Annotation of sys/dev/ic/z8530sc.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: z8530sc.c,v 1.6 2003/06/02 23:28:02 millert Exp $ */
! 2: /* $NetBSD: z8530sc.c,v 1.4 1996/05/17 19:30:34 gwr Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1994 Gordon W. Ross
! 6: * Copyright (c) 1992, 1993
! 7: * The Regents of the University of California. All rights reserved.
! 8: *
! 9: * This software was developed by the Computer Systems Engineering group
! 10: * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
! 11: * contributed to Berkeley.
! 12: *
! 13: * All advertising materials mentioning features or use of this software
! 14: * must display the following acknowledgement:
! 15: * This product includes software developed by the University of
! 16: * California, Lawrence Berkeley Laboratory.
! 17: *
! 18: * Redistribution and use in source and binary forms, with or without
! 19: * modification, are permitted provided that the following conditions
! 20: * are met:
! 21: * 1. Redistributions of source code must retain the above copyright
! 22: * notice, this list of conditions and the following disclaimer.
! 23: * 2. Redistributions in binary form must reproduce the above copyright
! 24: * notice, this list of conditions and the following disclaimer in the
! 25: * documentation and/or other materials provided with the distribution.
! 26: * 3. Neither the name of the University nor the names of its contributors
! 27: * may be used to endorse or promote products derived from this software
! 28: * without specific prior written permission.
! 29: *
! 30: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 31: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 32: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 33: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 34: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 35: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 36: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 37: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 38: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 39: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 40: * SUCH DAMAGE.
! 41: *
! 42: * @(#)zs.c 8.1 (Berkeley) 7/19/93
! 43: */
! 44:
! 45: /*
! 46: * Zilog Z8530 Dual UART driver (common part)
! 47: *
! 48: * This file contains the machine-independent parts of the
! 49: * driver common to tty and keyboard/mouse sub-drivers.
! 50: */
! 51:
! 52: #include <sys/param.h>
! 53: #include <sys/systm.h>
! 54: #include <sys/proc.h>
! 55: #include <sys/device.h>
! 56: #include <sys/conf.h>
! 57: #include <sys/file.h>
! 58: #include <sys/ioctl.h>
! 59: #include <sys/tty.h>
! 60: #include <sys/time.h>
! 61: #include <sys/kernel.h>
! 62: #include <sys/syslog.h>
! 63:
! 64: #include <dev/ic/z8530reg.h>
! 65: #include <machine/z8530var.h>
! 66:
! 67: static void zsnull_intr(struct zs_chanstate *);
! 68: static void zsnull_softint(struct zs_chanstate *);
! 69:
! 70: void
! 71: zs_break(cs, set)
! 72: struct zs_chanstate *cs;
! 73: int set;
! 74: {
! 75: int s;
! 76:
! 77: s = splzs();
! 78: if (set) {
! 79: cs->cs_preg[5] |= ZSWR5_BREAK;
! 80: cs->cs_creg[5] |= ZSWR5_BREAK;
! 81: } else {
! 82: cs->cs_preg[5] &= ~ZSWR5_BREAK;
! 83: cs->cs_creg[5] &= ~ZSWR5_BREAK;
! 84: }
! 85: zs_write_reg(cs, 5, cs->cs_creg[5]);
! 86: splx(s);
! 87: }
! 88:
! 89:
! 90: /*
! 91: * Compute the current baud rate given a ZSCC channel.
! 92: */
! 93: int
! 94: zs_getspeed(cs)
! 95: struct zs_chanstate *cs;
! 96: {
! 97: int tconst;
! 98:
! 99: tconst = zs_read_reg(cs, 12);
! 100: tconst |= zs_read_reg(cs, 13) << 8;
! 101: return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
! 102: }
! 103:
! 104: /*
! 105: * drain on-chip fifo
! 106: */
! 107: void
! 108: zs_iflush(cs)
! 109: struct zs_chanstate *cs;
! 110: {
! 111: u_char c, rr0, rr1;
! 112:
! 113: for (;;) {
! 114: /* Is there input available? */
! 115: rr0 = zs_read_csr(cs);
! 116: if ((rr0 & ZSRR0_RX_READY) == 0)
! 117: break;
! 118:
! 119: /*
! 120: * First read the status, because reading the data
! 121: * destroys the status of this char.
! 122: */
! 123: rr1 = zs_read_reg(cs, 1);
! 124: c = zs_read_data(cs);
! 125:
! 126: if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
! 127: /* Clear the receive error. */
! 128: zs_write_csr(cs, ZSWR0_RESET_ERRORS);
! 129: }
! 130: }
! 131: }
! 132:
! 133:
! 134: /*
! 135: * Write the given register set to the given zs channel in the proper order.
! 136: * The channel must not be transmitting at the time. The receiver will
! 137: * be disabled for the time it takes to write all the registers.
! 138: * Call this with interrupts disabled.
! 139: */
! 140: void
! 141: zs_loadchannelregs(cs)
! 142: struct zs_chanstate *cs;
! 143: {
! 144: u_char *reg;
! 145:
! 146: /* Copy "pending" regs to "current" */
! 147: bcopy((caddr_t)cs->cs_preg, (caddr_t)cs->cs_creg, 16);
! 148: reg = cs->cs_creg; /* current regs */
! 149:
! 150: zs_write_csr(cs, ZSM_RESET_ERR); /* XXX: reset error condition */
! 151:
! 152: #if 1
! 153: /*
! 154: * XXX: Is this really a good idea?
! 155: * XXX: Should go elsewhere! -gwr
! 156: */
! 157: zs_iflush(cs); /* XXX */
! 158: #endif
! 159:
! 160: /* baud clock divisor, stop bits, parity */
! 161: zs_write_reg(cs, 4, reg[4]);
! 162:
! 163: /* misc. TX/RX control bits */
! 164: zs_write_reg(cs, 10, reg[10]);
! 165:
! 166: /* char size, enable (RX/TX) */
! 167: zs_write_reg(cs, 3, reg[3] & ~ZSWR3_RX_ENABLE);
! 168: zs_write_reg(cs, 5, reg[5] & ~ZSWR5_TX_ENABLE);
! 169:
! 170: /* interrupt enables: TX, TX, STATUS */
! 171: zs_write_reg(cs, 1, reg[1]);
! 172:
! 173: #if 0
! 174: /*
! 175: * Registers 2 and 9 are special because they are
! 176: * actually common to both channels, but must be
! 177: * programmed through channel A. The "zsc" attach
! 178: * function takes care of setting these registers
! 179: * and they should not be touched thereafter.
! 180: */
! 181: /* interrupt vector */
! 182: zs_write_reg(cs, 2, reg[2]);
! 183: /* master interrupt control */
! 184: zs_write_reg(cs, 9, reg[9]);
! 185: #endif
! 186:
! 187: /* clock mode control */
! 188: zs_write_reg(cs, 11, reg[11]);
! 189:
! 190: /* baud rate (lo/hi) */
! 191: zs_write_reg(cs, 12, reg[12]);
! 192: zs_write_reg(cs, 13, reg[13]);
! 193:
! 194: /* Misc. control bits */
! 195: zs_write_reg(cs, 14, reg[14]);
! 196:
! 197: /* which lines cause status interrupts */
! 198: zs_write_reg(cs, 15, reg[15]);
! 199:
! 200: /* char size, enable (RX/TX)*/
! 201: zs_write_reg(cs, 3, reg[3]);
! 202: zs_write_reg(cs, 5, reg[5]);
! 203: }
! 204:
! 205:
! 206: /*
! 207: * ZS hardware interrupt. Scan all ZS channels. NB: we know here that
! 208: * channels are kept in (A,B) pairs.
! 209: *
! 210: * Do just a little, then get out; set a software interrupt if more
! 211: * work is needed.
! 212: *
! 213: * We deliberately ignore the vectoring Zilog gives us, and match up
! 214: * only the number of `reset interrupt under service' operations, not
! 215: * the order.
! 216: */
! 217: int
! 218: zsc_intr_hard(arg)
! 219: void *arg;
! 220: {
! 221: register struct zsc_softc *zsc = arg;
! 222: register struct zs_chanstate *cs_a;
! 223: register struct zs_chanstate *cs_b;
! 224: register int rval;
! 225: register u_char rr3;
! 226:
! 227: cs_a = &zsc->zsc_cs[0];
! 228: cs_b = &zsc->zsc_cs[1];
! 229: rval = 0;
! 230:
! 231: /* Note: only channel A has an RR3 */
! 232: rr3 = zs_read_reg(cs_a, 3);
! 233:
! 234: /* Handle receive interrupts first. */
! 235: if (rr3 & ZSRR3_IP_A_RX)
! 236: (*cs_a->cs_ops->zsop_rxint)(cs_a);
! 237: if (rr3 & ZSRR3_IP_B_RX)
! 238: (*cs_b->cs_ops->zsop_rxint)(cs_b);
! 239:
! 240: /* Handle status interrupts (i.e. flow control). */
! 241: if (rr3 & ZSRR3_IP_A_STAT)
! 242: (*cs_a->cs_ops->zsop_stint)(cs_a);
! 243: if (rr3 & ZSRR3_IP_B_STAT)
! 244: (*cs_b->cs_ops->zsop_stint)(cs_b);
! 245:
! 246: /* Handle transmit done interrupts. */
! 247: if (rr3 & ZSRR3_IP_A_TX)
! 248: (*cs_a->cs_ops->zsop_txint)(cs_a);
! 249: if (rr3 & ZSRR3_IP_B_TX)
! 250: (*cs_b->cs_ops->zsop_txint)(cs_b);
! 251:
! 252: /* Clear interrupt. */
! 253: if (rr3 & (ZSRR3_IP_A_RX | ZSRR3_IP_A_TX | ZSRR3_IP_A_STAT)) {
! 254: zs_write_csr(cs_a, ZSWR0_CLR_INTR);
! 255: rval |= 1;
! 256: }
! 257: if (rr3 & (ZSRR3_IP_B_RX | ZSRR3_IP_B_TX | ZSRR3_IP_B_STAT)) {
! 258: zs_write_csr(cs_b, ZSWR0_CLR_INTR);
! 259: rval |= 2;
! 260: }
! 261:
! 262: if ((cs_a->cs_softreq) || (cs_b->cs_softreq)) {
! 263: /* This is a machine-dependent function (or macro). */
! 264: zsc_req_softint(zsc);
! 265: }
! 266:
! 267: return (rval);
! 268: }
! 269:
! 270:
! 271: /*
! 272: * ZS software interrupt. Scan all channels for deferred interrupts.
! 273: */
! 274: int
! 275: zsc_intr_soft(arg)
! 276: void *arg;
! 277: {
! 278: register struct zsc_softc *zsc = arg;
! 279: register struct zs_chanstate *cs;
! 280: register int rval, unit;
! 281:
! 282: rval = 0;
! 283: for (unit = 0; unit < 2; unit++) {
! 284: cs = &zsc->zsc_cs[unit];
! 285:
! 286: /*
! 287: * The softint flag can be safely cleared once
! 288: * we have decided to call the softint routine.
! 289: * (No need to do splzs() first.)
! 290: */
! 291: if (cs->cs_softreq) {
! 292: cs->cs_softreq = 0;
! 293: (*cs->cs_ops->zsop_softint)(cs);
! 294: rval = 1;
! 295: }
! 296: }
! 297: return (rval);
! 298: }
! 299:
! 300:
! 301: static void
! 302: zsnull_intr(cs)
! 303: struct zs_chanstate *cs;
! 304: {
! 305: zs_write_reg(cs, 1, 0);
! 306: zs_write_reg(cs, 15, 0);
! 307: }
! 308:
! 309: static void
! 310: zsnull_softint(cs)
! 311: struct zs_chanstate *cs;
! 312: {
! 313: }
! 314:
! 315: struct zsops zsops_null = {
! 316: zsnull_intr, /* receive char available */
! 317: zsnull_intr, /* external/status */
! 318: zsnull_intr, /* xmit buffer empty */
! 319: zsnull_softint, /* process software interrupt */
! 320: };
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