Hi Johan, On Sun, 24 Apr 2016 15:36:35 +0200 Johan Hovold <[email protected]> wrote:
> On Mon, Feb 29, 2016 at 04:11:20PM +0300, Maksim Salau wrote: > > The adaptor can be found on development boards for 78k, RL78 and V850 > > microcontrollers produced by Renesas Electronics Corporation. > > > > This is not a full-featured USB to serial converter, however it allows > > basic communication and simple control which is enough for programming of > > on-board flash and debugging through a debug monitor. > > > > uPD78F0730 is a USB-enabled microcontroller with USB-to-UART conversion > > implemented in firmware. > > > > This chip is also present in some debugging adaptors which use it for > > USB-to-SPI conversion as well. The present driver doesn't cover SPI, > > only USB-to-UART conversion is supported. > > > > Signed-off-by: Maksim Salau <[email protected]> > > --- > > Thanks for submitting this driver, and sorry for the late review. The > code looks nice and clean, but I have some comments below. > Thank you for feedback. > > +/* Control signal bits in UPD78F0730_CMD_SET_DTR_RTS command */ > > +#define UPD78F0730_RESET_RTS 0x01 > > +#define UPD78F0730_RESET_DTR 0x02 > > Why are these named RESET? Looks like you use these bits to assert the > signals when reading the datasheet. > Indeed, it turned out that RTS and DTR signals are inverted: upd78f0730 has active-high levels, while others have active-low levels. To match others I added inversion. May be it'll be a good idea to make inversion optional by adding a module parameter. > > + if (cflag & CRTSCTS) { > > + dev_err(dev, "%s - hardware flow control is not supported\n", > > + __func__); > > dev_warn and clear the setting in termios. > > Looks like the device does support it though? There are means to enable it on protocol layer, but the CTS pin is not present. I doubt if any flow control will ever be used with the adaptor. I can add support for hardware flow control, but which flow control type should prevail if both are enabled? Only one flow control type can be enabled at a time according to the datasheet. Also I'm not sure if software flow control will be useful in the adaptor itself (due to small on-chip buffer size), software flow control implemented in a host can be more effective. Thanks, Maksim. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
