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freebsd-dev/sys/i386/isa/tw.c

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/*-
* Copyright (c) 1992, 1993, 1995 Eugene W. Stark
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Eugene W. Stark.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY EUGENE W. STARK (THE AUTHOR) ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "tw.h"
#if NTW > 0
/*
* Driver configuration parameters
*/
/*
* Time for 1/2 of a power line cycle, in microseconds.
* Change this to 10000 for 50Hz power. Phil Sampson
* (vk2jnt@gw.vk2jnt.ampr.org OR sampson@gidday.enet.dec.com)
* reports that this works (at least in Australia) using a
* TW7223 module (a local version of the TW523).
*/
#define HALFCYCLE 8333 /* 1/2 cycle = 8333us at 60Hz */
/*
* Undefine the following if you don't have the high-resolution "microtime"
* routines (leave defined for FreeBSD, which has them).
*/
#define HIRESTIME
/*
* End of driver configuration parameters
*/
/*
* FreeBSD Device Driver for X-10 POWERHOUSE (tm)
* Two-Way Power Line Interface, Model #TW523
*
* written by Eugene W. Stark (stark@cs.sunysb.edu)
* December 2, 1992
*
* NOTES:
*
* The TW523 is a carrier-current modem for home control/automation purposes.
* It is made by:
*
* X-10 Inc.
* 185A LeGrand Ave.
* Northvale, NJ 07647
* USA
* (201) 784-9700 or 1-800-526-0027
*
* X-10 Home Controls Inc.
* 1200 Aerowood Drive, Unit 20
* Mississauga, Ontario
* (416) 624-4446 or 1-800-387-3346
*
* The TW523 is designed for communications using the X-10 protocol,
* which is compatible with a number of home control systems, including
* Radio Shack "Plug 'n Power(tm)" and Stanley "Lightmaker(tm)."
* I bought my TW523 from:
*
* Home Control Concepts
* 9353-C Activity Road
* San Diego, CA 92126
* (619) 693-8887
*
* They supplied me with the TW523 (which has an RJ-11 four-wire modular
* telephone connector), a modular cable, an RJ-11 to DB-25 connector with
* internal wiring, documentation from X-10 on the TW523 (very good),
* an instruction manual by Home Control Concepts (not very informative),
* and a floppy disk containing binary object code of some demonstration/test
* programs and of a C function library suitable for controlling the TW523
* by an IBM PC under MS-DOS (not useful to me other than to verify that
* the unit worked). I suggest saving money and buying the bare TW523
* rather than the TW523 development kit (what I bought), because if you
* are running FreeBSD you don't really care about the DOS binaries.
*
* The interface to the TW-523 consists of four wires on the RJ-11 connector,
* which are jumpered to somewhat more wires on the DB-25 connector, which
* in turn is intended to plug into the PC parallel printer port. I dismantled
* the DB-25 connector to find out what they had done:
*
* Signal RJ-11 pin DB-25 pin(s) Parallel Port
* Transmit TX 4 (Y) 2, 4, 6, 8 Data out
* Receive RX 3 (G) 10, 14 -ACK, -AutoFeed
* Common 2 (R) 25 Common
* Zero crossing 1 (B) 17 -Select Input
*
* The zero crossing signal is used to synchronize transmission to the
* zero crossings of the AC line, as detailed in the X-10 documentation.
* It would be nice if one could generate interrupts with this signal,
* however one needs interrupts on both the rising and falling edges,
* and the -ACK signal to the parallel port interrupts only on the falling
* edge, so it can't be done without additional hardware.
*
* In this driver, the transmit function is performed in a non-interrupt-driven
* fashion, by polling the zero crossing signal to determine when a transition
* has occurred. This wastes CPU time during transmission, but it seems like
* the best that can be done without additional hardware. One problem with
* the scheme is that preemption of the CPU during transmission can cause loss
* of sync. The driver tries to catch this, by noticing that a long delay
* loop has somehow become foreshortened, and the transmission is aborted with
* an error return. It is up to the user level software to handle this
* situation (most likely by retrying the transmission).
*/
#include "param.h"
#include "systm.h"
#include "proc.h"
#include "conf.h"
#include "buf.h"
#include "kernel.h"
#include "ioctl.h"
#include "uio.h"
#include "syslog.h"
#include "select.h"
#ifdef DEVFS
#include <sys/devfsext.h>
#endif /*DEVFS*/
#define MIN(a,b) ((a)<(b)?(a):(b))
#ifdef HIRESTIME
#include <sys/time.h>
#endif /* HIRESTIME */
#include "i386/isa/isa_device.h"
/*
* Transmission is done by calling write() to send three byte packets of data.
* The first byte contains a four bit house code (0=A to 15=P).
* The second byte contains five bit unit/key code (0=unit 1 to 15=unit 16,
* 16=All Units Off to 31 = Status Request). The third byte specifies
* the number of times the packet is to be transmitted without any
* gaps between successive transmissions. Normally this is 2, as per
* the X-10 documentation, but sometimes (e.g. for bright and dim codes)
* it can be another value. Each call to write can specify an arbitrary
* number of data bytes. An incomplete packet is buffered until a subsequent
* call to write() provides data to complete it. At most one packet will
* actually be processed in any call to write(). Successive calls to write()
* leave a three-cycle gap between transmissions, per the X-10 documentation.
*
* Reception is done using read().
* The driver produces a series of three-character packets.
* In each packet, the first character consists of flags,
* the second character is a four bit house code (0-15),
* and the third character is a five bit key/function code (0-31).
* The flags are the following:
*/
#define TW_RCV_LOCAL 1 /* The packet arrived during a local transmission */
#define TW_RCV_ERROR 2 /* An invalid/corrupted packet was received */
/*
* IBM PC parallel port definitions relevant to TW523
*/
#define tw_data 0 /* Data to tw523 (R/W) */
#define tw_status 1 /* Status of tw523 (R) */
#define TWS_RDATA 0x40 /* tw523 receive data */
#define tw_control 2 /* Control tw523 (R/W) */
#define TWC_SYNC 0x08 /* tw523 sync (pin 17) */
#define TWC_ENA 0x10 /* tw523 interrupt enable */
/*
* Miscellaneous defines
*/
#define TWUNIT(dev) (minor(dev)) /* Extract unit number from device */
#define TWPRI (PZERO+8) /* I don't know any better, so let's */
/* use the same as the line printer */
int twprobe();
int twattach();
void twintr(int unit);
struct isa_driver twdriver = {
twprobe, twattach, "tw"
};
static d_open_t twopen;
static d_close_t twclose;
static d_read_t twread;
static d_write_t twwrite;
static d_select_t twselect;
#define CDEV_MAJOR 19
static struct cdevsw tw_cdevsw =
{ twopen, twclose, twread, twwrite, /*19*/
noioc, nullstop, nullreset, nodevtotty, /* tw */
twselect, nommap, nostrat, "tw", NULL, -1 };
/*
* Software control structure for TW523
*/
#define TWS_XMITTING 1 /* Transmission in progress */
#define TWS_RCVING 2 /* Reception in progress */
#define TWS_WANT 4 /* A process wants received data */
#define TWS_OPEN 8 /* Is it currently open? */
#define TW_SIZE 3*60 /* Enough for about 10 sec. of input */
struct tw_sc {
u_int sc_port; /* I/O Port */
u_int sc_state; /* Current software control state */
struct selinfo sc_selp; /* Information for select() */
u_char sc_xphase; /* Current state of sync (for transmitter) */
u_char sc_rphase; /* Current state of sync (for receiver) */
u_char sc_flags; /* Flags for current reception */
short sc_rcount; /* Number of bits received so far */
int sc_bits; /* Bits received so far */
u_char sc_pkt[3]; /* Packet not yet transmitted */
short sc_pktsize; /* How many bytes in the packet? */
u_char sc_buf[TW_SIZE]; /* We buffer our own input */
int sc_nextin; /* Next free slot in circular buffer */
int sc_nextout; /* First used slot in circular buffer */
#ifdef HIRESTIME
int sc_xtimes[22]; /* Times for bits in current xmit packet */
int sc_rtimes[22]; /* Times for bits in current rcv packet */
#endif /* HIRESTIME */
#ifdef DEVFS
void *devfs_token; /* store the devfs handle */
#endif
} tw_sc[NTW];
static void twdelay25();
static void twdelayn(int n);
static void twsetuptimes(int *a);
static int wait_for_zero(struct tw_sc *sc);
static int twgetbytes(struct tw_sc *sc, u_char *p, int cnt);
static int twsend(struct tw_sc *sc, int h, int k, int cnt);
static int next_zero(struct tw_sc *sc);
static int twchecktime(int target, int tol);
/*
* Counter value for delay loop.
* It is adjusted by twprobe so that the delay loop takes about 25us.
*/
#define TWDELAYCOUNT 161 /* Works on my 486DX/33 */
int twdelaycount;
/*
* Twdelay25 is used for very short delays of about 25us.
* It is implemented with a calibrated delay loop, and should be
* fairly accurate ... unless we are preempted by an interrupt.
*
* We use this to wait for zero crossings because the X-10 specs say we
* are supposed to assert carrier within 25us when one happens.
* I don't really believe we can do this, but the X-10 devices seem to be
* fairly forgiving.
*/
static void twdelay25()
{
int cnt;
for(cnt = twdelaycount; cnt; cnt--); /* Should take about 25us */
}
/*
* Twdelayn is used to time the length of the 1ms carrier pulse.
* This is not very critical, but if we have high-resolution time-of-day
* we check it every apparent 200us to make sure we don't get too far off
* if we happen to be interrupted during the delay.
*/
static void twdelayn(int n)
{
#ifdef HIRESTIME
int t, d;
struct timeval tv;
microtime(&tv);
t = tv.tv_usec;
t += n;
#endif /* HIRESTIME */
while(n > 0) {
twdelay25();
n -= 25;
#ifdef HIRESTIME
if((n & 0x7) == 0) {
microtime(&tv);
d = tv.tv_usec - t;
if(d >= 0 && d < 1000000) return;
}
#endif /* HIRESTIME */
}
}
int twprobe(idp)
struct isa_device *idp;
{
struct tw_sc sc;
int d;
int tries;
sc.sc_port = idp->id_iobase;
/*
* Iteratively check the timing of a few sync transitions, and adjust
* the loop delay counter, if necessary, to bring the timing reported
* by wait_for_zero() close to HALFCYCLE. Give up if anything
* ridiculous happens.
*/
if(twdelaycount == 0) { /* Only adjust timing for first unit */
twdelaycount = TWDELAYCOUNT;
for(tries = 0; tries < 10; tries++) {
sc.sc_xphase = inb(idp->id_iobase + tw_control) & TWC_SYNC;
if(wait_for_zero(&sc) >= 0) {
d = wait_for_zero(&sc);
if(d <= HALFCYCLE/100 || d >= HALFCYCLE*100) {
twdelaycount = 0;
return(0);
}
twdelaycount = (twdelaycount * d)/HALFCYCLE;
}
}
}
/*
* Now do a final check, just to make sure
*/
sc.sc_xphase = inb(idp->id_iobase + tw_control) & TWC_SYNC;
if(wait_for_zero(&sc) >= 0) {
d = wait_for_zero(&sc);
if(d <= (HALFCYCLE * 110)/100 && d >= (HALFCYCLE * 90)/100) return(1);
}
return(0);
}
int twattach(idp)
struct isa_device *idp;
{
struct tw_sc *sc;
char name[32];
int unit;
sc = &tw_sc[unit = idp->id_unit];
sc->sc_port = idp->id_iobase;
sc->sc_state = 0;
#ifdef DEVFS
/* path name devsw minor type uid gid perm*/
sprintf(name,"tw%d", unit);
sc->devfs_token = devfs_add_devsw( "/", name, &tw_cdevsw, unit,
DV_CHR, 0, 0, 0600);
#endif
return (1);
}
int twopen(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
struct tw_sc *sc = &tw_sc[TWUNIT(dev)];
int s;
s = spltty();
if(sc->sc_state == 0) {
sc->sc_state = TWS_OPEN;
sc->sc_nextin = sc->sc_nextout = 0;
sc->sc_pktsize = 0;
outb(sc->sc_port+tw_control, TWC_ENA);
}
splx(s);
return(0);
}
int twclose(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
struct tw_sc *sc = &tw_sc[TWUNIT(dev)];
int s;
int port = sc->sc_port;
s = spltty();
sc->sc_state = 0;
outb(sc->sc_port+tw_control, 0);
splx(s);
return(0);
}
int twread(dev, uio, ioflag)
dev_t dev;
struct uio *uio;
int ioflag;
{
u_char buf[3];
struct tw_sc *sc = &tw_sc[TWUNIT(dev)];
int error, cnt, s;
s = spltty();
cnt = MIN(uio->uio_resid, 3);
if((error = twgetbytes(sc, buf, cnt)) == 0) {
error = uiomove(buf, cnt, uio);
}
splx(s);
return(error);
}
int twwrite(dev, uio, ioflag)
dev_t dev;
struct uio *uio;
int ioflag;
{
struct tw_sc *sc;
int house, key, reps;
int s, error;
int cnt;
sc = &tw_sc[TWUNIT(dev)];
/*
* Note: Although I had intended to allow concurrent transmitters,
* there is a potential problem here if two processes both write
* into the sc_pkt buffer at the same time. The following code
* is an additional critical section that needs to be synchronized.
*/
s = spltty();
cnt = MIN(3 - sc->sc_pktsize, uio->uio_resid);
if(error = uiomove(&(sc->sc_pkt[sc->sc_pktsize]), cnt, uio)) {
splx(s);
return(error);
}
sc->sc_pktsize += cnt;
if(sc->sc_pktsize < 3) { /* Only transmit 3-byte packets */
splx(s);
return(0);
}
sc->sc_pktsize = 0;
/*
* Collect house code, key code, and rep count, and check for sanity.
*/
house = sc->sc_pkt[0];
key = sc->sc_pkt[1];
reps = sc->sc_pkt[2];
if(house >= 16 || key >= 32) {
splx(s);
return(ENODEV);
}
/*
* Synchronize with the receiver operating in the bottom half, and
* also with concurrent transmitters.
* We don't want to interfere with a packet currently being received,
* and we would like the receiver to recognize when a packet has
* originated locally.
*/
while(sc->sc_state & (TWS_RCVING | TWS_XMITTING)) {
if(error = tsleep((caddr_t)sc, TWPRI|PCATCH, "twwrite", 0)) {
splx(s);
return(error);
}
}
sc->sc_state |= TWS_XMITTING;
/*
* Everything looks OK, let's do the transmission.
*/
splx(s); /* Enable interrupts because this takes a LONG time */
error = twsend(sc, house, key, reps);
s = spltty();
sc->sc_state &= ~TWS_XMITTING;
wakeup((caddr_t)sc);
splx(s);
if(error) return(EIO);
else return(0);
}
/*
* Determine if there is data available for reading
*/
int twselect(dev, rw, p)
dev_t dev;
int rw;
struct proc *p;
{
struct tw_sc *sc;
int s;
sc = &tw_sc[TWUNIT(dev)];
s = spltty();
if(sc->sc_nextin != sc->sc_nextout) {
splx(s);
return(1);
}
selrecord(p, &sc->sc_selp);
splx(s);
return(0);
}
/*
* X-10 Protocol
*/
#define X10_START_LENGTH 4
char X10_START[] = { 1, 1, 1, 0 };
/*
* Each bit of the 4-bit house code and 5-bit key code
* is transmitted twice, once in true form, and then in
* complemented form. This is already taken into account
* in the following tables.
*/
#define X10_HOUSE_LENGTH 8
char X10_HOUSE[16][8] = {
0, 1, 1, 0, 1, 0, 0, 1, /* A = 0110 */
1, 0, 1, 0, 1, 0, 0, 1, /* B = 1110 */
0, 1, 0, 1, 1, 0, 0, 1, /* C = 0010 */
1, 0, 0, 1, 1, 0, 0, 1, /* D = 1010 */
0, 1, 0, 1, 0, 1, 1, 0, /* E = 0001 */
1, 0, 0, 1, 0, 1, 1, 0, /* F = 1001 */
0, 1, 1, 0, 0, 1, 1, 0, /* G = 0101 */
1, 0, 1, 0, 0, 1, 1, 0, /* H = 1101 */
0, 1, 1, 0, 1, 0, 1, 0, /* I = 0111 */
1, 0, 1, 0, 1, 0, 1, 0, /* J = 1111 */
0, 1, 0, 1, 1, 0, 1, 0, /* K = 0011 */
1, 0, 0, 1, 1, 0, 1, 0, /* L = 1011 */
0, 1, 0, 1, 0, 1, 0, 1, /* M = 0000 */
1, 0, 0, 1, 0, 1, 0, 1, /* N = 1000 */
0, 1, 1, 0, 0, 1, 0, 1, /* O = 0100 */
1, 0, 1, 0, 0, 1, 0, 1 /* P = 1100 */
};
#define X10_KEY_LENGTH 10
char X10_KEY[32][10] = {
0, 1, 1, 0, 1, 0, 0, 1, 0, 1, /* 01100 => 1 */
1, 0, 1, 0, 1, 0, 0, 1, 0, 1, /* 11100 => 2 */
0, 1, 0, 1, 1, 0, 0, 1, 0, 1, /* 00100 => 3 */
1, 0, 0, 1, 1, 0, 0, 1, 0, 1, /* 10100 => 4 */
0, 1, 0, 1, 0, 1, 1, 0, 0, 1, /* 00010 => 5 */
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, /* 10010 => 6 */
0, 1, 1, 0, 0, 1, 1, 0, 0, 1, /* 01010 => 7 */
1, 0, 1, 0, 0, 1, 1, 0, 0, 1, /* 11010 => 8 */
0, 1, 1, 0, 1, 0, 1, 0, 0, 1, /* 01110 => 9 */
1, 0, 1, 0, 1, 0, 1, 0, 0, 1, /* 11110 => 10 */
0, 1, 0, 1, 1, 0, 1, 0, 0, 1, /* 00110 => 11 */
1, 0, 0, 1, 1, 0, 1, 0, 0, 1, /* 10110 => 12 */
0, 1, 0, 1, 0, 1, 0, 1, 0, 1, /* 00000 => 13 */
1, 0, 0, 1, 0, 1, 0, 1, 0, 1, /* 10000 => 14 */
0, 1, 1, 0, 0, 1, 0, 1, 0, 1, /* 01000 => 15 */
1, 0, 1, 0, 0, 1, 0, 1, 0, 1, /* 11000 => 16 */
0, 1, 0, 1, 0, 1, 0, 1, 1, 0, /* 00001 => All Units Off */
0, 1, 0, 1, 0, 1, 1, 0, 1, 0, /* 00011 => All Units On */
0, 1, 0, 1, 1, 0, 0, 1, 1, 0, /* 00101 => On */
0, 1, 0, 1, 1, 0, 1, 0, 1, 0, /* 00111 => Off */
0, 1, 1, 0, 0, 1, 0, 1, 1, 0, /* 01001 => Dim */
0, 1, 1, 0, 0, 1, 1, 0, 1, 0, /* 01011 => Bright */
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, /* 01101 => All LIGHTS Off */
0, 1, 1, 0, 1, 0, 1, 0, 1, 0, /* 01111 => Extended Code */
1, 0, 0, 1, 0, 1, 0, 1, 1, 0, /* 10001 => Hail Request */
1, 0, 0, 1, 0, 1, 1, 0, 1, 0, /* 10011 => Hail Acknowledge */
1, 0, 0, 1, 1, 0, 0, 1, 1, 0, /* 10101 => Preset Dim 0 */
1, 0, 0, 1, 1, 0, 1, 0, 1, 0, /* 10111 => Preset Dim 1 */
1, 0, 1, 0, 0, 1, 0, 1, 0, 1, /* 11000 => Extended Data (analog) */
1, 0, 1, 0, 0, 1, 1, 0, 1, 0, /* 11011 => Status = on */
1, 0, 1, 0, 1, 0, 0, 1, 1, 0, /* 11101 => Status = off */
1, 0, 1, 0, 1, 0, 1, 0, 1, 0 /* 11111 => Status request */
};
/*
* Tables for mapping received X-10 code back to house/key number.
*/
short X10_HOUSE_INV[16] = { 12, 4, 2, 10, 14, 6, 0, 8,
13, 5, 3, 11, 15, 7, 1, 9 };
short X10_KEY_INV[32] = { 12, 16, 4, 17, 2, 18, 10, 19,
14, 20, 6, 21, 0, 22, 8, 23,
13, 24, 5, 25, 3, 26, 11, 27,
15, 28, 7, 29, 1, 30, 9, 31 };
/*
* Transmit a packet containing house code h and key code k
*/
#define TWRETRY 10 /* Try 10 times to sync with AC line */
static int twsend(sc, h, k, cnt)
struct tw_sc *sc;
int h, k, cnt;
{
int i;
int port = sc->sc_port;
/*
* Make sure we get a reliable sync with a power line zero crossing
*/
for(i = 0; i < TWRETRY; i++) {
if(wait_for_zero(sc) > 100) goto insync;
}
log(LOG_ERR, "TWXMIT: failed to sync.\n");
return(-1);
insync:
/*
* Be sure to leave 3 cycles space between transmissions
*/
for(i = 6; i > 0; i--)
if(next_zero(sc) < 0) return(-1);
/*
* The packet is transmitted cnt times, with no gaps.
*/
while(cnt--) {
/*
* Transmit the start code
*/
for(i = 0; i < X10_START_LENGTH; i++) {
outb(port+tw_data, X10_START[i] ? 0xff : 0x00); /* Waste no time! */
#ifdef HIRESTIME
if(i == 0) twsetuptimes(sc->sc_xtimes);
if(twchecktime(sc->sc_xtimes[i], HALFCYCLE/20) == 0) {
outb(port+tw_data, 0);
return(-1);
}
#endif /* HIRESTIME */
twdelayn(1000); /* 1ms pulse width */
outb(port+tw_data, 0);
if(next_zero(sc) < 0) return(-1);
}
/*
* Transmit the house code
*/
for(i = 0; i < X10_HOUSE_LENGTH; i++) {
outb(port+tw_data, X10_HOUSE[h][i] ? 0xff : 0x00); /* Waste no time! */
#ifdef HIRESTIME
if(twchecktime(sc->sc_xtimes[i+X10_START_LENGTH], HALFCYCLE/20) == 0) {
outb(port+tw_data, 0);
return(-1);
}
#endif /* HIRESTIME */
twdelayn(1000); /* 1ms pulse width */
outb(port+tw_data, 0);
if(next_zero(sc) < 0) return(-1);
}
/*
* Transmit the unit/key code
*/
for(i = 0; i < X10_KEY_LENGTH; i++) {
outb(port+tw_data, X10_KEY[k][i] ? 0xff : 0x00);
#ifdef HIRESTIME
if(twchecktime(sc->sc_xtimes[i+X10_START_LENGTH+X10_HOUSE_LENGTH],
HALFCYCLE/20) == 0) {
outb(port+tw_data, 0);
return(-1);
}
#endif /* HIRESTIME */
twdelayn(1000); /* 1ms pulse width */
outb(port+tw_data, 0);
if(next_zero(sc) < 0) return(-1);
}
}
return(0);
}
/*
* Waste CPU cycles to get in sync with a power line zero crossing.
* The value returned is roughly how many microseconds we wasted before
* seeing the transition. To avoid wasting time forever, we give up after
* waiting patiently for 1/4 sec (15 power line cycles at 60 Hz),
* which is more than the 11 cycles it takes to transmit a full
* X-10 packet.
*/
static int wait_for_zero(sc)
struct tw_sc *sc;
{
int i, old, new, max;
int port = sc->sc_port + tw_control;
old = sc->sc_xphase;
max = 10000; /* 10000 * 25us = 0.25 sec */
i = 0;
while(max--) {
new = inb(port) & TWC_SYNC;
if(new != old) {
sc->sc_xphase = new;
return(i*25);
}
i++;
twdelay25();
}
return(-1);
}
/*
* Wait for the next zero crossing transition, and if we don't have
* high-resolution time-of-day, check to see that the zero crossing
* appears to be arriving on schedule.
* We expect to be waiting almost a full half-cycle (8.333ms-1ms = 7.333ms).
* If we don't seem to wait very long, something is wrong (like we got
* preempted!) and we should abort the transmission because
* there's no telling how long it's really been since the
* last bit was transmitted.
*/
static int next_zero(sc)
struct tw_sc *sc;
{
int d;
#ifdef HIRESTIME
if((d = wait_for_zero(sc)) < 0) {
#else
if((d = wait_for_zero(sc)) < 6000 || d > 8500) {
/* No less than 6.0ms, no more than 8.5ms */
#endif /* HIRESTIME */
log(LOG_ERR, "TWXMIT framing error: %d\n", d);
return(-1);
}
return(0);
}
/*
* Put a three-byte packet into the circular buffer
* Should be called at priority spltty()
*/
static int twputpkt(sc, p)
struct tw_sc *sc;
u_char *p;
{
int i, next;
for(i = 0; i < 3; i++) {
next = sc->sc_nextin+1;
if(next >= TW_SIZE) next = 0;
if(next == sc->sc_nextout) { /* Buffer full */
/*
log(LOG_ERR, "TWRCV: Buffer overrun\n");
*/
return(1);
}
sc->sc_buf[sc->sc_nextin] = *p++;
sc->sc_nextin = next;
}
if(sc->sc_state & TWS_WANT) {
sc->sc_state &= ~TWS_WANT;
wakeup((caddr_t)(&sc->sc_buf));
}
selwakeup(&sc->sc_selp);
return(0);
}
/*
* Get bytes from the circular buffer
* Should be called at priority spltty()
*/
static int twgetbytes(sc, p, cnt)
struct tw_sc *sc;
u_char *p;
int cnt;
{
int error;
while(cnt--) {
while(sc->sc_nextin == sc->sc_nextout) { /* Buffer empty */
sc->sc_state |= TWS_WANT;
if(error = tsleep((caddr_t)(&sc->sc_buf), TWPRI|PCATCH, "twread", 0)) {
return(error);
}
}
*p++ = sc->sc_buf[sc->sc_nextout++];
if(sc->sc_nextout >= TW_SIZE) sc->sc_nextout = 0;
}
return(0);
}
/*
* Abort reception that has failed to complete in the required time.
*/
void twabortrcv(sc)
struct tw_sc *sc;
{
int s;
u_char pkt[3];
s = spltty();
sc->sc_state &= ~TWS_RCVING;
sc->sc_flags |= TW_RCV_ERROR;
pkt[0] = sc->sc_flags;
pkt[1] = pkt[2] = 0;
twputpkt(sc, pkt);
log(LOG_ERR, "TWRCV: aborting (%x, %d)\n", sc->sc_bits, sc->sc_rcount);
wakeup((caddr_t)sc);
splx(s);
}
/*
* This routine handles interrupts that occur when there is a falling
* transition on the RX input. There isn't going to be a transition
* on every bit (some are zero), but if we are smart and keep track of
* how long it's been since the last interrupt (via the zero crossing
* detect line and/or high-resolution time-of-day routine), we can
* reconstruct the transmission without having to poll.
*/
void twintr(unit)
int unit;
{
struct tw_sc *sc = &tw_sc[unit];
int port;
int newphase;
u_char pkt[3];
port = sc->sc_port;
/*
* Ignore any interrupts that occur if the device is not open.
*/
if(sc->sc_state == 0) return;
newphase = inb(port + tw_control) & TWC_SYNC;
/*
* NEW PACKET:
* If we aren't currently receiving a packet, set up a new packet
* and put in the first "1" bit that has just arrived.
* Arrange for the reception to be aborted if too much time goes by.
*/
if((sc->sc_state & TWS_RCVING) == 0) {
#ifdef HIRESTIME
twsetuptimes(sc->sc_rtimes);
#endif /* HIRESTIME */
sc->sc_state |= TWS_RCVING;
sc->sc_rcount = 1;
if(sc->sc_state & TWS_XMITTING) sc->sc_flags = TW_RCV_LOCAL;
else sc->sc_flags = 0;
sc->sc_bits = 0;
sc->sc_rphase = newphase;
timeout((timeout_func_t)twabortrcv, (caddr_t)sc, hz/4);
return;
}
/*
* START CODE:
* The second and third bits are a special case.
*/
if(sc->sc_rcount < 3) {
#ifdef HIRESTIME
if(twchecktime(sc->sc_rtimes[sc->sc_rcount], HALFCYCLE/3)
&& newphase != sc->sc_rphase) {
#else
if(newphase != sc->sc_rphase) {
#endif
sc->sc_rcount++;
} else {
/*
* Invalid start code -- abort reception.
*/
sc->sc_state &= ~TWS_RCVING;
sc->sc_flags |= TW_RCV_ERROR;
/*
pkt[0] = sc->sc_flags;
pkt[1] = pkt[2] = 0;
twputpkt(sc, pkt);
wakeup((caddr_t)sc);
*/
untimeout((timeout_func_t)twabortrcv, (caddr_t)sc);
log(LOG_ERR, "TWRCV: Invalid start code\n");
return;
}
if(sc->sc_rcount == 3) {
/*
* We've gotten three "1" bits in a row. The start code
* is really 1110, but this might be followed by a zero
* bit from the house code, so if we wait any longer we
* might be confused about the first house code bit.
* So, we guess that the start code is correct and insert
* the trailing zero without actually having seen it.
* We don't change sc_rphase in this case, because two
* bit arrivals in a row preserve parity.
*/
sc->sc_rcount++;
return;
}
/*
* Update sc_rphase to the current phase before returning.
*/
sc->sc_rphase = newphase;
return;
}
/*
* GENERAL CASE:
* Now figure out what the current bit is that just arrived.
* The X-10 protocol transmits each data bit twice: once in
* true form and once in complemented form on the next half
* cycle. So, there will be at least one interrupt per bit.
* By comparing the phase we see at the time of the interrupt
* with the saved sc_rphase, we can tell on which half cycle
* the interrupt occrred. This assumes, of course, that the
* packet is well-formed. We do the best we can at trying to
* catch errors by aborting if too much time has gone by, and
* by tossing out a packet if too many bits arrive, but the
* whole scheme is probably not as robust as if we had a nice
* interrupt on every half cycle of the power line.
* If we have high-resolution time-of-day routines, then we
* can do a bit more sanity checking.
*/
/*
* A complete packet is 22 half cycles.
*/
if(sc->sc_rcount <= 20) {
#ifdef HIRESTIME
if((newphase == sc->sc_rphase &&
twchecktime(sc->sc_rtimes[sc->sc_rcount+1], HALFCYCLE/3) == 0)
|| (newphase != sc->sc_rphase &&
twchecktime(sc->sc_rtimes[sc->sc_rcount], HALFCYCLE/3) == 0)) {
sc->sc_flags |= TW_RCV_ERROR;
} else {
#endif /* HIRESTIME */
sc->sc_bits = (sc->sc_bits << 1)
| ((newphase == sc->sc_rphase) ? 0x0 : 0x1);
sc->sc_rcount += 2;
#ifdef HIRESTIME
}
#endif /* HIRESTIME */
}
if(sc->sc_rcount >= 22 || sc->sc_flags & TW_RCV_ERROR) {
if(sc->sc_rcount != 22) {
sc->sc_flags |= TW_RCV_ERROR;
pkt[0] = sc->sc_flags;
pkt[1] = pkt[2] = 0;
} else {
pkt[0] = sc->sc_flags;
pkt[1] = X10_HOUSE_INV[(sc->sc_bits & 0x1e0) >> 5];
pkt[2] = X10_KEY_INV[sc->sc_bits & 0x1f];
}
sc->sc_state &= ~TWS_RCVING;
twputpkt(sc, pkt);
untimeout((timeout_func_t)twabortrcv, (caddr_t)sc);
if(sc->sc_flags & TW_RCV_ERROR)
log(LOG_ERR, "TWRCV: invalid packet: (%d, %x)\n",
sc->sc_rcount, sc->sc_bits);
wakeup((caddr_t)sc);
}
}
#ifdef HIRESTIME
/*
* Initialize an array of 22 times, starting from the current
* microtime and continuing for the next 21 half cycles.
* We use the times as a reference to make sure transmission
* or reception is on schedule.
*/
static void twsetuptimes(int *a)
{
struct timeval tv;
int i, t;
microtime(&tv);
t = tv.tv_usec;
for(i = 0; i < 22; i++) {
*a++ = t;
t += HALFCYCLE;
if(t >= 1000000) t -= 1000000;
}
}
/*
* Check the current time against a slot in a previously set up
* timing array, and make sure that it looks like we are still
* on schedule.
*/
static int twchecktime(int target, int tol)
{
struct timeval tv;
int t, d;
microtime(&tv);
t = tv.tv_usec;
d = (target - t) >= 0 ? (target - t) : (t - target);
if(d > 500000) d = 1000000-d;
if(d <= tol && d >= -tol) {
return(1);
} else {
log(LOG_ERR, "TWCHK: timing off by %dus (>= %dus)\n", d, tol);
return(0);
}
}
#endif /* HIRESTIME */
static tw_devsw_installed = 0;
static void tw_drvinit(void *unused)
{
dev_t dev;
if( ! tw_devsw_installed ) {
dev = makedev(CDEV_MAJOR, 0);
cdevsw_add(&dev,&tw_cdevsw, NULL);
tw_devsw_installed = 1;
}
}
SYSINIT(twdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,tw_drvinit,NULL)
#endif NTW
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