Re: [PATCH/RFC] Port of pdc202xx_new driver to libata

["Albert Lee" <albertcc@tw.ibm.com>]

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Hi, Jeff and Bart:

  Thanks for your review and sorry for the late reply.
The updated patch is attached for your review/comment.
(The patch is against libata-dev-2.6)

1.
> why not jus pata_pdc_new? or pata_pdc_27x?

 changed to "pata_pdc2027x".

2.
>  This table is redundant:
>* official names (more detailed) can be get from lspci
>* PDC_UDMA_[100,133] implies PDC_[100,133]_MHZ
>* max UDMA rate is available from ata_port_info etc.

Fixed.

3.
>> + /* For UDMA33, no 80c support is required */
>> + if ((ap->udma_mask & ~ATA_UDMA_MASK_40C) == 0)
>> +  goto cbl40;
>
>this can't happen

Removed.


4.
> pds_set_pio() should be called only once
> pdc_set_ultra() should be called only once

Fixed.

5.
>> + /* Enable the ROM */
>> + if (pdev->resource[PCI_ROM_RESOURCE].start) {
>> +  pci_write_config_dword(pdev, PCI_ROM_ADDRESS,
>> +   pdev->resource[PCI_ROM_RESOURCE].start | PCI_ROM_ADDRESS_ENABLE);
>> +  printk(KERN_INFO DRV_NAME ": ROM enabled at 0x%08lx\n",
>> +         pdev->resource[PCI_ROM_RESOURCE].start);
>> + }
> is this really needed?

Removed.

6.
>> +  * FIXME: If this driver happens to only be useful on Apple's K2, then
>> +  * we should check that here as it has a normal Serverworks ID
>> +  */
>
>cut'n'paste mistake

 Fixed.

7.
> pdc_hardware_init() seems to be the only reason
> why generic ata_pci_init_one() can't be used here,
> what about adding sth. like ->init_device() to
> struct ata_port_info?

 Could this be fixed later?
(I am afraid to touch the core. Need more time to study.)

Thanks,

Albert Lee

----- Original Message ----- 
From: "Jeff Garzik" <jgarzik@pobox.com>
To: "Bartlomiej Zolnierkiewicz" <bzolnier@gmail.com>; "Albert Lee"
<albertcc@tw.ibm.com>
Cc: "IDE Linux" <linux-ide@vger.kernel.org>
Sent: Thursday, October 14, 2004 3:58 AM
Subject: Re: [PATCH/RFC] Port of pdc202xx_new driver to libata


>
> I'll use this message to respond to both Albert and you (Bart).
>
> Bartlomiej Zolnierkiewicz wrote:
> > On Wed, 13 Oct 2004 18:06:19 +0800, Albert Lee <albertcc@tw.ibm.com>
wrote:
> >
> >>Hi, Jeff and Bart:
> >
> >
> > Hi!
> >
> >
> >>  I am trying to port the Promise pdc202xx_new driver to libata and
adding
> >>the
> >>PLL tuning code to it. (The motivation is hotplug of the Promise host
> >>adapter.)
> >
> >
> > I have libata version of pdc202xx_new for a long time now
> > but this one looks superior as it handles PLL. :-)
> >
> >
> >>The ported driver has been tested with pdc20269 and pdc20275 on i386 and
> >>x86_64 boxes, with 33 MHz PCI bus and 66 MHz PCI bus respectively.
> >>It seems to be working fine with harddisk drives.
>
> I got a report that sata_promise has problems in some >=66Mhz
> configurations, but works fine with 33Mhz configuration.  I bet I could
> learn a few things from this driver too, as the concepts probably apply
> to newer hardware.
>
>
> >>(However, CD-ROM drives not working yet, even when
> >>ATA_ENABLE_PATA and ATA_ENABLE_ATAPI are enabled.)
> >
> >
> > Somehow this doesn't surprise me...
>
> hehe :)
>
>
> >>My question is, in the current kernel, the IDE subsystem drives PATA
chips
> >>and libata drives SATA chips. Will PATA driver like this be accepted
into
> >>libata?
> >
> >
> > My opinion is: yes but not now, final answer is of course left to Jeff.
>
> With the progress currently being made, I think my preference would be
> to start collecting PATA drivers such this in my libata-dev queue.
>
> I would not send these PATA drivers upstream until the PATA to-do items
> are complete (see other email), but it would be nice to have a central
> location (both BK and patch on kernel.org) for developers and users to
> mess with PATA support.
>
> So, send PATA drivers to me and I will merge... but please understand
> that I will not send upstream for quite some time.
>
>
>
> >>Albert Lee
> >>(The patch is against 2.6.8.1.)
> >
> >
> > It seems your mail client screwed it.
> >
> > I will try to comment on the patch anyway...
>
> I agree with Bart's comments on the patch.  It was also mangled here.
>
> Albert, if you would resend a patch with Bart's fixes, I'll merge into
> libata-dev.
>
> My own comments:
>
> >> obj-$(CONFIG_SCSI_ATA_PIIX) += libata.o ata_piix.o
> >>> +obj-$(CONFIG_SCSI_PATA_PDC_NEW) += libata.o pata_pdc202xx_new.o
> >
> >
> > why not jus pata_pdc_new? or pata_pdc_27x?
>
> I would prefer to eliminate the "_new" suffix.  Other than that I don't
> really care.  If I had written the driver, I would have named it
> pata_pdc202xx I suppose.
>
>
> > +} pdc_pata_controller_tbl [] = {
> >> + { "Ultra100 TX2",        PDC_UDMA_100, PDC_100_MHZ }, /* pdc20268 */
> >> + { "Ultra133 TX2",        PDC_UDMA_133, PDC_133_MHZ }, /* pdc20269 */
> >> + { "FastTrak LP/TX2/TX4", PDC_UDMA_100, PDC_100_MHZ }, /* pdc20270 */
> >> + { "FastTrak TX2000",     PDC_UDMA_133, PDC_133_MHZ }, /* pdc20271 */
> >> + { "MBUltra133",          PDC_UDMA_133, PDC_133_MHZ }, /* pdc20275 */
> >> + { "MBFastTrak 133 Lite", PDC_UDMA_133, PDC_133_MHZ }, /* pdc20276 */
> >> + { "SBFastTrak 133 Lite", PDC_UDMA_133, PDC_133_MHZ }, /* pdc20277 */
> >> +};
>
> In general I prefer to eliminate _all_ "marketing strings" from all
> drivers.  Model names appear on the market far faster than any
> maintainer could hope to keep up.  (granted, this is old hardware and
> not changing, in this case)  So as a general rule, it is preferred to
> only use strings when absolutely necessary, eliminating them completely
> if at all possible.
>
> > what exacty (besides PLL support) are the advantages
> > of libata driver?
>
> IDE controller hotplug is a lot easier, and proper locking is already
> there :)
>
> Jeff
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-ide" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

[-- Attachment #2: pdc2027x.diff --]
[-- Type: application/octet-stream, Size: 25770 bytes --]

diff -Nru libata-pdc-2.6-ori/drivers/scsi/Kconfig libata-pdc-2.6/drivers/scsi/Kconfig
--- libata-pdc-2.6-ori/drivers/scsi/Kconfig	2004-10-18 17:25:52.000000000 +0800
+++ libata-pdc-2.6/drivers/scsi/Kconfig	2004-10-18 17:27:36.759587840 +0800
@@ -441,6 +441,14 @@
 
 	  If unsure, say N.
 
+config SCSI_PATA_PDC2027X
+	tristate "Promise PATA 2027x support"
+	depends on SCSI_SATA && PCI
+	help
+	  This option enables support for Promise PATA pdc20268 to pdc20277 host adapters.
+
+	  If unsure, say N.
+
 config SCSI_SATA_PROMISE
 	tristate "Promise SATA TX2/TX4 support"
 	depends on SCSI_SATA && PCI
diff -Nru libata-pdc-2.6-ori/drivers/scsi/Makefile libata-pdc-2.6/drivers/scsi/Makefile
--- libata-pdc-2.6-ori/drivers/scsi/Makefile	2004-10-18 17:25:52.000000000 +0800
+++ libata-pdc-2.6/drivers/scsi/Makefile	2004-10-18 17:27:36.796582216 +0800
@@ -124,6 +124,7 @@
 obj-$(CONFIG_SCSI_SATA_AHCI)	+= libata.o ahci.o
 obj-$(CONFIG_SCSI_SATA_SVW)	+= libata.o sata_svw.o
 obj-$(CONFIG_SCSI_ATA_PIIX)	+= libata.o ata_piix.o
+obj-$(CONFIG_SCSI_PATA_PDC2027X)+= libata.o pata_pdc2027x.o
 obj-$(CONFIG_SCSI_SATA_PROMISE)	+= libata.o sata_promise.o
 obj-$(CONFIG_SCSI_SATA_SIL)	+= libata.o sata_sil.o
 obj-$(CONFIG_SCSI_SATA_VIA)	+= libata.o sata_via.o
diff -Nru libata-pdc-2.6-ori/drivers/scsi/pata_pdc2027x.c libata-pdc-2.6/drivers/scsi/pata_pdc2027x.c
--- libata-pdc-2.6-ori/drivers/scsi/pata_pdc2027x.c	1970-01-01 08:00:00.000000000 +0800
+++ libata-pdc-2.6/drivers/scsi/pata_pdc2027x.c	2004-10-18 17:27:37.993400272 +0800
@@ -0,0 +1,758 @@
+/*
+ *  Promise PATA TX2/TX4/TX2000/133 IDE driver for pdc20268 to pdc20277.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ *  Ported to libata by:
+ *  Albert Lee <albertcc@tw.ibm.com> IBM Corporation 
+ *
+ *  Copyright (C) 1998-2002		Andre Hedrick <andre@linux-ide.org>
+ *  Portions Copyright (C) 1999 Promise Technology, Inc.
+ *
+ *  Author: Frank Tiernan (frankt@promise.com)
+ *  Released under terms of General Public License
+ * 
+ * 
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include "scsi.h"
+#include <scsi/scsi_host.h>
+#include <linux/libata.h>
+#include <asm/io.h>
+
+#define DRV_NAME	"pata_pdc2027x"
+#define DRV_VERSION	"0.52"
+#undef PDC_DEBUG
+#undef PDC_20276_QUIRK
+#undef PDC_20270_QUIRK
+
+#ifdef PDC_DEBUG
+#define PDPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__, ## args)
+#else
+#define PDPRINTK(fmt, args...)
+#endif
+
+enum {
+	PDC_UDMA_100        = 0,
+	PDC_UDMA_133        = 1,
+	
+	PDC_100_MHZ         = 100000000,
+	PDC_133_MHZ         = 133333333,
+};
+
+static int pdc2027x_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
+static void pdc2027x_remove_one(struct pci_dev *pdev);
+static void pdc2027x_phy_reset(struct ata_port *ap);
+static void pdc2027x_set_piomode(struct ata_port *ap, struct ata_device *adev);
+static void pdc2027x_set_dmamode(struct ata_port *ap, struct ata_device *adev);
+
+/* 
+ * ATA Timing Tables based on 133MHz controller clock.
+ * These tables are only used when the controller is in 133MHz clock.
+ * If the controller is in 100MHz clock, the ASIC hardware will 
+ * set the timing registers automatically when "set feature" command 
+ * issued to the device. However, if the controller clock is 133MHz, 
+ * the following tables must be used.
+ */
+static struct pdc2027x_pio_timing {
+	u8 value0, value1, value2;
+} pdc2027x_pio_timing_tbl [] = {
+	{ 0xfb, 0x2b, 0xac }, /* PIO mode 0 */
+	{ 0x46, 0x29, 0xa4 }, /* PIO mode 1 */
+	{ 0x23, 0x26, 0x64 }, /* PIO mode 2 */
+	{ 0x27, 0x0d, 0x35 }, /* PIO mode 3, IORDY on, Prefetch off */
+	{ 0x23, 0x09, 0x25 }, /* PIO mode 4, IORDY on, Prefetch off */
+};
+
+static struct pdc2027x_mdma_timing {
+	u8 value0, value1;
+} pdc2027x_mdma_timing_tbl [] = {
+	{ 0xdf, 0x5f }, /* MDMA mode 0 */
+	{ 0x6b, 0x27 }, /* MDMA mode 1 */
+	{ 0x69, 0x25 }, /* MDMA mode 2 */
+};
+
+static struct pdc2027x_udma_timing {
+	u8 value0, value1, value2;
+} pdc2027x_udma_timing_tbl [] = {
+	{ 0x4a, 0x0f, 0xd5 }, /* UDMA mode 0 */
+	{ 0x3a, 0x0a, 0xd0 }, /* UDMA mode 1 */
+	{ 0x2a, 0x07, 0xcd }, /* UDMA mode 2 */
+	{ 0x1a, 0x05, 0xcd }, /* UDMA mode 3 */
+	{ 0x1a, 0x03, 0xcd }, /* UDMA mode 4 */
+	{ 0x1a, 0x02, 0xcb }, /* UDMA mode 5 */
+	{ 0x1a, 0x01, 0xcb }, /* UDMA mode 6 */
+};
+
+static struct pci_device_id pdc2027x_pci_tbl[] = {
+#ifdef ATA_ENABLE_PATA
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20268, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_100 },
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20269, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_133 },
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20270, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_100 },
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20271, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_133 },
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20275, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_133 },
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20276, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_133 },
+	{ PCI_VENDOR_ID_PROMISE, PCI_DEVICE_ID_PROMISE_20277, PCI_ANY_ID, PCI_ANY_ID, 0, 0, PDC_UDMA_133 },
+#endif
+	{ }	/* terminate list */
+};
+
+static struct pci_driver pdc2027x_pci_driver = {
+	.name			= DRV_NAME,
+	.id_table		= pdc2027x_pci_tbl,
+	.probe			= pdc2027x_init_one,
+	.remove			= __devexit_p(pdc2027x_remove_one),
+};
+
+static Scsi_Host_Template pdc2027x_sht = {
+	.module			= THIS_MODULE,
+	.name			= DRV_NAME,
+	.queuecommand		= ata_scsi_queuecmd,
+	.eh_strategy_handler	= ata_scsi_error,
+	.can_queue		= ATA_DEF_QUEUE,
+	.this_id		= ATA_SHT_THIS_ID,
+	.sg_tablesize		= LIBATA_MAX_PRD,
+	.max_sectors		= ATA_MAX_SECTORS,
+	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,
+	.emulated		= ATA_SHT_EMULATED,
+	.use_clustering		= ATA_SHT_USE_CLUSTERING,
+	.proc_name		= DRV_NAME,
+	.dma_boundary		= ATA_DMA_BOUNDARY,
+	.slave_configure	= ata_scsi_slave_config,
+	.bios_param		= ata_std_bios_param,
+};
+
+static struct ata_port_operations pdc2027x_pata_ops = {
+	.port_disable		= ata_port_disable,
+	.set_piomode		= pdc2027x_set_piomode,   
+	.set_dmamode		= pdc2027x_set_dmamode,  
+
+	.tf_load		= ata_tf_load,
+	.tf_read		= ata_tf_read,
+	.check_status		= ata_check_status,
+	.exec_command		= ata_exec_command,
+	.dev_select		= ata_std_dev_select,
+
+	.phy_reset		= pdc2027x_phy_reset,   
+
+	.bmdma_setup            = ata_bmdma_setup,
+	.bmdma_start            = ata_bmdma_start,
+	.qc_prep		= ata_qc_prep,
+	.qc_issue		= ata_qc_issue_prot,
+	.eng_timeout		= ata_eng_timeout,
+
+	.irq_handler		= ata_interrupt,
+	.irq_clear              = ata_bmdma_irq_clear,
+
+	.port_start		= ata_port_start,
+	.port_stop		= ata_port_stop,
+};
+
+static struct ata_port_info pdc2027x_port_info[] = {
+	/* PDC_UDMA_100 */
+	{
+		.sht		= &pdc2027x_sht,
+		.host_flags	= ATA_FLAG_NO_LEGACY | ATA_FLAG_SLAVE_POSS | 
+		                  ATA_FLAG_SRST,
+		.pio_mask	= 0x03, /* pio3-4 */
+		.mwdma_mask	= 0x06, /* mwdma1-2 */
+		.udma_mask	= ATA_UDMA5,
+		.port_ops	= &pdc2027x_pata_ops,
+	},
+	/* PDC_UDMA_133 */
+	{
+		.sht		= &pdc2027x_sht,
+		.host_flags	= ATA_FLAG_NO_LEGACY | ATA_FLAG_SLAVE_POSS | 
+                        	  ATA_FLAG_SRST,
+		.pio_mask	= 0x03, /* pio3-4 */
+		.mwdma_mask	= 0x06, /* mwdma1-2 */
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &pdc2027x_pata_ops,
+	},
+};
+
+MODULE_AUTHOR("Andre Hedrick, Frank Tiernan, Albert Lee");
+MODULE_DESCRIPTION("libata driver module for Promise PDC20268 to PDC20277");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(pci, pdc2027x_pci_tbl);
+
+/**
+ * pdc_get_indexed_reg - Set pdc202xx extended register
+ * @ap: Port to which the extended register is set
+ * @index: index of the extended register
+ */
+static u8 pdc_get_indexed_reg(struct ata_port *ap, u8 index)
+{
+	u8 tmp8;
+
+	outb(index, ap->ioaddr.bmdma_addr + 1); 
+	tmp8 = inb(ap->ioaddr.bmdma_addr + 3);
+
+	PDPRINTK("Get index reg%X[%X] \n", index, tmp8);
+	return tmp8;
+}
+/**
+ * pdc_set_indexed_reg - Read pdc202xx extended register
+ * @ap: Port to which the extended register is read
+ * @index: index of the extended register
+ */
+static void pdc_set_indexed_reg(struct ata_port *ap, u8 index, u8 value)
+{
+	outb(index, ap->ioaddr.bmdma_addr + 1); 
+	outb(value, ap->ioaddr.bmdma_addr + 3);
+	PDPRINTK("Set index reg%X[%X] \n", index, value);
+}
+/**
+ *	pdc2027x_pata_cbl_detect - Probe host controller cable detect info
+ *	@ap: Port for which cable detect info is desired
+ *
+ *	Read 80c cable indicator from Promise extended register.  
+ *      This register is latched when the system is reset.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+static void pdc2027x_cbl_detect(struct ata_port *ap)
+{
+	u8 cbl40c;
+
+	/* check cable detect results */
+	cbl40c = pdc_get_indexed_reg(ap, 0x0b) & 0x04;
+
+	if (cbl40c)
+		goto cbl40;
+
+	PDPRINTK("No cable or 80-conductor cable on port %d\n", ap->port_no);
+
+	ap->cbl = ATA_CBL_PATA80;
+	return;
+
+cbl40:
+	printk(KERN_INFO DRV_NAME ": 40-conductor cable detected on port %d\n", ap->port_no);
+	ap->cbl = ATA_CBL_PATA40;
+	ap->udma_mask &= ATA_UDMA_MASK_40C;
+}
+/**
+ * pdc2027x_port_enabled - Check extended register at 0x04 to see whether the port is enabled.
+ * @ap: Port to check
+ */
+static inline int pdc2027x_port_enabled(struct ata_port *ap)
+{
+	return pdc_get_indexed_reg(ap, 0x04) & 0x02;
+}
+/**
+ *	pdc2027x_phy_reset - Probe specified port on PATA host controller
+ *	@ap: Port to probe
+ *
+ *	Probe PATA phy.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+static void pdc2027x_phy_reset(struct ata_port *ap)
+{
+	/* Check whether port enabled */
+	if (!pdc2027x_port_enabled(ap)) {
+		ata_port_disable(ap);
+		printk(KERN_INFO "ata%u: port disabled. ignoring.\n", ap->id);
+		return;
+	}
+
+	pdc2027x_cbl_detect(ap);
+	ata_port_probe(ap);
+	ata_bus_reset(ap);
+}
+/**
+ *	pdc2027x_set_piomode - Initialize host controller PATA PIO timings
+ *	@ap: Port to configure
+ *	@adev: um
+ *	@pio: PIO mode, 0 - 4
+ *
+ *	Set PIO mode for device.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+static void pdc2027x_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	unsigned int pio      = adev->pio_mode - XFER_PIO_0;
+	unsigned int drive_dn = (ap->port_no ? 2 : 0) + adev->devno;
+	u8 adj		      = (drive_dn%2) ? 0x08 : 0x00;
+	u8 tmp8;
+
+
+	PDPRINTK("adev->pio_mode[%X]\n", adev->pio_mode);
+
+	/* Sanity check */
+	if(pio > 4) {
+		printk(KERN_ERR DRV_NAME ": Unknown pio mode [%d] ignored\n", pio);
+		return;
+
+	}
+
+	/* Set the PIO timing registers using value table for 133MHz */
+	PDPRINTK("Set pio regs... \n");
+
+	pdc_set_indexed_reg(ap, 0x0c + adj, pdc2027x_pio_timing_tbl[pio].value0);
+	pdc_set_indexed_reg(ap, 0x0d + adj, pdc2027x_pio_timing_tbl[pio].value1);
+	pdc_set_indexed_reg(ap, 0x13 + adj, pdc2027x_pio_timing_tbl[pio].value2);
+
+	PDPRINTK("Set pio regs done\n");
+
+	/*
+	 *  Check whether the device supports turning off IORDY.
+	 * For PIO3 and above, the device must support IORDY and set bit 10 
+	 */
+	if (adev->id[49] & 0x400) { 
+		/* IORDY_EN & PREFETCH_EN */
+		/* Turn on Prefetch */
+		tmp8 = pdc_get_indexed_reg(ap, 0x13 + adj);
+		pdc_set_indexed_reg(ap, 0x13 + adj, tmp8 | 0x03);
+
+		PDPRINTK("Turn on prefetch\n");
+	}
+
+	printk(KERN_INFO DRV_NAME ": Set to pio mode[%u] \n", pio);
+}
+/**
+ *	pdc2027x_set_dmamode - Initialize host controller PATA UDMA timings
+ *	@ap: Port to configure
+ *	@adev: um
+ *	@udma: udma mode, XFER_UDMA_0 to XFER_UDMA_6
+ *
+ *	Set UDMA mode for device.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+static void pdc2027x_set_dmamode(struct ata_port *ap, struct ata_device *adev)
+{
+	unsigned int dma_mode	= adev->dma_mode;
+	unsigned int drive_dn	= (ap->port_no ? 2 : 0) + adev->devno;
+	u8 adj			= (drive_dn%2) ? 0x08 : 0x00;
+	u8 tmp8;
+
+	if((dma_mode >= XFER_UDMA_0) && 
+	   (dma_mode <= XFER_UDMA_6)) {
+		/* Set the UDMA timing registers with value table for 133MHz */
+		unsigned int udma_mode = dma_mode & 0x07;
+
+		if (dma_mode == XFER_UDMA_2) {
+			/*
+			 * Turn off tHOLD.
+			 * If tHOLD is '1', the hardware will add half clock for data hold time.
+			 * This code segment seems to be no effect. tHOLD will be overwritten below.
+			 */
+			tmp8 = pdc_get_indexed_reg(ap, 0x10 + adj);
+			pdc_set_indexed_reg(ap, 0x10 + adj, tmp8 & 0x7f);
+		} 
+
+		PDPRINTK("Set udma regs... \n");
+		pdc_set_indexed_reg(ap, 0x10 + adj, pdc2027x_udma_timing_tbl[udma_mode].value0);
+		pdc_set_indexed_reg(ap, 0x11 + adj, pdc2027x_udma_timing_tbl[udma_mode].value1);
+		pdc_set_indexed_reg(ap, 0x12 + adj, pdc2027x_udma_timing_tbl[udma_mode].value2);
+		PDPRINTK("Set udma regs done\n");
+		
+		printk(KERN_INFO DRV_NAME ": Set to udma mode[%u] \n", udma_mode);
+
+	} else  if((dma_mode >= XFER_MW_DMA_0) && 
+		   (dma_mode <= XFER_MW_DMA_2)) {
+		/* Set the MDMA timing registers with value table for 133MHz */
+		unsigned int mdma_mode = dma_mode & 0x07;
+
+		PDPRINTK("Set mdma regs... \n");
+		pdc_set_indexed_reg(ap, 0x0e + adj, pdc2027x_mdma_timing_tbl[mdma_mode].value0);
+		pdc_set_indexed_reg(ap, 0x0f + adj, pdc2027x_mdma_timing_tbl[mdma_mode].value1);
+		PDPRINTK("Set mdma regs done\n");
+		
+		printk(KERN_INFO DRV_NAME ": Set to mdma mode[%u] \n", mdma_mode);
+	} else {
+		printk(KERN_ERR DRV_NAME ": Unknown dma mode [%u] ignored\n", dma_mode);
+	}
+}
+/**
+ * adjust_pll - Adjust the PLL input clock in Hz.
+ *
+ * @pdc_controller: controller specific information
+ * @probe_ent: For the port address
+ * @pll_clock: The input of PLL in HZ
+ */
+static void pdc_adjust_pll(struct ata_probe_ent *probe_ent, long pll_clock, unsigned int board_idx) 
+{
+
+	u8 pll_ctl0, pll_ctl1;
+	long pll_clock_khz = pll_clock / 1000;
+	long pout_required = board_idx? PDC_133_MHZ:PDC_100_MHZ;
+	long ratio = pout_required / pll_clock_khz;
+	int F, R;
+	
+
+	/* Sanity check */
+	if (unlikely(pll_clock_khz < 5000L || pll_clock_khz > 70000L)) {
+		printk(KERN_ERR DRV_NAME ": Invalid PLL input clock %ldkHz, give up!\n", pll_clock_khz);
+		return;
+	} 
+
+#ifdef PDC_DEBUG
+	PDPRINTK("pout_required is %ld\n", pout_required);
+
+	/* Show the current clock value of PLL control register
+	 * (maybe already configured by the firmware)
+	 */
+	outb(0x02, probe_ent->port[1].bmdma_addr + 0x01);
+	pll_ctl0 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+	outb(0x03, probe_ent->port[1].bmdma_addr + 0x01);
+	pll_ctl1 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+
+	PDPRINTK("pll_ctl[%X][%X]\n", pll_ctl0, pll_ctl1);
+#endif
+
+	/* 
+	 * Calculate the ratio of F, R and OD
+	 * POUT = (F + 2) / (( R + 2) * NO)
+	 */
+	if (ratio < 8600L) { // 8.6x
+		/* Using NO = 0x01, R = 0x0D */
+		R = 0x0d;
+	} else if (ratio < 12900L) { // 12.9x
+		/* Using NO = 0x01, R = 0x08 */
+		R = 0x08;
+	} else if (ratio < 16100L) { // 16.1x
+		/* Using NO = 0x01, R = 0x06 */
+		R = 0x06;
+	} else if (ratio < 64000L) { // 64x
+		R = 0x00;
+	} else {
+		/* Invalid ratio */
+		printk(KERN_ERR DRV_NAME ": Invalid ratio %ld, give up!\n", ratio);
+		return;
+	}
+
+	F = (ratio * (R+2)) / 1000 - 2;
+
+	if (unlikely(F < 0 || F > 127)) {
+		/* Invalid F */
+		printk(KERN_ERR DRV_NAME ": F[%d] invalid!\n", F);
+		return;
+	}
+
+	PDPRINTK("F[%d] R[%d] ratio*1000[%ld]\n", F, R, ratio);
+
+	pll_ctl0 = (u8) F;
+	pll_ctl1 = (u8) R;
+
+	PDPRINTK("Writing pll_ctl[%X][%X]\n", pll_ctl0, pll_ctl1);
+
+	outb(0x02,     probe_ent->port[1].bmdma_addr + 0x01);
+	outb(pll_ctl0, probe_ent->port[1].bmdma_addr + 0x03);
+	outb(0x03,     probe_ent->port[1].bmdma_addr + 0x01);
+	outb(pll_ctl1, probe_ent->port[1].bmdma_addr + 0x03);
+
+	/* Wait the PLL circuit to be stable */
+	mdelay(30);
+
+#ifdef PDC_DEBUG
+	/*
+	 *  Show the current clock value of PLL control register
+	 * (maybe configured by the firmware)
+	 */
+	outb(0x02, probe_ent->port[1].bmdma_addr + 0x01);
+	pll_ctl0 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+	outb(0x03, probe_ent->port[1].bmdma_addr + 0x01);
+	pll_ctl1 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+
+	PDPRINTK("pll_ctl[%X][%X]\n", pll_ctl0, pll_ctl1);
+#endif
+
+	return;
+}
+/**
+ * detect_pll_input_clock - Detect the PLL input clock in Hz.
+ * @probe_ent: for the port address
+ * Ex. 16949000 on 33MHz PCI bus for pdc20275. 
+ *     Half of the PCI clock.
+ */
+static long pdc_detect_pll_input_clock(struct ata_probe_ent *probe_ent) 
+{
+	u8 scr1;
+	unsigned long ctr0;
+	unsigned long ctr1;
+	unsigned long ctr2 = 0;
+	unsigned long ctr3 = 0;
+
+	unsigned long start_count, end_count;
+	long pll_clock;
+
+	/* Read current counter value */
+	outb(0x20, probe_ent->port[0].bmdma_addr + 0x01);
+	ctr0 = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	outb(0x21, probe_ent->port[0].bmdma_addr + 0x01);
+	ctr1 = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	
+	outb(0x20, probe_ent->port[1].bmdma_addr + 0x01);
+	ctr2 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+	outb(0x21, probe_ent->port[1].bmdma_addr + 0x01);
+	ctr3 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+
+	start_count = (ctr3 << 23 ) | (ctr2 << 15) | (ctr1 << 8) | ctr0;
+
+	PDPRINTK("ctr0[%lX] ctr1[%lX] ctr2 [%lX] ctr3 [%lX]\n", ctr0, ctr1, ctr2, ctr3);
+
+	/* Start the test mode */
+	outb(0x01, probe_ent->port[0].bmdma_addr + 0x01);
+	scr1 = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	PDPRINTK("scr1[%X]\n", scr1);
+	outb(scr1 | 0x40, probe_ent->port[0].bmdma_addr + 0x03);
+
+	/* Let the counter run for 1000 us. */
+	udelay(1000);
+
+	/* Read the counter values again */
+	outb(0x20, probe_ent->port[0].bmdma_addr + 0x01);
+	ctr0 = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	outb(0x21, probe_ent->port[0].bmdma_addr + 0x01);
+	ctr1 = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	
+	outb(0x20, probe_ent->port[1].bmdma_addr + 0x01);
+	ctr2 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+	outb(0x21, probe_ent->port[1].bmdma_addr + 0x01);
+	ctr3 = inb(probe_ent->port[1].bmdma_addr + 0x03);
+
+	end_count = (ctr3 << 23 ) | (ctr2 << 15) | (ctr1 << 8) | ctr0;
+
+	PDPRINTK("ctr0[%lX] ctr1[%lX] ctr2 [%lX] ctr3 [%lX]\n", ctr0, ctr1, ctr2, ctr3);
+
+	/* Stop the test mode */
+	outb(0x01, probe_ent->port[0].bmdma_addr + 0x01);
+	scr1 = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	PDPRINTK("scr1[%X]\n", scr1);
+	outb(scr1 & 0xBF, probe_ent->port[0].bmdma_addr + 0x03);
+
+	/* calculate the input clock in Hz */
+	pll_clock = (long) ((start_count - end_count) * 1000);
+
+	PDPRINTK("start[%lu] end[%lu] \n", start_count, end_count);
+	PDPRINTK("PLL input clock[%ld]Hz\n", pll_clock);
+
+	return pll_clock;
+}
+/**
+ * pdc_hardware_init - Initialize the hardware.
+ * @pdev: instance of pci_dev found
+ * @pdc_controller: controller specific information
+ * @pe:  for the port address
+ */
+static int pdc_hardware_init(struct pci_dev *pdev, struct ata_probe_ent *pe, unsigned int board_idx)
+{
+	long pll_clock;
+
+	/* Enable the ROM */
+	/*
+	if (pdev->resource[PCI_ROM_RESOURCE].start) {
+		pci_write_config_dword(pdev, PCI_ROM_ADDRESS,
+			pdev->resource[PCI_ROM_RESOURCE].start | PCI_ROM_ADDRESS_ENABLE);
+		printk(KERN_INFO DRV_NAME ": ROM enabled at 0x%08lx\n",
+		       pdev->resource[PCI_ROM_RESOURCE].start);
+	}
+	*/
+
+	/*
+	 * Detect PLL input clock rate.
+	 * On some system, where PCI bus is running at non-standard clock rate.
+	 * Ex. 25MHz or 40MHz, we have to adjust the cycle_time.
+	 * The pdc20275 controller employs PLL circuit to help correct timing registers setting.
+	 */
+	pll_clock = pdc_detect_pll_input_clock(pe);
+
+	if(pll_clock < 0) /* counter overflow? Try again. */
+		pll_clock = pdc_detect_pll_input_clock(pe);
+
+	printk(KERN_INFO DRV_NAME ": PLL input clock %ld kHz\n", pll_clock/1000);
+
+	/* Adjust PLL control register */
+	pdc_adjust_pll(pe, pll_clock, board_idx);
+
+	return 0;
+}
+/**
+ * pdc2027x_init_one - PCI probe function
+ * Called when an instance of PCI adapter is inserted.
+ * This function checks whether the hardware is supported,
+ * initialize hardware and register an instance of ata_host_set to 
+ * libata by providing struct ata_probe_ent and ata_device_add().
+ * (implements struct pci_driver.probe() )
+ * 
+ * @pdev: instance of pci_dev found
+ * @ent:  matching entry in the id_tbl[]
+ */
+static int __devinit pdc2027x_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	static int printed_version;
+	unsigned int board_idx = (unsigned int) ent->driver_data;
+
+	struct ata_probe_ent *probe_ent = NULL;
+	int rc;
+
+	if (!printed_version++)
+		printk(KERN_DEBUG DRV_NAME " version " DRV_VERSION "\n");
+
+#ifdef PDC_20276_QUIRK
+	/*
+	 * Skip Promise PDC20276 attached to I2O RAID controller 
+	 */
+	if ((pdev->device == PCI_DEVICE_ID_PROMISE_20276) &&
+	    (pdev->bus->self) &&
+	    (pdev->bus->self->vendor == PCI_VENDOR_ID_INTEL) &&
+	    ((pdev->bus->self->device == PCI_DEVICE_ID_INTEL_I960) ||
+	     (pdev->bus->self->device == PCI_DEVICE_ID_INTEL_I960RM))) {
+		printk(KERN_INFO DRV_NAME ": Skipping Promise PDC20276 "
+		       "attached to I2O RAID controller.\n");
+		return -ENODEV;
+	}
+#endif
+
+#ifdef PDC_20270_QUIRK
+	/*
+	 * Special IRQ handling for Promise PDC20270 attached to the 
+	 * DEC DC21150 PCI south bridge.  (DC21150 PCI bridge can be found 
+	 * on Compaq ProLiant 800 and ProLiant 1600 servers.) 
+	 * FIXME: Not tested yet on libata.
+	 */
+	if ((pdev->device == PCI_DEVICE_ID_PROMISE_20270) &&
+	    (pdev->bus->self) &&
+	    (pdev->bus->self->vendor == PCI_VENDOR_ID_DEC) &&
+	    (pdev->bus->self->device == PCI_DEVICE_ID_DEC_21150)) {
+		struct pci_dev *findev = NULL;
+
+		if (PCI_SLOT(pdev->devfn) & 2) {
+			/* This pdc20270 is in PCI slot with bit 1 set.
+			 * Find the other pdc20270 in PCI slot with bit 1 cleared.
+			 * If found, override my IRQ setting to irq of that device.
+			 */
+			//d->extra = 0; // No extra DMA address on pdc20270
+					   
+			while ((findev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, findev)) != NULL) {
+				if ((findev->vendor == pdev->vendor) &&
+				    (findev->device == pdev->device) &&
+				    (!(PCI_SLOT(findev->devfn) & 2))) {
+					
+					if (pdev->irq != findev->irq) {
+						// Override the IRQ setting
+						pdev->irq = findev->irq;
+						break;
+					}
+				}
+			}
+		}
+
+	}
+#endif
+
+	rc = pci_enable_device(pdev);
+	if (rc)
+		return rc;
+
+	rc = pci_request_regions(pdev, DRV_NAME);
+	if (rc)
+		goto err_out;
+
+	rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
+	if (rc)
+		goto err_out_regions;
+
+	rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
+	if (rc)
+		goto err_out_regions;
+
+	/* Prepare the probe entry */
+	probe_ent = kmalloc(sizeof(*probe_ent), GFP_KERNEL);
+	if (probe_ent == NULL) {
+		rc = -ENOMEM;
+		goto err_out_regions;
+	}
+
+	memset(probe_ent, 0, sizeof(*probe_ent));
+	probe_ent->pdev = pdev;
+	INIT_LIST_HEAD(&probe_ent->node);
+
+	probe_ent->sht		= pdc2027x_port_info[board_idx].sht;
+	probe_ent->host_flags	= pdc2027x_port_info[board_idx].host_flags;
+	probe_ent->pio_mask	= pdc2027x_port_info[board_idx].pio_mask;
+	probe_ent->udma_mask	= pdc2027x_port_info[board_idx].udma_mask;
+	probe_ent->port_ops	= pdc2027x_port_info[board_idx].port_ops;
+
+       	probe_ent->irq = pdev->irq;
+       	probe_ent->irq_flags = SA_SHIRQ;
+
+	probe_ent->port[0].cmd_addr = pci_resource_start(pdev, 0);
+	ata_std_ports(&probe_ent->port[0]);
+	probe_ent->port[0].altstatus_addr =
+		probe_ent->port[0].ctl_addr =
+		pci_resource_start(pdev, 1) | ATA_PCI_CTL_OFS;
+	probe_ent->port[0].bmdma_addr = pci_resource_start(pdev, 4);
+
+	probe_ent->port[1].cmd_addr = pci_resource_start(pdev, 2);
+	ata_std_ports(&probe_ent->port[1]);
+	probe_ent->port[1].altstatus_addr =
+		probe_ent->port[1].ctl_addr =
+		pci_resource_start(pdev, 3) | ATA_PCI_CTL_OFS;
+	probe_ent->port[1].bmdma_addr = pci_resource_start(pdev, 4) + 8;
+
+	probe_ent->n_ports = 2;
+
+	pci_set_master(pdev);
+	//pci_enable_intx(pdev);
+
+	/* initialize adapter */
+	if(pdc_hardware_init(pdev, probe_ent, board_idx) != 0)
+		goto err_out_free_ent;
+
+	ata_device_add(probe_ent);
+	kfree(probe_ent);
+
+	return 0;
+
+err_out_free_ent:
+	kfree(probe_ent);
+err_out_regions:
+	pci_release_regions(pdev);
+err_out:
+	pci_disable_device(pdev);
+	return rc;
+}
+/**
+ * pdc2027x_remove_one - Called to remove a single instance of the
+ * adapter.
+ *
+ * @dev: The PCI device to remove.
+ * FIXME: module load/unload not working yet
+ */
+static void __devexit pdc2027x_remove_one(struct pci_dev *pdev)
+{
+	ata_pci_remove_one(pdev);
+}
+/**
+ * pdc2027x_init - Called after this module is loaded into the kernel.
+ */
+static int __init pdc2027x_init(void)
+{
+	return pci_module_init(&pdc2027x_pci_driver);
+}
+/**
+ * pdc2027x_exit - Called before this module unloaded from the kernel
+ */
+static void __exit pdc2027x_exit(void)
+{
+	pci_unregister_driver(&pdc2027x_pci_driver);
+}
+
+module_init(pdc2027x_init);
+module_exit(pdc2027x_exit);