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linux/drivers/ata/pata_it8213.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

329 lines
8.5 KiB
C

/*
* pata_it8213.c - iTE Tech. Inc. IT8213 PATA driver
*
* The IT8213 is a very Intel ICH like device for timing purposes, having
* a similar register layout and the same split clock arrangement. Cable
* detection is different, and it does not have slave channels or all the
* clutter of later ICH/SATA setups.
*/
#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_it8213"
#define DRV_VERSION "0.0.3"
/**
* it8213_pre_reset - check for 40/80 pin
* @link: link
* @deadline: deadline jiffies for the operation
*
* Filter out ports by the enable bits before doing the normal reset
* and probe.
*/
static int it8213_pre_reset(struct ata_link *link, unsigned long deadline)
{
static const struct pci_bits it8213_enable_bits[] = {
{ 0x41U, 1U, 0x80UL, 0x80UL }, /* port 0 */
};
struct ata_port *ap = link->ap;
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
if (!pci_test_config_bits(pdev, &it8213_enable_bits[ap->port_no]))
return -ENOENT;
return ata_std_prereset(link, deadline);
}
/**
* it8213_error_handler - Probe specified port on PATA host controller
* @ap: Port to probe
*
* LOCKING:
* None (inherited from caller).
*/
static void it8213_error_handler(struct ata_port *ap)
{
ata_bmdma_drive_eh(ap, it8213_pre_reset, ata_std_softreset, NULL, ata_std_postreset);
}
/**
* it8213_cable_detect - check for 40/80 pin
* @ap: Port
*
* Perform cable detection for the 8213 ATA interface. This is
* different to the PIIX arrangement
*/
static int it8213_cable_detect(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
u8 tmp;
pci_read_config_byte(pdev, 0x42, &tmp);
if (tmp & 2) /* The initial docs are incorrect */
return ATA_CBL_PATA40;
return ATA_CBL_PATA80;
}
/**
* it8213_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 it8213_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. The 8213 is a clone so very similar
*/
static const /* ISP RTC */
u8 timings[][2] = { { 0, 0 },
{ 0, 0 },
{ 1, 0 },
{ 2, 1 },
{ 2, 3 }, };
if (pio > 2)
control |= 1; /* TIME1 enable */
if (ata_pio_need_iordy(adev)) /* PIO 3/4 require IORDY */
control |= 2; /* IORDY enable */
/* Bit 2 is set for ATAPI on the IT8213 - reverse of ICH/PIIX */
if (adev->class != ATA_DEV_ATA)
control |= 4;
pci_read_config_word(dev, idetm_port, &idetm_data);
/* Enable PPE, IE and TIME as appropriate */
if (adev->devno == 0) {
idetm_data &= 0xCCF0;
idetm_data |= control;
idetm_data |= (timings[pio][0] << 12) |
(timings[pio][1] << 8);
} else {
u8 slave_data;
idetm_data &= 0xCC0F;
idetm_data |= (control << 4);
/* Slave timing in separate register */
pci_read_config_byte(dev, 0x44, &slave_data);
slave_data &= 0xF0;
slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << 4;
pci_write_config_byte(dev, 0x44, slave_data);
}
idetm_data |= 0x4000; /* Ensure SITRE is enabled */
pci_write_config_word(dev, idetm_port, idetm_data);
}
/**
* it8213_set_dmamode - Initialize host controller PATA DMA timings
* @ap: Port whose timings we are configuring
* @adev: Device to program
*
* Set UDMA/MWDMA mode for device, in host controller PCI config space.
* This device is basically an ICH alike.
*
* LOCKING:
* None (inherited from caller).
*/
static void it8213_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
struct pci_dev *dev = to_pci_dev(ap->host->dev);
u16 master_data;
u8 speed = adev->dma_mode;
int devid = adev->devno;
u8 udma_enable;
static const /* ISP RTC */
u8 timings[][2] = { { 0, 0 },
{ 0, 0 },
{ 1, 0 },
{ 2, 1 },
{ 2, 3 }, };
pci_read_config_word(dev, 0x40, &master_data);
pci_read_config_byte(dev, 0x48, &udma_enable);
if (speed >= XFER_UDMA_0) {
unsigned int udma = adev->dma_mode - XFER_UDMA_0;
u16 udma_timing;
u16 ideconf;
int u_clock, u_speed;
/* Clocks follow the PIIX style */
u_speed = min(2 - (udma & 1), udma);
if (udma == 5)
u_clock = 0x1000; /* 100Mhz */
else if (udma > 2)
u_clock = 1; /* 66Mhz */
else
u_clock = 0; /* 33Mhz */
udma_enable |= (1 << devid);
/* Load the UDMA mode number */
pci_read_config_word(dev, 0x4A, &udma_timing);
udma_timing &= ~(3 << (4 * devid));
udma_timing |= (udma & 3) << (4 * devid);
pci_write_config_word(dev, 0x4A, udma_timing);
/* Load the clock selection */
pci_read_config_word(dev, 0x54, &ideconf);
ideconf &= ~(0x1001 << devid);
ideconf |= u_clock << devid;
pci_write_config_word(dev, 0x54, ideconf);
} else {
/*
* 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;
u8 slave_data;
static const unsigned int needed_pio[3] = {
XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
};
int pio = needed_pio[mwdma] - XFER_PIO_0;
control = 3; /* IORDY|TIME1 */
/* 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 */
if (devid) { /* Slave */
master_data &= 0xFF4F; /* Mask out IORDY|TIME1|DMAONLY */
master_data |= control << 4;
pci_read_config_byte(dev, 0x44, &slave_data);
slave_data &= (0x0F + 0xE1 * ap->port_no);
/* Load the matching timing */
slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << (ap->port_no ? 4 : 0);
pci_write_config_byte(dev, 0x44, slave_data);
} else { /* Master */
master_data &= 0xCCF4; /* Mask out IORDY|TIME1|DMAONLY
and master timing bits */
master_data |= control;
master_data |=
(timings[pio][0] << 12) |
(timings[pio][1] << 8);
}
udma_enable &= ~(1 << devid);
pci_write_config_word(dev, 0x40, master_data);
}
pci_write_config_byte(dev, 0x48, udma_enable);
}
static struct scsi_host_template it8213_sht = {
ATA_BMDMA_SHT(DRV_NAME),
};
static struct ata_port_operations it8213_ops = {
.inherits = &ata_bmdma_port_ops,
.cable_detect = it8213_cable_detect,
.set_piomode = it8213_set_piomode,
.set_dmamode = it8213_set_dmamode,
.error_handler = it8213_error_handler,
};
/**
* it8213_init_one - Register 8213 ATA PCI device with kernel services
* @pdev: PCI device to register
* @ent: Entry in it8213_pci_tbl matching with @pdev
*
* Called from kernel PCI layer.
*
* LOCKING:
* Inherited from PCI layer (may sleep).
*
* RETURNS:
* Zero on success, or -ERRNO value.
*/
static int it8213_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
static int printed_version;
static const struct ata_port_info info = {
.sht = &it8213_sht,
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = 0x1f, /* pio0-4 */
.mwdma_mask = 0x07, /* mwdma0-2 */
.udma_mask = ATA_UDMA4, /* FIXME: want UDMA 100? */
.port_ops = &it8213_ops,
};
/* Current IT8213 stuff is single port */
const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };
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 it8213_pci_tbl[] = {
{ PCI_VDEVICE(ITE, PCI_DEVICE_ID_ITE_8213), },
{ } /* terminate list */
};
static struct pci_driver it8213_pci_driver = {
.name = DRV_NAME,
.id_table = it8213_pci_tbl,
.probe = it8213_init_one,
.remove = ata_pci_remove_one,
#ifdef CONFIG_PM
.suspend = ata_pci_device_suspend,
.resume = ata_pci_device_resume,
#endif
};
static int __init it8213_init(void)
{
return pci_register_driver(&it8213_pci_driver);
}
static void __exit it8213_exit(void)
{
pci_unregister_driver(&it8213_pci_driver);
}
module_init(it8213_init);
module_exit(it8213_exit);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("SCSI low-level driver for the ITE 8213");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, it8213_pci_tbl);
MODULE_VERSION(DRV_VERSION);