android_kernel_motorola_sm6225/drivers/ata/pata_oldpiix.c
Tejun Heo 029cfd6b74 libata: implement and use ops inheritance
libata lets low level drivers build ata_port_operations table and
register it with libata core layer.  This allows low level drivers
high level of flexibility but also burdens them with lots of
boilerplate entries.

This becomes worse for drivers which support related similar
controllers which differ slightly.  They share most of the operations
except for a few.  However, the driver still needs to list all
operations for each variant.  This results in large number of
duplicate entries, which is not only inefficient but also error-prone
as it becomes very difficult to tell what the actual differences are.

This duplicate boilerplates all over the low level drivers also make
updating the core layer exteremely difficult and error-prone.  When
compounded with multi-branched development model, it ends up
accumulating inconsistencies over time.  Some of those inconsistencies
cause immediate problems and fixed.  Others just remain there dormant
making maintenance increasingly difficult.

To rectify the problem, this patch implements ata_port_operations
inheritance.  To allow LLDs to easily re-use their own ops tables
overriding only specific methods, this patch implements poor man's
class inheritance.  An ops table has ->inherits field which can be set
to any ops table as long as it doesn't create a loop.  When the host
is started, the inheritance chain is followed and any operation which
isn't specified is taken from the nearest ancestor which has it
specified.  This operation is called finalization and done only once
per an ops table and the LLD doesn't have to do anything special about
it other than making the ops table non-const such that libata can
update it.

libata provides four base ops tables lower drivers can inherit from -
base, sata, pmp, sff and bmdma.  To avoid overriding these ops
accidentaly, these ops are declared const and LLDs should always
inherit these instead of using them directly.

After finalization, all the ops table are identical before and after
the patch except for setting .irq_handler to ata_interrupt in drivers
which didn't use to.  The .irq_handler doesn't have any actual effect
and the field will soon be removed by later patch.

* sata_sx4 is still using old style EH and currently doesn't take
  advantage of ops inheritance.

Signed-off-by: Tejun Heo <htejun@gmail.com>
2008-04-17 15:44:17 -04:00

305 lines
7.9 KiB
C

/*
* pata_oldpiix.c - Intel PATA/SATA controllers
*
* (C) 2005 Red Hat <alan@redhat.com>
*
* Some parts based on ata_piix.c by Jeff Garzik and others.
*
* Early PIIX differs significantly from the later PIIX as it lacks
* SITRE and the slave timing registers. This means that you have to
* set timing per channel, or be clever. Libata tells us whenever it
* does drive selection and we use this to reload the timings.
*
* Because of these behaviour differences PIIX gets its own driver module.
*/
#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 <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/ata.h>
#define DRV_NAME "pata_oldpiix"
#define DRV_VERSION "0.5.5"
/**
* oldpiix_pre_reset - probe begin
* @link: ATA link
* @deadline: deadline jiffies for the operation
*
* Set up cable type and use generic probe init
*/
static int oldpiix_pre_reset(struct ata_link *link, unsigned long deadline)
{
struct ata_port *ap = link->ap;
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
static const struct pci_bits oldpiix_enable_bits[] = {
{ 0x41U, 1U, 0x80UL, 0x80UL }, /* port 0 */
{ 0x43U, 1U, 0x80UL, 0x80UL }, /* port 1 */
};
if (!pci_test_config_bits(pdev, &oldpiix_enable_bits[ap->port_no]))
return -ENOENT;
return ata_std_prereset(link, deadline);
}
/**
* oldpiix_pata_error_handler - Probe specified port on PATA host controller
* @ap: Port to probe
* @classes:
*
* LOCKING:
* None (inherited from caller).
*/
static void oldpiix_pata_error_handler(struct ata_port *ap)
{
ata_bmdma_drive_eh(ap, oldpiix_pre_reset, ata_std_softreset, NULL, ata_std_postreset);
}
/**
* oldpiix_set_piomode - Initialize host controller PATA PIO timings
* @ap: Port whose timings we are configuring
* @adev: Device whose timings we are configuring
*
* Set PIO mode for device, in host controller PCI config space.
*
* LOCKING:
* None (inherited from caller).
*/
static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
{
unsigned int pio = adev->pio_mode - XFER_PIO_0;
struct pci_dev *dev = to_pci_dev(ap->host->dev);
unsigned int idetm_port= ap->port_no ? 0x42 : 0x40;
u16 idetm_data;
int control = 0;
/*
* See Intel Document 298600-004 for the timing programing rules
* for PIIX/ICH. Note that the early PIIX does not have the slave
* timing port at 0x44.
*/
static const /* ISP RTC */
u8 timings[][2] = { { 0, 0 },
{ 0, 0 },
{ 1, 0 },
{ 2, 1 },
{ 2, 3 }, };
if (pio > 1)
control |= 1; /* TIME */
if (ata_pio_need_iordy(adev))
control |= 2; /* IE */
/* Intel specifies that the prefetch/posting is for disk only */
if (adev->class == ATA_DEV_ATA)
control |= 4; /* PPE */
pci_read_config_word(dev, idetm_port, &idetm_data);
/*
* Set PPE, IE and TIME as appropriate.
* Clear the other drive's timing bits.
*/
if (adev->devno == 0) {
idetm_data &= 0xCCE0;
idetm_data |= control;
} else {
idetm_data &= 0xCC0E;
idetm_data |= (control << 4);
}
idetm_data |= (timings[pio][0] << 12) |
(timings[pio][1] << 8);
pci_write_config_word(dev, idetm_port, idetm_data);
/* Track which port is configured */
ap->private_data = adev;
}
/**
* oldpiix_set_dmamode - Initialize host controller PATA DMA timings
* @ap: Port whose timings we are configuring
* @adev: Device to program
* @isich: True if the device is an ICH and has IOCFG registers
*
* Set MWDMA mode for device, in host controller PCI config space.
*
* LOCKING:
* None (inherited from caller).
*/
static void oldpiix_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
struct pci_dev *dev = to_pci_dev(ap->host->dev);
u8 idetm_port = ap->port_no ? 0x42 : 0x40;
u16 idetm_data;
static const /* ISP RTC */
u8 timings[][2] = { { 0, 0 },
{ 0, 0 },
{ 1, 0 },
{ 2, 1 },
{ 2, 3 }, };
/*
* MWDMA is driven by the PIO timings. We must also enable
* IORDY unconditionally along with TIME1. PPE has already
* been set when the PIO timing was set.
*/
unsigned int mwdma = adev->dma_mode - XFER_MW_DMA_0;
unsigned int control;
const unsigned int needed_pio[3] = {
XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
};
int pio = needed_pio[mwdma] - XFER_PIO_0;
pci_read_config_word(dev, idetm_port, &idetm_data);
control = 3; /* IORDY|TIME0 */
/* Intel specifies that the PPE functionality is for disk only */
if (adev->class == ATA_DEV_ATA)
control |= 4; /* PPE enable */
/* If the drive MWDMA is faster than it can do PIO then
we must force PIO into PIO0 */
if (adev->pio_mode < needed_pio[mwdma])
/* Enable DMA timing only */
control |= 8; /* PIO cycles in PIO0 */
/* Mask out the relevant control and timing bits we will load. Also
clear the other drive TIME register as a precaution */
if (adev->devno == 0) {
idetm_data &= 0xCCE0;
idetm_data |= control;
} else {
idetm_data &= 0xCC0E;
idetm_data |= (control << 4);
}
idetm_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
pci_write_config_word(dev, idetm_port, idetm_data);
/* Track which port is configured */
ap->private_data = adev;
}
/**
* oldpiix_qc_issue_prot - command issue
* @qc: command pending
*
* Called when the libata layer is about to issue a command. We wrap
* this interface so that we can load the correct ATA timings if
* necessary. Our logic also clears TIME0/TIME1 for the other device so
* that, even if we get this wrong, cycles to the other device will
* be made PIO0.
*/
static unsigned int oldpiix_qc_issue_prot(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct ata_device *adev = qc->dev;
if (adev != ap->private_data) {
oldpiix_set_piomode(ap, adev);
if (adev->dma_mode)
oldpiix_set_dmamode(ap, adev);
}
return ata_qc_issue_prot(qc);
}
static struct scsi_host_template oldpiix_sht = {
ATA_BMDMA_SHT(DRV_NAME),
};
static struct ata_port_operations oldpiix_pata_ops = {
.inherits = &ata_bmdma_port_ops,
.qc_issue = oldpiix_qc_issue_prot,
.cable_detect = ata_cable_40wire,
.set_piomode = oldpiix_set_piomode,
.set_dmamode = oldpiix_set_dmamode,
.error_handler = oldpiix_pata_error_handler,
};
/**
* oldpiix_init_one - Register PIIX ATA PCI device with kernel services
* @pdev: PCI device to register
* @ent: Entry in oldpiix_pci_tbl matching with @pdev
*
* Called from kernel PCI layer. We probe for combined mode (sigh),
* and then hand over control to libata, for it to do the rest.
*
* LOCKING:
* Inherited from PCI layer (may sleep).
*
* RETURNS:
* Zero on success, or -ERRNO value.
*/
static int oldpiix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
static int printed_version;
static const struct ata_port_info info = {
.sht = &oldpiix_sht,
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = 0x1f, /* pio0-4 */
.mwdma_mask = 0x07, /* mwdma1-2 */
.port_ops = &oldpiix_pata_ops,
};
const struct ata_port_info *ppi[] = { &info, NULL };
if (!printed_version++)
dev_printk(KERN_DEBUG, &pdev->dev,
"version " DRV_VERSION "\n");
return ata_pci_init_one(pdev, ppi);
}
static const struct pci_device_id oldpiix_pci_tbl[] = {
{ PCI_VDEVICE(INTEL, 0x1230), },
{ } /* terminate list */
};
static struct pci_driver oldpiix_pci_driver = {
.name = DRV_NAME,
.id_table = oldpiix_pci_tbl,
.probe = oldpiix_init_one,
.remove = ata_pci_remove_one,
#ifdef CONFIG_PM
.suspend = ata_pci_device_suspend,
.resume = ata_pci_device_resume,
#endif
};
static int __init oldpiix_init(void)
{
return pci_register_driver(&oldpiix_pci_driver);
}
static void __exit oldpiix_exit(void)
{
pci_unregister_driver(&oldpiix_pci_driver);
}
module_init(oldpiix_init);
module_exit(oldpiix_exit);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("SCSI low-level driver for early PIIX series controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, oldpiix_pci_tbl);
MODULE_VERSION(DRV_VERSION);