prep_setup.c

一个2.4.21版本的嵌入式linux内核

	seq_printf(m, "machine\t\t: PReP %s\n", Motherboard_map_name);

	/* report amount and type of L2 cache present */
	seq_printf(m, "l2 cache\t: ");
	switch (cachew & L2CACHE_MASK) {
		case L2CACHE_512KB:
			seq_printf(m, "512KiB");
			break;
		case L2CACHE_256KB:
			seq_printf(m, "256KiB");
			break;
		case L2CACHE_1MB:
			seq_printf(m, "1MiB");
			break;
		case L2CACHE_NONE:
			seq_printf(m, "none\n");
			goto no_l2;
			break;
		default:
			seq_printf(m, "%x\n", cachew);
	}

	seq_printf(m, ", parity %s",
			(cachew & L2CACHE_PARITY)? "enabled" : "disabled");

	seq_printf(m, " SRAM:");

	switch ( ((cachew & 0xf0) >> 4) & ~(0x3) ) {
		case 1: seq_printf(m, "synchronous, parity, flow-through\n");
				break;
		case 2: seq_printf(m, "asynchronous, no parity\n");
				break;
		case 3: seq_printf(m, "asynchronous, parity\n");
				break;
		default:seq_printf(m, "synchronous, pipelined, no parity\n");
				break;
	}

no_l2:
#ifdef CONFIG_PREP_RESIDUAL
	/* print info about SIMMs */
	if (res->ResidualLength != 0) {
		int i;
		seq_printf(m, "simms\t\t: ");
		for (i = 0; (res->ActualNumMemories) && (i < MAX_MEMS); i++) {
			if (res->Memories[i].SIMMSize != 0)
				seq_printf(m, "%d:%ldM ", i,
					(res->Memories[i].SIMMSize > 1024) ? 
					res->Memories[i].SIMMSize>>20 : 
					res->Memories[i].SIMMSize);
		}
		seq_printf(m, "\n");
	}
#endif

	return 0;
}

static void __prep
prep_restart(char *cmd)
{
#define PREP_SP92	0x92	/* Special Port 92 */
	__cli(); /* no interrupts */

	/* set exception prefix high - to the prom */
	_nmask_and_or_msr(0, MSR_IP);

	/* make sure bit 0 (reset) is a 0 */
	outb( inb(PREP_SP92) & ~1L , PREP_SP92);
	/* signal a reset to system control port A - soft reset */
	outb( inb(PREP_SP92) | 1 , PREP_SP92);

	while ( 1 ) ;
	/* not reached */
#undef PREP_SP92
}

static void __prep
prep_halt(void)
{
	__cli(); /* no interrupts */

	/* set exception prefix high - to the prom */
	_nmask_and_or_msr(0, MSR_IP);

	while ( 1 ) ;
	/* not reached */
}

/* Carrera is the power manager in the Thinkpads. Unfortunately not much is
 * known about it, so we can't power down.
 */
static void __prep
prep_carrera_poweroff(void)
{
	prep_halt();
}

/*
 * On most IBM PReP's, power management is handled by a Signetics 87c750
 * behind the Utah component on the ISA bus. To access the 750 you must write
 * a series of nibbles to port 0x82a (decoded by the Utah). This is described
 * somewhat in the IBM Carolina Technical Specification.
 * -Hollis
 */
static void __prep
utah_sig87c750_setbit(unsigned int bytenum, unsigned int bitnum, int value)
{
	/*
	 * byte1: 0 0 0 1 0  d  a5 a4
	 * byte2: 0 0 0 1 a3 a2 a1 a0
	 *
	 * d = the bit's value, enabled or disabled
	 * (a5 a4 a3) = the byte number, minus 20
	 * (a2 a1 a0) = the bit number
	 *
	 * example: set the 5th bit of byte 21 (21.5)
	 *     a5 a4 a3 = 001 (byte 1)
	 *     a2 a1 a0 = 101 (bit 5)
	 *
	 *     byte1 = 0001 0100 (0x14)
	 *     byte2 = 0001 1101 (0x1d)
	 */
	unsigned char byte1=0x10, byte2=0x10;

	/* the 750's '20.0' is accessed as '0.0' through Utah (which adds 20) */
	bytenum -= 20;

	byte1 |= (!!value) << 2;		/* set d */
	byte1 |= (bytenum >> 1) & 0x3;	/* set a5, a4 */

	byte2 |= (bytenum & 0x1) << 3;	/* set a3 */
	byte2 |= bitnum & 0x7;			/* set a2, a1, a0 */

	outb(byte1, PREP_IBM_PM1);	/* first nibble */
	mb();
	udelay(100);				/* important: let controller recover */

	outb(byte2, PREP_IBM_PM1);	/* second nibble */
	mb();
	udelay(100);				/* important: let controller recover */
}

static void __prep
prep_sig750_poweroff(void)
{
	/* tweak the power manager found in most IBM PRePs (except Thinkpads) */
	unsigned long flags;
	__cli();
	/* set exception prefix high - to the prom */
	save_flags( flags );
	restore_flags( flags|MSR_IP );

	utah_sig87c750_setbit(21, 5, 1); /* set bit 21.5, "PMEXEC_OFF" */

	while (1) ;
	/* not reached */
}

static int __prep
prep_show_percpuinfo(struct seq_file *m, int i)
{
	/* PREP's without residual data will give incorrect values here */
	seq_printf(m, "clock\t\t: ");
#ifdef CONFIG_PREP_RESIDUAL	
	if (res->ResidualLength)
		seq_printf(m, "%ldMHz\n",
			   (res->VitalProductData.ProcessorHz > 1024) ?
			   res->VitalProductData.ProcessorHz / 1000000 :
			   res->VitalProductData.ProcessorHz);
	else
#endif /* CONFIG_PREP_RESIDUAL */
		seq_printf(m, "???\n");

	return 0;
}

#ifdef CONFIG_SOUND_CS4232 
static long __init masktoint(unsigned int i)
{
	int t = -1;
	while (i >> ++t)
		;
	return (t-1);
}

/*
 * ppc_cs4232_dma and ppc_cs4232_dma2 are used in include/asm/dma.h
 * to distinguish sound dma-channels from others. This is because 
 * blocksize on 16 bit dma-channels 5,6,7 is 128k, but
 * the cs4232.c uses 64k like on 8 bit dma-channels 0,1,2,3
 */

static void __init prep_init_sound(void)
{
	PPC_DEVICE *audiodevice = NULL;

	/*
	 * Get the needed resource informations from residual data.
	 * 
	 */
#ifdef CONFIG_PREP_RESIDUAL
	audiodevice = residual_find_device(~0, NULL, MultimediaController,
			AudioController, -1, 0);
	if (audiodevice != NULL) {
		PnP_TAG_PACKET *pkt;

		pkt = PnP_find_packet((unsigned char *)&res->DevicePnPHeap[audiodevice->AllocatedOffset],
				S5_Packet, 0);
		if (pkt != NULL)
			ppc_cs4232_dma = masktoint(pkt->S5_Pack.DMAMask);
		pkt = PnP_find_packet((unsigned char*)&res->DevicePnPHeap[audiodevice->AllocatedOffset],
				S5_Packet, 1);
		if (pkt != NULL)
			ppc_cs4232_dma2 = masktoint(pkt->S5_Pack.DMAMask);
	}
#endif

	/*
	 * These are the PReP specs' defaults for the cs4231.  We use these
	 * as fallback incase we don't have residual data.
	 * At least the IBM Thinkpad 850 with IDE DMA Channels at 6 and 7 
	 * will use the other values.
	 */
	if (audiodevice == NULL) {
		switch (_prep_type) {
		case _PREP_IBM:
			ppc_cs4232_dma = 1;
			ppc_cs4232_dma2 = -1;
			break;
		default: 
			ppc_cs4232_dma = 6;
			ppc_cs4232_dma2 = 7;
		}
	}

	/*
	 * Find a way to push these informations to the cs4232 driver
	 * Give it out with printk, when not in cmd_line?
	 * Append it to  cmd_line and saved_command_line?
	 * Format is cs4232=io,irq,dma,dma2
	 */
}
#endif /* CONFIG_SOUND_CS4232 */

/*
 * Fill out screen_info according to the residual data. This allows us to use
 * at least vesafb.
 */
static void __init
prep_init_vesa(void)
{
#if defined(CONFIG_PREP_RESIDUAL) && \
	(defined(CONFIG_FB_VGA16) || defined(CONFIG_FB_VGA_16_MODULE) || \
	 defined(CONFIG_FB_VESA))
	PPC_DEVICE *vgadev;

	vgadev = residual_find_device(~0, NULL, DisplayController, SVGAController,
									-1, 0);
	if (vgadev != NULL) {
		PnP_TAG_PACKET *pkt;

		pkt = PnP_find_large_vendor_packet(
				(unsigned char *)&res->DevicePnPHeap[vgadev->AllocatedOffset],
				0x04, 0); /* 0x04 = Display Tag */
		if (pkt != NULL) {
			unsigned char *ptr = (unsigned char *)pkt;

			if (ptr[4]) {
				/* graphics mode */
				screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;

				screen_info.lfb_depth = ptr[4] * 8;

				screen_info.lfb_width = swab16(*(short *)(ptr+6));
				screen_info.lfb_height = swab16(*(short *)(ptr+8));
				screen_info.lfb_linelength = swab16(*(short *)(ptr+10));

				screen_info.lfb_base = swab32(*(long *)(ptr+12));
				screen_info.lfb_size = swab32(*(long *)(ptr+20)) / 65536;
			}
		}
	}
#endif /* CONFIG_PREP_RESIDUAL */
}

static void __init
prep_setup_arch(void)
{
	unsigned char reg;
	int is_ide=0;

	/* init to some ~sane value until calibrate_delay() runs */
	loops_per_jiffy = 50000000;
	
	/* Lookup PCI host bridges */
	prep_find_bridges();
	
	/* Set up floppy in PS/2 mode */
	outb(0x09, SIO_CONFIG_RA);
	reg = inb(SIO_CONFIG_RD);
	reg = (reg & 0x3F) | 0x40;
	outb(reg, SIO_CONFIG_RD);
	outb(reg, SIO_CONFIG_RD);	/* Have to write twice to change! */

	switch ( _prep_type )
	{
	case _PREP_IBM:
		reg = inb(PREP_IBM_PLANAR);
		printk(KERN_INFO "IBM planar ID: %08x", reg);
		switch (reg) {
			case PREP_IBM_SANDALFOOT:
				prep_gen_enable_l2();
				setup_ibm_pci = prep_sandalfoot_setup_pci;
				ppc_md.power_off = prep_sig750_poweroff;
				ppc_md.show_cpuinfo = prep_sandalfoot_cpuinfo;
				break;
			case PREP_IBM_THINKPAD:
				prep_gen_enable_l2();
				setup_ibm_pci = prep_thinkpad_setup_pci;
				ppc_md.power_off = prep_carrera_poweroff;
				ppc_md.show_cpuinfo = prep_thinkpad_cpuinfo;
				break;
			default:
				printk(" -- unknown! Assuming Carolina");
			case PREP_IBM_CAROLINA_IDE_0:
			case PREP_IBM_CAROLINA_IDE_1:
			case PREP_IBM_CAROLINA_IDE_2:
				is_ide = 1;
			case PREP_IBM_CAROLINA_SCSI_0:
			case PREP_IBM_CAROLINA_SCSI_1:
			case PREP_IBM_CAROLINA_SCSI_2:
			case PREP_IBM_CAROLINA_SCSI_3:
				prep_carolina_enable_l2();
				setup_ibm_pci = prep_carolina_setup_pci;
				ppc_md.power_off = prep_sig750_poweroff;
				ppc_md.show_cpuinfo = prep_carolina_cpuinfo;
				break;
			case PREP_IBM_TIGER1_133:
			case PREP_IBM_TIGER1_166:
			case PREP_IBM_TIGER1_180:
			case PREP_IBM_TIGER1_xxx:
			case PREP_IBM_TIGER1_333:
				prep_carolina_enable_l2();
				setup_ibm_pci = prep_tiger1_setup_pci;
				ppc_md.power_off = prep_sig750_poweroff;
				ppc_md.show_cpuinfo = prep_tiger1_cpuinfo;
				break;
		}
		printk("\n");

		/* default root device */
		if (is_ide)
			ROOT_DEV = to_kdev_t(0x0303); /* hda3 */
		else
			ROOT_DEV = to_kdev_t(0x0803); /* sda3 */

		break;
	case _PREP_Motorola:
		prep_gen_enable_l2();
		ppc_md.power_off = prep_halt;
		ppc_md.show_cpuinfo = prep_mot_cpuinfo;

#ifdef CONFIG_BLK_DEV_INITRD
		if (initrd_start)
			ROOT_DEV = MKDEV(RAMDISK_MAJOR, 0); /* /dev/ram */
		else
#endif
#ifdef CONFIG_ROOT_NFS
			ROOT_DEV = to_kdev_t(0x00ff); /* /dev/nfs */
#else
			ROOT_DEV = to_kdev_t(0x0802); /* /dev/sda2 */
#endif
		break;
	}

	/* Read in NVRAM data */ 
	init_prep_nvram();

	/* if no bootargs, look in NVRAM */
	if ( cmd_line[0] == '\0' ) {
		char *bootargs;
		 bootargs = prep_nvram_get_var("bootargs");
		 if (bootargs != NULL) {
			 strcpy(cmd_line, bootargs);
			 /* again.. */
			 strcpy(saved_command_line, cmd_line);
		}
	}

#ifdef CONFIG_SOUND_CS4232 
	prep_init_sound();
#endif /* CONFIG_SOUND_CS4232 */

	prep_init_vesa();

	switch (_prep_type) {
	case _PREP_Motorola:
		raven_init();
		break;
	case _PREP_IBM:
		ibm_prep_init();
		break;
	}

#ifdef CONFIG_VGA_CONSOLE