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/*-
* 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/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", 0);
}
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, iicbus;
/* add generic bit-banging code */
bitbang = device_add_child(dev, "iicbb", -1);
/* 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);
}
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 getSDA(device_t ppbus)
{
if((ppb_rstr(ppbus)&SDA_in)==SDA_in)
return 1;
else
return 0;
}
static void setSDA(device_t ppbus, char val)
{
if(val==0)
ppb_wdtr(ppbus, (u_char)SDA_out);
else
ppb_wdtr(ppbus, (u_char)~SDA_out);
}
static void setSCL(device_t ppbus, unsigned char val)
{
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 */
setSDA(ppbus, 1);
setSCL(ppbus, 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);
/* reset bus */
setSDA(ppbus, 1);
setSCL(ppbus, 1);
return (IIC_ENOADDR);
}
static void
lpbb_setlines(device_t dev, int ctrl, int data)
{
device_t ppbus = device_get_parent(dev);
setSCL(ppbus, ctrl);
setSDA(ppbus, data);
}
static int
lpbb_getdataline(device_t dev)
{
device_t ppbus = device_get_parent(dev);
return (getSDA(ppbus));
}
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_setlines, lpbb_setlines),
DEVMETHOD(iicbb_getdataline, lpbb_getdataline),
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);
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