FreeCalypso > hg > freecalypso-hwlab
view linux-patch/orig-202007/ftdi_sio.c.patch @ 176:fb2f6497ba53 default tip
doc/Linux-DTR-RTS-flaw: point to new location of this article
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Dec 2023 19:37:20 +0000 |
parents | e2161ac7d641 |
children |
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--- ftdi_sio.c.orig 2016-06-24 09:18:38.000000000 -0800 +++ ftdi_sio.c 2020-07-28 15:33:04.022945400 -0800 @@ -73,6 +73,8 @@ 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; @@ -83,15 +85,19 @@ struct ftdi_sio_quirk { int (*probe)(struct usb_serial *); /* Special settings for probed ports. */ - void (*port_probe)(struct ftdi_private *); + void (*port_probe)(struct usb_serial_port *, struct ftdi_private *); }; static int ftdi_jtag_probe(struct usb_serial *serial); static int ftdi_NDI_device_setup(struct usb_serial *serial); 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 ftdi_private *priv); -static void ftdi_HE_TIRA1_setup(struct ftdi_private *priv); +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 struct ftdi_sio_quirk ftdi_jtag_quirk = { .probe = ftdi_jtag_probe, @@ -117,6 +123,10 @@ .probe = ftdi_8u2232c_probe, }; +static 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: @@ -1008,6 +1018,13 @@ { USB_DEVICE(ICPDAS_VID, ICPDAS_I7560U_PID) }, { USB_DEVICE(ICPDAS_VID, ICPDAS_I7561U_PID) }, { USB_DEVICE(ICPDAS_VID, ICPDAS_I7563U_PID) }, + /* FreeCalypso USB adapters */ + { USB_DEVICE(FTDI_VID, FTDI_FALCONIA_JTAG_BUF_PID), + .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 */ }; @@ -1804,7 +1821,7 @@ priv->flags = ASYNC_LOW_LATENCY; if (quirk && quirk->port_probe) - quirk->port_probe(priv); + quirk->port_probe(port, priv); usb_set_serial_port_data(port, priv); @@ -1820,7 +1837,8 @@ /* Setup for the USB-UIRT device, which requires hardwired * baudrate (38400 gets mapped to 312500) */ /* Called from usbserial:serial_probe */ -static void ftdi_USB_UIRT_setup(struct ftdi_private *priv) +static void ftdi_USB_UIRT_setup(struct usb_serial_port *port, + struct ftdi_private *priv) { priv->flags |= ASYNC_SPD_CUST; priv->custom_divisor = 77; @@ -1830,7 +1848,8 @@ /* Setup for the HE-TIRA1 device, which requires hardwired * baudrate (38400 gets mapped to 100000) and RTS-CTS enabled. */ -static void ftdi_HE_TIRA1_setup(struct ftdi_private *priv) +static void ftdi_HE_TIRA1_setup(struct usb_serial_port *port, + struct ftdi_private *priv) { priv->flags |= ASYNC_SPD_CUST; priv->custom_divisor = 240; @@ -1926,6 +1945,37 @@ 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); @@ -1976,9 +2026,10 @@ } } /* 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); } @@ -2316,7 +2367,8 @@ 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); }