> > So in theory we can persuade libata to drive original MFM/RLL disks with
> > relatively few changes
>
> Crazy :)
Would look something like this (but with geometry handling and some setup
work)
/**
* An original IDE/ST412/ST506 driver for libata
*
* Information for hardware archeologists
* - IDE is the original pre ATA and 'EIDE' specification interface
* emulating ST412 with some oddments nailed on
* - ST412 is the normal PC/AT attachment
* - ST506 is the prehistoric version
*
* This driver will not (currently) handle ST506 unless you set the
* precomp value. Nor will it handle the original '8 head' protocol, nor
* drives not capable of the 35uS stepper rate. I might fix this for
* fun one day if I can find an old enough drive that still works
*
* How we work the compatibility ATA to ST412
* ------------------------------------------
*
* Mostly this works as pass through to libata as IDE and ATA were
* designed to be compatible in the IDE->ATA direction. The ST412
* interface ctrl register maps to the ATA ctl register (which is why it
* has lots of 'obsolete' bits). nIEN and SRST map to the IRQ mask
* bit on the controller and the controller soft reset.
*
* Original IDE works on the same command set as ST412 as far as we
* care (we don't do formatting etc). Some later IDE drives insist
* that we tell them their geometry (Initialize Drive) and they also
* support better error handling (DIAGNOSE), but we can do that as
* it'll just get rejected by the MFM era controller.
*
* The drive select is also cunning arranged so that '512 bytes with ECC'
* to the controller is in fact 0xA0 (aka the 'obsolete' bits in ATA)
*
* The big limit on original IDE is that only the BIOS knows the c/h/s
* parameters for the drive. For MFM/RLL you can sneak a peek at the
* partition table and guess but not alas for early IDE as it requires
* you set the geometry before it'll let you look!
*
* ST506
* -----
*
* ST506 requires we set 8 v 16 heads correctly and that we provide
* write precomp and a couple of other additional values. If you have
* a specific application involving rescuing such an ancient disk in
* a lab somewhere then let me know, although its probably easier and
* safer to read a disk that old in a data recovery lab
*/
#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>
#include <linux/platform_device.h>
#define DRV_NAME "pata_hd"
#define DRV_VERSION "0.0.1"
#define NR_HOST 2
struct platform_device *atahd_device[NR_HOST];
static struct ata_host *atahd_host[NR_HOST];
struct atahd_disk {
/* Geometry for faking IDENTIFY */
u16 cyls;
u8 heads;
u8 sectors;
/* Not currently supported - 35uS always used */
u8 seekrate;
/* Precompensation for older ST506 */
u8 wprecomp;
unsigned int legacy:1; /* Drive is actually ATA-1+ */
unsigned int ide:1; /* Drive is original IDE */
unsigned int lba:1; /* Original IDE in LBA mode */
u8 bios_ident; /* BIOS id of drive */
}
static struct atahd_param {
struct atahd_disk param[2]; /* Drive parameters */
int device; /* Tracking current device */
int present; /* Mask of present devices */
};
static struct atahd_param atahd_param[NR_HOST];
static int nr_atahd_host;
static int bios_ident = 0x80;
/**
* atahd_tf_load - send taskfile registers to host controller
* @ap: Port to which output is sent
* @tf: ATA taskfile register set
*
* Outputs ATA taskfile to ST506/414 host controller.
*
* LOCKING:
* Inherited from caller.
*/
void atahd_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
{
struct ata_ioports *ioaddr = &ap->ioaddr;
unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
if (!p->param[p->device].legacy) {
ata_tf_load(ap, tf);
return;
}
if (tf->ctl != ap->last_ctl) {
iowrite8(tf->ctl, ioaddr->ctl_addr);
ap->last_ctl = tf->ctl;
ata_wait_idle(ap);
}
if (is_addr) {
/* ST-506 requires the precomp value is loaded, ST-412, IDE
and later it is done by the drive. This causes no problem
for ST-506 driving IDE but for IDE driving ST we need to
fill in the blanks. Later ST-506 drives don't generally
use the hardware precomp signal either */
if (p->param[p->device].wprecomp)
iowrite8(p->param[p.device].wprecomp, ioaddr->feature_addr);
else
iowrite8(tf->feature, ioaddr->feature_addr);
iowrite8(tf->nsect, ioaddr->nsect_addr);
iowrite8(tf->lbal, ioaddr->lbal_addr);
iowrite8(tf->lbam, ioaddr->lbam_addr);
iowrite8(tf->lbah, ioaddr->lbah_addr);
VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
tf->feature,
tf->nsect,
tf->lbal,
tf->lbam,
tf->lbah);
}
if (tf->flags & ATA_TFLAG_DEVICE) {
iowrite8(tf->device, ioaddr->device_addr);
VPRINTK("device 0x%X\n", tf->device);
}
ata_wait_idle(ap);
}
/**
* atahd_data_xfer - Transfer data by PIO
* @adev: device to target
* @buf: data buffer
* @buflen: buffer length
* @write_data: read/write
*
* Transfer data from/to the device data register by PIO.
*
* LOCKING:
* Inherited from caller.
*/
static int atahd_data_xfer(struct ata_device *adev, unsigned char *buf,
unsigned int buflen, int write_data)
{
int r = 0;
unsigned long flags;
local_irq_save(flags);
r = ata_data_xfer(adev, buf, buflen, write_data);
local_irq_restore(flags);
return r;
}
#if 0
static void atahd_id_data()
{
BUG_ON(write_data);
memset(buf, 0, 512);
id[0] = 0x8000; /* ATA */
id[1] = d->cyls;
id[2] = 0xC837;
id[3] = d->heads;
id[6] = d->sectors;
memset(id + 10, " ", 20);
/* FIXME: Set some kind of unique serial */
memcpy(id + 23, "ATAHD001", 8);
memcpy(id + 27, "ATA HD EMULATION OF MFM/RLL ", 40);
id[47] = 0x8000;
id[49] = 0x30;
}
#endif
static unigned int atahd_emulate_id(struct ata_queued_cmd *qc)
{
struct atahd_param *p = qc->ap->private_data;
u16 *id = kzalloc(512, GFP_ATOMIC);
if (id == NULL)
return AC_ERR_INVALID;
ata_dev_select(qc->ap, qc->dev->devno, 1, 0);
/* Fill in the data block */
ata_qc_complete(qc);
kfree(id);
return 0;
}
static unsigned int atahd_qc_issue_prot(struct ata_queued_cmd *qc)
{
struct atahd_param *p = qc->ap->private_data;
/* Non legacy devices need no care and attention */
if (!p->param[p->device].legacy)
return ata_qc_issue_prot(qc);
/* ST412/ST506 controller path [or early equivalen IDE] */
switch(qc->tf.command) {
/* Don't do read/write multi - the 1010 can do it but we've
no idea how much SRAM is on the board */
case ATA_CMD_PIO_READ:
case ATA_CMD_PIO_WRITE:
case ATA_CMD_VERIFY:
case 0x10: /* pre-ATA command 0x10: Restore */
return ata_qc_issue_prot(qc);
/* Must fake */
case ATA_CMD_ID_ATA:
return atahd_emulate_id(qc);
/* May work on some very early IDE but will abort on ST412
which is fine */
case ATA_CMD_INIT_DEV_PARAMS:
return ata_qc_issue_prot(qc);
/* Also internally the controller supports formatting etc */
default:
return AC_ERR_INVALID;
}
}
static struct scsi_host_template atahd_sht = {
.module = THIS_MODULE,
.name = DRV_NAME,
.ioctl = ata_scsi_ioctl,
.queuecommand = ata_scsi_queuecmd,
.can_queue = ATA_DEF_QUEUE,
.this_id = ATA_SHT_THIS_ID,
.sg_tablesize = LIBATA_MAX_PRD,
.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,
.slave_destroy = ata_scsi_slave_destroy,
.bios_param = ata_std_bios_param,
};
static struct ata_port_operations atahd_port_ops = {
.port_disable = ata_port_disable,
.tf_load = atahd_tf_load,
.tf_read = ata_tf_read,
.check_status = atahd_check_status,
.exec_command = ata_exec_command,
.dev_select = ata_std_dev_select,
.freeze = ata_bmdma_freeze,
.thaw = ata_bmdma_thaw,
.error_handler = ata_bmdma_error_handler,
.post_internal_cmd = ata_bmdma_post_internal_cmd,
.cable_detect = ata_cable_40wire,
.qc_prep = ata_qc_prep,
.qc_issue = atahd_qc_issue_prot,
.data_xfer = atahd_data_xfer,
.irq_clear = ata_bmdma_irq_clear,
.irq_on = ata_irq_on,
.irq_ack = ata_irq_ack,
.port_start = ata_sff_port_start,
};
/**
* st416_poll - run polled command
* @port; I/O port base
* @cmd command byte
*
* Issue a polled no-data command to the ST412 interface. We
* cannot do register games here. An ST412 has the registers on
* the controller not on the drive. Instead we issue command 0x10
* 'RESTORE, 35uS stepping'. A working ST412 drive will assert TRKZ
* and the command finish. A working ATA drive may either nop the
* command or return aborted (as its a retired command). A bust ST412
* drive or missing device will timeout or finish the steppjng and
* fail to assert TRKZ
*
* This code path is only used during booting and early probing.
*/
static int st416_poll(unsigned long port, u8 cmd, u8 *err)
{
u8 status;
u8 err;
unsigned long timeout = jiffies + 5 * HZ;
iowrite8(cmd, port + ATA_REG_CMD);
ndelay(400);
*err = 0;
while (time_before(jiffies, timeout)) {
status = ioread8(port + ATA_REG_STATUS);
if ((status & ATA_BUSY) == 0) {
if (status & ATA_ERR) {
*err = ioread8(port + ATA_REG_ERR);
/* Aborted the command */
if (err & ATA_ABORTED)
return 0;
/* Drive didn't step back to track zero -
missing or bust */
if (*err & 0x01)
return -ENODEV;
return 0;
}
return 0;
}
}
return -ENODEV;
}
/*
* Probe sequence for ST412 and later devices
*
* Firstly we select the device. It should respond. If it does not
* then it is not present (ST412). We then issue the RESTORE command
* which is retired pre-ATA. ATA will either no-op it, or abort it.
* ST412 will track the drive back to track zero. If this fails with
* a timeout or TRKZ then the drive is bust or missing.
*
* Thus
* 0x10 ABORT -> ATA
* 0x10 no TRKZ -> Bust/Missing
* 0x10 OK -> ST412 or ATA
*
* We then issue 0x90 which is mandatory for all ATA
*
* 0x90 ABORT -> ST412/Early IDE
* 0x90 OK -> Probably ATA
*
* If libata gains the ability to handle IDENTIFY being refused (eg
* for early ATA) we can skip everything past the TRKZ check
*/
static int st416_probe_drive(unsigned long io, int dev, struct atahd_param *p)
{
unsigned long timeout = jiffies + 7 * HZ;
p->param[dev].legacty = 0;
/* ST506/412: Restore 512 bytes with ECC setting
ATA: This sequence is intentionally the ATA drive select
*/
if (dev)
iowrite8(ATA_DEVICE_OBS | ATA_DEV1, io + ATA_REG_DEVICE);
iowrite8(ATA_DEVICE_OBS, io + ATA_REG_DEVICE);
while (time_before(jiffies, timeout)) {
status = ioread8(port + ATA_REG_STATUS);
if ((status & (ATA_DRDY|ATA_BUSY)) == ATA_DRDY) {
/* ST506/412: Set the seek stepper: Restore drive 0, 35uS step
IDE: Harmless no-op
*/
if (st416_poll(io, 0x10, &err) == 0) {
/* Try issuing EDD - mandatory for all ATA but causes
an abort with ST412 / early IDE */
if (st416_poll(io, 0x90, &err) == 0) {
if (err & ATA_ABORTED)
p->param[dev].legacy = 1;
}
p->present |= 1 << dev;
p->param[dev].bios_ident = bios_ident++;
return 0;
}
return -ENODEV;
}
}
return -ETIMEDOUT;
}
static void st416_setup(unsigned long io, unsigned long ctl, struct atahd_param *p)
{
u8 err;
/* Reset the ST506/412 controller: For ATA this does a reset on
the attached devices but the rest of the logic is the same */
iowrite8(ATA_NIEN|ATA_SRST, ctl);
msleep(10);
iowrite8(ATA_NIEN, ctl);
st416_probe_drive(io, 0, p);
st416_probe_drive(io, 1, p);
}
/**
* atahd_init_one - attach a qdi interface
* @io: I/O port start
* @irq: interrupt line
*
* Register an ISA bus IDE interface. Such interfaces are PIO and we
* assume do not support IRQ sharing.
*/
static __init int atahd_init_one(unsigned long port, unsigned long io, int irq)
{
struct platform_device *pdev;
struct ata_host *host;
struct ata_port *ap;
void __iomem *io_addr, *ctl_addr;
int ret;
/*
* Look for a controller. It should SRST and respond sanely
* to a RESTORE command. Should do more checks here and in
* pata_legacy for controller presence.
*/
if (st416_setup(io_addr, ctl_addr, &atahd_param[nr_atahd_host]) < 0)
return 0;
/*
* Fill in a probe structure first of all
*/
pdev = platform_device_register_simple(DRV_NAME, nr_atahd_host, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
ret = -ENOMEM;
io_addr = devm_ioport_map(&pdev->dev, io, 8);
ctl_addr = devm_ioport_map(&pdev->dev, io + 0x206, 1);
if (!io_addr || !ctl_addr)
goto fail;
ret = -ENOMEM;
host = ata_host_alloc(&pdev->dev, 1);
if (!host)
goto fail;
ap = host->ports[0];
ap->ops = &atahd_port_ops;
ap->pio_mask = 0x01;
ap->flags = ATA_FLAG_SLAVE_POSS | ATA_FLAG_NO_IORDY;
ap->ioaddr.cmd_addr = io_addr;
ap->ioaddr.altstatus_addr = ctl_addr;
ap->ioaddr.ctl_addr = ctl_addr;
ata_std_ports(&ap->ioaddr);
/* activate */
ret = ata_host_activate(host, irq, ata_interrupt, 0, &atahd_sht);
if (ret)
goto fail;
ap->private_data = &atahd_param[nr_atahd_host];
atahd_host[nr_atahd_host++] = host;
return 0;
fail:
platform_device_unregister(pdev);
return ret;
}
/**
* atahd_init - attach qdi interfaces
*
* Attach qdi IDE interfaces by scanning the ports it may occupy.
*/
static __init int atahd_init(void)
{
unsigned long flags;
static const unsigned long atahd_port[2] = { 0x170, 0x1F0 };
static const int atahd_irq[2] = { 14, 15 };
int ct = 0;
int i;
for (i = 0; i < 2; i++) {
unsigned long port = atahd_port[i];
if (atahd_init_one(port, port + 0x206, atahd_irq[i]) == 0)
ct++;
}
if (ct != 0)
return 0;
return -ENODEV;
}
static __exit void atahd_exit(void)
{
int i;
for (i = 0; i < nr_atahd_host; i++) {
ata_host_detach(atahd_host[i]);
platform_device_unregister(atahd_device[i]);
}
}
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for PC/AT hard disk");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
module_init(atahd_init);
module_exit(atahd_exit);
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