FreeBSD/Linux Kernel Cross Reference
sys/dev/ppbus/lpbb.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 void lpbb_print_child(device_t, 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,      lpbb_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,
            DRIVER_TYPE_MISC,
            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));
   }
   
   static void
   lpbb_print_child(device_t bus, device_t dev)
   {
           printf(" on %s%d", device_get_name(bus), device_get_unit(bus));
   
           return;
   }
   
   DRIVER_MODULE(lpbb, root, lpbb_driver, lpbb_devclass, 0, 0);

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