static void pmz_irda_setup()

in serial/pmac_zilog.c [1100:1227]

• 105 lines of code
• 21 McCabe index (conditional complexity)

static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
{
	u8 cmdbyte;
	int t, version;

	switch (*baud) {
	/* SIR modes */
	case 2400:
		cmdbyte = 0x53;
		break;
	case 4800:
		cmdbyte = 0x52;
		break;
	case 9600:
		cmdbyte = 0x51;
		break;
	case 19200:
		cmdbyte = 0x50;
		break;
	case 38400:
		cmdbyte = 0x4f;
		break;
	case 57600:
		cmdbyte = 0x4e;
		break;
	case 115200:
		cmdbyte = 0x4d;
		break;
	/* The FIR modes aren't really supported at this point, how
	 * do we select the speed ? via the FCR on KeyLargo ?
	 */
	case 1152000:
		cmdbyte = 0;
		break;
	case 4000000:
		cmdbyte = 0;
		break;
	default: /* 9600 */
		cmdbyte = 0x51;
		*baud = 9600;
		break;
	}

	/* Wait for transmitter to drain */
	t = 10000;
	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0
	       || (read_zsreg(uap, R1) & ALL_SNT) == 0) {
		if (--t <= 0) {
			pmz_error("transmitter didn't drain\n");
			return;
		}
		udelay(10);
	}

	/* Drain the receiver too */
	t = 100;
	(void)read_zsdata(uap);
	(void)read_zsdata(uap);
	(void)read_zsdata(uap);
	mdelay(10);
	while (read_zsreg(uap, R0) & Rx_CH_AV) {
		read_zsdata(uap);
		mdelay(10);
		if (--t <= 0) {
			pmz_error("receiver didn't drain\n");
			return;
		}
	}

	/* Switch to command mode */
	uap->curregs[R5] |= DTR;
	write_zsreg(uap, R5, uap->curregs[R5]);
	zssync(uap);
	mdelay(1);

	/* Switch SCC to 19200 */
	pmz_convert_to_zs(uap, CS8, 0, 19200);		
	pmz_load_zsregs(uap, uap->curregs);
	mdelay(1);

	/* Write get_version command byte */
	write_zsdata(uap, 1);
	t = 5000;
	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
		if (--t <= 0) {
			pmz_error("irda_setup timed out on get_version byte\n");
			goto out;
		}
		udelay(10);
	}
	version = read_zsdata(uap);

	if (version < 4) {
		pmz_info("IrDA: dongle version %d not supported\n", version);
		goto out;
	}

	/* Send speed mode */
	write_zsdata(uap, cmdbyte);
	t = 5000;
	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
		if (--t <= 0) {
			pmz_error("irda_setup timed out on speed mode byte\n");
			goto out;
		}
		udelay(10);
	}
	t = read_zsdata(uap);
	if (t != cmdbyte)
		pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte);

	pmz_info("IrDA setup for %ld bps, dongle version: %d\n",
		 *baud, version);

	(void)read_zsdata(uap);
	(void)read_zsdata(uap);
	(void)read_zsdata(uap);

 out:
	/* Switch back to data mode */
	uap->curregs[R5] &= ~DTR;
	write_zsreg(uap, R5, uap->curregs[R5]);
	zssync(uap);

	(void)read_zsdata(uap);
	(void)read_zsdata(uap);
	(void)read_zsdata(uap);
}