ppntinit.c

simple MIPS EJTAG u-boot loader

static int parport_epp(void)
{
	/* If EPP timeout bit clear then EPP available */
	if (!pp_nt_epp_clear_timeout())
		return 0;  /* No way to clear timeout */

	/*
	 * Theory:
	 *     Write two values to the EPP address register and
	 *     read them back. When the transfer times out, the state of
	 *     the EPP register is undefined in some cases (EPP 1.9?) but
	 *     in others (EPP 1.7, ECPEPP?) it is possible to read back
	 *     its value.
	 */

	pp_nt_epp_clear_timeout();
	usleep(30); /* Wait for possible EPP timeout */

	parport_nt_write_eppaddr(0x55);
	pp_nt_epp_clear_timeout();
	usleep(30); /* Wait for possible EPP timeout */

	if (parport_nt_read_eppaddr() == 0x55) {
		parport_nt_write_eppaddr(0xaa);
		pp_nt_epp_clear_timeout();
		usleep(30); /* Wait for possible EPP timeout */
		if (parport_nt_read_eppaddr() == 0xaa) {
			pp_nt_epp_clear_timeout();
			return PARPORT_MODE_PCEPP;
		}
	}

	/*
	 * Theory:
	 *	Bit 0 of STR is the EPP timeout bit, this bit is 0
	 *	when EPP is possible and is set high when an EPP timeout
	 *	occurs (EPP uses the HALT line to stop the CPU while it does
	 *	the byte transfer, an EPP timeout occurs if the attached
	 *	device fails to respond after 10 micro seconds).
	 *
	 *	This bit is cleared by either reading it (National Semi)
	 *	or writing a 1 to the bit (SMC, UMC, WinBond), others ???
	 *	This bit is always high in non EPP modes.
	 */

	parport_nt_frob_control(0x20, 0x20);
	parport_nt_frob_control(0x10, 0x10);
	pp_nt_epp_clear_timeout();
	
	parport_nt_read_eppdata();
	usleep(30);  /* Wait for possible EPP timeout */
	
	if (parport_nt_read_status() & 0x01) {
		pp_nt_epp_clear_timeout();
		return PARPORT_MODE_PCEPP;
	}
	return 0;
}

static int parport_ecpepp(void)
{
	int mode;
	unsigned char oecr;

	oecr = parport_nt_read_econtrol();
	/* Search for SMC style EPP+ECP mode */
	parport_nt_write_econtrol(0x80);
	mode = parport_epp();
	parport_nt_write_econtrol(oecr);
       	return mode ? PARPORT_MODE_PCECPEPP : 0;
}

/* Detect PS/2 support.
 *
 * Bit 5 (0x20) sets the PS/2 data direction; setting this high
 * allows us to read data from the data lines.  In theory we would get back
 * 0xff but any peripheral attached to the port may drag some or all of the
 * lines down to zero.  So if we get back anything that isn't the contents
 * of the data register we deem PS/2 support to be present. 
 *
 * Some SPP ports have "half PS/2" ability - you can't turn off the line
 * drivers, but an external peripheral with sufficiently beefy drivers of
 * its own can overpower them and assert its own levels onto the bus, from
 * where they can then be read back as normal.  Ports with this property
 * and the right type of device attached are likely to fail the SPP test,
 * (as they will appear to have stuck bits) and so the fact that they might
 * be misdetected here is rather academic. 
 */

static int parport_ps2(void)
{
	int ok = 0;
	unsigned char octr = parport_nt_read_control();
  
	pp_nt_epp_clear_timeout();

	parport_nt_write_control(octr | 0x20);  /* try to tri-state the buffer */
	
	parport_nt_write_data(0x55);
	if (parport_nt_read_data() != 0x55) ok++;
	parport_nt_write_data(0xaa);
	if (parport_nt_read_data() != 0xaa) ok++;

	parport_nt_write_control(octr);          /* cancel input mode */

	return ok ? PARPORT_MODE_PCPS2 : 0;
}

static int parport_ecpps2(void)
{
	int mode;
	unsigned char oecr;

	oecr = parport_nt_read_econtrol();
	parport_nt_write_econtrol(0x20);
      	mode = parport_ps2();
	parport_nt_write_econtrol(oecr);
	return mode ? PARPORT_MODE_PCECPPS2 : 0;
}

/* ---------------------------------------------------------------------- */

#define SERVICENAME        "eppflex"
#define SERVICEDISPLAYNAME "Baycom EPPFLEX"
//#define SERVICEBINARY      "\"\\??\\g:\\nteppflex\\eppflex.sys\""
#define SERVICEBINARY      "System32\\drivers\\eppflex.sys"

static int start_service(void)
{
        int ret = -1;
        SC_HANDLE hscm, hserv;
        
        hscm = OpenSCManager(NULL, NULL, SC_MANAGER_CREATE_SERVICE);
        if (!hscm) {
                lprintf(5, "Cannot open SC manager, error 0x%08lx\n", GetLastError());
                return -1;
        }
        hserv = CreateService(hscm, SERVICENAME, SERVICEDISPLAYNAME,
                              SERVICE_ALL_ACCESS, SERVICE_KERNEL_DRIVER, SERVICE_DEMAND_START, SERVICE_ERROR_NORMAL,
                              SERVICEBINARY, NULL, NULL, NULL, NULL, NULL);
        if (!hserv) {
                lprintf(5, "Cannot create service, error 0x%08lx\n", GetLastError());
                hserv = OpenService(hscm, SERVICENAME, SERVICE_ALL_ACCESS);
                if (!hserv) {
                        lprintf(5, "Cannot open service, error 0x%08lx\n", GetLastError());
                        goto closescm;
                }
        }
        if (!StartService(hserv, 0, NULL)) {
                lprintf(5, "Cannot start service, error 0x%08lx\n", GetLastError());
                goto closeserv;
        }
        lprintf(1, "Service %s started successfully\n", SERVICENAME);
        ret = 0;

  closeserv:
        if (!CloseServiceHandle(hserv))
                lprintf(5, "Cannot close service handle, error 0x%08lx\n", GetLastError());
  closescm:
        if (!CloseServiceHandle(hscm))
                lprintf(5, "Cannot close service manager handle, error 0x%08lx\n", GetLastError());
        return ret;
}

static int stop_service(void)
{
        int ret = -1;
        SC_HANDLE hscm, hserv;
        SERVICE_STATUS sstat;
        
        hscm = OpenSCManager(NULL, NULL, SC_MANAGER_CREATE_SERVICE);
        if (!hscm) {
                lprintf(5, "Cannot open SC manager, error 0x%08lx\n", GetLastError());
                return -1;
        }
        hserv = OpenService(hscm, SERVICENAME, SERVICE_ALL_ACCESS);
        if (!hserv) {
                lprintf(5, "Cannot open service, error 0x%08lx\n", GetLastError());
                goto closescm;
        }
        ret = 0;
        if (!ControlService(hserv, SERVICE_CONTROL_STOP, &sstat)) {
                lprintf(5, "Cannot delete service, error 0x%08lx\n", GetLastError());
                ret = -1;
        }
        if (!DeleteService(hserv)) {
                lprintf(5, "Cannot delete service, error 0x%08lx\n", GetLastError());
                ret = -1;
        }
        if (!ret)
                lprintf(1, "Service %s stopped successfully\n", SERVICENAME);
        if (!CloseServiceHandle(hserv))
                lprintf(5, "Cannot close service handle, error 0x%08lx\n", GetLastError());
  closescm:
        if (!CloseServiceHandle(hscm))
                lprintf(5, "Cannot close service manager handle, error 0x%08lx\n", GetLastError());
        return ret;
}

/* ---------------------------------------------------------------------- */

void parport_stop_nt(void)
{
        if (pp_nt_handle != INVALID_HANDLE_VALUE)
                CloseHandle(pp_nt_handle);
	pp_nt_handle = INVALID_HANDLE_VALUE;
        stop_service();
}

/* ---------------------------------------------------------------------- */

int parport_init_nt_flags(unsigned int portnr, unsigned int flags)
{
        char buf[32];

	if (pp_nt_handle != INVALID_HANDLE_VALUE)
		CloseHandle(pp_nt_handle);
        start_service();
        snprintf(buf, sizeof(buf), "\\\\.\\eppflex\\%u", portnr);
	pp_nt_handle = CreateFile(buf, GENERIC_READ | GENERIC_WRITE,
                                  FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
                                  OPEN_EXISTING, 0, NULL);
	if (pp_nt_handle == INVALID_HANDLE_VALUE) {
		lprintf(0, "Cannot open eppflex.sys driver, error 0x%08lx\n", GetLastError());
		goto err;
	}
	pp_nt_flags = FLAGS_PCSPP;
	if (!parport_spp()) {
		lprintf(0, "No parport present\n");
		goto err;
	}
	if (parport_ecr()) {
		pp_nt_flags |= FLAGS_PCECR;
		pp_nt_flags |= parport_ecp();
		pp_nt_flags |= parport_ecpps2();
		pp_nt_flags |= parport_ecpepp();
		if ((flags & PPFLAG_FORCEHWEPP) && 
		    (pp_nt_flags & (FLAGS_PCPS2|FLAGS_PCECPPS2)) &&
		    !(pp_nt_flags & (FLAGS_PCEPP|FLAGS_PCECPEPP)))
			pp_nt_flags |= FLAGS_PCECPEPP;
		else
			flags &= ~PPFLAG_FORCEHWEPP;
	} else {
		pp_nt_flags |= parport_ps2();
		pp_nt_flags |= parport_epp();
		if ((flags & PPFLAG_FORCEHWEPP) && 
		    (pp_nt_flags & (FLAGS_PCPS2|FLAGS_PCECPPS2)) &&
		    !(pp_nt_flags & (FLAGS_PCEPP|FLAGS_PCECPEPP)))
			pp_nt_flags |= FLAGS_PCEPP;
		else
			flags &= ~PPFLAG_FORCEHWEPP;
	}
	lprintf(0, "Parport capabilities: SPP%s%s%s%s%s%s\n",
		(pp_nt_flags & FLAGS_PCPS2) ? ", PS2" : "",
		(pp_nt_flags & FLAGS_PCEPP) ? ((flags & PPFLAG_FORCEHWEPP) ? ", EPP (forced)" : ", EPP") : "",
		(pp_nt_flags & FLAGS_PCECR) ? ", ECR" : "",
		(pp_nt_flags & FLAGS_PCECP) ? ", ECP" : "",
		(pp_nt_flags & FLAGS_PCECPEPP) ? ((flags & PPFLAG_FORCEHWEPP) ? ", ECPEPP (forced)" : ", ECPEPP") : "",
		(pp_nt_flags & FLAGS_PCECPPS2) ? ", ECPPS2" : "");
	if (!(pp_nt_flags & (FLAGS_PCPS2 | FLAGS_PCECPPS2)))  {
		lprintf(0, "Parport does not even support PS/2 mode, cannot use it\n");
		goto err;
	}
	lprintf(0, "Parport using NT eppflex.sys hardware access");
	if (pp_nt_flags & FLAGS_PCECR)
		parport_nt_write_econtrol(0x30); /* PS/2 mode */
	parport_ops = parport_nt_ops;
	if ((flags & PPFLAG_SWEMULECP) || !(pp_nt_flags & FLAGS_PCECP)) {
		parport_ops.parport_ecp_write_data = parport_nt_emul_ops.parport_ecp_write_data;
		parport_ops.parport_ecp_read_data = parport_nt_emul_ops.parport_ecp_read_data;
		parport_ops.parport_ecp_write_addr = parport_nt_emul_ops.parport_ecp_write_addr;
		lprintf(0, ", emulating ECP");
	}
	if ((flags & PPFLAG_SWEMULEPP) || !(pp_nt_flags & (FLAGS_PCEPP | FLAGS_PCECPEPP))) {
		parport_ops.parport_epp_write_data = parport_nt_emul_ops.parport_epp_write_data;
		parport_ops.parport_epp_read_data = parport_nt_emul_ops.parport_epp_read_data;
		parport_ops.parport_epp_write_addr = parport_nt_emul_ops.parport_epp_write_addr;
		parport_ops.parport_epp_read_addr = parport_nt_emul_ops.parport_epp_read_addr;
		lprintf(0, ", emulating EPP");
	}
	lprintf(0, "\n");
	return 0;

  err:
        parport_stop_nt();
	return -1;
}

int parport_init_nt(unsigned int portnr)
{
        return parport_init_nt_flags(portnr, 0);
}