int __init led_init()

in led.c [684:767]

• 68 lines of code
• 18 McCabe index (conditional complexity)

int __init led_init(void)
{
	struct pdc_chassis_info chassis_info;
	int ret;

	snprintf(lcd_text_default, sizeof(lcd_text_default),
		"Linux %s", init_utsname()->release);

	/* Work around the buggy PDC of KittyHawk-machines */
	switch (CPU_HVERSION) {
	case 0x580:		/* KittyHawk DC2-100 (K100) */
	case 0x581:		/* KittyHawk DC3-120 (K210) */
	case 0x582:		/* KittyHawk DC3 100 (K400) */
	case 0x583:		/* KittyHawk DC3 120 (K410) */
	case 0x58B:		/* KittyHawk DC2 100 (K200) */
		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
		lcd_no_led_support = 1;
		goto found;	/* use the preinitialized values of lcd_info */
	}

	/* initialize the struct, so that we can check for valid return values */
	lcd_info.model = DISPLAY_MODEL_NONE;
	chassis_info.actcnt = chassis_info.maxcnt = 0;

	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
	if (ret == PDC_OK) {
		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
			 "lcd_width=%d, cmd_delay=%u,\n"
			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
		         __FILE__, lcd_info.model,
			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
			 __FILE__, sizeof(lcd_info), 
			 chassis_info.actcnt, chassis_info.maxcnt));
		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
			__FILE__, lcd_info.lcd_cmd_reg_addr, 
			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,  
			lcd_info.reset_cmd2, lcd_info.act_enable ));
	
		/* check the results. Some machines have a buggy PDC */
		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
			goto not_found;

		switch (lcd_info.model) {
		case DISPLAY_MODEL_LCD:		/* LCD display */
			if (chassis_info.actcnt < 
				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
				goto not_found;
			if (!lcd_info.act_enable) {
				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
				goto not_found;
			}
			break;

		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
			printk(KERN_INFO "PDC reported no LCD or LED.\n");
			goto not_found;

		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
				goto not_found;
			break;

		default:
			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
			       lcd_info.model);
			goto not_found;
		} /* switch() */

found:
		/* register the LCD/LED driver */
		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
		return 0;

	} else { /* if() */
		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
	}

not_found:
	lcd_info.model = DISPLAY_MODEL_NONE;
	return 1;
}