[PATCH] Winchiphead CH340/1: support modem control and status lines, more baudrates - Kernel

This is a discussion on [PATCH] Winchiphead CH340/1: support modem control and status lines, more baudrates - Kernel ; Patch against current git as of last night (so 2.6.26). * Add support for all baudrates, not just a hard coded set. * Make it possible to control modem control and status lines. Signed-off-by: Tollef Fog Heen --- This is ...

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Thread: [PATCH] Winchiphead CH340/1: support modem control and status lines, more baudrates

  1. [PATCH] Winchiphead CH340/1: support modem control and status lines, more baudrates


    Patch against current git as of last night (so 2.6.26).

    * Add support for all baudrates, not just a hard coded set.
    * Make it possible to control modem control and status lines.

    Signed-off-by: Tollef Fog Heen

    ---

    This is a cleanup of Werner Conelius' patch in
    http://kerneltrap.org/mailarchive/li...07/9/21/265323 which
    should be more acceptable to mainline. Feel free to put him as author
    rather than me.

    diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
    index 1f7c86b..d233146 100644
    --- a/drivers/usb/serial/ch341.c
    +++ b/drivers/usb/serial/ch341.c
    @@ -1,5 +1,6 @@
    /*
    * Copyright 2007, Frank A Kingswood
    + * Copyright 2007, Werner Cornelius cornelius-consult.de>
    *
    * ch341.c implements a serial port driver for the Winchiphead CH341.
    *
    @@ -24,6 +25,36 @@
    #define DEFAULT_BAUD_RATE 2400
    #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 +65,12 @@ 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 +106,28 @@ 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 +135,18 @@ 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 +158,15 @@ 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 +209,7 @@ 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 +221,12 @@ 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 +245,10 @@ 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 +261,34 @@ error: kfree(priv);
    return r;
    }

    +static void ch341_close(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 (port->tty) {
    + c_cflag = port->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 usb_serial_port *port, struct file *filp)
    {
    @@ -241,14 +299,13 @@ static int ch341_open(struct usb_serial_port *port, struct file *filp)
    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;

    @@ -256,6 +313,16 @@ static int ch341_open(struct usb_serial_port *port, struct file *filp)
    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(port, NULL);
    + return -EPROTO;
    + }
    +
    r = usb_serial_generic_open(port, filp);

    out: return r;
    @@ -270,38 +337,190 @@ static void ch341_set_termios(struct usb_serial_port *port,
    struct ch341_private *priv = usb_get_serial_port_data(port);
    struct tty_struct *tty = port->tty;
    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 usb_serial_port *port, struct file *file,
    + unsigned int set, unsigned int clear)
    +{
    + 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,
    + unsigned int cmd, unsigned long arg)
    +{
    + 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 usb_serial_port *port, struct file *file)
    +{
    + 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;
    }

    static struct usb_driver ch341_driver = {
    @@ -317,12 +536,20 @@ 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_interrupt_in = 1,
    + .num_bulk_in = 1,
    + .num_bulk_out = 1,
    + .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)


    --
    Tollef Fog Heen
    UNIX is user friendly, it's just picky about who its friends are
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  2. Re: [PATCH] Winchiphead CH340/1: support modem control and status lines, more baudrates

    On 22/07/08 08:18, Tollef Fog Heen wrote:
    > Patch against current git as of last night (so 2.6.26).
    >
    > * Add support for all baudrates, not just a hard coded set.
    > * Make it possible to control modem control and status lines.
    >
    > Signed-off-by: Tollef Fog Heen
    >
    > ---
    >
    > This is a cleanup of Werner Conelius' patch in
    > http://kerneltrap.org/mailarchive/li...07/9/21/265323 which
    > should be more acceptable to mainline. Feel free to put him as author
    > rather than me.


    The correct format should be:

    From: Werner Cornelius



    Signed-off-by: Werner Cornelius
    Signed-off-by: Tollef Fog Heen

    However, this patch no longer applies to current git because of usb
    serial changes to include a 'tty' function parameter.

    --
    Simon Arlott
    --
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