/*
* pata_sl82c105.c - SL82C105 PATA for new ATA layer
* (C) 2005 Red Hat Inc
*
* Based in part on linux/drivers/ide/pci/sl82c105.c
* SL82C105/Winbond 553 IDE driver
*
* and in part on the documentation and errata sheet
*
*
* Note: The controller like many controllers has shared timings for
* PIO and DMA. We thus flip to the DMA timings in dma_start and flip back
* in the dma_stop function. Thus we actually don't need a set_dmamode
* method as the PIO method is always called and will set the right PIO
* timing parameters.
*/
#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/scsi_host.h>
#include <linux/libata.h>
#define DRV_NAME "pata_sl82c105"
#define DRV_VERSION "0.3.3"
enum {
/*
* SL82C105 PCI config register 0x40 bits.
*/
CTRL_IDE_IRQB = (1 << 30),
CTRL_IDE_IRQA = (1 << 28),
CTRL_LEGIRQ = (1 << 11),
CTRL_P1F16 = (1 << 5),
CTRL_P1EN = (1 << 4),
CTRL_P0F16 = (1 << 1),
CTRL_P0EN = (1 << 0)
};
/**
* sl82c105_pre_reset - probe begin
* @link: ATA link
* @deadline: deadline jiffies for the operation
*
* Set up cable type and use generic probe init
*/
static int sl82c105_pre_reset(struct ata_link *link, unsigned long deadline)
{
static const struct pci_bits sl82c105_enable_bits[] = {
{ 0x40, 1, 0x01, 0x01 },
{ 0x40, 1, 0x10, 0x10 }
};
struct ata_port *ap = link->ap;
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
if (ap->port_no && !pci_test_config_bits(pdev, &sl82c105_enable_bits[ap->port_no]))
return -ENOENT;
return ata_sff_prereset(link, deadline);
}
/**
* sl82c105_configure_piomode - set chip PIO timing
* @ap: ATA interface
* @adev: ATA device
* @pio: PIO mode
*
* Called to do the PIO mode setup. Our timing registers are shared
* so a configure_dmamode call will undo any work we do here and vice
* versa
*/
static void sl82c105_configure_piomode(struct ata_port *ap, struct ata_device *adev, int pio)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
static u16 pio_timing[5] = {
0x50D, 0x407, 0x304, 0x242, 0x240
};
u16 dummy;
int timing = 0x44 + (8 * ap->port_no) + (4 * adev->devno);
pci_write_config_word(pdev, timing, pio_timing[pio]);
/* Can we lose this oddity of the old driver */
pci_read_config_word(pdev, timing, &dummy);
}
/**
* sl82c105_set_piomode - set initial PIO mode data
* @ap: ATA interface
* @adev: ATA device
*
* Called to do the PIO mode setup. Our timing registers are shared
* but we want to set the PIO timing by default.
*/
static void sl82c105_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
sl82c105_configure_piomode(ap, adev, adev->pio_mode - XFER_PIO_0);
}
/**
* sl82c105_configure_dmamode - set DMA mode in chip
* @ap: ATA interface
* @adev: ATA device
*
* Load DMA cycle times into the chip ready for a DMA transfer
* to occur.
*/
static void sl82c105_configure_dmamode(struct ata_port *ap, struct ata_device *adev)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
static u16 dma_timing[3] = {
0x707, 0x201, 0x200
};
u16 dummy;
int timing = 0x44 + (8 * ap->port_no) + (4 * adev->devno);
int dma = adev->dma_mode - XFER_MW_DMA_0;
pci_write_config_word(pdev, timing, dma_timing[dma]);
/* Can we lose this oddity of the old driver */
pci_read_config_word(pdev, timing, &dummy);
}
/**
* sl82c105_reset_engine - Reset the DMA engine
* @ap: ATA interface
*
* The sl82c105 has some serious problems with the DMA engine
* when transfers don't run as expected or ATAPI is used. The
* recommended fix is to reset the engine each use using a chip
* test register.
*/
static void sl82c105_reset_engine(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
u16 val;
pci_read_config_word(pdev, 0x7E, &val);
pci_write_config_word(pdev, 0x7E, val | 4);
pci_write_config_word(pdev, 0x7E, val & ~4);
}
/**
* sl82c105_bmdma_start - DMA engine begin
* @qc: ATA command
*
* Reset the DMA engine each use as recommended by the errata
* document.
*
* FIXME: if we switch clock at BMDMA start/end we might get better
* PIO performance on DMA capable devices.
*/
static void sl82c105_bmdma_start(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
udelay(100);
sl82c105_reset_engine(ap);
udelay(100);
/* Set the clocks for DMA */
sl82c105_configure_dmamode(ap, qc->dev);
/* Activate DMA */
ata_bmdma_start(qc);
}
/**
* sl82c105_bmdma_end - DMA engine stop
* @qc: ATA command
*
* Reset the DMA engine each use as recommended by the errata
* document.
*
* This function is also called to turn off DMA when a timeout occurs
* during DMA operation. In both cases we need to reset the engine,
* so no actual eng_timeout handler is required.
*
* We assume bmdma_stop is always called if bmdma_start as called. If
* not then we may need to wrap qc_issue.
*/
static void sl82c105_bmdma_stop(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
ata_bmdma_stop(qc);
sl82c105_reset_engine(ap);
udelay(100);
/* This will redo the initial setup of the DMA device to matching
PIO timings */
sl82c105_set_piomode(ap, qc->dev);
}
/**
* sl82c105_qc_defer - implement serialization
* @qc: command
*
* We must issue one command per host not per channel because
* of the reset bug.
*
* Q: is the scsi host lock sufficient ?
*/
static int sl82c105_qc_defer(struct ata_queued_cmd *qc)
{
struct ata_host *host = qc->ap->host;
struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
int rc;
/* First apply the usual rules */
rc = ata_std_qc_defer(qc);
if (rc != 0)
return rc;
/* Now apply serialization rules. Only allow a command if the
other channel state machine is idle */
if (alt && alt->qc_active)
return ATA_DEFER_PORT;
return 0;
}
static struct scsi_host_template sl82c105_sht = {
ATA_BMDMA_SHT(DRV_NAME),
};
static struct ata_port_operations sl82c105_port_ops = {
.inherits = &ata_bmdma_port_ops,
.qc_defer = sl82c105_qc_defer,
.bmdma_start = sl82c105_bmdma_start,
.bmdma_stop = sl82c105_bmdma_stop,
.cable_detect = ata_cable_40wire,
.set_piomode = sl82c105_set_piomode,
.prereset = sl82c105_pre_reset,
};
/**
* sl82c105_bridge_revision - find bridge version
* @pdev: PCI device for the ATA function
*
* Locates the PCI bridge associated with the ATA function and
* providing it is a Winbond 553 reports the revision. If it cannot
* find a revision or the right device it returns -1
*/
static int sl82c105_bridge_revision(struct pci_dev *pdev)
{
struct pci_dev *bridge;
/*
* The bridge should be part of the same device, but function 0.
*/
bridge = pci_get_slot(pdev->bus,
PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
if (!bridge)
return -1;
/*
* Make sure it is a Winbond 553 and is an ISA bridge.
*/
if (bridge->vendor != PCI_VENDOR_ID_WINBOND ||
bridge->device != PCI_DEVICE_ID_WINBOND_83C553 ||
bridge->class >> 8 != PCI_CLASS_BRIDGE_ISA) {
pci_dev_put(bridge);
return -1;
}
/*
* We need to find function 0's revision, not function 1
*/
pci_dev_put(bridge);
return bridge->revision;
}
static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
static const struct ata_port_info info_dma = {
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.port_ops = &sl82c105_port_ops
};
static const struct ata_port_info info_early = {
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.port_ops = &sl82c105_port_ops
};
/* for now use only the first port */
const struct ata_port_info *ppi[] = { &info_early,
NULL };
u32 val;
int rev;
int rc;
rc = pcim_enable_device(dev);
if (rc)
return rc;
rev = sl82c105_bridge_revision(dev);
if (rev == -1)
dev_printk(KERN_WARNING, &dev->dev, "pata_sl82c105: Unable to find bridge, disabling DMA.\n");
else if (rev <= 5)
dev_printk(KERN_WARNING, &dev->dev, "pata_sl82c105: Early bridge revision, no DMA available.\n");
else
ppi[0] = &info_dma;
pci_read_config_dword(dev, 0x40, &val);
val |= CTRL_P0EN | CTRL_P0F16 | CTRL_P1F16;
pci_write_config_dword(dev, 0x40, val);
return ata_pci_sff_init_one(dev, ppi, &sl82c105_sht, NULL, 0);
}
static const struct pci_device_id sl82c105[] = {
{ PCI_VDEVICE(WINBOND, PCI_DEVICE_ID_WINBOND_82C105), },
{ },
};
static struct pci_driver sl82c105_pci_driver = {
.name = DRV_NAME,
.id_table = sl82c105,
.probe = sl82c105_init_one,
.remove = ata_pci_remove_one
};
static int __init sl82c105_init(void)
{
return pci_register_driver(&sl82c105_pci_driver);
}
static void __exit sl82c105_exit(void)
{
pci_unregister_driver(&sl82c105_pci_driver);
}
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for Sl82c105");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, sl82c105);
MODULE_VERSION(DRV_VERSION);
module_init(sl82c105_init);
module_exit(sl82c105_exit);
