From f4c1a8379a6d1ba39ac7b87f75d1352ef05cffff Mon Sep 17 00:00:00 2001 From: Werner Cornelius Date: Fri, 16 Jan 2009 21:02:41 +0100 Subject: [PATCH] USB: usb-serial ch341: support for DTR/RTS/CTS commit 664d5df92e88b6ef091048a802b3750f4e989180 upstream. Fixup of Werner Cornelius patch to the ch341 USB-serial driver, which adds: - support all baudrates, not just a hard-coded set - support for controlling DTR, RTS and CTS Features still missing: - character length other than 8 bits - parity settings - break control I adapted his patch for the new usb_serial API introduced in 2.6.25-git8 by Alan Cox on 22 July 2008. Non-compliance to the new API was a reason for refusing a similar patch from Tollef Fog Heen. Usage example by Tollef Fog Heen : TEMPer USB thermometer based on a patch by: From: Tollef Fog Heen * Implement support for all baud rates rather than just a hard coded set. * Make it possible to control status and control lines * Grab a bunch of #defines from FreeBSD to reduce the number of magic numbers in the file Signed-off-by: Werner Cornelius Signed-off-by: Boris Hajduk Cc: Alan Cox Signed-off-by: Tollef Fog Heen Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ch341.c | 374 ++++++++++++++++++++++++++++++------- 1 file changed, 302 insertions(+), 72 deletions(-) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index d33d39d9b7e..ab4cc277aa6 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -1,5 +1,7 @@ /* * Copyright 2007, Frank A Kingswood + * Copyright 2007, Werner Cornelius + * Copyright 2009, Boris Hajduk * * ch341.c implements a serial port driver for the Winchiphead CH341. * @@ -21,9 +23,39 @@ #include #include -#define DEFAULT_BAUD_RATE 2400 +#define DEFAULT_BAUD_RATE 9600 #define DEFAULT_TIMEOUT 1000 +/* flags for IO-Bits */ +#define CH341_BIT_RTS (1 << 6) +#define CH341_BIT_DTR (1 << 5) + +/******************************/ +/* interrupt pipe definitions */ +/******************************/ +/* always 4 interrupt bytes */ +/* first irq byte normally 0x08 */ +/* second irq byte base 0x7d + below */ +/* third irq byte base 0x94 + below */ +/* fourth irq byte normally 0xee */ + +/* second interrupt byte */ +#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */ + +/* status returned in third interrupt answer byte, inverted in data + from irq */ +#define CH341_BIT_CTS 0x01 +#define CH341_BIT_DSR 0x02 +#define CH341_BIT_RI 0x04 +#define CH341_BIT_DCD 0x08 +#define CH341_BITS_MODEM_STAT 0x0f /* all bits */ + +/*******************************/ +/* baudrate calculation factor */ +/*******************************/ +#define CH341_BAUDBASE_FACTOR 1532620800 +#define CH341_BAUDBASE_DIVMAX 3 + static int debug; static struct usb_device_id id_table [] = { @@ -34,9 +66,12 @@ static struct usb_device_id id_table [] = { MODULE_DEVICE_TABLE(usb, id_table); struct ch341_private { - unsigned baud_rate; - u8 dtr; - u8 rts; + spinlock_t lock; /* access lock */ + wait_queue_head_t delta_msr_wait; /* wait queue for modem status */ + unsigned baud_rate; /* set baud rate */ + u8 line_control; /* set line control value RTS/DTR */ + u8 line_status; /* active status of modem control inputs */ + u8 multi_status_change; /* status changed multiple since last call */ }; static int ch341_control_out(struct usb_device *dev, u8 request, @@ -72,37 +107,28 @@ static int ch341_set_baudrate(struct usb_device *dev, { short a, b; int r; + unsigned long factor; + short divisor; dbg("ch341_set_baudrate(%d)", priv->baud_rate); - switch (priv->baud_rate) { - case 2400: - a = 0xd901; - b = 0x0038; - break; - case 4800: - a = 0x6402; - b = 0x001f; - break; - case 9600: - a = 0xb202; - b = 0x0013; - break; - case 19200: - a = 0xd902; - b = 0x000d; - break; - case 38400: - a = 0x6403; - b = 0x000a; - break; - case 115200: - a = 0xcc03; - b = 0x0008; - break; - default: + + if (!priv->baud_rate) return -EINVAL; + factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate); + divisor = CH341_BAUDBASE_DIVMAX; + + while ((factor > 0xfff0) && divisor) { + factor >>= 3; + divisor--; } + if (factor > 0xfff0) + return -EINVAL; + + factor = 0x10000 - factor; + a = (factor & 0xff00) | divisor; + b = factor & 0xff; + r = ch341_control_out(dev, 0x9a, 0x1312, a); if (!r) r = ch341_control_out(dev, 0x9a, 0x0f2c, b); @@ -110,19 +136,18 @@ static int ch341_set_baudrate(struct usb_device *dev, return r; } -static int ch341_set_handshake(struct usb_device *dev, - struct ch341_private *priv) +static int ch341_set_handshake(struct usb_device *dev, u8 control) { - dbg("ch341_set_handshake(%d,%d)", priv->dtr, priv->rts); - return ch341_control_out(dev, 0xa4, - ~((priv->dtr?1<<5:0)|(priv->rts?1<<6:0)), 0); + dbg("ch341_set_handshake(0x%02x)", control); + return ch341_control_out(dev, 0xa4, ~control, 0); } -static int ch341_get_status(struct usb_device *dev) +static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv) { char *buffer; int r; const unsigned size = 8; + unsigned long flags; dbg("ch341_get_status()"); @@ -134,10 +159,15 @@ static int ch341_get_status(struct usb_device *dev) if (r < 0) goto out; - /* Not having the datasheet for the CH341, we ignore the bytes returned - * from the device. Return error if the device did not respond in time. - */ - r = 0; + /* setup the private status if available */ + if (r == 2) { + r = 0; + spin_lock_irqsave(&priv->lock, flags); + priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT; + priv->multi_status_change = 0; + spin_unlock_irqrestore(&priv->lock, flags); + } else + r = -EPROTO; out: kfree(buffer); return r; @@ -180,7 +210,7 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) goto out; /* expect 0xff 0xee */ - r = ch341_get_status(dev); + r = ch341_get_status(dev, priv); if (r < 0) goto out; @@ -192,12 +222,12 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) if (r < 0) goto out; - r = ch341_set_handshake(dev, priv); + r = ch341_set_handshake(dev, priv->line_control); if (r < 0) goto out; /* expect 0x9f 0xee */ - r = ch341_get_status(dev); + r = ch341_get_status(dev, priv); out: kfree(buffer); return r; @@ -216,9 +246,10 @@ static int ch341_attach(struct usb_serial *serial) if (!priv) return -ENOMEM; + spin_lock_init(&priv->lock); + init_waitqueue_head(&priv->delta_msr_wait); priv->baud_rate = DEFAULT_BAUD_RATE; - priv->dtr = 1; - priv->rts = 1; + priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR; r = ch341_configure(serial->dev, priv); if (r < 0) @@ -231,6 +262,35 @@ error: kfree(priv); return r; } +static void ch341_close(struct tty_struct *tty, struct usb_serial_port *port, + struct file *filp) +{ + struct ch341_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + unsigned int c_cflag; + + dbg("%s - port %d", __func__, port->number); + + /* shutdown our urbs */ + dbg("%s - shutting down urbs", __func__); + usb_kill_urb(port->write_urb); + usb_kill_urb(port->read_urb); + usb_kill_urb(port->interrupt_in_urb); + + if (tty) { + c_cflag = tty->termios->c_cflag; + if (c_cflag & HUPCL) { + /* drop DTR and RTS */ + spin_lock_irqsave(&priv->lock, flags); + priv->line_control = 0; + spin_unlock_irqrestore(&priv->lock, flags); + ch341_set_handshake(port->serial->dev, 0); + } + } + wake_up_interruptible(&priv->delta_msr_wait); +} + + /* open this device, set default parameters */ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port, struct file *filp) @@ -242,14 +302,13 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port, dbg("ch341_open()"); priv->baud_rate = DEFAULT_BAUD_RATE; - priv->dtr = 1; - priv->rts = 1; + priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR; r = ch341_configure(serial->dev, priv); if (r) goto out; - r = ch341_set_handshake(serial->dev, priv); + r = ch341_set_handshake(serial->dev, priv->line_control); if (r) goto out; @@ -257,6 +316,16 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port, if (r) goto out; + dbg("%s - submitting interrupt urb", __func__); + port->interrupt_in_urb->dev = serial->dev; + r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); + if (r) { + dev_err(&port->dev, "%s - failed submitting interrupt urb," + " error %d\n", __func__, r); + ch341_close(tty, port, NULL); + return -EPROTO; + } + r = usb_serial_generic_open(tty, port, filp); out: return r; @@ -270,38 +339,194 @@ static void ch341_set_termios(struct tty_struct *tty, { struct ch341_private *priv = usb_get_serial_port_data(port); unsigned baud_rate; + unsigned long flags; dbg("ch341_set_termios()"); + if (!tty || !tty->termios) + return; + baud_rate = tty_get_baud_rate(tty); - switch (baud_rate) { - case 2400: - case 4800: - case 9600: - case 19200: - case 38400: - case 115200: - priv->baud_rate = baud_rate; - break; - default: - dbg("Rate %d not supported, using %d", - baud_rate, DEFAULT_BAUD_RATE); - priv->baud_rate = DEFAULT_BAUD_RATE; + priv->baud_rate = baud_rate; + + if (baud_rate) { + spin_lock_irqsave(&priv->lock, flags); + priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS); + spin_unlock_irqrestore(&priv->lock, flags); + ch341_set_baudrate(port->serial->dev, priv); + } else { + spin_lock_irqsave(&priv->lock, flags); + priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS); + spin_unlock_irqrestore(&priv->lock, flags); } - ch341_set_baudrate(port->serial->dev, priv); + ch341_set_handshake(port->serial->dev, priv->line_control); /* Unimplemented: * (cflag & CSIZE) : data bits [5, 8] * (cflag & PARENB) : parity {NONE, EVEN, ODD} * (cflag & CSTOPB) : stop bits [1, 2] */ +} + +static int ch341_tiocmset(struct tty_struct *tty, struct file *file, + unsigned int set, unsigned int clear) +{ + struct usb_serial_port *port = tty->driver_data; + struct ch341_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + u8 control; + + spin_lock_irqsave(&priv->lock, flags); + if (set & TIOCM_RTS) + priv->line_control |= CH341_BIT_RTS; + if (set & TIOCM_DTR) + priv->line_control |= CH341_BIT_DTR; + if (clear & TIOCM_RTS) + priv->line_control &= ~CH341_BIT_RTS; + if (clear & TIOCM_DTR) + priv->line_control &= ~CH341_BIT_DTR; + control = priv->line_control; + spin_unlock_irqrestore(&priv->lock, flags); + + return ch341_set_handshake(port->serial->dev, control); +} + +static void ch341_read_int_callback(struct urb *urb) +{ + struct usb_serial_port *port = (struct usb_serial_port *) urb->context; + unsigned char *data = urb->transfer_buffer; + unsigned int actual_length = urb->actual_length; + int status; + + dbg("%s (%d)", __func__, port->number); + + switch (urb->status) { + case 0: + /* success */ + break; + case -ECONNRESET: + case -ENOENT: + case -ESHUTDOWN: + /* this urb is terminated, clean up */ + dbg("%s - urb shutting down with status: %d", __func__, + urb->status); + return; + default: + dbg("%s - nonzero urb status received: %d", __func__, + urb->status); + goto exit; + } + + usb_serial_debug_data(debug, &port->dev, __func__, + urb->actual_length, urb->transfer_buffer); + + if (actual_length >= 4) { + struct ch341_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + + spin_lock_irqsave(&priv->lock, flags); + priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT; + if ((data[1] & CH341_MULT_STAT)) + priv->multi_status_change = 1; + spin_unlock_irqrestore(&priv->lock, flags); + wake_up_interruptible(&priv->delta_msr_wait); + } + +exit: + status = usb_submit_urb(urb, GFP_ATOMIC); + if (status) + dev_err(&urb->dev->dev, + "%s - usb_submit_urb failed with result %d\n", + __func__, status); +} + +static int wait_modem_info(struct usb_serial_port *port, unsigned int arg) +{ + struct ch341_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + u8 prevstatus; + u8 status; + u8 changed; + u8 multi_change = 0; + + spin_lock_irqsave(&priv->lock, flags); + prevstatus = priv->line_status; + priv->multi_status_change = 0; + spin_unlock_irqrestore(&priv->lock, flags); + + while (!multi_change) { + interruptible_sleep_on(&priv->delta_msr_wait); + /* see if a signal did it */ + if (signal_pending(current)) + return -ERESTARTSYS; + + spin_lock_irqsave(&priv->lock, flags); + status = priv->line_status; + multi_change = priv->multi_status_change; + spin_unlock_irqrestore(&priv->lock, flags); + + changed = prevstatus ^ status; + + if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) || + ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) || + ((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) || + ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) { + return 0; + } + prevstatus = status; + } + + return 0; +} + +/*static int ch341_ioctl(struct usb_serial_port *port, struct file *file,*/ +static int ch341_ioctl(struct tty_struct *tty, struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct usb_serial_port *port = tty->driver_data; + dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd); + + switch (cmd) { + case TIOCMIWAIT: + dbg("%s (%d) TIOCMIWAIT", __func__, port->number); + return wait_modem_info(port, arg); + + default: + dbg("%s not supported = 0x%04x", __func__, cmd); + break; + } + + return -ENOIOCTLCMD; +} + +static int ch341_tiocmget(struct tty_struct *tty, struct file *file) +{ + struct usb_serial_port *port = tty->driver_data; + struct ch341_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + u8 mcr; + u8 status; + unsigned int result; + + dbg("%s (%d)", __func__, port->number); + + spin_lock_irqsave(&priv->lock, flags); + mcr = priv->line_control; + status = priv->line_status; + spin_unlock_irqrestore(&priv->lock, flags); + + result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0) + | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0) + | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0) + | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0) + | ((status & CH341_BIT_RI) ? TIOCM_RI : 0) + | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0); + + dbg("%s - result = %x", __func__, result); - /* Copy back the old hardware settings */ - tty_termios_copy_hw(tty->termios, old_termios); - /* And re-encode with the new baud */ - tty_encode_baud_rate(tty, baud_rate, baud_rate); + return result; } @@ -339,12 +564,17 @@ static struct usb_serial_driver ch341_device = { .owner = THIS_MODULE, .name = "ch341-uart", }, - .id_table = id_table, - .usb_driver = &ch341_driver, - .num_ports = 1, - .open = ch341_open, - .set_termios = ch341_set_termios, - .attach = ch341_attach, + .id_table = id_table, + .usb_driver = &ch341_driver, + .num_ports = 1, + .open = ch341_open, + .close = ch341_close, + .ioctl = ch341_ioctl, + .set_termios = ch341_set_termios, + .tiocmget = ch341_tiocmget, + .tiocmset = ch341_tiocmset, + .read_int_callback = ch341_read_int_callback, + .attach = ch341_attach, }; static int __init ch341_init(void) -- 2.20.1