piix.c

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/*
 *  linux/drivers/ide/pci/piix.c	Version 0.54	Sep 5, 2007
 *
 *  Copyright (C) 1998-1999 Andrzej Krzysztofowicz, Author and Maintainer
 *  Copyright (C) 1998-2000 Andre Hedrick <[e-mail]>
 *  Copyright (C) 2003 Red Hat Inc <[e-mail]>
 *  Copyright (C) 2006-2007 MontaVista Software, Inc. <[e-mail]>
 *
 *  May be copied or modified under the terms of the GNU General Public License
 *
 *  PIO mode setting function for Intel chipsets.
 *  For use instead of BIOS settings.
 *
 * 40-41
 * 42-43
 * 
 *                 41
 *                 43
 *
 * | PIO 0       | c0 | 80 | 0 |
 * | PIO 2 | SW2 | d0 | 90 | 4 |
 * | PIO 3 | MW1 | e1 | a1 | 9 |
 * | PIO 4 | MW2 | e3 | a3 | b |
 *
 * sitre = word40 & 0x4000; primary
 * sitre = word42 & 0x4000; secondary
 *
 * 44 8421|8421    hdd|hdb
 *
 * 48 8421         hdd|hdc|hdb|hda udma enabled
 *
 *    0001         hda
 *    0010         hdb
 *    0100         hdc
 *    1000         hdd
 *
 * 4a 84|21        hdb|hda
 * 4b 84|21        hdd|hdc
 *
 *    ata-33/82371AB
 *    ata-33/82371EB
 *    ata-33/82801AB            ata-66/82801AA
 *    00|00 udma 0              00|00 reserved
 *    01|01 udma 1              01|01 udma 3
 *    10|10 udma 2              10|10 udma 4
 *    11|11 reserved            11|11 reserved
 *
 * 54 8421|8421    ata66 drive|ata66 enable
 *
 * pci_read_config_word(HWIF(drive)->pci_dev, 0x40, &reg40);
 * pci_read_config_word(HWIF(drive)->pci_dev, 0x42, &reg42);
 * pci_read_config_word(HWIF(drive)->pci_dev, 0x44, &reg44);
 * pci_read_config_byte(HWIF(drive)->pci_dev, 0x48, &reg48);
 * pci_read_config_word(HWIF(drive)->pci_dev, 0x4a, &reg4a);
 * pci_read_config_byte(HWIF(drive)->pci_dev, 0x54, &reg54);
 *
 * Documentation
 *	Publically available from Intel web site. Errata documentation
 * is also publically available. As an aide to anyone hacking on this
 * driver the list of errata that are relevant is below.going back to
 * PIIX4. Older device documentation is now a bit tricky to find.
 *
 * Errata of note:
 *
 * Unfixable
 *	PIIX4    errata #9	- Only on ultra obscure hw
 *	ICH3	 errata #13     - Not observed to affect real hw
 *				  by Intel
 *
 * Things we must deal with
 *	PIIX4	errata #10	- BM IDE hang with non UDMA
 *				  (must stop/start dma to recover)
 *	440MX   errata #15	- As PIIX4 errata #10
 *	PIIX4	errata #15	- Must not read control registers
 * 				  during a PIO transfer
 *	440MX   errata #13	- As PIIX4 errata #15
 *	ICH2	errata #21	- DMA mode 0 doesn't work right
 *	ICH0/1  errata #55	- As ICH2 errata #21
 *	ICH2	spec c #9	- Extra operations needed to handle
 *				  drive hotswap [NOT YET SUPPORTED]
 *	ICH2    spec c #20	- IDE PRD must not cross a 64K boundary
 *				  and must be dword aligned
 *	ICH2    spec c #24	- UDMA mode 4,5 t85/86 should be 6ns not 3.3
 *
 * Should have been BIOS fixed:
 *	450NX:	errata #19	- DMA hangs on old 450NX
 *	450NX:  errata #20	- DMA hangs on old 450NX
 *	450NX:  errata #25	- Corruption with DMA on old 450NX
 *	ICH3    errata #15      - IDE deadlock under high load
 *				  (BIOS must set dev 31 fn 0 bit 23)
 *	ICH3	errata #18	- Don't use native mode
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/hdreg.h>
#include <linux/ide.h>
#include <linux/delay.h>
#include <linux/init.h>

#include <asm/io.h>

static int no_piix_dma;

/**
 *	piix_set_pio_mode	-	set host controller for PIO mode
 *	@drive: drive
 *	@pio: PIO mode number
 *
 *	Set the interface PIO mode based upon the settings done by AMI BIOS.
 */

static void piix_set_pio_mode(ide_drive_t *drive, const u8 pio)
{
	ide_hwif_t *hwif	= HWIF(drive);
	struct pci_dev *dev	= hwif->pci_dev;
	int is_slave		= drive->dn & 1;
	int master_port		= hwif->channel ? 0x42 : 0x40;
	int slave_port		= 0x44;
	unsigned long flags;
	u16 master_data;
	u8 slave_data;
	static DEFINE_SPINLOCK(tune_lock);
	int control = 0;

				     /* ISP  RTC */
	static const u8 timings[][2]= {
					{ 0, 0 },
					{ 0, 0 },
					{ 1, 0 },
					{ 2, 1 },
					{ 2, 3 }, };

	/*
	 * Master vs slave is synchronized above us but the slave register is
	 * shared by the two hwifs so the corner case of two slave timeouts in
	 * parallel must be locked.
	 */
	spin_lock_irqsave(&tune_lock, flags);
	pci_read_config_word(dev, master_port, &master_data);

	if (pio > 1)
		control |= 1;	/* Programmable timing on */
	if (drive->media == ide_disk)
		control |= 4;	/* Prefetch, post write */
	if (pio > 2)
		control |= 2;	/* IORDY */
	if (is_slave) {
		master_data |=  0x4000;
		master_data &= ~0x0070;
		if (pio > 1) {
			/* Set PPE, IE and TIME */
			master_data |= control << 4;
		}
		pci_read_config_byte(dev, slave_port, &slave_data);
		slave_data &= hwif->channel ? 0x0f : 0xf0;
		slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) <<
			       (hwif->channel ? 4 : 0);
	} else {
		master_data &= ~0x3307;
		if (pio > 1) {
			/* enable PPE, IE and TIME */
			master_data |= control;
		}
		master_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
	}
	pci_write_config_word(dev, master_port, master_data);
	if (is_slave)
		pci_write_config_byte(dev, slave_port, slave_data);
	spin_unlock_irqrestore(&tune_lock, flags);
}

/**
 *	piix_set_dma_mode	-	set host controller for DMA mode
 *	@drive: drive
 *	@speed: DMA mode
 *
 *	Set a PIIX host controller to the desired DMA mode.  This involves
 *	programming the right timing data into the PCI configuration space.
 */

static void piix_set_dma_mode(ide_drive_t *drive, const u8 speed)
{
	ide_hwif_t *hwif	= HWIF(drive);
	struct pci_dev *dev	= hwif->pci_dev;
	u8 maslave		= hwif->channel ? 0x42 : 0x40;
	int a_speed		= 3 << (drive->dn * 4);
	int u_flag		= 1 << drive->dn;
	int v_flag		= 0x01 << drive->dn;
	int w_flag		= 0x10 << drive->dn;
	int u_speed		= 0;
	int			sitre;
	u16			reg4042, reg4a;
	u8			reg48, reg54, reg55;

	pci_read_config_word(dev, maslave, &reg4042);
	sitre = (reg4042 & 0x4000) ? 1 : 0;
	pci_read_config_byte(dev, 0x48, &reg48);
	pci_read_config_word(dev, 0x4a, &reg4a);
	pci_read_config_byte(dev, 0x54, &reg54);
	pci_read_config_byte(dev, 0x55, &reg55);

	switch(speed) {
		case XFER_UDMA_4:
		case XFER_UDMA_2:	u_speed = 2 << (drive->dn * 4); break;
		case XFER_UDMA_5:
		case XFER_UDMA_3:
		case XFER_UDMA_1:	u_speed = 1 << (drive->dn * 4); break;
		case XFER_UDMA_0:	u_speed = 0 << (drive->dn * 4); break;
		case XFER_MW_DMA_2:
		case XFER_MW_DMA_1:
		case XFER_SW_DMA_2:	break;
		default:		return;
	}

	if (speed >= XFER_UDMA_0) {
		if (!(reg48 & u_flag))
			pci_write_config_byte(dev, 0x48, reg48 | u_flag);
		if (speed == XFER_UDMA_5) {
			pci_write_config_byte(dev, 0x55, (u8) reg55|w_flag);
		} else {
			pci_write_config_byte(dev, 0x55, (u8) reg55 & ~w_flag);
		}
		if ((reg4a & a_speed) != u_speed)
			pci_write_config_word(dev, 0x4a, (reg4a & ~a_speed) | u_speed);
		if (speed > XFER_UDMA_2) {
			if (!(reg54 & v_flag))
				pci_write_config_byte(dev, 0x54, reg54 | v_flag);
		} else
			pci_write_config_byte(dev, 0x54, reg54 & ~v_flag);
	} else {
		const u8 mwdma_to_pio[] = { 0, 3, 4 };
		u8 pio;

		if (reg48 & u_flag)
			pci_write_config_byte(dev, 0x48, reg48 & ~u_flag);
		if (reg4a & a_speed)
			pci_write_config_word(dev, 0x4a, reg4a & ~a_speed);
		if (reg54 & v_flag)
			pci_write_config_byte(dev, 0x54, reg54 & ~v_flag);
		if (reg55 & w_flag)
			pci_write_config_byte(dev, 0x55, (u8) reg55 & ~w_flag);

		if (speed >= XFER_MW_DMA_0)
			pio = mwdma_to_pio[speed - XFER_MW_DMA_0];
		else
			pio = 2; /* only SWDMA2 is allowed */

		piix_set_pio_mode(drive, pio);
	}
}

/**
 *	init_chipset_ich	-	set up the ICH chipset
 *	@dev: PCI device to set up
 *	@name: Name of the device
 *
 *	Initialize the PCI device as required.  For the ICH this turns
 *	out to be nice and simple.
 */

static unsigned int __devinit init_chipset_ich(struct pci_dev *dev, const char *name)
{
	u32 extra = 0;