freebsd-skq/sys/dev/ppbus/lpbb.c
1999-08-28 01:08:13 +00:00

310 lines
7.1 KiB
C

/*-
* Copyright (c) 1998 Nicolas Souchu, Marc Bouget
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $FreeBSD$
*
*/
/*
* I2C Bit-Banging over parallel port
*
* See the Official Philips interface description in lpbb(4)
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <machine/clock.h>
#include <dev/ppbus/ppbconf.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbb_if.h"
/* iicbus softc */
struct lpbb_softc {
struct ppb_device lpbb_dev;
};
static int lpbb_detect(struct lpbb_softc *);
static int lpbb_probe(device_t);
static int lpbb_attach(device_t);
static int lpbb_callback(device_t, int, caddr_t *);
static void lpbb_setlines(device_t, int, int);
static int lpbb_getdataline(device_t);
static int lpbb_reset(device_t, u_char, u_char, u_char *);
static devclass_t lpbb_devclass;
static device_method_t lpbb_methods[] = {
/* device interface */
DEVMETHOD(device_probe, lpbb_probe),
DEVMETHOD(device_attach, lpbb_attach),
/* bus interface */
DEVMETHOD(bus_print_child, bus_generic_print_child),
/* iicbb interface */
DEVMETHOD(iicbb_callback, lpbb_callback),
DEVMETHOD(iicbb_setlines, lpbb_setlines),
DEVMETHOD(iicbb_getdataline, lpbb_getdataline),
DEVMETHOD(iicbb_reset, lpbb_reset),
{ 0, 0 }
};
static driver_t lpbb_driver = {
"lpbb",
lpbb_methods,
sizeof(struct lpbb_softc),
};
/*
* Make ourselves visible as a ppbus driver
*/
static struct ppb_device *lpbb_ppb_probe(struct ppb_data *ppb);
static int lpbb_ppb_attach(struct ppb_device *dev);
#define MAXLPBB 8 /* XXX not much better! */
static struct lpbb_softc *lpbbdata[MAXLPBB];
static int nlpbb = 0;
#ifdef KERNEL
static struct ppb_driver lpbbdriver = {
lpbb_ppb_probe, lpbb_ppb_attach, "lpbb"
};
DATA_SET(ppbdriver_set, lpbbdriver);
#endif /* KERNEL */
static int
lpbb_probe(device_t dev)
{
struct lpbb_softc *sc = lpbbdata[device_get_unit(dev)];
struct lpbb_softc *scdst = (struct lpbb_softc *)device_get_softc(dev);
/* XXX copy softc. Yet, ppbus device is sc->lpbb_dev, but will be
* dev->parent when ppbus will be ported to the new bus architecture */
bcopy(sc, scdst, sizeof(struct lpbb_softc));
device_set_desc(dev, "parallel I2C bit-banging interface");
/* probe done by ppbus initialization */
return (0);
}
static int
lpbb_attach(device_t dev)
{
device_t bitbang, iicbus;
/* add generic bit-banging code */
bitbang = device_add_child(dev, "iicbb", -1, NULL);
/* add the iicbus to the tree */
iicbus = iicbus_alloc_bus(bitbang);
device_probe_and_attach(bitbang);
/* XXX should be in iicbb_attach! */
device_probe_and_attach(iicbus);
return (0);
}
/*
* lppbb_ppb_probe()
*/
static struct ppb_device *
lpbb_ppb_probe(struct ppb_data *ppb)
{
struct lpbb_softc *sc;
sc = (struct lpbb_softc *) malloc(sizeof(struct lpbb_softc),
M_TEMP, M_NOWAIT);
if (!sc) {
printf("lpbb: cannot malloc!\n");
return (0);
}
bzero(sc, sizeof(struct lpbb_softc));
lpbbdata[nlpbb] = sc;
/*
* ppbus dependent initialisation.
*/
sc->lpbb_dev.id_unit = nlpbb;
sc->lpbb_dev.name = lpbbdriver.name;
sc->lpbb_dev.ppb = ppb;
sc->lpbb_dev.intr = 0;
if (!lpbb_detect(sc)) {
free(sc, M_TEMP);
return (NULL);
}
/* Ok, go to next device on next probe */
nlpbb ++;
/* XXX wrong according to new bus architecture. ppbus needs to be
* ported
*/
return (&sc->lpbb_dev);
}
static int
lpbb_ppb_attach(struct ppb_device *dev)
{
/* add the parallel port I2C interface to the bus tree */
if (!device_add_child(root_bus, "lpbb", dev->id_unit, NULL))
return (0);
return (1);
}
static int
lpbb_callback(device_t dev, int index, caddr_t *data)
{
struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev);
int error = 0;
int how;
switch (index) {
case IIC_REQUEST_BUS:
/* request the ppbus */
how = *(int *)data;
error = ppb_request_bus(&sc->lpbb_dev, how);
break;
case IIC_RELEASE_BUS:
/* release the ppbus */
error = ppb_release_bus(&sc->lpbb_dev);
break;
default:
error = EINVAL;
}
return (error);
}
#define SDA_out 0x80
#define SCL_out 0x08
#define SDA_in 0x80
#define SCL_in 0x08
#define ALIM 0x20
#define I2CKEY 0x50
static int getSDA(struct lpbb_softc *sc)
{
if((ppb_rstr(&sc->lpbb_dev)&SDA_in)==SDA_in)
return 1;
else
return 0;
}
static void setSDA(struct lpbb_softc *sc, char val)
{
if(val==0)
ppb_wdtr(&sc->lpbb_dev, (u_char)SDA_out);
else
ppb_wdtr(&sc->lpbb_dev, (u_char)~SDA_out);
}
static void setSCL(struct lpbb_softc *sc, unsigned char val)
{
if(val==0)
ppb_wctr(&sc->lpbb_dev, (u_char)(ppb_rctr(&sc->lpbb_dev)&~SCL_out));
else
ppb_wctr(&sc->lpbb_dev, (u_char)(ppb_rctr(&sc->lpbb_dev)|SCL_out));
}
static int lpbb_detect(struct lpbb_softc *sc)
{
if (ppb_request_bus(&sc->lpbb_dev, PPB_DONTWAIT)) {
printf("lpbb: can't allocate ppbus\n");
return (0);
}
/* reset bus */
setSDA(sc, 1);
setSCL(sc, 1);
if ((ppb_rstr(&sc->lpbb_dev) & I2CKEY) ||
((ppb_rstr(&sc->lpbb_dev) & ALIM) != ALIM)) {
ppb_release_bus(&sc->lpbb_dev);
return (0);
}
ppb_release_bus(&sc->lpbb_dev);
return (1);
}
static int
lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr)
{
struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev);
/* reset bus */
setSDA(sc, 1);
setSCL(sc, 1);
return (IIC_ENOADDR);
}
static void
lpbb_setlines(device_t dev, int ctrl, int data)
{
struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev);
setSCL(sc, ctrl);
setSDA(sc, data);
}
static int
lpbb_getdataline(device_t dev)
{
struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev);
return (getSDA(sc));
}
DRIVER_MODULE(lpbb, root, lpbb_driver, lpbb_devclass, 0, 0);