USB: usb-serial ch341: support for DTR/RTS/CTS
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 <http://err.no/src/TEMPer.c>
Signed-off-by: Werner Cornelius <Werner.Cornelius@cornelius-consult.de>
Signed-off-by: Boris Hajduk <boris@hajduk.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Werner Cornelius
Greg Kroah-Hartman
parent
bcbbbfc169
commit
664d5df92e
@ -1,5 +1,7 @@
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/*
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* Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
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* Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
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* Copyright 2009, Boris Hajduk <boris@hajduk.org>
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*
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* ch341.c implements a serial port driver for the Winchiphead CH341.
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*
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@ -21,9 +23,39 @@
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#include <linux/usb/serial.h>
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#include <linux/serial.h>
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#define DEFAULT_BAUD_RATE 2400
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#define DEFAULT_BAUD_RATE 9600
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#define DEFAULT_TIMEOUT 1000
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/* flags for IO-Bits */
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#define CH341_BIT_RTS (1 << 6)
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#define CH341_BIT_DTR (1 << 5)
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/******************************/
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/* interrupt pipe definitions */
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/******************************/
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/* always 4 interrupt bytes */
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/* first irq byte normally 0x08 */
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/* second irq byte base 0x7d + below */
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/* third irq byte base 0x94 + below */
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/* fourth irq byte normally 0xee */
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/* second interrupt byte */
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#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
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/* status returned in third interrupt answer byte, inverted in data
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from irq */
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#define CH341_BIT_CTS 0x01
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#define CH341_BIT_DSR 0x02
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#define CH341_BIT_RI 0x04
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#define CH341_BIT_DCD 0x08
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#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
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/*******************************/
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/* baudrate calculation factor */
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/*******************************/
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#define CH341_BAUDBASE_FACTOR 1532620800
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#define CH341_BAUDBASE_DIVMAX 3
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static int debug;
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static struct usb_device_id id_table [] = {
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@ -34,9 +66,12 @@ static struct usb_device_id id_table [] = {
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MODULE_DEVICE_TABLE(usb, id_table);
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struct ch341_private {
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unsigned baud_rate;
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u8 dtr;
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u8 rts;
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spinlock_t lock; /* access lock */
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wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
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unsigned baud_rate; /* set baud rate */
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u8 line_control; /* set line control value RTS/DTR */
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u8 line_status; /* active status of modem control inputs */
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u8 multi_status_change; /* status changed multiple since last call */
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};
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static int ch341_control_out(struct usb_device *dev, u8 request,
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@ -72,37 +107,28 @@ static int ch341_set_baudrate(struct usb_device *dev,
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{
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short a, b;
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int r;
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unsigned long factor;
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short divisor;
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dbg("ch341_set_baudrate(%d)", priv->baud_rate);
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switch (priv->baud_rate) {
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case 2400:
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a = 0xd901;
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b = 0x0038;
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break;
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case 4800:
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a = 0x6402;
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b = 0x001f;
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break;
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case 9600:
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a = 0xb202;
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b = 0x0013;
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break;
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case 19200:
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a = 0xd902;
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b = 0x000d;
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break;
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case 38400:
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a = 0x6403;
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b = 0x000a;
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break;
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case 115200:
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a = 0xcc03;
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b = 0x0008;
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break;
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default:
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if (!priv->baud_rate)
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return -EINVAL;
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factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
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divisor = CH341_BAUDBASE_DIVMAX;
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while ((factor > 0xfff0) && divisor) {
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factor >>= 3;
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divisor--;
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}
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if (factor > 0xfff0)
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return -EINVAL;
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factor = 0x10000 - factor;
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a = (factor & 0xff00) | divisor;
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b = factor & 0xff;
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r = ch341_control_out(dev, 0x9a, 0x1312, a);
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if (!r)
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r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
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@ -110,19 +136,18 @@ static int ch341_set_baudrate(struct usb_device *dev,
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return r;
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}
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static int ch341_set_handshake(struct usb_device *dev,
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struct ch341_private *priv)
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static int ch341_set_handshake(struct usb_device *dev, u8 control)
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{
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dbg("ch341_set_handshake(%d,%d)", priv->dtr, priv->rts);
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return ch341_control_out(dev, 0xa4,
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~((priv->dtr?1<<5:0)|(priv->rts?1<<6:0)), 0);
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dbg("ch341_set_handshake(0x%02x)", control);
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return ch341_control_out(dev, 0xa4, ~control, 0);
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}
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static int ch341_get_status(struct usb_device *dev)
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static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
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{
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char *buffer;
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int r;
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const unsigned size = 8;
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unsigned long flags;
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dbg("ch341_get_status()");
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@ -134,10 +159,15 @@ static int ch341_get_status(struct usb_device *dev)
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if (r < 0)
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goto out;
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/* Not having the datasheet for the CH341, we ignore the bytes returned
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* from the device. Return error if the device did not respond in time.
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*/
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r = 0;
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/* setup the private status if available */
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if (r == 2) {
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r = 0;
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spin_lock_irqsave(&priv->lock, flags);
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priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
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priv->multi_status_change = 0;
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spin_unlock_irqrestore(&priv->lock, flags);
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} else
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r = -EPROTO;
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out: kfree(buffer);
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return r;
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@ -180,7 +210,7 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
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goto out;
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/* expect 0xff 0xee */
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r = ch341_get_status(dev);
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r = ch341_get_status(dev, priv);
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if (r < 0)
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goto out;
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@ -192,12 +222,12 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
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if (r < 0)
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goto out;
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r = ch341_set_handshake(dev, priv);
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r = ch341_set_handshake(dev, priv->line_control);
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if (r < 0)
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goto out;
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/* expect 0x9f 0xee */
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r = ch341_get_status(dev);
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r = ch341_get_status(dev, priv);
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out: kfree(buffer);
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return r;
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@ -216,9 +246,10 @@ static int ch341_attach(struct usb_serial *serial)
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if (!priv)
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return -ENOMEM;
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spin_lock_init(&priv->lock);
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init_waitqueue_head(&priv->delta_msr_wait);
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priv->baud_rate = DEFAULT_BAUD_RATE;
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priv->dtr = 1;
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priv->rts = 1;
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priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
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r = ch341_configure(serial->dev, priv);
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if (r < 0)
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@ -231,6 +262,35 @@ error: kfree(priv);
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return r;
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}
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static void ch341_close(struct tty_struct *tty, struct usb_serial_port *port,
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struct file *filp)
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{
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struct ch341_private *priv = usb_get_serial_port_data(port);
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unsigned long flags;
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unsigned int c_cflag;
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dbg("%s - port %d", __func__, port->number);
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/* shutdown our urbs */
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dbg("%s - shutting down urbs", __func__);
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usb_kill_urb(port->write_urb);
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usb_kill_urb(port->read_urb);
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usb_kill_urb(port->interrupt_in_urb);
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if (tty) {
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c_cflag = tty->termios->c_cflag;
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if (c_cflag & HUPCL) {
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/* drop DTR and RTS */
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spin_lock_irqsave(&priv->lock, flags);
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priv->line_control = 0;
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spin_unlock_irqrestore(&priv->lock, flags);
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ch341_set_handshake(port->serial->dev, 0);
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}
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}
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wake_up_interruptible(&priv->delta_msr_wait);
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}
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/* open this device, set default parameters */
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static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
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struct file *filp)
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@ -242,14 +302,13 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
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dbg("ch341_open()");
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priv->baud_rate = DEFAULT_BAUD_RATE;
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priv->dtr = 1;
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priv->rts = 1;
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priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
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r = ch341_configure(serial->dev, priv);
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if (r)
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goto out;
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r = ch341_set_handshake(serial->dev, priv);
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r = ch341_set_handshake(serial->dev, priv->line_control);
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if (r)
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goto out;
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@ -257,6 +316,16 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
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if (r)
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goto out;
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dbg("%s - submitting interrupt urb", __func__);
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port->interrupt_in_urb->dev = serial->dev;
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r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
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if (r) {
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dev_err(&port->dev, "%s - failed submitting interrupt urb,"
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" error %d\n", __func__, r);
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ch341_close(tty, port, NULL);
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return -EPROTO;
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}
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r = usb_serial_generic_open(tty, port, filp);
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out: return r;
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@ -270,38 +339,194 @@ static void ch341_set_termios(struct tty_struct *tty,
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{
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struct ch341_private *priv = usb_get_serial_port_data(port);
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unsigned baud_rate;
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unsigned long flags;
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dbg("ch341_set_termios()");
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if (!tty || !tty->termios)
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return;
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baud_rate = tty_get_baud_rate(tty);
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switch (baud_rate) {
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case 2400:
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case 4800:
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case 9600:
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case 19200:
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case 38400:
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case 115200:
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priv->baud_rate = baud_rate;
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break;
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default:
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dbg("Rate %d not supported, using %d",
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baud_rate, DEFAULT_BAUD_RATE);
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priv->baud_rate = DEFAULT_BAUD_RATE;
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priv->baud_rate = baud_rate;
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if (baud_rate) {
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spin_lock_irqsave(&priv->lock, flags);
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priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
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spin_unlock_irqrestore(&priv->lock, flags);
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ch341_set_baudrate(port->serial->dev, priv);
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} else {
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spin_lock_irqsave(&priv->lock, flags);
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priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
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spin_unlock_irqrestore(&priv->lock, flags);
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}
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ch341_set_baudrate(port->serial->dev, priv);
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ch341_set_handshake(port->serial->dev, priv->line_control);
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/* Unimplemented:
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* (cflag & CSIZE) : data bits [5, 8]
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* (cflag & PARENB) : parity {NONE, EVEN, ODD}
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* (cflag & CSTOPB) : stop bits [1, 2]
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*/
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}
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/* Copy back the old hardware settings */
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tty_termios_copy_hw(tty->termios, old_termios);
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/* And re-encode with the new baud */
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tty_encode_baud_rate(tty, baud_rate, baud_rate);
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static int ch341_tiocmset(struct tty_struct *tty, struct file *file,
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unsigned int set, unsigned int clear)
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{
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struct usb_serial_port *port = tty->driver_data;
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struct ch341_private *priv = usb_get_serial_port_data(port);
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unsigned long flags;
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u8 control;
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spin_lock_irqsave(&priv->lock, flags);
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if (set & TIOCM_RTS)
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priv->line_control |= CH341_BIT_RTS;
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if (set & TIOCM_DTR)
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priv->line_control |= CH341_BIT_DTR;
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if (clear & TIOCM_RTS)
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priv->line_control &= ~CH341_BIT_RTS;
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if (clear & TIOCM_DTR)
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priv->line_control &= ~CH341_BIT_DTR;
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control = priv->line_control;
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spin_unlock_irqrestore(&priv->lock, flags);
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return ch341_set_handshake(port->serial->dev, control);
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}
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static void ch341_read_int_callback(struct urb *urb)
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{
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struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
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unsigned char *data = urb->transfer_buffer;
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unsigned int actual_length = urb->actual_length;
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int status;
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dbg("%s (%d)", __func__, port->number);
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switch (urb->status) {
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case 0:
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/* success */
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break;
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case -ECONNRESET:
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case -ENOENT:
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case -ESHUTDOWN:
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/* this urb is terminated, clean up */
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dbg("%s - urb shutting down with status: %d", __func__,
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urb->status);
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return;
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default:
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dbg("%s - nonzero urb status received: %d", __func__,
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urb->status);
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goto exit;
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}
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usb_serial_debug_data(debug, &port->dev, __func__,
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urb->actual_length, urb->transfer_buffer);
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if (actual_length >= 4) {
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struct ch341_private *priv = usb_get_serial_port_data(port);
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unsigned long flags;
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spin_lock_irqsave(&priv->lock, flags);
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priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
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if ((data[1] & CH341_MULT_STAT))
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priv->multi_status_change = 1;
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spin_unlock_irqrestore(&priv->lock, flags);
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wake_up_interruptible(&priv->delta_msr_wait);
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}
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exit:
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status = usb_submit_urb(urb, GFP_ATOMIC);
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if (status)
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dev_err(&urb->dev->dev,
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"%s - usb_submit_urb failed with result %d\n",
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__func__, status);
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}
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static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
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{
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struct ch341_private *priv = usb_get_serial_port_data(port);
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unsigned long flags;
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u8 prevstatus;
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u8 status;
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u8 changed;
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u8 multi_change = 0;
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spin_lock_irqsave(&priv->lock, flags);
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prevstatus = priv->line_status;
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priv->multi_status_change = 0;
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spin_unlock_irqrestore(&priv->lock, flags);
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while (!multi_change) {
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interruptible_sleep_on(&priv->delta_msr_wait);
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/* see if a signal did it */
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if (signal_pending(current))
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return -ERESTARTSYS;
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spin_lock_irqsave(&priv->lock, flags);
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status = priv->line_status;
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multi_change = priv->multi_status_change;
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spin_unlock_irqrestore(&priv->lock, flags);
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changed = prevstatus ^ status;
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if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
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((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
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((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) ||
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((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
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return 0;
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}
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prevstatus = status;
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}
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return 0;
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}
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/*static int ch341_ioctl(struct usb_serial_port *port, struct file *file,*/
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static int ch341_ioctl(struct tty_struct *tty, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct usb_serial_port *port = tty->driver_data;
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dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
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switch (cmd) {
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case TIOCMIWAIT:
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dbg("%s (%d) TIOCMIWAIT", __func__, port->number);
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return wait_modem_info(port, arg);
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default:
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dbg("%s not supported = 0x%04x", __func__, cmd);
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break;
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}
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return -ENOIOCTLCMD;
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}
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static int ch341_tiocmget(struct tty_struct *tty, struct file *file)
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||||
{
|
||||
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);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
static struct usb_driver ch341_driver = {
|
||||
@ -317,12 +542,17 @@ 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)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user