[PATCH v9 4/5] i2c: aspeed: added driver for Aspeed I2C

[Brendan Higgins]

On Fri, Jun 2, 2017 at 5:02 AM, Benjamin Herrenschmidt
<benh at kernel.crashing.org> wrote:
> On Fri, 2017-06-02 at 01:46 -0700, Brendan Higgins wrote:
>> Added initial master support for Aspeed I2C controller. Supports
>> fourteen busses present in AST24XX and AST25XX BMC SoCs by Aspeed.
>>
>> Signed-off-by: Brendan Higgins <brendanhiggins at google.com>
>
> Reviewed-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> ---
>
> Just spotted a completely minor/tivial nit:
>
>> +static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
>> +                               struct i2c_msg *msgs, int num)
>> +{
>> +     struct aspeed_i2c_bus *bus = adap->algo_data;
>> +     unsigned long time_left, flags;
>> +     int ret = 0;
>> +
>> +     spin_lock_irqsave(&bus->lock, flags);
>> +     bus->cmd_err = 0;
>         ^^^^^^^^^^^^^^^^^
>
> This is probably unnecessary now since it's initialized further down.

Nope, reset uses cmd_err as well. Maybe reset should initialize it? Not sure.

>
>> +     /* If bus is busy, attempt recovery. We assume a single master
>> +      * environment.
>> +      */
>> +     if (readl(bus->base + ASPEED_I2C_CMD_REG) & ASPEED_I2CD_BUS_BUSY_STS) {
>> +             spin_unlock_irqrestore(&bus->lock, flags);
>> +             ret = aspeed_i2c_recover_bus(bus);
>> +             if (ret)
>> +                     return ret;
>> +             spin_lock_irqsave(&bus->lock, flags);
>> +     }
>> +
>> +     bus->cmd_err = 0;
>> +     bus->msgs = msgs;
>> +     bus->msgs_index = 0;
>> +     bus->msgs_count = num;
>
> Now I'd like Andrew to give it a spin as he's currently
> testing/debugging some i2c related stuff to be 100% certain it works
> fine on our systems.

If you haven't done this yet, you should try version 10 instead.