FreeCalypso > hg > freecalypso-hwlab
view linux-patch/minpatch-4.9.240/0003-USB-serial-ftdi_sio-add-support-for-FreeCalypso-DUAR.patch @ 124:6c4567dd8946
fc-simtool: add non-interactive one-shot command (or script) mode
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Thu, 28 Jan 2021 18:56:34 +0000 |
parents | d7a1e7a6d6ba |
children |
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From 8edb5017764d4ad9d90a631c420caca41827cd6e Mon Sep 17 00:00:00 2001 From: "Mychaela N. Falconia" <falcon@freecalypso.org> Date: Fri, 2 Oct 2020 18:01:12 +0000 Subject: [PATCH 3/3] USB: serial: ftdi_sio: add support for FreeCalypso DUART28C adapter 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 PWON and RESET controls on Calypso targets. The circuit is wired such that BDBUS[24] high (RTS/DTR inactive) is the normal state with Iota VRPC controls NOT activated, whereas BDBUS[24] low (RTS or DTR active) turn ON the corresponding open drain control signal 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 PWON 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. These special userspace applications are responsible for making the needed pulse with a TIOCMBIS, delay, TIOCMBIC sequence. 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 | 61 +++++++++++++++++++++++++++++++++++---- drivers/usb/serial/ftdi_sio_ids.h | 1 + 2 files changed, 57 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 878ab4e5625c..443aee847556 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -73,6 +73,8 @@ 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; @@ -92,6 +94,7 @@ static int ftdi_stmclite_probe(struct usb_serial *serial); static int ftdi_8u2232c_probe(struct usb_serial *serial); static void ftdi_USB_UIRT_setup(struct usb_serial_port *port); static void ftdi_HE_TIRA1_setup(struct usb_serial_port *port); +static void ftdi_duart28c_setup(struct usb_serial_port *port); static const struct ftdi_sio_quirk ftdi_jtag_quirk = { .probe = ftdi_jtag_probe, @@ -117,6 +120,10 @@ 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: @@ -1037,6 +1044,8 @@ 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 */ }; @@ -1961,6 +1970,39 @@ 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 PWON and RESET controls + * on Calypso targets. The circuit is wired such that BDBUS[24] high + * (RTS/DTR inactive) is the normal state with Iota VRPC controls + * NOT activated, whereas BDBUS[24] low (RTS or DTR active) turn ON + * the corresponding open drain control signal 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 PWON 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. + * These special userspace applications are responsible for making the + * needed pulse with a TIOCMBIS, delay, TIOCMBIC sequence. + * + * 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 = usb_get_serial_port_data(port); + struct usb_serial *serial = port->serial; + struct usb_interface *intf = serial->interface; + int ifnum = intf->cur_altsetting->desc.bInterfaceNumber; + + if (ifnum == 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); @@ -2010,10 +2052,18 @@ static void ftdi_dtr_rts(struct usb_serial_port *port, int on) dev_err(&port->dev, "error from flowcontrol urb\n"); } } - /* drop RTS and DTR */ - if (on) - set_mctrl(port, TIOCM_DTR | TIOCM_RTS); - else + /* + * Assert or negate RTS and DTR as requested. When DUART28C + * quirk is applied, we suppress automatic assertion, but + * automatic negation on device close is retained - these + * special control signals are meant to be pulsed, and leaving + * either of them stuck on when the responsible userspace + * program has terminated unexpectedly is undesirable. + */ + if (on) { + if (!priv->no_auto_dtr_rts) + set_mctrl(port, TIOCM_DTR | TIOCM_RTS); + } else clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); } @@ -2355,7 +2405,8 @@ 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); } diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h index f3302516a1e4..f756b80cb361 100644 --- a/drivers/usb/serial/ftdi_sio_ids.h +++ b/drivers/usb/serial/ftdi_sio_ids.h @@ -44,6 +44,7 @@ */ #define FTDI_FALCONIA_JTAG_BUF_PID 0x7150 #define FTDI_FALCONIA_JTAG_UNBUF_PID 0x7151 +#define FTDI_FALCONIA_DUART28C_PID 0x7152 /* Sienna Serial Interface by Secyourit GmbH */ #define FTDI_SIENNA_PID 0x8348 -- 2.9.0