| Message ID | 20200916015644.B89E1374026F@freecalypso.org |
|---|---|
| State | New |
| Headers | show |
| Series | a family of FTDI-based devices that need ftdi_sio quirks | expand |
On Wed, Sep 16, 2020 at 01:56:44AM +0000, Mychaela N. Falconia wrote: > FreeCalypso DUART28C is an FT2232D-based USB to dual UART adapter > with a special quirk: Channel B RTS and DTR outputs (BDBUS2 and BDBUS4 > on the chip) have been repurposed to drive power and reset controls > on Calypso targets. The circuit is wired such that BDBUS[24] high > (RTS/DTR inactive) is the normal state with power/reset control > NOT activated, whereas BDBUS[24] low (RTS or DTR active) turn ON > the corresponding power/reset control drivers. > > A special ftdi_sio driver quirk is needed in order to suppress > automatic assertion of DTR & RTS on device open: this device's > special power and reset control drivers MUST NOT be activated > when the port is ordinarily opened for plain serial communication, > instead they must only be activated when a special userspace > application explicitly requests such activation with a TIOCMBIS ioctl. > > The special quirk is conditionalized on the DUART28C adapter's custom > USB ID, and is further limited to FT2232D Channel B only: Channel A > is wired normally, with the chip's ADBUS2 and ADBUS4 outputs > actually being RTS and DTR rather than something else. > > Signed-off-by: Mychaela N. Falconia <falcon@freecalypso.org> > --- > drivers/usb/serial/ftdi_sio.c | 51 +++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 47 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c > index cdf4f4e05fb2..73c6b4e2c3e4 100644 > --- a/drivers/usb/serial/ftdi_sio.c > +++ b/drivers/usb/serial/ftdi_sio.c > @@ -69,6 +69,8 @@ struct ftdi_private { > this value */ > int force_rtscts; /* if non-zero, force RTS-CTS to always > be enabled */ > + int no_auto_dtr_rts; /* if non-zero, suppress automatic assertion > + of DTR & RTS on device open */ > > unsigned int latency; /* latency setting in use */ > unsigned short max_packet_size; > @@ -99,6 +101,8 @@ static void ftdi_USB_UIRT_setup(struct usb_serial_port *port, > struct ftdi_private *priv); > static void ftdi_HE_TIRA1_setup(struct usb_serial_port *port, > struct ftdi_private *priv); > +static void ftdi_duart28c_setup(struct usb_serial_port *port, > + struct ftdi_private *priv); > > static const struct ftdi_sio_quirk ftdi_jtag_quirk = { > .probe = ftdi_jtag_probe, > @@ -124,6 +128,10 @@ static const struct ftdi_sio_quirk ftdi_8u2232c_quirk = { > .probe = ftdi_8u2232c_probe, > }; > > +static const struct ftdi_sio_quirk ftdi_duart28c_quirk = { > + .port_probe = ftdi_duart28c_setup, > +}; > + > /* > * The 8U232AM has the same API as the sio except for: > * - it can support MUCH higher baudrates; up to: > @@ -1044,6 +1052,8 @@ static const struct usb_device_id id_table_combined[] = { > .driver_info = (kernel_ulong_t)&ftdi_jtag_quirk }, > { USB_DEVICE(FTDI_VID, FTDI_FALCONIA_JTAG_UNBUF_PID), > .driver_info = (kernel_ulong_t)&ftdi_jtag_quirk }, > + { USB_DEVICE(FTDI_VID, FTDI_FALCONIA_DUART28C_PID), > + .driver_info = (kernel_ulong_t)&ftdi_duart28c_quirk }, Make sure that this patch adds the dual-port PID define as well. > { } /* Terminating entry */ > }; > > @@ -2388,6 +2398,37 @@ static int ftdi_stmclite_probe(struct usb_serial *serial) > return 0; > } > > +/* > + * FreeCalypso DUART28C is an FT2232D-based USB to dual UART adapter > + * with a special quirk: Channel B RTS and DTR outputs (BDBUS2 and BDBUS4 > + * on the chip) have been repurposed to drive power and reset controls > + * on Calypso targets. The circuit is wired such that BDBUS[24] high > + * (RTS/DTR inactive) is the normal state with power/reset control > + * NOT activated, whereas BDBUS[24] low (RTS or DTR active) turn ON > + * the corresponding power/reset control drivers. > + * > + * A special ftdi_sio driver quirk is needed in order to suppress > + * automatic assertion of DTR & RTS on device open: this device's > + * special power and reset control drivers MUST NOT be activated > + * when the port is ordinarily opened for plain serial communication, > + * instead they must only be activated when a special userspace > + * application explicitly requests such activation with a TIOCMBIS ioctl. > + * > + * The special quirk must be applied only to FT2232D Channel B: > + * Channel A is wired normally, with the chip's ADBUS2 and ADBUS4 outputs > + * actually being RTS and DTR rather than something else. > + */ > +static void ftdi_duart28c_setup(struct usb_serial_port *port, > + struct ftdi_private *priv) > +{ > + struct usb_serial *serial = port->serial; > + struct usb_device *udev = serial->dev; > + struct usb_interface *interface = serial->interface; > + > + if (interface == udev->actconfig->interface[1]) Driver's shouldn't rely on the order of these pointers. I've prepared a patch to fix up the other instances in this driver, and please use bNumInterfaces here as well. > + priv->no_auto_dtr_rts = 1; > +} > + > static int ftdi_sio_port_remove(struct usb_serial_port *port) > { > struct ftdi_private *priv = usb_get_serial_port_data(port); > @@ -2440,9 +2481,10 @@ static void ftdi_dtr_rts(struct usb_serial_port *port, int on) > } > } > /* drop RTS and DTR */ > - if (on) > - set_mctrl(port, TIOCM_DTR | TIOCM_RTS); > - else > + if (on) { > + if (!priv->no_auto_dtr_rts) > + set_mctrl(port, TIOCM_DTR | TIOCM_RTS); > + } else > clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); If we are to add this, then you shouldn't allow for automatic deassert either. > } > > @@ -2790,7 +2832,8 @@ static void ftdi_set_termios(struct tty_struct *tty, > dev_err(ddev, "%s urb failed to set baudrate\n", __func__); > mutex_unlock(&priv->cfg_lock); > /* Ensure RTS and DTR are raised when baudrate changed from 0 */ > - if (old_termios && (old_termios->c_cflag & CBAUD) == B0) > + if (old_termios && (old_termios->c_cflag & CBAUD) == B0 > + && !priv->no_auto_dtr_rts) > set_mctrl(port, TIOCM_DTR | TIOCM_RTS); Same here. > } And then there's CRTSCTS of course... Johan
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index cdf4f4e05fb2..73c6b4e2c3e4 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -69,6 +69,8 @@ struct ftdi_private { this value */ int force_rtscts; /* if non-zero, force RTS-CTS to always be enabled */ + int no_auto_dtr_rts; /* if non-zero, suppress automatic assertion + of DTR & RTS on device open */ unsigned int latency; /* latency setting in use */ unsigned short max_packet_size; @@ -99,6 +101,8 @@ static void ftdi_USB_UIRT_setup(struct usb_serial_port *port, struct ftdi_private *priv); static void ftdi_HE_TIRA1_setup(struct usb_serial_port *port, struct ftdi_private *priv); +static void ftdi_duart28c_setup(struct usb_serial_port *port, + struct ftdi_private *priv); static const struct ftdi_sio_quirk ftdi_jtag_quirk = { .probe = ftdi_jtag_probe, @@ -124,6 +128,10 @@ static const struct ftdi_sio_quirk ftdi_8u2232c_quirk = { .probe = ftdi_8u2232c_probe, }; +static const struct ftdi_sio_quirk ftdi_duart28c_quirk = { + .port_probe = ftdi_duart28c_setup, +}; + /* * The 8U232AM has the same API as the sio except for: * - it can support MUCH higher baudrates; up to: @@ -1044,6 +1052,8 @@ static const struct usb_device_id id_table_combined[] = { .driver_info = (kernel_ulong_t)&ftdi_jtag_quirk }, { USB_DEVICE(FTDI_VID, FTDI_FALCONIA_JTAG_UNBUF_PID), .driver_info = (kernel_ulong_t)&ftdi_jtag_quirk }, + { USB_DEVICE(FTDI_VID, FTDI_FALCONIA_DUART28C_PID), + .driver_info = (kernel_ulong_t)&ftdi_duart28c_quirk }, { } /* Terminating entry */ }; @@ -2388,6 +2398,37 @@ static int ftdi_stmclite_probe(struct usb_serial *serial) return 0; } +/* + * FreeCalypso DUART28C is an FT2232D-based USB to dual UART adapter + * with a special quirk: Channel B RTS and DTR outputs (BDBUS2 and BDBUS4 + * on the chip) have been repurposed to drive power and reset controls + * on Calypso targets. The circuit is wired such that BDBUS[24] high + * (RTS/DTR inactive) is the normal state with power/reset control + * NOT activated, whereas BDBUS[24] low (RTS or DTR active) turn ON + * the corresponding power/reset control drivers. + * + * A special ftdi_sio driver quirk is needed in order to suppress + * automatic assertion of DTR & RTS on device open: this device's + * special power and reset control drivers MUST NOT be activated + * when the port is ordinarily opened for plain serial communication, + * instead they must only be activated when a special userspace + * application explicitly requests such activation with a TIOCMBIS ioctl. + * + * The special quirk must be applied only to FT2232D Channel B: + * Channel A is wired normally, with the chip's ADBUS2 and ADBUS4 outputs + * actually being RTS and DTR rather than something else. + */ +static void ftdi_duart28c_setup(struct usb_serial_port *port, + struct ftdi_private *priv) +{ + struct usb_serial *serial = port->serial; + struct usb_device *udev = serial->dev; + struct usb_interface *interface = serial->interface; + + if (interface == udev->actconfig->interface[1]) + priv->no_auto_dtr_rts = 1; +} + static int ftdi_sio_port_remove(struct usb_serial_port *port) { struct ftdi_private *priv = usb_get_serial_port_data(port); @@ -2440,9 +2481,10 @@ static void ftdi_dtr_rts(struct usb_serial_port *port, int on) } } /* drop RTS and DTR */ - if (on) - set_mctrl(port, TIOCM_DTR | TIOCM_RTS); - else + if (on) { + if (!priv->no_auto_dtr_rts) + set_mctrl(port, TIOCM_DTR | TIOCM_RTS); + } else clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); } @@ -2790,7 +2832,8 @@ static void ftdi_set_termios(struct tty_struct *tty, dev_err(ddev, "%s urb failed to set baudrate\n", __func__); mutex_unlock(&priv->cfg_lock); /* Ensure RTS and DTR are raised when baudrate changed from 0 */ - if (old_termios && (old_termios->c_cflag & CBAUD) == B0) + if (old_termios && (old_termios->c_cflag & CBAUD) == B0 + && !priv->no_auto_dtr_rts) set_mctrl(port, TIOCM_DTR | TIOCM_RTS); }
FreeCalypso DUART28C is an FT2232D-based USB to dual UART adapter with a special quirk: Channel B RTS and DTR outputs (BDBUS2 and BDBUS4 on the chip) have been repurposed to drive power and reset controls on Calypso targets. The circuit is wired such that BDBUS[24] high (RTS/DTR inactive) is the normal state with power/reset control NOT activated, whereas BDBUS[24] low (RTS or DTR active) turn ON the corresponding power/reset control drivers. A special ftdi_sio driver quirk is needed in order to suppress automatic assertion of DTR & RTS on device open: this device's special power and reset control drivers MUST NOT be activated when the port is ordinarily opened for plain serial communication, instead they must only be activated when a special userspace application explicitly requests such activation with a TIOCMBIS ioctl. The special quirk is conditionalized on the DUART28C adapter's custom USB ID, and is further limited to FT2232D Channel B only: Channel A is wired normally, with the chip's ADBUS2 and ADBUS4 outputs actually being RTS and DTR rather than something else. Signed-off-by: Mychaela N. Falconia <falcon@freecalypso.org> --- drivers/usb/serial/ftdi_sio.c | 51 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 47 insertions(+), 4 deletions(-)