func_ctrl_reg_val, ASPEED_I2C_FUN_CTRL_REG);
>> >
>> > Can't the hardware work both as master and slave on the same bus?
>> The hardware can work as master and slave on the same bus. This is how IPMB over i2c works on Aspeed.

I no longer disable master when a slave is registered. I was concerned
about adding multimaster support because I don't think it will play
nicely with bus recovery; should we maybe provide a device tree option
to turn multimaster support on which will disable bus recovery, since
someone else might be using it?

> Thanks! Then the driver should support this. Maybe it is an idea to
> first upstream the master support and add the slave support
> incrementally?

Yeah, probably a good idea. Slave support is now added in

> Regards,
>    Wolfram

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