Re: [PATCH v10 3/5] mfd: Add driver for RAVE Supervisory Processor

[Andrey Smirnov <andrew.smirnov@gmail.com>]

On Sun, Nov 5, 2017 at 7:38 AM, Johan Hovold <johan@kernel.org> wrote:
> On Tue, Oct 31, 2017 at 09:36:54AM -0700, Andrey Smirnov wrote:
>> Add a driver for RAVE Supervisory Processor, an MCU implementing
>> various bits of housekeeping functionality (watchdoging, backlight
>> control, LED control, etc) on RAVE family of products by Zodiac
>> Inflight Innovations.
>>
>> This driver implementes core MFD/serdev device as well as
>> communication subroutines necessary for commanding the device.
>>
>> Cc: linux-kernel@vger.kernel.org
>> Cc: cphealy@gmail.com
>> Cc: Lucas Stach <l.stach@pengutronix.de>
>> Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
>> Cc: Lee Jones <lee.jones@linaro.org>
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: Pavel Machek <pavel@ucw.cz>
>> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Rob Herring <robh@kernel.org>
>> Cc: Johan Hovold <johan@kernel.org>
>> Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
>> Tested-by: Chris Healy <cphealy@gmail.com>
>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>> ---
>
>> +int rave_sp_exec(struct rave_sp *sp,
>> +              void *__data,  size_t data_size,
>> +              void *reply_data, size_t reply_data_size)
>> +{
>> +     struct rave_sp_reply reply = {
>> +             .data     = reply_data,
>> +             .length   = reply_data_size,
>> +             .received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
>> +     };
>> +     unsigned char *data = __data;
>> +     int command, ret = 0;
>> +     u8 ackid;
>> +
>> +     command = sp->variant->cmd.translate(data[0]);
>> +     if (command < 0)
>> +             return command;
>> +
>> +     ackid       = atomic_inc_return(&sp->ackid);
>> +     reply.ackid = ackid;
>> +     reply.code  = rave_sp_reply_code((u8)command),
>> +
>> +     mutex_lock(&sp->bus_lock);
>> +
>> +     mutex_lock(&sp->reply_lock);
>> +     sp->reply = &reply;
>> +     mutex_unlock(&sp->reply_lock);
>> +
>> +     data[0] = command;
>> +     data[1] = ackid;
>> +
>> +     rave_sp_write(sp, data, data_size);
>> +
>> +     if (!wait_for_completion_timeout(&reply.received, HZ)) {
>> +             dev_err(&sp->serdev->dev, "Command timeout\n");
>> +             ret = -ETIMEDOUT;
>> +
>> +             mutex_lock(&sp->reply_lock);
>> +             sp->reply = NULL;
>> +             mutex_unlock(&sp->reply_lock);
>> +     }
>> +
>> +     mutex_unlock(&sp->bus_lock);
>> +     return ret;
>> +}
>> +EXPORT_SYMBOL(rave_sp_exec);
>
> EXPORT_SYMBOL_GPL?
>

Yep, will change in v11.

>> +static int rave_sp_receive_buf(struct serdev_device *serdev,
>> +                            const unsigned char *buf, size_t size)
>> +{
>> +     struct device *dev  = &serdev->dev;
>> +     struct rave_sp *sp = dev_get_drvdata(dev);
>> +     struct rave_sp_deframer *deframer = &sp->deframer;
>> +     const unsigned char *src = buf;
>> +     const unsigned char *end = buf + size;
>> +     bool reset_framer = false;
>> +
>> +     while (src < end) {
>> +             const unsigned char byte = *src++;
>> +
>> +             switch (deframer->state) {
>> +             case RAVE_SP_EXPECT_SOF:
>> +                     if (byte == RAVE_SP_STX)
>> +                             deframer->state = RAVE_SP_EXPECT_DATA;
>> +                     continue;
>> +
>> +             case RAVE_SP_EXPECT_DATA:
>> +                     switch (byte) {
>> +                     case RAVE_SP_ETX:
>> +                             rave_sp_receive_frame(sp,
>> +                                                   deframer->data,
>> +                                                   deframer->length);
>> +                             reset_framer = true;
>> +                             break;
>> +                     case RAVE_SP_STX:
>> +                             dev_warn(dev, "Bad frame: STX before ETX\n");
>> +                             reset_framer = true;
>> +                             break;
>> +                     case RAVE_SP_DLE:
>> +                             deframer->state = RAVE_SP_EXPECT_ESCAPED_DATA;
>> +                             continue;
>> +                     }
>> +
>> +             case RAVE_SP_EXPECT_ESCAPED_DATA: /* FALLTHROUGH */
>
> The fallthrough comment should precede the case statement (or you will
> soon receive a patch from the people working enabling
> -Wimplicit-fallthrough).
>

Sure, will change in v11.

>> +                     deframer->data[deframer->length++] = byte;
>> +
>> +                     if (deframer->length == sizeof(deframer->data)) {
>> +                             dev_warn(dev, "Bad frame: Too long\n");
>> +                             reset_framer = true;
>> +                             break;
>> +                     }
>> +
>> +                     deframer->state = RAVE_SP_EXPECT_DATA;
>> +                     break;
>> +             }
>> +     }
>> +
>> +     if (reset_framer) {
>> +             deframer->state  = RAVE_SP_EXPECT_SOF;
>> +             deframer->length = 0;
>> +     }
>> +
>> +     return src - buf;
>> +}
>
>> +MODULE_LICENSE("GPL v2");
>
> This doesn't match the license text (GPL-2.0+).
>

Will update in v11.

>> +MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
>> +MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
>> +MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
>> +MODULE_DESCRIPTION("RAVE SP core driver");
>> diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig
>> index c11db8bceea1..989d38b587bf 100644
>> --- a/drivers/platform/Kconfig
>> +++ b/drivers/platform/Kconfig
>> @@ -8,3 +8,4 @@ endif
>>  source "drivers/platform/goldfish/Kconfig"
>>
>>  source "drivers/platform/chrome/Kconfig"
>> +
>
> This chunk should not be here.
>

Missed this one. Will remove in v11.

>> diff --git a/include/linux/rave-sp.h b/include/linux/rave-sp.h
>> new file mode 100644
>> index 000000000000..811929afc1a9
>> --- /dev/null
>> +++ b/include/linux/rave-sp.h
>
> I think this one should live in include/linux/mfd/

My bad, forgot to move that file. Will do in v11.

Thanks,
Andrey Smirnov