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freebsd/sys/dev/ppbus/lpbb.c
Bernd Walter 338cad62ab This makes ppbus childs like lpt and ppi succesfully connect to more
than just the first ppbus.
The child drivers always tried to attach unit 0.

Reviewed by:	gallatin
Approved by:	gallatin
2002-04-07 22:06:20 +00:00

225 lines
5.1 KiB
C

/*-
* Copyright (c) 1998, 2001 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/uio.h>
#include <dev/ppbus/ppbconf.h>
#include "ppbus_if.h"
#include <dev/ppbus/ppbio.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbb_if.h"
static int lpbb_detect(device_t dev);
static void
lpbb_identify(driver_t *driver, device_t parent)
{
BUS_ADD_CHILD(parent, 0, "lpbb", -1);
}
static int
lpbb_probe(device_t dev)
{
/* Perhaps call this during identify instead? */
if (!lpbb_detect(dev))
return (ENXIO);
device_set_desc(dev, "Parallel I2C bit-banging interface");
return (0);
}
static int
lpbb_attach(device_t dev)
{
device_t bitbang;
/* add generic bit-banging code */
bitbang = device_add_child(dev, "iicbb", -1);
device_probe_and_attach(bitbang);
return (0);
}
static int
lpbb_callback(device_t dev, int index, caddr_t *data)
{
device_t ppbus = device_get_parent(dev);
int error = 0;
int how;
switch (index) {
case IIC_REQUEST_BUS:
/* request the ppbus */
how = *(int *)data;
error = ppb_request_bus(ppbus, dev, how);
break;
case IIC_RELEASE_BUS:
/* release the ppbus */
error = ppb_release_bus(ppbus, 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 lpbb_getscl(device_t dev)
{
return ((ppb_rstr(device_get_parent(dev)) & SCL_in) == SCL_in);
}
static int lpbb_getsda(device_t dev)
{
return ((ppb_rstr(device_get_parent(dev)) & SDA_in) == SDA_in);
}
static void lpbb_setsda(device_t dev, char val)
{
device_t ppbus = device_get_parent(dev);
if(val==0)
ppb_wdtr(ppbus, (u_char)SDA_out);
else
ppb_wdtr(ppbus, (u_char)~SDA_out);
}
static void lpbb_setscl(device_t dev, unsigned char val)
{
device_t ppbus = device_get_parent(dev);
if(val==0)
ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out));
else
ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out));
}
static int lpbb_detect(device_t dev)
{
device_t ppbus = device_get_parent(dev);
if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
device_printf(dev, "can't allocate ppbus\n");
return (0);
}
/* reset bus */
lpbb_setsda(dev, 1);
lpbb_setscl(dev, 1);
if ((ppb_rstr(ppbus) & I2CKEY) ||
((ppb_rstr(ppbus) & ALIM) != ALIM)) {
ppb_release_bus(ppbus, dev);
return (0);
}
ppb_release_bus(ppbus, dev);
return (1);
}
static int
lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr)
{
device_t ppbus = device_get_parent(dev);
if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
device_printf(dev, "can't allocate ppbus\n");
return (0);
}
/* reset bus */
lpbb_setsda(dev, 1);
lpbb_setscl(dev, 1);
ppb_release_bus(ppbus, dev);
return (IIC_ENOADDR);
}
static devclass_t lpbb_devclass;
static device_method_t lpbb_methods[] = {
/* device interface */
DEVMETHOD(device_identify, lpbb_identify),
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_setsda, lpbb_setsda),
DEVMETHOD(iicbb_setscl, lpbb_setscl),
DEVMETHOD(iicbb_getsda, lpbb_getsda),
DEVMETHOD(iicbb_getscl, lpbb_getscl),
DEVMETHOD(iicbb_reset, lpbb_reset),
{ 0, 0 }
};
static driver_t lpbb_driver = {
"lpbb",
lpbb_methods,
1,
};
DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0);
MODULE_DEPEND(lpbb, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER);
MODULE_VERSION(lpbb, 1);