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Commit 39a66b8d authored by Craig Shelley's avatar Craig Shelley Committed by Greg Kroah-Hartman
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[PATCH] USB: CP2101 Add support for flow control 



Added support to get/set flow control line levels using TIOCMGET and
TIOCMSET.
Added support for RTSCTS hardware flow control.
cp2101_get_config and cp2101_set_config modified to support long request
strings, required for configuring flow control.

Signed-off-by: default avatarCraig Shelley <craig@microtron.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 719df469

drivers/usb/serial/cp2101.c

+275 −88
Original line number Diff line number Diff line
@@ -7,6 +7,14 @@ 
 *	modify it under the terms of the GNU General Public License version

 *	2 as published by the Free Software Foundation.

 *

 * Support to set flow control line levels using TIOCMGET and TIOCMSET

 * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow

 * control thanks to Munir Nassar nassarmu@real-time.com

 *

 * Outstanding Issues:

 *  Buffers are not flushed when the port is opened.

 *  Multiple calls to write() may fail with "Resource temporarily unavailable"

 *

 */



#include <linux/config.h>
@@ -24,7 +32,7 @@ 
/*

 * Version Information

 */

#define DRIVER_VERSION "v0.03"

#define DRIVER_VERSION "v0.04"

#define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"



/*
@@ -35,6 +43,9 @@ static void cp2101_cleanup(struct usb_serial_port*); 
static void cp2101_close(struct usb_serial_port*, struct file*);

static void cp2101_get_termios(struct usb_serial_port*);

static void cp2101_set_termios(struct usb_serial_port*, struct termios*);

static int cp2101_tiocmget (struct usb_serial_port *, struct file *);

static int cp2101_tiocmset (struct usb_serial_port *, struct file *,

		unsigned int, unsigned int);

static void cp2101_break_ctl(struct usb_serial_port*, int);

static int cp2101_startup (struct usb_serial *);

static void cp2101_shutdown(struct usb_serial*);
@@ -43,8 +54,9 @@ static void cp2101_shutdown(struct usb_serial*); 
static int debug;



static struct usb_device_id id_table [] = {

	{USB_DEVICE(0x10c4, 0xea60) },	/*Silicon labs factory default*/

	{USB_DEVICE(0x10ab, 0x10c5) },	/*Siemens MC60 Cable*/

	{ USB_DEVICE(0x10C4, 0xEA60) },	/* Silicon Labs factory default */

	{ USB_DEVICE(0x10C4, 0x80CA) },	/* Degree Controls Inc */

	{ USB_DEVICE(0x10AB, 0x10C5) },	/* Siemens MC60 Cable */

	{ } /* Terminating Entry */

};
@@ -70,6 +82,8 @@ static struct usb_serial_device_type cp2101_device = { 
	.close			= cp2101_close,

	.break_ctl		= cp2101_break_ctl,

	.set_termios		= cp2101_set_termios,

	.tiocmget 		= cp2101_tiocmget,

	.tiocmset		= cp2101_tiocmset,

	.attach			= cp2101_startup,

	.shutdown		= cp2101_shutdown,

};
@@ -83,8 +97,8 @@ static struct usb_serial_device_type cp2101_device = { 
#define CP2101_BAUDRATE		0x01	/* (BAUD_RATE_GEN_FREQ / baudrate) */

#define CP2101_BITS		0x03	/* 0x(0)(databits)(parity)(stopbits) */

#define CP2101_BREAK		0x05	/* On / Off */

#define CP2101_DTRRTS		0x07	/*101 / 202  ???*/

#define CP2101_CONFIG_16	0x13	/*16 bytes of config data ???*/

#define CP2101_CONTROL		0x07	/* Flow control line states */

#define CP2101_MODEMCTL		0x13	/* Modem controls */

#define CP2101_CONFIG_6		0x19	/* 6 bytes of config data ??? */



/* CP2101_UART */
@@ -96,6 +110,7 @@ static struct usb_serial_device_type cp2101_device = { 


/* CP2101_BITS */

#define BITS_DATA_MASK		0X0f00

#define BITS_DATA_5		0X0500

#define BITS_DATA_6		0X0600

#define BITS_DATA_7		0X0700

#define BITS_DATA_8		0X0800
@@ -112,64 +127,137 @@ static struct usb_serial_device_type cp2101_device = { 
#define BITS_STOP_1		0x0000

#define BITS_STOP_1_5		0x0001

#define BITS_STOP_2		0x0002



/* CP2101_BREAK */

#define BREAK_ON		0x0000

#define BREAK_OFF		0x0001



/* CP2101_CONTROL */

#define CONTROL_DTR		0x0001

#define CONTROL_RTS		0x0002

#define CONTROL_CTS		0x0010

#define CONTROL_DSR		0x0020

#define CONTROL_RING		0x0040

#define CONTROL_DCD		0x0080

#define CONTROL_WRITE_DTR	0x0100

#define CONTROL_WRITE_RTS	0x0200



static int cp2101_get_config(struct usb_serial_port* port, u8 request)

/*

 * cp2101_get_config

 * Reads from the CP2101 configuration registers

 * 'size' is specified in bytes.

 * 'data' is a pointer to a pre-allocated array of integers large

 * enough to hold 'size' bytes (with 4 bytes to each integer)

 */

static int cp2101_get_config(struct usb_serial_port* port, u8 request,

		unsigned int *data, int size)

{

	struct usb_serial *serial = port->serial;

	unsigned char buf[4];

	unsigned int value;

	int result, i;

	u32 *buf;

	int result, i, length;



	/* Number of integers required to contain the array */

	length = (((size - 1) | 3) + 1)/4;



	buf = kmalloc (length * sizeof(u32), GFP_KERNEL);

	memset(buf, 0, length * sizeof(u32));



	if (!buf) {

		dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);

		return -ENOMEM;

	}



	/* For get requests, the request number must be incremented */

	request++;



	/*Issue the request, attempting to read 4 bytes*/

	/* Issue the request, attempting to read 'size' bytes */

	result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0),

				request, REQTYPE_DEVICE_TO_HOST, 0x0000,

				0, buf, 4, 300);

				0, buf, size, 300);



	if (result < 0) {

		dev_err(&port->dev, "%s - Unable to send config request, "

				"request=0x%x result=%d\n",

				__FUNCTION__, request, result);

		return result;

	}

	/* Convert data into an array of integers */

	for (i=0; i<length; i++)

		data[i] = le32_to_cpu(buf[i]);



	/*Assemble each byte read into an integer value*/

	value = 0;

	for (i=0; i<4 && i<result; i++)

		value |= (buf[i] << (i * 8));

	kfree(buf);



	dbg( " %s - request=0x%x result=%d value=0x%x",

			__FUNCTION__, request, result, value);

	if (result != size) {

		dev_err(&port->dev, "%s - Unable to send config request, "

				"request=0x%x size=%d result=%d\n",

				__FUNCTION__, request, size, result);

		return -EPROTO;

	}



	return value;

	return 0;

}



static int cp2101_set_config(struct usb_serial_port* port, u8 request, u16 value)

/*

 * cp2101_set_config

 * Writes to the CP2101 configuration registers

 * Values less than 16 bits wide are sent directly

 * 'size' is specified in bytes.

 */

static int cp2101_set_config(struct usb_serial_port* port, u8 request,

		unsigned int *data, int size)

{

	struct usb_serial *serial = port->serial;

	int result;

	result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0),

			request, REQTYPE_HOST_TO_DEVICE, value,

			0, NULL, 0, 300);

	u32 *buf;

	int result, i, length;



	if (result <0) {

		dev_err(&port->dev, "%s - Unable to send config request, "

				"request=0x%x value=0x%x result=%d\n",

				__FUNCTION__, request, value, result);

		return result;

	/* Number of integers required to contain the array */

	length = (((size - 1) | 3) + 1)/4;



	buf = kmalloc(length * sizeof(u32), GFP_KERNEL);

	if (!buf) {

		dev_err(&port->dev, "%s - out of memory.\n",

				__FUNCTION__);

		return -ENOMEM;

	}



	/* Array of integers into bytes */

	for (i = 0; i < length; i++)

		buf[i] = cpu_to_le32(data[i]);



	if (size > 2) {

		result = usb_control_msg (serial->dev,

				usb_sndctrlpipe(serial->dev, 0),

				request, REQTYPE_HOST_TO_DEVICE, 0x0000,

				0, buf, size, 300);

	} else {

		result = usb_control_msg (serial->dev,

				usb_sndctrlpipe(serial->dev, 0),

				request, REQTYPE_HOST_TO_DEVICE, data[0],

				0, NULL, 0, 300);

	}



	dbg(" %s - request=0x%x value=0x%x result=%d",

			__FUNCTION__, request, value, result);

	kfree(buf);



	if ((size > 2 && result != size) || result < 0) {

		dev_err(&port->dev, "%s - Unable to send request, "

				"request=0x%x size=%d result=%d\n",

				__FUNCTION__, request, size, result);

		return -EPROTO;

	}



	/* Single data value */

	result = usb_control_msg (serial->dev,

			usb_sndctrlpipe(serial->dev, 0),

			request, REQTYPE_HOST_TO_DEVICE, data[0],

			0, NULL, 0, 300);

	return 0;

}



/*

 * cp2101_set_config_single

 * Convenience function for calling cp2101_set_config on single data values

 * without requiring an integer pointer

 */

static inline int cp2101_set_config_single(struct usb_serial_port* port,

		u8 request, unsigned int data)

{

	return cp2101_set_config(port, request, &data, 2);

}



static int cp2101_open (struct usb_serial_port *port, struct file *filp)

{

	struct usb_serial *serial = port->serial;
@@ -177,7 +265,7 @@ static int cp2101_open (struct usb_serial_port *port, struct file *filp) 


	dbg("%s - port %d", __FUNCTION__, port->number);



	if (cp2101_set_config(port, CP2101_UART, UART_ENABLE)) {

	if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) {

		dev_err(&port->dev, "%s - Unable to enable UART\n",

				__FUNCTION__);

		return -EPROTO;
@@ -201,6 +289,9 @@ static int cp2101_open (struct usb_serial_port *port, struct file *filp) 
	/* Configure the termios structure */

	cp2101_get_termios(port);



	/* Set the DTR and RTS pins low */

	cp2101_tiocmset(port, NULL, TIOCM_DTR | TIOCM_RTS, 0);



	return 0;

}
@@ -228,16 +319,18 @@ static void cp2101_close (struct usb_serial_port *port, struct file * filp) 
	usb_kill_urb(port->write_urb);

	usb_kill_urb(port->read_urb);



	cp2101_set_config(port, CP2101_UART, UART_DISABLE);

	cp2101_set_config_single(port, CP2101_UART, UART_DISABLE);

}



/* cp2101_get_termios*/

/* Reads the baud rate, data bits, parity and stop bits from the device*/

/* Corrects any unsupported values*/

/* Configures the termios structure to reflect the state of the device*/

/*

 * cp2101_get_termios

 * Reads the baud rate, data bits, parity, stop bits and flow control mode

 * from the device, corrects any unsupported values, and configures the

 * termios structure to reflect the state of the device

 */

static void cp2101_get_termios (struct usb_serial_port *port)

{

	unsigned int cflag;

	unsigned int cflag, modem_ctl[4];

	int baud;

	int bits;
@@ -249,7 +342,7 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
	}

	cflag = port->tty->termios->c_cflag;



	baud = cp2101_get_config(port, CP2101_BAUDRATE);

	cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2);

	/* Convert to baudrate */

	if (baud)

		baud = BAUD_RATE_GEN_FREQ / baud;
@@ -257,7 +350,8 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
	dbg("%s - baud rate = %d", __FUNCTION__, baud);

	cflag &= ~CBAUD;

	switch (baud) {

		/* The baud rates which are commented out below

		/*

		 * The baud rates which are commented out below

		 * appear to be supported by the device

		 * but are non-standard

		 */
@@ -284,14 +378,18 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
			dbg("%s - Baud rate is not supported, "

					"using 9600 baud", __FUNCTION__);

			cflag |= B9600;

			cp2101_set_config(port, CP2101_BAUDRATE,

			cp2101_set_config_single(port, CP2101_BAUDRATE,

					(BAUD_RATE_GEN_FREQ/9600));

			break;

	}



	bits = cp2101_get_config(port, CP2101_BITS);

	cp2101_get_config(port, CP2101_BITS, &bits, 2);

	cflag &= ~CSIZE;

	switch(bits & BITS_DATA_MASK) {

		case BITS_DATA_5:

			dbg("%s - data bits = 5", __FUNCTION__);

			cflag |= CS5;

			break;

		case BITS_DATA_6:

			dbg("%s - data bits = 6", __FUNCTION__);

			cflag |= CS6;
@@ -310,7 +408,7 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
			cflag |= CS8;

			bits &= ~BITS_DATA_MASK;

			bits |= BITS_DATA_8;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

		default:

			dbg("%s - Unknown number of data bits, "
@@ -318,7 +416,7 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
			cflag |= CS8;

			bits &= ~BITS_DATA_MASK;

			bits |= BITS_DATA_8;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

	}
@@ -341,21 +439,21 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
					"disabling parity)", __FUNCTION__);

			cflag &= ~PARENB;

			bits &= ~BITS_PARITY_MASK;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

		case BITS_PARITY_SPACE:

			dbg("%s - parity = SPACE (not supported, "

					"disabling parity)", __FUNCTION__);

			cflag &= ~PARENB;

			bits &= ~BITS_PARITY_MASK;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

		default:

			dbg("%s - Unknown parity mode, "

					"disabling parity", __FUNCTION__);

			cflag &= ~PARENB;

			bits &= ~BITS_PARITY_MASK;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

	}
@@ -366,9 +464,9 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
			break;

		case BITS_STOP_1_5:

			dbg("%s - stop bits = 1.5 (not supported, "

					"using 1 stop bit", __FUNCTION__);

					"using 1 stop bit)", __FUNCTION__);

			bits &= ~BITS_STOP_MASK;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

		case BITS_STOP_2:

			dbg("%s - stop bits = 2", __FUNCTION__);
@@ -378,10 +476,19 @@ static void cp2101_get_termios (struct usb_serial_port *port) 
			dbg("%s - Unknown number of stop bits, "

					"using 1 stop bit", __FUNCTION__);

			bits &= ~BITS_STOP_MASK;

			cp2101_set_config(port, CP2101_BITS, bits);

			cp2101_set_config(port, CP2101_BITS, &bits, 2);

			break;

	}



	cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);

	if (modem_ctl[0] & 0x0008) {

		dbg("%s - flow control = CRTSCTS", __FUNCTION__);

		cflag |= CRTSCTS;

	} else {

		dbg("%s - flow control = NONE", __FUNCTION__);

		cflag &= ~CRTSCTS;

	}



	port->tty->termios->c_cflag = cflag;

}
@@ -389,8 +496,8 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
		struct termios *old_termios)

{

	unsigned int cflag, old_cflag=0;

	int baud=0;

	int bits;

	int baud=0, bits;

	unsigned int modem_ctl[4];



	dbg("%s - port %d", __FUNCTION__, port->number);
@@ -400,7 +507,7 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
	}

	cflag = port->tty->termios->c_cflag;



	/* check that they really want us to change something */

	/* Check that they really want us to change something */

	if (old_termios) {

		if ((cflag == old_termios->c_cflag) &&

				(RELEVANT_IFLAG(port->tty->termios->c_iflag)
@@ -415,7 +522,8 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
	/* If the baud rate is to be updated*/

	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {

		switch (cflag & CBAUD) {

			/* The baud rates which are commented out below

			/*

			 * The baud rates which are commented out below

			 * appear to be supported by the device

			 * but are non-standard

			 */
@@ -448,7 +556,7 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
		if (baud) {

			dbg("%s - Setting baud rate to %d baud", __FUNCTION__,

					baud);

			if (cp2101_set_config(port, CP2101_BAUDRATE,

			if (cp2101_set_config_single(port, CP2101_BAUDRATE,

						(BAUD_RATE_GEN_FREQ / baud)))

				dev_err(&port->dev, "Baud rate requested not "

						"supported by device\n");
@@ -457,9 +565,13 @@ static void cp2101_set_termios (struct usb_serial_port *port, 


	/* If the number of data bits is to be updated */

	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {

		bits = cp2101_get_config(port, CP2101_BITS);

		cp2101_get_config(port, CP2101_BITS, &bits, 2);

		bits &= ~BITS_DATA_MASK;

		switch (cflag & CSIZE) {

			case CS5:

				bits |= BITS_DATA_5;

				dbg("%s - data bits = 5", __FUNCTION__);

				break;

			case CS6:

				bits |= BITS_DATA_6;

				dbg("%s - data bits = 6", __FUNCTION__);
@@ -483,13 +595,13 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
				bits |= BITS_DATA_8;

				break;

		}

		if (cp2101_set_config(port, CP2101_BITS, bits))

		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))

			dev_err(&port->dev, "Number of data bits requested "

					"not supported by device\n");

	}



	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {

		bits = cp2101_get_config(port, CP2101_BITS);

		cp2101_get_config(port, CP2101_BITS, &bits, 2);

		bits &= ~BITS_PARITY_MASK;

		if (cflag & PARENB) {

			if (cflag & PARODD) {
@@ -500,13 +612,13 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
				dbg("%s - parity = EVEN", __FUNCTION__);

			}

		}

		if (cp2101_set_config(port, CP2101_BITS, bits))

		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))

			dev_err(&port->dev, "Parity mode not supported "

					"by device\n");

	}



	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {

		bits = cp2101_get_config(port, CP2101_BITS);

		cp2101_get_config(port, CP2101_BITS, &bits, 2);

		bits &= ~BITS_STOP_MASK;

		if (cflag & CSTOPB) {

			bits |= BITS_STOP_2;
@@ -515,15 +627,90 @@ static void cp2101_set_termios (struct usb_serial_port *port, 
			bits |= BITS_STOP_1;

			dbg("%s - stop bits = 1", __FUNCTION__);

		}

		if (cp2101_set_config(port, CP2101_BITS, bits))

		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))

			dev_err(&port->dev, "Number of stop bits requested "

					"not supported by device\n");

	}



	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {

		cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);

		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",

				__FUNCTION__, modem_ctl[0], modem_ctl[1],

				modem_ctl[2], modem_ctl[3]);



		if (cflag & CRTSCTS) {

			modem_ctl[0] &= ~0x7B;

			modem_ctl[0] |= 0x09;

			modem_ctl[1] = 0x80;

			dbg("%s - flow control = CRTSCTS", __FUNCTION__);

		} else {

			modem_ctl[0] &= ~0x7B;

			modem_ctl[0] |= 0x01;

			modem_ctl[1] |= 0x40;

			dbg("%s - flow control = NONE", __FUNCTION__);

		}



		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",

				__FUNCTION__, modem_ctl[0], modem_ctl[1],

				modem_ctl[2], modem_ctl[3]);

		cp2101_set_config(port, CP2101_MODEMCTL, modem_ctl, 16);

	}



}



static int cp2101_tiocmset (struct usb_serial_port *port, struct file *file,

		unsigned int set, unsigned int clear)

{

	int control = 0;



	dbg("%s - port %d", __FUNCTION__, port->number);



	if (set & TIOCM_RTS) {

		control |= CONTROL_RTS;

		control |= CONTROL_WRITE_RTS;

	}

	if (set & TIOCM_DTR) {

		control |= CONTROL_DTR;

		control |= CONTROL_WRITE_DTR;

	}

	if (clear & TIOCM_RTS) {

		control &= ~CONTROL_RTS;

		control |= CONTROL_WRITE_RTS;

	}

	if (clear & TIOCM_DTR) {

		control &= ~CONTROL_DTR;

		control |= CONTROL_WRITE_DTR;

	}



	dbg("%s - control = 0x%.4x", __FUNCTION__, control);



	return cp2101_set_config(port, CP2101_CONTROL, &control, 2);



}



static int cp2101_tiocmget (struct usb_serial_port *port, struct file *file)

{

	int control, result;



	dbg("%s - port %d", __FUNCTION__, port->number);



	cp2101_get_config(port, CP2101_CONTROL, &control, 1);



	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)

		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)

		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)

		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)

		|((control & CONTROL_RING)? TIOCM_RI  : 0)

		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);



	dbg("%s - control = 0x%.2x", __FUNCTION__, control);



	return result;

}



static void cp2101_break_ctl (struct usb_serial_port *port, int break_state)

{

	u16 state;

	int state;



	dbg("%s - port %d", __FUNCTION__, port->number);

	if (break_state == 0)
@@ -532,7 +719,7 @@ static void cp2101_break_ctl (struct usb_serial_port *port, int break_state) 
		state = BREAK_ON;

	dbg("%s - turning break %s", __FUNCTION__,

			state==BREAK_OFF ? "off" : "on");

	cp2101_set_config(port, CP2101_BREAK, state);

	cp2101_set_config(port, CP2101_BREAK, &state, 2);

}



static int cp2101_startup (struct usb_serial *serial)
@@ -548,7 +735,7 @@ static void cp2101_shutdown (struct usb_serial *serial) 


	dbg("%s", __FUNCTION__);



	/* stop reads and writes on all ports */

	/* Stop reads and writes on all ports */

	for (i=0; i < serial->num_ports; ++i) {

		cp2101_cleanup(serial->port[i]);

	}