[RFC] remove the paride driver

[RFC] remove the paride driver

[Christoph Hellwig]

Hi Jens,

the paride driver has been unmaintained for a while and is a significant
maintainance burden, including the fact that it is one of the last
users of the block layer bounce buffering code.  This patch suggest
to remove it assuming no users complain loduly.

Ondrej: you're the last known users, so please speak up if you still
have a use case!

Re: [PATCH] block: remove paride

[Jens Axboe]

On 12/23/21 4:35 AM, Christoph Hellwig wrote:
> From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>

Hmm?

-- 
Jens Axboe

Re: [PATCH] block: remove paride

[Christoph Hellwig]

On Thu, Dec 23, 2021 at 07:16:22AM -0700, Jens Axboe wrote:
> On 12/23/21 4:35 AM, Christoph Hellwig wrote:
> > From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
> 
> Hmm?

Oops.  git-rebease mess as I accidentally folded this into the loop
patch before splitting it out again..

Re: [RFC] remove the paride driver

[Jens Axboe]

On 12/23/21 4:35 AM, Christoph Hellwig wrote:
> Hi Jens,
> 
> the paride driver has been unmaintained for a while and is a significant
> maintainance burden, including the fact that it is one of the last
> users of the block layer bounce buffering code.  This patch suggest
> to remove it assuming no users complain loduly.

It really should be removed imho. To give folks a chance to pipe up,
might be more reasonable to queue it up post the 5.17 merge window. I
expect a lot of people are going to be less attentive the next few weeks
than usual, and that really isn't a lot of warning to give even with an
-rc8 planned.

-- 
Jens Axboe

Re: [RFC] remove the paride driver

[Ondrej Zary]

On Thursday 23 December 2021 12:35:03 Christoph Hellwig wrote:
> Hi Jens,
> 
> the paride driver has been unmaintained for a while and is a significant
> maintainance burden, including the fact that it is one of the last
> users of the block layer bounce buffering code.  This patch suggest
> to remove it assuming no users complain loduly.
> 
> Ondrej: you're the last known users, so please speak up if you still
> have a use case!

Looks like I really need to do the libata conversion.

-- 
Ondrej Zary

Re: [RFC] remove the paride driver

[Jens Axboe]

On 12/23/21 10:29 AM, Ondrej Zary wrote:
> On Thursday 23 December 2021 12:35:03 Christoph Hellwig wrote:
>> Hi Jens,
>>
>> the paride driver has been unmaintained for a while and is a significant
>> maintainance burden, including the fact that it is one of the last
>> users of the block layer bounce buffering code.  This patch suggest
>> to remove it assuming no users complain loduly.
>>
>> Ondrej: you're the last known users, so please speak up if you still
>> have a use case!
> 
> Looks like I really need to do the libata conversion.

That would indeed be great! As mentioned in my reply, I don't want to
remove drivers that are actively being used. Is the libata conversion
something you are going to do, or is it more of a dream at this point?
Ideally we get that done first, and then remove paride.

-- 
Jens Axboe

Re: [RFC] remove the paride driver

[Ondrej Zary]

On Thursday 23 December 2021 19:33:21 Jens Axboe wrote:
> On 12/23/21 10:29 AM, Ondrej Zary wrote:
> > On Thursday 23 December 2021 12:35:03 Christoph Hellwig wrote:
> >> Hi Jens,
> >>
> >> the paride driver has been unmaintained for a while and is a significant
> >> maintainance burden, including the fact that it is one of the last
> >> users of the block layer bounce buffering code.  This patch suggest
> >> to remove it assuming no users complain loduly.
> >>
> >> Ondrej: you're the last known users, so please speak up if you still
> >> have a use case!
> > 
> > Looks like I really need to do the libata conversion.
> 
> That would indeed be great! As mentioned in my reply, I don't want to
> remove drivers that are actively being used. Is the libata conversion
> something you are going to do, or is it more of a dream at this point?
> Ideally we get that done first, and then remove paride.

Haven't started yet. But I'm increasing its priority in my todo list.

-- 
Ondrej Zary

Re: [RFC] remove the paride driver

[Christoph Hellwig]

On Thu, Dec 23, 2021 at 11:34:46PM +0100, Ondrej Zary wrote:
> > That would indeed be great! As mentioned in my reply, I don't want to
> > remove drivers that are actively being used. Is the libata conversion
> > something you are going to do, or is it more of a dream at this point?
> > Ideally we get that done first, and then remove paride.
> 
> Haven't started yet. But I'm increasing its priority in my todo list.

Ok.  We'll keep the paride code in the current from for now then.

Re: [RFC] remove the paride driver

[Ondrej Zary]

On Friday 24 December 2021 06:56:44 Christoph Hellwig wrote:
> On Thu, Dec 23, 2021 at 11:34:46PM +0100, Ondrej Zary wrote:
> > > That would indeed be great! As mentioned in my reply, I don't want to
> > > remove drivers that are actively being used. Is the libata conversion
> > > something you are going to do, or is it more of a dream at this point?
> > > Ideally we get that done first, and then remove paride.
> > 
> > Haven't started yet. But I'm increasing its priority in my todo list.
> 
> Ok.  We'll keep the paride code in the current from for now then.

Here's the first version that works somehow. Detected LS-120 drive (epat) and
even mounted the filesystem and copied files! The code is crap (missing error
handling, unclaim/dicconnect, unregister, oopses on reboot, etc.).

The pata_parport_* functions are copied from libata-sff.c and modified not to
use ioread/iowrite. The pi_* functions are copied from paride.c and slightly
modified. The original paride protocol modules can register without any
changes.

I'm not sure about the device model integration (required by libata?).
It currently registers "pata_parport" bus with a "new_device" sysfs file
which is used to create new devices. I wonder if it's the correct way - it's
not possible to simply modprobe something with parameters to get a working
drive.

[  130.605256] paride: epat registered as protocol 0
[  132.363939] xxx: 0x378 is parport0
[  132.374746] xxx: epat: port 0x378, mode 0, ccr 0, test=(0,256,0)
[  132.374777] xxx: Sharing parport0 at 0x378
[  132.374918] xxx: epat 1.02, Shuttle EPAT chip c6 at 0x378,
[  132.374922] mode 0 (4-bit), delay 0
[  132.374950] pi_init ok!
[  132.377377] alloc_ok!
[  132.394447] scsi host4: pata_parport
[  132.394623] ata5: PATA max PIO0
[  132.613339] ata5.00: ATAPI: LS-120 COSM   04              UHD Floppy, 0270M09T, max PIO2
[  132.694550] scsi 4:0:0:0: Direct-Access     MATSHITA LS-120 COSM   04 0270 PQ: 0 ANSI: 5
[  132.729748] sd 4:0:0:0: Attached scsi generic sg1 type 0
[  132.760779] sd 4:0:0:0: [sdb] Media removed, stopped polling
[  132.792602] sd 4:0:0:0: [sdb] Attached SCSI removable disk
[  151.142037] sd 4:0:0:0: [sdb] Read Capacity(16) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
[  151.142090] sd 4:0:0:0: [sdb] Sense not available.
[  151.204874] sd 4:0:0:0: [sdb] 246528 512-byte logical blocks: (126 MB/120 MiB)
[  151.226471] sd 4:0:0:0: [sdb] Write Protect is on
[  151.226514] sd 4:0:0:0: [sdb] Mode Sense: 00 66 31 80
[  151.320880] sdb: detected capacity change from 0 to 246528
[  152.090211]  sdb:

From ddfc09664e5800c57cda4908ccf1ba4db92e94c4 Mon Sep 17 00:00:00 2001
From: Ondrej Zary <linux@zary.sk>
Date: Sun, 30 Jan 2022 21:09:39 +0100
Subject: [PATCH] pata_parport: first preview

---
 drivers/ata/Kconfig        |   6 +
 drivers/ata/Makefile       |   2 +
 drivers/ata/pata_parport.c | 688 +++++++++++++++++++++++++++++++++++++
 3 files changed, 696 insertions(+)
 create mode 100644 drivers/ata/pata_parport.c

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index cb54631fd950..f2e130ff67d9 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -1161,6 +1161,12 @@ config PATA_WINBOND_VLB
 	  Support for the Winbond W83759A controller on Vesa Local Bus
 	  systems.
 
+config PATA_PARPORT
+	tristate "Parallel port IDE device support"
+	depends on PARPORT_PC
+	help
+	  Support for Parallel port IDE devices.
+
 comment "Generic fallback / legacy drivers"
 
 config PATA_ACPI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index b8aebfb14e82..77145834a585 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -114,6 +114,8 @@ obj-$(CONFIG_PATA_SAMSUNG_CF)	+= pata_samsung_cf.o
 
 obj-$(CONFIG_PATA_PXA)		+= pata_pxa.o
 
+obj-$(CONFIG_PATA_PARPORT)	+= pata_parport.o
+
 # Should be last but two libata driver
 obj-$(CONFIG_PATA_ACPI)		+= pata_acpi.o
 # Should be last but one libata driver
diff --git a/drivers/ata/pata_parport.c b/drivers/ata/pata_parport.c
new file mode 100644
index 000000000000..1edbbe9d9687
--- /dev/null
+++ b/drivers/ata/pata_parport.c
@@ -0,0 +1,688 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/libata.h>
+#include <linux/parport.h>
+#include "paride.h"
+
+#define DRV_NAME "pata_parport"
+
+#define MAX_PROTOS	32
+static struct pi_protocol *protocols[MAX_PROTOS];
+
+static unsigned int pata_parport_devchk(struct ata_port *ap, unsigned int device)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+	u8 nsect, lbal;
+
+	ap->ops->sff_dev_select(ap, device);
+
+	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0x55);
+	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
+
+	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0xaa);
+	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0x55);
+
+	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 055);
+	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
+
+	nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
+	lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
+
+	if ((nsect == 0x55) && (lbal == 0xaa))
+		return 1;	/* we found a device */
+
+	return 0;		/* nothing found */
+}
+
+static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask,
+				      unsigned long deadline)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+	/* software reset.  causes dev0 to be selected */
+	pi->proto->write_regr(pi, 1, 6, ap->ctl);
+	udelay(20);	/* FIXME: flush */
+	pi->proto->write_regr(pi, 1, 6, ap->ctl | ATA_SRST);
+	udelay(20);	/* FIXME: flush */
+	pi->proto->write_regr(pi, 1, 6, ap->ctl);
+	ap->last_ctl = ap->ctl;
+
+	/* wait the port to become ready */
+	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
+}
+
+int pata_parport_softreset(struct ata_link *link, unsigned int *classes,
+			   unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
+	unsigned int devmask = 0;
+	int rc;
+	u8 err;
+
+	/* determine if device 0/1 are present */
+	if (pata_parport_devchk(ap, 0))
+		devmask |= (1 << 0);
+	if (slave_possible && pata_parport_devchk(ap, 1))
+		devmask |= (1 << 1);
+
+	/* select device 0 again */
+	ap->ops->sff_dev_select(ap, 0);
+
+	/* issue bus reset */
+	rc = pata_parport_bus_softreset(ap, devmask, deadline);
+	/* if link is occupied, -ENODEV too is an error */
+	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
+		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
+		return rc;
+	}
+
+	/* determine by signature whether we have ATA or ATAPI devices */
+	classes[0] = ata_sff_dev_classify(&link->device[0],
+					  devmask & (1 << 0), &err);
+	if (slave_possible && err != 0x81)
+		classes[1] = ata_sff_dev_classify(&link->device[1],
+						  devmask & (1 << 1), &err);
+
+	return 0;
+}
+
+u8 pata_parport_check_status(struct ata_port *ap)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+//	printk("%s\n", __FUNCTION__);
+	return pi->proto->read_regr(pi, 0, ATA_REG_STATUS);
+}
+
+u8 pata_parport_check_altstatus(struct ata_port *ap)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+//	printk("%s\n", __FUNCTION__);
+	return pi->proto->read_regr(pi, 1, 6);
+}
+
+void pata_parport_dev_select(struct ata_port *ap, unsigned int device)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+	u8 tmp;
+//	printk("%s\n", __FUNCTION__);
+	if (device == 0)
+		tmp = ATA_DEVICE_OBS;
+	else
+		tmp = ATA_DEVICE_OBS | ATA_DEV1;
+
+	pi->proto->write_regr(pi, 0, ATA_REG_DEVICE, tmp);
+	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
+}
+
+void pata_parport_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
+//	printk("%s\n", __FUNCTION__);
+	if (tf->ctl != ap->last_ctl) {
+		pi->proto->write_regr(pi, 1, 6, tf->ctl);
+		ap->last_ctl = tf->ctl;
+		ata_wait_idle(ap);
+	}
+
+	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
+		pi->proto->write_regr(pi, 0, ATA_REG_FEATURE, tf->hob_feature);
+		pi->proto->write_regr(pi, 0, ATA_REG_NSECT, tf->hob_nsect);
+		pi->proto->write_regr(pi, 0, ATA_REG_LBAL, tf->hob_lbal);
+		pi->proto->write_regr(pi, 0, ATA_REG_LBAM, tf->hob_lbam);
+		pi->proto->write_regr(pi, 0, ATA_REG_LBAH, tf->hob_lbah);
+	}
+
+	if (is_addr) {
+		pi->proto->write_regr(pi, 0, ATA_REG_FEATURE, tf->feature);
+		pi->proto->write_regr(pi, 0, ATA_REG_NSECT, tf->nsect);
+		pi->proto->write_regr(pi, 0, ATA_REG_LBAL, tf->lbal);
+		pi->proto->write_regr(pi, 0, ATA_REG_LBAM, tf->lbam);
+		pi->proto->write_regr(pi, 0, ATA_REG_LBAH, tf->lbah);
+	}
+
+	if (tf->flags & ATA_TFLAG_DEVICE)
+		pi->proto->write_regr(pi, 0, ATA_REG_DEVICE, tf->device);
+
+	ata_wait_idle(ap);
+}
+
+void pata_parport_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+//	printk("%s\n", __FUNCTION__);
+	tf->command = pi->proto->read_regr(pi, 0, ATA_REG_STATUS);
+	tf->feature = pi->proto->read_regr(pi, 0, ATA_REG_ERR);
+	tf->nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
+	tf->lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
+	tf->lbam = pi->proto->read_regr(pi, 0, ATA_REG_LBAM);
+	tf->lbah = pi->proto->read_regr(pi, 0, ATA_REG_LBAH);
+	tf->device = pi->proto->read_regr(pi, 0, ATA_REG_DEVICE);
+
+	if (tf->flags & ATA_TFLAG_LBA48) {
+		pi->proto->write_regr(pi, 1, 6, tf->ctl | ATA_HOB);
+		tf->hob_feature = pi->proto->read_regr(pi, 0, ATA_REG_ERR);
+		tf->hob_nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
+		tf->hob_lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
+		tf->hob_lbam = pi->proto->read_regr(pi, 0, ATA_REG_LBAM);
+		tf->hob_lbah = pi->proto->read_regr(pi, 0, ATA_REG_LBAH);
+		pi->proto->write_regr(pi, 1, 6, tf->ctl);
+		ap->last_ctl = tf->ctl;
+	}
+}
+
+void pata_parport_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
+{
+	struct pi_adapter *pi = ap->host->private_data;
+//	printk("%s\n", __FUNCTION__);
+	pi->proto->write_regr(pi, 0, ATA_REG_CMD, tf->command);
+	ata_sff_pause(ap);
+}
+
+unsigned int pata_parport_data_xfer(struct ata_queued_cmd *qc, unsigned char *buf,
+			       unsigned int buflen, int rw)
+{
+	struct ata_port *ap = qc->dev->link->ap;
+	struct pi_adapter *pi = ap->host->private_data;
+//	printk("%s\n", __FUNCTION__);
+	if (rw == READ)
+		pi->proto->read_block(pi, buf, buflen);
+	else
+		pi->proto->write_block(pi, buf, buflen);
+
+	return buflen;
+}
+
+void pata_parport_drain_fifo(struct ata_queued_cmd *qc)
+{
+	int count;
+	struct ata_port *ap;
+	struct pi_adapter *pi;
+	char junk[2];
+//	printk("%s\n", __FUNCTION__);
+	/* We only need to flush incoming data when a command was running */
+	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
+		return;
+
+	ap = qc->ap;
+	pi = ap->host->private_data;
+	/* Drain up to 64K of data before we give up this recovery method */
+	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
+						&& count < 65536; count += 2)
+		pi->proto->read_block(pi, junk, 2);
+
+	if (count)
+		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
+
+}
+
+void pata_parport_lost_interrupt(struct ata_port *ap)
+{
+	u8 status;
+	struct ata_queued_cmd *qc;
+//	printk("%s\n", __FUNCTION__);
+	/* Only one outstanding command per SFF channel */
+	qc = ata_qc_from_tag(ap, ap->link.active_tag);
+	/* We cannot lose an interrupt on a non-existent or polled command */
+	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
+		return;
+	/* See if the controller thinks it is still busy - if so the command
+	   isn't a lost IRQ but is still in progress */
+	status = pata_parport_check_altstatus(ap);
+	if (status & ATA_BUSY)
+		return;
+
+	/* There was a command running, we are no longer busy and we have
+	   no interrupt. */
+	ata_port_warn(ap, "lost interrupt (Status 0x%x)\n",
+								status);
+	/* Run the host interrupt logic as if the interrupt had not been
+	   lost */
+	ata_sff_port_intr(ap, qc);
+}
+
+static struct ata_port_operations pata_parport_port_ops = {
+	.qc_prep		= ata_noop_qc_prep,
+	.qc_issue		= ata_sff_qc_issue,
+	.qc_fill_rtf		= ata_sff_qc_fill_rtf,
+
+	.freeze			= ata_sff_freeze,
+	.thaw			= ata_sff_thaw,
+	.prereset		= ata_sff_prereset,
+	.softreset		= pata_parport_softreset,
+	.postreset		= ata_sff_postreset,
+	.error_handler		= ata_sff_error_handler,
+	.sched_eh		= ata_std_sched_eh,
+	.end_eh			= ata_std_end_eh,
+
+	.sff_dev_select		= pata_parport_dev_select,
+	.sff_check_status	= pata_parport_check_status,
+	.sff_check_altstatus	= pata_parport_check_altstatus,
+	.sff_tf_load		= pata_parport_tf_load,
+	.sff_tf_read		= pata_parport_tf_read,
+	.sff_exec_command	= pata_parport_exec_command,
+	.sff_data_xfer		= pata_parport_data_xfer,
+	.sff_drain_fifo		= pata_parport_drain_fifo,
+
+	.lost_interrupt		= pata_parport_lost_interrupt,
+};
+
+static const struct ata_port_info pata_parport_port_info = {
+	.flags		= ATA_FLAG_SLAVE_POSS | ATA_FLAG_PIO_POLLING,
+	.pio_mask	= ATA_PIO0,
+	/* No DMA */
+	.port_ops	= &pata_parport_port_ops,
+};
+
+int paride_register(struct pi_protocol *pr)
+{
+	int k;
+
+	for (k = 0; k < MAX_PROTOS; k++)
+		if (protocols[k] && !strcmp(pr->name, protocols[k]->name)) {
+			printk("paride: %s protocol already registered\n",
+			       pr->name);
+			return -1;
+		}
+	k = 0;
+	while ((k < MAX_PROTOS) && (protocols[k]))
+		k++;
+	if (k == MAX_PROTOS) {
+		printk("paride: protocol table full\n");
+		return -1;
+	}
+	protocols[k] = pr;
+	pr->index = k;
+	printk("paride: %s registered as protocol %d\n", pr->name, k);
+	return 0;
+}
+
+EXPORT_SYMBOL(paride_register);
+
+void paride_unregister(struct pi_protocol *pr)
+{
+	if (!pr)
+		return;
+	if (protocols[pr->index] != pr) {
+		printk("paride: %s not registered\n", pr->name);
+		return;
+	}
+	protocols[pr->index] = NULL;
+}
+
+EXPORT_SYMBOL(paride_unregister);
+
+
+
+static DEFINE_SPINLOCK(pi_spinlock);
+
+static void pi_wake_up(void *p)
+{
+	PIA *pi = (PIA *) p;
+	unsigned long flags;
+	void (*cont) (void) = NULL;
+
+	spin_lock_irqsave(&pi_spinlock, flags);
+
+	if (pi->claim_cont && !parport_claim(pi->pardev)) {
+		cont = pi->claim_cont;
+		pi->claim_cont = NULL;
+		pi->claimed = 1;
+	}
+
+	spin_unlock_irqrestore(&pi_spinlock, flags);
+
+	wake_up(&(pi->parq));
+
+	if (cont)
+		cont();
+}
+
+static void pi_claim(PIA * pi)
+{
+	if (pi->claimed)
+		return;
+	pi->claimed = 1;
+	if (pi->pardev)
+		wait_event(pi->parq,
+			   !parport_claim((struct pardevice *) pi->pardev));
+}
+
+static void pi_unclaim(PIA * pi)
+{
+	pi->claimed = 0;
+	if (pi->pardev)
+		parport_release((struct pardevice *) (pi->pardev));
+}
+
+static void pi_unregister_parport(PIA * pi)
+{
+	if (pi->pardev) {
+		parport_unregister_device((struct pardevice *) (pi->pardev));
+		pi->pardev = NULL;
+	}
+}
+
+static int default_test_proto(PIA * pi, char *scratch, int verbose)
+{
+	int j, k;
+	int e[2] = { 0, 0 };
+
+	pi->proto->connect(pi);
+
+	for (j = 0; j < 2; j++) {
+		pi->proto->write_regr(pi, 0, 6, 0xa0 + j * 0x10);
+		for (k = 0; k < 256; k++) {
+			pi->proto->write_regr(pi, 0, 2, k ^ 0xaa);
+			pi->proto->write_regr(pi, 0, 3, k ^ 0x55);
+			if (pi->proto->read_regr(pi, 0, 2) != (k ^ 0xaa))
+				e[j]++;
+		}
+	}
+	pi->proto->disconnect(pi);
+
+	if (verbose)
+		printk("%s: %s: port 0x%x, mode  %d, test=(%d,%d)\n",
+		       pi->device, pi->proto->name, pi->port,
+		       pi->mode, e[0], e[1]);
+
+	return (e[0] && e[1]);	/* not here if both > 0 */
+}
+
+static int pi_test_proto(PIA * pi, char *scratch, int verbose)
+{
+	int res;
+
+	pi_claim(pi);
+	if (pi->proto->test_proto)
+		res = pi->proto->test_proto(pi, scratch, verbose);
+	else
+		res = default_test_proto(pi, scratch, verbose);
+	pi_unclaim(pi);
+
+	return res;
+}
+
+static int pi_register_parport(PIA *pi, int verbose, int unit)
+{
+	struct parport *port;
+	struct pardev_cb par_cb;
+
+	port = parport_find_base(pi->port);
+	if (!port)
+		return 0;
+	memset(&par_cb, 0, sizeof(par_cb));
+	par_cb.wakeup = pi_wake_up;
+	par_cb.private = (void *)pi;
+	pi->pardev = parport_register_dev_model(port, pi->device, &par_cb,
+						unit);
+	parport_put_port(port);
+	if (!pi->pardev)
+		return 0;
+
+	init_waitqueue_head(&pi->parq);
+
+	if (verbose)
+		printk("%s: 0x%x is %s\n", pi->device, pi->port, port->name);
+
+	pi->parname = (char *) port->name;
+
+	return 1;
+}
+
+static int pi_probe_mode(PIA * pi, int max, char *scratch, int verbose)
+{
+	int best, range;
+
+	if (pi->mode != -1) {
+		if (pi->mode >= max)
+			return 0;
+		range = 3;
+		if (pi->mode >= pi->proto->epp_first)
+			range = 8;
+		if ((range == 8) && (pi->port % 8))
+			return 0;
+		pi->reserved = range;
+		return (!pi_test_proto(pi, scratch, verbose));
+	}
+	best = -1;
+	for (pi->mode = 0; pi->mode < max; pi->mode++) {
+		range = 3;
+		if (pi->mode >= pi->proto->epp_first)
+			range = 8;
+		if ((range == 8) && (pi->port % 8))
+			break;
+		pi->reserved = range;
+		if (!pi_test_proto(pi, scratch, verbose))
+			best = pi->mode;
+	}
+	pi->mode = best;
+	return (best > -1);
+}
+
+
+static int pi_probe_unit(PIA * pi, int unit, char *scratch, int verbose)
+{
+	int max, s, e;
+
+	s = unit;
+	e = s + 1;
+
+	if (s == -1) {
+		s = 0;
+		e = pi->proto->max_units;
+	}
+
+	if (!pi_register_parport(pi, verbose, s))
+		return 0;
+
+	if (pi->proto->test_port) {
+		pi_claim(pi);
+		max = pi->proto->test_port(pi);
+		pi_unclaim(pi);
+	} else
+		max = pi->proto->max_mode;
+
+	if (pi->proto->probe_unit) {
+		pi_claim(pi);
+		for (pi->unit = s; pi->unit < e; pi->unit++)
+			if (pi->proto->probe_unit(pi)) {
+				pi_unclaim(pi);
+				if (pi_probe_mode(pi, max, scratch, verbose))
+					return 1;
+				pi_unregister_parport(pi);
+				return 0;
+			}
+		pi_unclaim(pi);
+		pi_unregister_parport(pi);
+		return 0;
+	}
+
+	if (!pi_probe_mode(pi, max, scratch, verbose)) {
+		pi_unregister_parport(pi);
+		return 0;
+	}
+	return 1;
+
+}
+
+int pi_init(PIA * pi, int autoprobe, int port, int mode,
+	int unit, int protocol, int delay, char *scratch,
+	int devtype, int verbose, char *device)
+{
+	int p, k, s, e;
+	int lpts[7] = { 0x3bc, 0x378, 0x278, 0x268, 0x27c, 0x26c, 0 };
+
+	s = protocol;
+	e = s + 1;
+
+	if (!protocols[0])
+		request_module("paride_protocol");
+
+	if (autoprobe) {
+		s = 0;
+		e = MAX_PROTOS;
+	} else if ((s < 0) || (s >= MAX_PROTOS) || (port <= 0) ||
+		   (!protocols[s]) || (unit < 0) ||
+		   (unit >= protocols[s]->max_units)) {
+		printk("%s: Invalid parameters\n", device);
+		return 0;
+	}
+
+	for (p = s; p < e; p++) {
+		struct pi_protocol *proto = protocols[p];
+		if (!proto)
+			continue;
+		/* still racy */
+		if (!try_module_get(proto->owner))
+			continue;
+		pi->proto = proto;
+		pi->private = 0;
+		if (proto->init_proto && proto->init_proto(pi) < 0) {
+			pi->proto = NULL;
+			module_put(proto->owner);
+			continue;
+		}
+		if (delay == -1)
+			pi->delay = pi->proto->default_delay;
+		else
+			pi->delay = delay;
+		pi->devtype = devtype;
+		pi->device = device;
+
+		pi->parname = NULL;
+		pi->pardev = NULL;
+		init_waitqueue_head(&pi->parq);
+		pi->claimed = 0;
+		pi->claim_cont = NULL;
+
+		pi->mode = mode;
+		if (port != -1) {
+			pi->port = port;
+			if (pi_probe_unit(pi, unit, scratch, verbose))
+				break;
+			pi->port = 0;
+		} else {
+			k = 0;
+			while ((pi->port = lpts[k++]))
+				if (pi_probe_unit
+				    (pi, unit, scratch, verbose))
+					break;
+			if (pi->port)
+				break;
+		}
+		if (pi->proto->release_proto)
+			pi->proto->release_proto(pi);
+		module_put(proto->owner);
+	}
+
+	if (!pi->port) {
+		if (autoprobe)
+			printk("%s: Autoprobe failed\n", device);
+		else
+			printk("%s: Adapter not found\n", device);
+		return 0;
+	}
+
+	if (pi->parname)
+		printk("%s: Sharing %s at 0x%x\n", pi->device,
+		       pi->parname, pi->port);
+
+	pi->proto->log_adapter(pi, scratch, verbose);
+
+	return 1;
+}
+
+static struct scsi_host_template pata_parport_sht = {
+	ATA_PIO_SHT(DRV_NAME),
+};
+
+static ssize_t new_device_store(struct bus_type *bus, const char *buf, size_t count)
+{
+	struct pi_adapter *pi;
+	int retval;
+	int autoprobe, port, mode, unit, protocol, delay;
+	int fields = 0;
+	struct device dev;
+	const struct ata_port_info *ppi[] = { &pata_parport_port_info };
+	struct ata_host *host;
+	char scratch[512];
+
+	fields = sscanf(buf, "%x %d %d %d %d",
+			&port, &mode, &unit, &protocol, &delay);
+	if (fields < 5)
+		return -EINVAL;
+
+	memset(&dev, 0, sizeof(dev));
+	dev.parent = bus->dev_root;
+	dev.bus = bus;
+	dev_set_name(&dev, "pata_parport%d", 0);////
+	retval = device_register(&dev);
+	if (retval) {
+		printk("register failed\n");
+		return retval;
+	}
+
+	pi = devm_kzalloc(&dev, sizeof(struct pi_adapter), GFP_KERNEL);
+	if (!pi) {
+		//device_unregister
+		return -ENOMEM;
+	}
+
+	if (!pi_init(pi, autoprobe, port, mode, unit, protocol, delay, scratch, PI_PD, 2, "xxx"))
+		return -ENODEV;
+
+	printk("pi_init ok!\n");
+	pi_claim(pi);
+	pi->proto->connect(pi);
+	host = ata_host_alloc_pinfo(&dev, ppi, 1);
+	if (!host) {
+		/* pi_deinit??? */
+		return -ENOMEM;
+	}
+	host->private_data = pi;
+	printk("alloc_ok!\n");
+	if (ata_host_activate(host, 0, NULL, 0, &pata_parport_sht)) {
+		/* dealloc, pi_deinit??? */
+		return -EIO;
+	}
+
+	return count;
+}
+static BUS_ATTR_WO(new_device);
+
+static struct bus_type pata_parport_bus = {
+	.name = "pata_parport",
+};
+
+static __init int pata_parport_init(void)
+{
+	int error;
+
+	error = bus_register(&pata_parport_bus);
+	if (error) {
+		pr_err("failed to register pata_parport bus, error: %d\n", error);
+		return error;
+	}
+	error = bus_create_file(&pata_parport_bus, &bus_attr_new_device);
+	if (error) {
+		pr_err("unable to create sysfs file, error: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static __exit void pata_parport_exit(void)
+{
+	bus_remove_file(&pata_parport_bus, &bus_attr_new_device);
+	bus_unregister(&pata_parport_bus);
+}
+
+MODULE_AUTHOR("Ondrej Zary");
+MODULE_DESCRIPTION("driver for parallel port ATA adapters");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("paride");
+
+module_init(pata_parport_init);
+module_exit(pata_parport_exit);
-- 
Ondrej Zary

Re: [RFC] remove the paride driver

[Christoph Hellwig]

On Sun, Jan 30, 2022 at 09:14:43PM +0100, Ondrej Zary wrote:
> Here's the first version that works somehow. Detected LS-120 drive (epat) and
> even mounted the filesystem and copied files! The code is crap (missing error
> handling, unclaim/dicconnect, unregister, oopses on reboot, etc.).
> 
> The pata_parport_* functions are copied from libata-sff.c and modified not to
> use ioread/iowrite. The pi_* functions are copied from paride.c and slightly
> modified. The original paride protocol modules can register without any
> changes.

Nice!

> I'm not sure about the device model integration (required by libata?).
> It currently registers "pata_parport" bus with a "new_device" sysfs file
> which is used to create new devices. I wonder if it's the correct way - it's
> not possible to simply modprobe something with parameters to get a working
> drive.

Not sure.  Maybe Damien as the new libata maintainer has any idea what
to best do about that.

> 
> [  130.605256] paride: epat registered as protocol 0
> [  132.363939] xxx: 0x378 is parport0
> [  132.374746] xxx: epat: port 0x378, mode 0, ccr 0, test=(0,256,0)
> [  132.374777] xxx: Sharing parport0 at 0x378
> [  132.374918] xxx: epat 1.02, Shuttle EPAT chip c6 at 0x378,
> [  132.374922] mode 0 (4-bit), delay 0
> [  132.374950] pi_init ok!
> [  132.377377] alloc_ok!
> [  132.394447] scsi host4: pata_parport
> [  132.394623] ata5: PATA max PIO0
> [  132.613339] ata5.00: ATAPI: LS-120 COSM   04              UHD Floppy, 0270M09T, max PIO2
> [  132.694550] scsi 4:0:0:0: Direct-Access     MATSHITA LS-120 COSM   04 0270 PQ: 0 ANSI: 5
> [  132.729748] sd 4:0:0:0: Attached scsi generic sg1 type 0
> [  132.760779] sd 4:0:0:0: [sdb] Media removed, stopped polling
> [  132.792602] sd 4:0:0:0: [sdb] Attached SCSI removable disk
> [  151.142037] sd 4:0:0:0: [sdb] Read Capacity(16) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
> [  151.142090] sd 4:0:0:0: [sdb] Sense not available.
> [  151.204874] sd 4:0:0:0: [sdb] 246528 512-byte logical blocks: (126 MB/120 MiB)
> [  151.226471] sd 4:0:0:0: [sdb] Write Protect is on
> [  151.226514] sd 4:0:0:0: [sdb] Mode Sense: 00 66 31 80
> [  151.320880] sdb: detected capacity change from 0 to 246528
> [  152.090211]  sdb:
> 
> From ddfc09664e5800c57cda4908ccf1ba4db92e94c4 Mon Sep 17 00:00:00 2001
> From: Ondrej Zary <linux@zary.sk>
> Date: Sun, 30 Jan 2022 21:09:39 +0100
> Subject: [PATCH] pata_parport: first preview
> 
> ---
>  drivers/ata/Kconfig        |   6 +
>  drivers/ata/Makefile       |   2 +
>  drivers/ata/pata_parport.c | 688 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 696 insertions(+)
>  create mode 100644 drivers/ata/pata_parport.c
> 
> diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
> index cb54631fd950..f2e130ff67d9 100644
> --- a/drivers/ata/Kconfig
> +++ b/drivers/ata/Kconfig
> @@ -1161,6 +1161,12 @@ config PATA_WINBOND_VLB
>  	  Support for the Winbond W83759A controller on Vesa Local Bus
>  	  systems.
>  
> +config PATA_PARPORT
> +	tristate "Parallel port IDE device support"
> +	depends on PARPORT_PC
> +	help
> +	  Support for Parallel port IDE devices.
> +
>  comment "Generic fallback / legacy drivers"
>  
>  config PATA_ACPI
> diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
> index b8aebfb14e82..77145834a585 100644
> --- a/drivers/ata/Makefile
> +++ b/drivers/ata/Makefile
> @@ -114,6 +114,8 @@ obj-$(CONFIG_PATA_SAMSUNG_CF)	+= pata_samsung_cf.o
>  
>  obj-$(CONFIG_PATA_PXA)		+= pata_pxa.o
>  
> +obj-$(CONFIG_PATA_PARPORT)	+= pata_parport.o
> +
>  # Should be last but two libata driver
>  obj-$(CONFIG_PATA_ACPI)		+= pata_acpi.o
>  # Should be last but one libata driver
> diff --git a/drivers/ata/pata_parport.c b/drivers/ata/pata_parport.c
> new file mode 100644
> index 000000000000..1edbbe9d9687
> --- /dev/null
> +++ b/drivers/ata/pata_parport.c
> @@ -0,0 +1,688 @@
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/libata.h>
> +#include <linux/parport.h>
> +#include "paride.h"
> +
> +#define DRV_NAME "pata_parport"
> +
> +#define MAX_PROTOS	32
> +static struct pi_protocol *protocols[MAX_PROTOS];
> +
> +static unsigned int pata_parport_devchk(struct ata_port *ap, unsigned int device)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +	u8 nsect, lbal;
> +
> +	ap->ops->sff_dev_select(ap, device);
> +
> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0x55);
> +	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
> +
> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0xaa);
> +	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0x55);
> +
> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 055);
> +	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
> +
> +	nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
> +	lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
> +
> +	if ((nsect == 0x55) && (lbal == 0xaa))
> +		return 1;	/* we found a device */
> +
> +	return 0;		/* nothing found */
> +}
> +
> +static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask,
> +				      unsigned long deadline)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +	/* software reset.  causes dev0 to be selected */
> +	pi->proto->write_regr(pi, 1, 6, ap->ctl);
> +	udelay(20);	/* FIXME: flush */
> +	pi->proto->write_regr(pi, 1, 6, ap->ctl | ATA_SRST);
> +	udelay(20);	/* FIXME: flush */
> +	pi->proto->write_regr(pi, 1, 6, ap->ctl);
> +	ap->last_ctl = ap->ctl;
> +
> +	/* wait the port to become ready */
> +	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
> +}
> +
> +int pata_parport_softreset(struct ata_link *link, unsigned int *classes,
> +			   unsigned long deadline)
> +{
> +	struct ata_port *ap = link->ap;
> +	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
> +	unsigned int devmask = 0;
> +	int rc;
> +	u8 err;
> +
> +	/* determine if device 0/1 are present */
> +	if (pata_parport_devchk(ap, 0))
> +		devmask |= (1 << 0);
> +	if (slave_possible && pata_parport_devchk(ap, 1))
> +		devmask |= (1 << 1);
> +
> +	/* select device 0 again */
> +	ap->ops->sff_dev_select(ap, 0);
> +
> +	/* issue bus reset */
> +	rc = pata_parport_bus_softreset(ap, devmask, deadline);
> +	/* if link is occupied, -ENODEV too is an error */
> +	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
> +		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
> +		return rc;
> +	}
> +
> +	/* determine by signature whether we have ATA or ATAPI devices */
> +	classes[0] = ata_sff_dev_classify(&link->device[0],
> +					  devmask & (1 << 0), &err);
> +	if (slave_possible && err != 0x81)
> +		classes[1] = ata_sff_dev_classify(&link->device[1],
> +						  devmask & (1 << 1), &err);
> +
> +	return 0;
> +}
> +
> +u8 pata_parport_check_status(struct ata_port *ap)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +//	printk("%s\n", __FUNCTION__);
> +	return pi->proto->read_regr(pi, 0, ATA_REG_STATUS);
> +}
> +
> +u8 pata_parport_check_altstatus(struct ata_port *ap)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +//	printk("%s\n", __FUNCTION__);
> +	return pi->proto->read_regr(pi, 1, 6);
> +}
> +
> +void pata_parport_dev_select(struct ata_port *ap, unsigned int device)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +	u8 tmp;
> +//	printk("%s\n", __FUNCTION__);
> +	if (device == 0)
> +		tmp = ATA_DEVICE_OBS;
> +	else
> +		tmp = ATA_DEVICE_OBS | ATA_DEV1;
> +
> +	pi->proto->write_regr(pi, 0, ATA_REG_DEVICE, tmp);
> +	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
> +}
> +
> +void pata_parport_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
> +//	printk("%s\n", __FUNCTION__);
> +	if (tf->ctl != ap->last_ctl) {
> +		pi->proto->write_regr(pi, 1, 6, tf->ctl);
> +		ap->last_ctl = tf->ctl;
> +		ata_wait_idle(ap);
> +	}
> +
> +	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
> +		pi->proto->write_regr(pi, 0, ATA_REG_FEATURE, tf->hob_feature);
> +		pi->proto->write_regr(pi, 0, ATA_REG_NSECT, tf->hob_nsect);
> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAL, tf->hob_lbal);
> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAM, tf->hob_lbam);
> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAH, tf->hob_lbah);
> +	}
> +
> +	if (is_addr) {
> +		pi->proto->write_regr(pi, 0, ATA_REG_FEATURE, tf->feature);
> +		pi->proto->write_regr(pi, 0, ATA_REG_NSECT, tf->nsect);
> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAL, tf->lbal);
> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAM, tf->lbam);
> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAH, tf->lbah);
> +	}
> +
> +	if (tf->flags & ATA_TFLAG_DEVICE)
> +		pi->proto->write_regr(pi, 0, ATA_REG_DEVICE, tf->device);
> +
> +	ata_wait_idle(ap);
> +}
> +
> +void pata_parport_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +//	printk("%s\n", __FUNCTION__);
> +	tf->command = pi->proto->read_regr(pi, 0, ATA_REG_STATUS);
> +	tf->feature = pi->proto->read_regr(pi, 0, ATA_REG_ERR);
> +	tf->nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
> +	tf->lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
> +	tf->lbam = pi->proto->read_regr(pi, 0, ATA_REG_LBAM);
> +	tf->lbah = pi->proto->read_regr(pi, 0, ATA_REG_LBAH);
> +	tf->device = pi->proto->read_regr(pi, 0, ATA_REG_DEVICE);
> +
> +	if (tf->flags & ATA_TFLAG_LBA48) {
> +		pi->proto->write_regr(pi, 1, 6, tf->ctl | ATA_HOB);
> +		tf->hob_feature = pi->proto->read_regr(pi, 0, ATA_REG_ERR);
> +		tf->hob_nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
> +		tf->hob_lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
> +		tf->hob_lbam = pi->proto->read_regr(pi, 0, ATA_REG_LBAM);
> +		tf->hob_lbah = pi->proto->read_regr(pi, 0, ATA_REG_LBAH);
> +		pi->proto->write_regr(pi, 1, 6, tf->ctl);
> +		ap->last_ctl = tf->ctl;
> +	}
> +}
> +
> +void pata_parport_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
> +{
> +	struct pi_adapter *pi = ap->host->private_data;
> +//	printk("%s\n", __FUNCTION__);
> +	pi->proto->write_regr(pi, 0, ATA_REG_CMD, tf->command);
> +	ata_sff_pause(ap);
> +}
> +
> +unsigned int pata_parport_data_xfer(struct ata_queued_cmd *qc, unsigned char *buf,
> +			       unsigned int buflen, int rw)
> +{
> +	struct ata_port *ap = qc->dev->link->ap;
> +	struct pi_adapter *pi = ap->host->private_data;
> +//	printk("%s\n", __FUNCTION__);
> +	if (rw == READ)
> +		pi->proto->read_block(pi, buf, buflen);
> +	else
> +		pi->proto->write_block(pi, buf, buflen);
> +
> +	return buflen;
> +}
> +
> +void pata_parport_drain_fifo(struct ata_queued_cmd *qc)
> +{
> +	int count;
> +	struct ata_port *ap;
> +	struct pi_adapter *pi;
> +	char junk[2];
> +//	printk("%s\n", __FUNCTION__);
> +	/* We only need to flush incoming data when a command was running */
> +	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
> +		return;
> +
> +	ap = qc->ap;
> +	pi = ap->host->private_data;
> +	/* Drain up to 64K of data before we give up this recovery method */
> +	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
> +						&& count < 65536; count += 2)
> +		pi->proto->read_block(pi, junk, 2);
> +
> +	if (count)
> +		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
> +
> +}
> +
> +void pata_parport_lost_interrupt(struct ata_port *ap)
> +{
> +	u8 status;
> +	struct ata_queued_cmd *qc;
> +//	printk("%s\n", __FUNCTION__);
> +	/* Only one outstanding command per SFF channel */
> +	qc = ata_qc_from_tag(ap, ap->link.active_tag);
> +	/* We cannot lose an interrupt on a non-existent or polled command */
> +	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
> +		return;
> +	/* See if the controller thinks it is still busy - if so the command
> +	   isn't a lost IRQ but is still in progress */
> +	status = pata_parport_check_altstatus(ap);
> +	if (status & ATA_BUSY)
> +		return;
> +
> +	/* There was a command running, we are no longer busy and we have
> +	   no interrupt. */
> +	ata_port_warn(ap, "lost interrupt (Status 0x%x)\n",
> +								status);
> +	/* Run the host interrupt logic as if the interrupt had not been
> +	   lost */
> +	ata_sff_port_intr(ap, qc);
> +}
> +
> +static struct ata_port_operations pata_parport_port_ops = {
> +	.qc_prep		= ata_noop_qc_prep,
> +	.qc_issue		= ata_sff_qc_issue,
> +	.qc_fill_rtf		= ata_sff_qc_fill_rtf,
> +
> +	.freeze			= ata_sff_freeze,
> +	.thaw			= ata_sff_thaw,
> +	.prereset		= ata_sff_prereset,
> +	.softreset		= pata_parport_softreset,
> +	.postreset		= ata_sff_postreset,
> +	.error_handler		= ata_sff_error_handler,
> +	.sched_eh		= ata_std_sched_eh,
> +	.end_eh			= ata_std_end_eh,
> +
> +	.sff_dev_select		= pata_parport_dev_select,
> +	.sff_check_status	= pata_parport_check_status,
> +	.sff_check_altstatus	= pata_parport_check_altstatus,
> +	.sff_tf_load		= pata_parport_tf_load,
> +	.sff_tf_read		= pata_parport_tf_read,
> +	.sff_exec_command	= pata_parport_exec_command,
> +	.sff_data_xfer		= pata_parport_data_xfer,
> +	.sff_drain_fifo		= pata_parport_drain_fifo,
> +
> +	.lost_interrupt		= pata_parport_lost_interrupt,
> +};
> +
> +static const struct ata_port_info pata_parport_port_info = {
> +	.flags		= ATA_FLAG_SLAVE_POSS | ATA_FLAG_PIO_POLLING,
> +	.pio_mask	= ATA_PIO0,
> +	/* No DMA */
> +	.port_ops	= &pata_parport_port_ops,
> +};
> +
> +int paride_register(struct pi_protocol *pr)
> +{
> +	int k;
> +
> +	for (k = 0; k < MAX_PROTOS; k++)
> +		if (protocols[k] && !strcmp(pr->name, protocols[k]->name)) {
> +			printk("paride: %s protocol already registered\n",
> +			       pr->name);
> +			return -1;
> +		}
> +	k = 0;
> +	while ((k < MAX_PROTOS) && (protocols[k]))
> +		k++;
> +	if (k == MAX_PROTOS) {
> +		printk("paride: protocol table full\n");
> +		return -1;
> +	}
> +	protocols[k] = pr;
> +	pr->index = k;
> +	printk("paride: %s registered as protocol %d\n", pr->name, k);
> +	return 0;
> +}
> +
> +EXPORT_SYMBOL(paride_register);
> +
> +void paride_unregister(struct pi_protocol *pr)
> +{
> +	if (!pr)
> +		return;
> +	if (protocols[pr->index] != pr) {
> +		printk("paride: %s not registered\n", pr->name);
> +		return;
> +	}
> +	protocols[pr->index] = NULL;
> +}
> +
> +EXPORT_SYMBOL(paride_unregister);
> +
> +
> +
> +static DEFINE_SPINLOCK(pi_spinlock);
> +
> +static void pi_wake_up(void *p)
> +{
> +	PIA *pi = (PIA *) p;
> +	unsigned long flags;
> +	void (*cont) (void) = NULL;
> +
> +	spin_lock_irqsave(&pi_spinlock, flags);
> +
> +	if (pi->claim_cont && !parport_claim(pi->pardev)) {
> +		cont = pi->claim_cont;
> +		pi->claim_cont = NULL;
> +		pi->claimed = 1;
> +	}
> +
> +	spin_unlock_irqrestore(&pi_spinlock, flags);
> +
> +	wake_up(&(pi->parq));
> +
> +	if (cont)
> +		cont();
> +}
> +
> +static void pi_claim(PIA * pi)
> +{
> +	if (pi->claimed)
> +		return;
> +	pi->claimed = 1;
> +	if (pi->pardev)
> +		wait_event(pi->parq,
> +			   !parport_claim((struct pardevice *) pi->pardev));
> +}
> +
> +static void pi_unclaim(PIA * pi)
> +{
> +	pi->claimed = 0;
> +	if (pi->pardev)
> +		parport_release((struct pardevice *) (pi->pardev));
> +}
> +
> +static void pi_unregister_parport(PIA * pi)
> +{
> +	if (pi->pardev) {
> +		parport_unregister_device((struct pardevice *) (pi->pardev));
> +		pi->pardev = NULL;
> +	}
> +}
> +
> +static int default_test_proto(PIA * pi, char *scratch, int verbose)
> +{
> +	int j, k;
> +	int e[2] = { 0, 0 };
> +
> +	pi->proto->connect(pi);
> +
> +	for (j = 0; j < 2; j++) {
> +		pi->proto->write_regr(pi, 0, 6, 0xa0 + j * 0x10);
> +		for (k = 0; k < 256; k++) {
> +			pi->proto->write_regr(pi, 0, 2, k ^ 0xaa);
> +			pi->proto->write_regr(pi, 0, 3, k ^ 0x55);
> +			if (pi->proto->read_regr(pi, 0, 2) != (k ^ 0xaa))
> +				e[j]++;
> +		}
> +	}
> +	pi->proto->disconnect(pi);
> +
> +	if (verbose)
> +		printk("%s: %s: port 0x%x, mode  %d, test=(%d,%d)\n",
> +		       pi->device, pi->proto->name, pi->port,
> +		       pi->mode, e[0], e[1]);
> +
> +	return (e[0] && e[1]);	/* not here if both > 0 */
> +}
> +
> +static int pi_test_proto(PIA * pi, char *scratch, int verbose)
> +{
> +	int res;
> +
> +	pi_claim(pi);
> +	if (pi->proto->test_proto)
> +		res = pi->proto->test_proto(pi, scratch, verbose);
> +	else
> +		res = default_test_proto(pi, scratch, verbose);
> +	pi_unclaim(pi);
> +
> +	return res;
> +}
> +
> +static int pi_register_parport(PIA *pi, int verbose, int unit)
> +{
> +	struct parport *port;
> +	struct pardev_cb par_cb;
> +
> +	port = parport_find_base(pi->port);
> +	if (!port)
> +		return 0;
> +	memset(&par_cb, 0, sizeof(par_cb));
> +	par_cb.wakeup = pi_wake_up;
> +	par_cb.private = (void *)pi;
> +	pi->pardev = parport_register_dev_model(port, pi->device, &par_cb,
> +						unit);
> +	parport_put_port(port);
> +	if (!pi->pardev)
> +		return 0;
> +
> +	init_waitqueue_head(&pi->parq);
> +
> +	if (verbose)
> +		printk("%s: 0x%x is %s\n", pi->device, pi->port, port->name);
> +
> +	pi->parname = (char *) port->name;
> +
> +	return 1;
> +}
> +
> +static int pi_probe_mode(PIA * pi, int max, char *scratch, int verbose)
> +{
> +	int best, range;
> +
> +	if (pi->mode != -1) {
> +		if (pi->mode >= max)
> +			return 0;
> +		range = 3;
> +		if (pi->mode >= pi->proto->epp_first)
> +			range = 8;
> +		if ((range == 8) && (pi->port % 8))
> +			return 0;
> +		pi->reserved = range;
> +		return (!pi_test_proto(pi, scratch, verbose));
> +	}
> +	best = -1;
> +	for (pi->mode = 0; pi->mode < max; pi->mode++) {
> +		range = 3;
> +		if (pi->mode >= pi->proto->epp_first)
> +			range = 8;
> +		if ((range == 8) && (pi->port % 8))
> +			break;
> +		pi->reserved = range;
> +		if (!pi_test_proto(pi, scratch, verbose))
> +			best = pi->mode;
> +	}
> +	pi->mode = best;
> +	return (best > -1);
> +}
> +
> +
> +static int pi_probe_unit(PIA * pi, int unit, char *scratch, int verbose)
> +{
> +	int max, s, e;
> +
> +	s = unit;
> +	e = s + 1;
> +
> +	if (s == -1) {
> +		s = 0;
> +		e = pi->proto->max_units;
> +	}
> +
> +	if (!pi_register_parport(pi, verbose, s))
> +		return 0;
> +
> +	if (pi->proto->test_port) {
> +		pi_claim(pi);
> +		max = pi->proto->test_port(pi);
> +		pi_unclaim(pi);
> +	} else
> +		max = pi->proto->max_mode;
> +
> +	if (pi->proto->probe_unit) {
> +		pi_claim(pi);
> +		for (pi->unit = s; pi->unit < e; pi->unit++)
> +			if (pi->proto->probe_unit(pi)) {
> +				pi_unclaim(pi);
> +				if (pi_probe_mode(pi, max, scratch, verbose))
> +					return 1;
> +				pi_unregister_parport(pi);
> +				return 0;
> +			}
> +		pi_unclaim(pi);
> +		pi_unregister_parport(pi);
> +		return 0;
> +	}
> +
> +	if (!pi_probe_mode(pi, max, scratch, verbose)) {
> +		pi_unregister_parport(pi);
> +		return 0;
> +	}
> +	return 1;
> +
> +}
> +
> +int pi_init(PIA * pi, int autoprobe, int port, int mode,
> +	int unit, int protocol, int delay, char *scratch,
> +	int devtype, int verbose, char *device)
> +{
> +	int p, k, s, e;
> +	int lpts[7] = { 0x3bc, 0x378, 0x278, 0x268, 0x27c, 0x26c, 0 };
> +
> +	s = protocol;
> +	e = s + 1;
> +
> +	if (!protocols[0])
> +		request_module("paride_protocol");
> +
> +	if (autoprobe) {
> +		s = 0;
> +		e = MAX_PROTOS;
> +	} else if ((s < 0) || (s >= MAX_PROTOS) || (port <= 0) ||
> +		   (!protocols[s]) || (unit < 0) ||
> +		   (unit >= protocols[s]->max_units)) {
> +		printk("%s: Invalid parameters\n", device);
> +		return 0;
> +	}
> +
> +	for (p = s; p < e; p++) {
> +		struct pi_protocol *proto = protocols[p];
> +		if (!proto)
> +			continue;
> +		/* still racy */
> +		if (!try_module_get(proto->owner))
> +			continue;
> +		pi->proto = proto;
> +		pi->private = 0;
> +		if (proto->init_proto && proto->init_proto(pi) < 0) {
> +			pi->proto = NULL;
> +			module_put(proto->owner);
> +			continue;
> +		}
> +		if (delay == -1)
> +			pi->delay = pi->proto->default_delay;
> +		else
> +			pi->delay = delay;
> +		pi->devtype = devtype;
> +		pi->device = device;
> +
> +		pi->parname = NULL;
> +		pi->pardev = NULL;
> +		init_waitqueue_head(&pi->parq);
> +		pi->claimed = 0;
> +		pi->claim_cont = NULL;
> +
> +		pi->mode = mode;
> +		if (port != -1) {
> +			pi->port = port;
> +			if (pi_probe_unit(pi, unit, scratch, verbose))
> +				break;
> +			pi->port = 0;
> +		} else {
> +			k = 0;
> +			while ((pi->port = lpts[k++]))
> +				if (pi_probe_unit
> +				    (pi, unit, scratch, verbose))
> +					break;
> +			if (pi->port)
> +				break;
> +		}
> +		if (pi->proto->release_proto)
> +			pi->proto->release_proto(pi);
> +		module_put(proto->owner);
> +	}
> +
> +	if (!pi->port) {
> +		if (autoprobe)
> +			printk("%s: Autoprobe failed\n", device);
> +		else
> +			printk("%s: Adapter not found\n", device);
> +		return 0;
> +	}
> +
> +	if (pi->parname)
> +		printk("%s: Sharing %s at 0x%x\n", pi->device,
> +		       pi->parname, pi->port);
> +
> +	pi->proto->log_adapter(pi, scratch, verbose);
> +
> +	return 1;
> +}
> +
> +static struct scsi_host_template pata_parport_sht = {
> +	ATA_PIO_SHT(DRV_NAME),
> +};
> +
> +static ssize_t new_device_store(struct bus_type *bus, const char *buf, size_t count)
> +{
> +	struct pi_adapter *pi;
> +	int retval;
> +	int autoprobe, port, mode, unit, protocol, delay;
> +	int fields = 0;
> +	struct device dev;
> +	const struct ata_port_info *ppi[] = { &pata_parport_port_info };
> +	struct ata_host *host;
> +	char scratch[512];
> +
> +	fields = sscanf(buf, "%x %d %d %d %d",
> +			&port, &mode, &unit, &protocol, &delay);
> +	if (fields < 5)
> +		return -EINVAL;
> +
> +	memset(&dev, 0, sizeof(dev));
> +	dev.parent = bus->dev_root;
> +	dev.bus = bus;
> +	dev_set_name(&dev, "pata_parport%d", 0);////
> +	retval = device_register(&dev);
> +	if (retval) {
> +		printk("register failed\n");
> +		return retval;
> +	}
> +
> +	pi = devm_kzalloc(&dev, sizeof(struct pi_adapter), GFP_KERNEL);
> +	if (!pi) {
> +		//device_unregister
> +		return -ENOMEM;
> +	}
> +
> +	if (!pi_init(pi, autoprobe, port, mode, unit, protocol, delay, scratch, PI_PD, 2, "xxx"))
> +		return -ENODEV;
> +
> +	printk("pi_init ok!\n");
> +	pi_claim(pi);
> +	pi->proto->connect(pi);
> +	host = ata_host_alloc_pinfo(&dev, ppi, 1);
> +	if (!host) {
> +		/* pi_deinit??? */
> +		return -ENOMEM;
> +	}
> +	host->private_data = pi;
> +	printk("alloc_ok!\n");
> +	if (ata_host_activate(host, 0, NULL, 0, &pata_parport_sht)) {
> +		/* dealloc, pi_deinit??? */
> +		return -EIO;
> +	}
> +
> +	return count;
> +}
> +static BUS_ATTR_WO(new_device);
> +
> +static struct bus_type pata_parport_bus = {
> +	.name = "pata_parport",
> +};
> +
> +static __init int pata_parport_init(void)
> +{
> +	int error;
> +
> +	error = bus_register(&pata_parport_bus);
> +	if (error) {
> +		pr_err("failed to register pata_parport bus, error: %d\n", error);
> +		return error;
> +	}
> +	error = bus_create_file(&pata_parport_bus, &bus_attr_new_device);
> +	if (error) {
> +		pr_err("unable to create sysfs file, error: %d\n", error);
> +		return error;
> +	}
> +
> +	return 0;
> +}
> +
> +static __exit void pata_parport_exit(void)
> +{
> +	bus_remove_file(&pata_parport_bus, &bus_attr_new_device);
> +	bus_unregister(&pata_parport_bus);
> +}
> +
> +MODULE_AUTHOR("Ondrej Zary");
> +MODULE_DESCRIPTION("driver for parallel port ATA adapters");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("paride");
> +
> +module_init(pata_parport_init);
> +module_exit(pata_parport_exit);
> -- 
> Ondrej Zary
---end quoted text---

Re: [RFC] remove the paride driver

[Damien Le Moal]

On 2/2/22 23:13, Christoph Hellwig wrote:
> On Sun, Jan 30, 2022 at 09:14:43PM +0100, Ondrej Zary wrote:
>> Here's the first version that works somehow. Detected LS-120 drive (epat) and
>> even mounted the filesystem and copied files! The code is crap (missing error
>> handling, unclaim/dicconnect, unregister, oopses on reboot, etc.).
>>
>> The pata_parport_* functions are copied from libata-sff.c and modified not to
>> use ioread/iowrite. The pi_* functions are copied from paride.c and slightly
>> modified. The original paride protocol modules can register without any
>> changes.
> 
> Nice!
> 
>> I'm not sure about the device model integration (required by libata?).
>> It currently registers "pata_parport" bus with a "new_device" sysfs file
>> which is used to create new devices. I wonder if it's the correct way - it's
>> not possible to simply modprobe something with parameters to get a working
>> drive.
> 
> Not sure.  Maybe Damien as the new libata maintainer has any idea what
> to best do about that.

Well, that is a first, no other driver define their own bus :)
Given that new_device_store() gets the port, protocol, delay etc from
the user, I guess that there is no way to automatically probe the
parallel port adapter to find out what devices are on it ?

If yes, then I think this is fine. I cannot think of any other method to
do it, unless your platform uses a device tree file, in which case the
setup should be passed using that file (like so many other platform
ata/pata drivers do).

> 
>>
>> [  130.605256] paride: epat registered as protocol 0
>> [  132.363939] xxx: 0x378 is parport0
>> [  132.374746] xxx: epat: port 0x378, mode 0, ccr 0, test=(0,256,0)
>> [  132.374777] xxx: Sharing parport0 at 0x378
>> [  132.374918] xxx: epat 1.02, Shuttle EPAT chip c6 at 0x378,
>> [  132.374922] mode 0 (4-bit), delay 0
>> [  132.374950] pi_init ok!
>> [  132.377377] alloc_ok!
>> [  132.394447] scsi host4: pata_parport
>> [  132.394623] ata5: PATA max PIO0
>> [  132.613339] ata5.00: ATAPI: LS-120 COSM   04              UHD Floppy, 0270M09T, max PIO2
>> [  132.694550] scsi 4:0:0:0: Direct-Access     MATSHITA LS-120 COSM   04 0270 PQ: 0 ANSI: 5
>> [  132.729748] sd 4:0:0:0: Attached scsi generic sg1 type 0
>> [  132.760779] sd 4:0:0:0: [sdb] Media removed, stopped polling
>> [  132.792602] sd 4:0:0:0: [sdb] Attached SCSI removable disk
>> [  151.142037] sd 4:0:0:0: [sdb] Read Capacity(16) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
>> [  151.142090] sd 4:0:0:0: [sdb] Sense not available.
>> [  151.204874] sd 4:0:0:0: [sdb] 246528 512-byte logical blocks: (126 MB/120 MiB)
>> [  151.226471] sd 4:0:0:0: [sdb] Write Protect is on
>> [  151.226514] sd 4:0:0:0: [sdb] Mode Sense: 00 66 31 80
>> [  151.320880] sdb: detected capacity change from 0 to 246528
>> [  152.090211]  sdb:
>>
>> From ddfc09664e5800c57cda4908ccf1ba4db92e94c4 Mon Sep 17 00:00:00 2001
>> From: Ondrej Zary <linux@zary.sk>
>> Date: Sun, 30 Jan 2022 21:09:39 +0100
>> Subject: [PATCH] pata_parport: first preview
>>
>> ---
>>  drivers/ata/Kconfig        |   6 +
>>  drivers/ata/Makefile       |   2 +
>>  drivers/ata/pata_parport.c | 688 +++++++++++++++++++++++++++++++++++++
>>  3 files changed, 696 insertions(+)
>>  create mode 100644 drivers/ata/pata_parport.c
>>
>> diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
>> index cb54631fd950..f2e130ff67d9 100644
>> --- a/drivers/ata/Kconfig
>> +++ b/drivers/ata/Kconfig
>> @@ -1161,6 +1161,12 @@ config PATA_WINBOND_VLB
>>  	  Support for the Winbond W83759A controller on Vesa Local Bus
>>  	  systems.
>>  
>> +config PATA_PARPORT
>> +	tristate "Parallel port IDE device support"
>> +	depends on PARPORT_PC
>> +	help
>> +	  Support for Parallel port IDE devices.
>> +
>>  comment "Generic fallback / legacy drivers"
>>  
>>  config PATA_ACPI
>> diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
>> index b8aebfb14e82..77145834a585 100644
>> --- a/drivers/ata/Makefile
>> +++ b/drivers/ata/Makefile
>> @@ -114,6 +114,8 @@ obj-$(CONFIG_PATA_SAMSUNG_CF)	+= pata_samsung_cf.o
>>  
>>  obj-$(CONFIG_PATA_PXA)		+= pata_pxa.o
>>  
>> +obj-$(CONFIG_PATA_PARPORT)	+= pata_parport.o
>> +
>>  # Should be last but two libata driver
>>  obj-$(CONFIG_PATA_ACPI)		+= pata_acpi.o
>>  # Should be last but one libata driver
>> diff --git a/drivers/ata/pata_parport.c b/drivers/ata/pata_parport.c
>> new file mode 100644
>> index 000000000000..1edbbe9d9687
>> --- /dev/null
>> +++ b/drivers/ata/pata_parport.c
>> @@ -0,0 +1,688 @@
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/libata.h>
>> +#include <linux/parport.h>
>> +#include "paride.h"
>> +
>> +#define DRV_NAME "pata_parport"
>> +
>> +#define MAX_PROTOS	32
>> +static struct pi_protocol *protocols[MAX_PROTOS];
>> +
>> +static unsigned int pata_parport_devchk(struct ata_port *ap, unsigned int device)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +	u8 nsect, lbal;
>> +
>> +	ap->ops->sff_dev_select(ap, device);
>> +
>> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0x55);
>> +	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
>> +
>> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0xaa);
>> +	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0x55);
>> +
>> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 055);
>> +	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
>> +
>> +	nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
>> +	lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
>> +
>> +	if ((nsect == 0x55) && (lbal == 0xaa))
>> +		return 1;	/* we found a device */
>> +
>> +	return 0;		/* nothing found */
>> +}
>> +
>> +static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask,
>> +				      unsigned long deadline)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +	/* software reset.  causes dev0 to be selected */
>> +	pi->proto->write_regr(pi, 1, 6, ap->ctl);
>> +	udelay(20);	/* FIXME: flush */
>> +	pi->proto->write_regr(pi, 1, 6, ap->ctl | ATA_SRST);
>> +	udelay(20);	/* FIXME: flush */
>> +	pi->proto->write_regr(pi, 1, 6, ap->ctl);
>> +	ap->last_ctl = ap->ctl;
>> +
>> +	/* wait the port to become ready */
>> +	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
>> +}
>> +
>> +int pata_parport_softreset(struct ata_link *link, unsigned int *classes,
>> +			   unsigned long deadline)
>> +{
>> +	struct ata_port *ap = link->ap;
>> +	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
>> +	unsigned int devmask = 0;
>> +	int rc;
>> +	u8 err;
>> +
>> +	/* determine if device 0/1 are present */
>> +	if (pata_parport_devchk(ap, 0))
>> +		devmask |= (1 << 0);
>> +	if (slave_possible && pata_parport_devchk(ap, 1))
>> +		devmask |= (1 << 1);
>> +
>> +	/* select device 0 again */
>> +	ap->ops->sff_dev_select(ap, 0);
>> +
>> +	/* issue bus reset */
>> +	rc = pata_parport_bus_softreset(ap, devmask, deadline);
>> +	/* if link is occupied, -ENODEV too is an error */
>> +	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
>> +		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
>> +		return rc;
>> +	}
>> +
>> +	/* determine by signature whether we have ATA or ATAPI devices */
>> +	classes[0] = ata_sff_dev_classify(&link->device[0],
>> +					  devmask & (1 << 0), &err);
>> +	if (slave_possible && err != 0x81)
>> +		classes[1] = ata_sff_dev_classify(&link->device[1],
>> +						  devmask & (1 << 1), &err);
>> +
>> +	return 0;
>> +}
>> +
>> +u8 pata_parport_check_status(struct ata_port *ap)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +//	printk("%s\n", __FUNCTION__);
>> +	return pi->proto->read_regr(pi, 0, ATA_REG_STATUS);
>> +}
>> +
>> +u8 pata_parport_check_altstatus(struct ata_port *ap)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +//	printk("%s\n", __FUNCTION__);
>> +	return pi->proto->read_regr(pi, 1, 6);
>> +}
>> +
>> +void pata_parport_dev_select(struct ata_port *ap, unsigned int device)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +	u8 tmp;
>> +//	printk("%s\n", __FUNCTION__);
>> +	if (device == 0)
>> +		tmp = ATA_DEVICE_OBS;
>> +	else
>> +		tmp = ATA_DEVICE_OBS | ATA_DEV1;
>> +
>> +	pi->proto->write_regr(pi, 0, ATA_REG_DEVICE, tmp);
>> +	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
>> +}
>> +
>> +void pata_parport_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
>> +//	printk("%s\n", __FUNCTION__);
>> +	if (tf->ctl != ap->last_ctl) {
>> +		pi->proto->write_regr(pi, 1, 6, tf->ctl);
>> +		ap->last_ctl = tf->ctl;
>> +		ata_wait_idle(ap);
>> +	}
>> +
>> +	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
>> +		pi->proto->write_regr(pi, 0, ATA_REG_FEATURE, tf->hob_feature);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_NSECT, tf->hob_nsect);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAL, tf->hob_lbal);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAM, tf->hob_lbam);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAH, tf->hob_lbah);
>> +	}
>> +
>> +	if (is_addr) {
>> +		pi->proto->write_regr(pi, 0, ATA_REG_FEATURE, tf->feature);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_NSECT, tf->nsect);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAL, tf->lbal);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAM, tf->lbam);
>> +		pi->proto->write_regr(pi, 0, ATA_REG_LBAH, tf->lbah);
>> +	}
>> +
>> +	if (tf->flags & ATA_TFLAG_DEVICE)
>> +		pi->proto->write_regr(pi, 0, ATA_REG_DEVICE, tf->device);
>> +
>> +	ata_wait_idle(ap);
>> +}
>> +
>> +void pata_parport_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +//	printk("%s\n", __FUNCTION__);
>> +	tf->command = pi->proto->read_regr(pi, 0, ATA_REG_STATUS);
>> +	tf->feature = pi->proto->read_regr(pi, 0, ATA_REG_ERR);
>> +	tf->nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
>> +	tf->lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
>> +	tf->lbam = pi->proto->read_regr(pi, 0, ATA_REG_LBAM);
>> +	tf->lbah = pi->proto->read_regr(pi, 0, ATA_REG_LBAH);
>> +	tf->device = pi->proto->read_regr(pi, 0, ATA_REG_DEVICE);
>> +
>> +	if (tf->flags & ATA_TFLAG_LBA48) {
>> +		pi->proto->write_regr(pi, 1, 6, tf->ctl | ATA_HOB);
>> +		tf->hob_feature = pi->proto->read_regr(pi, 0, ATA_REG_ERR);
>> +		tf->hob_nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
>> +		tf->hob_lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);
>> +		tf->hob_lbam = pi->proto->read_regr(pi, 0, ATA_REG_LBAM);
>> +		tf->hob_lbah = pi->proto->read_regr(pi, 0, ATA_REG_LBAH);
>> +		pi->proto->write_regr(pi, 1, 6, tf->ctl);
>> +		ap->last_ctl = tf->ctl;
>> +	}
>> +}
>> +
>> +void pata_parport_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
>> +{
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +//	printk("%s\n", __FUNCTION__);
>> +	pi->proto->write_regr(pi, 0, ATA_REG_CMD, tf->command);
>> +	ata_sff_pause(ap);
>> +}
>> +
>> +unsigned int pata_parport_data_xfer(struct ata_queued_cmd *qc, unsigned char *buf,
>> +			       unsigned int buflen, int rw)
>> +{
>> +	struct ata_port *ap = qc->dev->link->ap;
>> +	struct pi_adapter *pi = ap->host->private_data;
>> +//	printk("%s\n", __FUNCTION__);
>> +	if (rw == READ)
>> +		pi->proto->read_block(pi, buf, buflen);
>> +	else
>> +		pi->proto->write_block(pi, buf, buflen);
>> +
>> +	return buflen;
>> +}
>> +
>> +void pata_parport_drain_fifo(struct ata_queued_cmd *qc)
>> +{
>> +	int count;
>> +	struct ata_port *ap;
>> +	struct pi_adapter *pi;
>> +	char junk[2];
>> +//	printk("%s\n", __FUNCTION__);
>> +	/* We only need to flush incoming data when a command was running */
>> +	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
>> +		return;
>> +
>> +	ap = qc->ap;
>> +	pi = ap->host->private_data;
>> +	/* Drain up to 64K of data before we give up this recovery method */
>> +	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
>> +						&& count < 65536; count += 2)
>> +		pi->proto->read_block(pi, junk, 2);
>> +
>> +	if (count)
>> +		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
>> +
>> +}
>> +
>> +void pata_parport_lost_interrupt(struct ata_port *ap)
>> +{
>> +	u8 status;
>> +	struct ata_queued_cmd *qc;
>> +//	printk("%s\n", __FUNCTION__);
>> +	/* Only one outstanding command per SFF channel */
>> +	qc = ata_qc_from_tag(ap, ap->link.active_tag);
>> +	/* We cannot lose an interrupt on a non-existent or polled command */
>> +	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
>> +		return;
>> +	/* See if the controller thinks it is still busy - if so the command
>> +	   isn't a lost IRQ but is still in progress */
>> +	status = pata_parport_check_altstatus(ap);
>> +	if (status & ATA_BUSY)
>> +		return;
>> +
>> +	/* There was a command running, we are no longer busy and we have
>> +	   no interrupt. */
>> +	ata_port_warn(ap, "lost interrupt (Status 0x%x)\n",
>> +								status);
>> +	/* Run the host interrupt logic as if the interrupt had not been
>> +	   lost */
>> +	ata_sff_port_intr(ap, qc);
>> +}
>> +
>> +static struct ata_port_operations pata_parport_port_ops = {
>> +	.qc_prep		= ata_noop_qc_prep,
>> +	.qc_issue		= ata_sff_qc_issue,
>> +	.qc_fill_rtf		= ata_sff_qc_fill_rtf,
>> +
>> +	.freeze			= ata_sff_freeze,
>> +	.thaw			= ata_sff_thaw,
>> +	.prereset		= ata_sff_prereset,
>> +	.softreset		= pata_parport_softreset,
>> +	.postreset		= ata_sff_postreset,
>> +	.error_handler		= ata_sff_error_handler,
>> +	.sched_eh		= ata_std_sched_eh,
>> +	.end_eh			= ata_std_end_eh,
>> +
>> +	.sff_dev_select		= pata_parport_dev_select,
>> +	.sff_check_status	= pata_parport_check_status,
>> +	.sff_check_altstatus	= pata_parport_check_altstatus,
>> +	.sff_tf_load		= pata_parport_tf_load,
>> +	.sff_tf_read		= pata_parport_tf_read,
>> +	.sff_exec_command	= pata_parport_exec_command,
>> +	.sff_data_xfer		= pata_parport_data_xfer,
>> +	.sff_drain_fifo		= pata_parport_drain_fifo,
>> +
>> +	.lost_interrupt		= pata_parport_lost_interrupt,
>> +};
>> +
>> +static const struct ata_port_info pata_parport_port_info = {
>> +	.flags		= ATA_FLAG_SLAVE_POSS | ATA_FLAG_PIO_POLLING,
>> +	.pio_mask	= ATA_PIO0,
>> +	/* No DMA */
>> +	.port_ops	= &pata_parport_port_ops,
>> +};
>> +
>> +int paride_register(struct pi_protocol *pr)
>> +{
>> +	int k;
>> +
>> +	for (k = 0; k < MAX_PROTOS; k++)
>> +		if (protocols[k] && !strcmp(pr->name, protocols[k]->name)) {
>> +			printk("paride: %s protocol already registered\n",
>> +			       pr->name);
>> +			return -1;
>> +		}
>> +	k = 0;
>> +	while ((k < MAX_PROTOS) && (protocols[k]))
>> +		k++;
>> +	if (k == MAX_PROTOS) {
>> +		printk("paride: protocol table full\n");
>> +		return -1;
>> +	}
>> +	protocols[k] = pr;
>> +	pr->index = k;
>> +	printk("paride: %s registered as protocol %d\n", pr->name, k);
>> +	return 0;
>> +}
>> +
>> +EXPORT_SYMBOL(paride_register);
>> +
>> +void paride_unregister(struct pi_protocol *pr)
>> +{
>> +	if (!pr)
>> +		return;
>> +	if (protocols[pr->index] != pr) {
>> +		printk("paride: %s not registered\n", pr->name);
>> +		return;
>> +	}
>> +	protocols[pr->index] = NULL;
>> +}
>> +
>> +EXPORT_SYMBOL(paride_unregister);
>> +
>> +
>> +
>> +static DEFINE_SPINLOCK(pi_spinlock);
>> +
>> +static void pi_wake_up(void *p)
>> +{
>> +	PIA *pi = (PIA *) p;
>> +	unsigned long flags;
>> +	void (*cont) (void) = NULL;
>> +
>> +	spin_lock_irqsave(&pi_spinlock, flags);
>> +
>> +	if (pi->claim_cont && !parport_claim(pi->pardev)) {
>> +		cont = pi->claim_cont;
>> +		pi->claim_cont = NULL;
>> +		pi->claimed = 1;
>> +	}
>> +
>> +	spin_unlock_irqrestore(&pi_spinlock, flags);
>> +
>> +	wake_up(&(pi->parq));
>> +
>> +	if (cont)
>> +		cont();
>> +}
>> +
>> +static void pi_claim(PIA * pi)
>> +{
>> +	if (pi->claimed)
>> +		return;
>> +	pi->claimed = 1;
>> +	if (pi->pardev)
>> +		wait_event(pi->parq,
>> +			   !parport_claim((struct pardevice *) pi->pardev));
>> +}
>> +
>> +static void pi_unclaim(PIA * pi)
>> +{
>> +	pi->claimed = 0;
>> +	if (pi->pardev)
>> +		parport_release((struct pardevice *) (pi->pardev));
>> +}
>> +
>> +static void pi_unregister_parport(PIA * pi)
>> +{
>> +	if (pi->pardev) {
>> +		parport_unregister_device((struct pardevice *) (pi->pardev));
>> +		pi->pardev = NULL;
>> +	}
>> +}
>> +
>> +static int default_test_proto(PIA * pi, char *scratch, int verbose)
>> +{
>> +	int j, k;
>> +	int e[2] = { 0, 0 };
>> +
>> +	pi->proto->connect(pi);
>> +
>> +	for (j = 0; j < 2; j++) {
>> +		pi->proto->write_regr(pi, 0, 6, 0xa0 + j * 0x10);
>> +		for (k = 0; k < 256; k++) {
>> +			pi->proto->write_regr(pi, 0, 2, k ^ 0xaa);
>> +			pi->proto->write_regr(pi, 0, 3, k ^ 0x55);
>> +			if (pi->proto->read_regr(pi, 0, 2) != (k ^ 0xaa))
>> +				e[j]++;
>> +		}
>> +	}
>> +	pi->proto->disconnect(pi);
>> +
>> +	if (verbose)
>> +		printk("%s: %s: port 0x%x, mode  %d, test=(%d,%d)\n",
>> +		       pi->device, pi->proto->name, pi->port,
>> +		       pi->mode, e[0], e[1]);
>> +
>> +	return (e[0] && e[1]);	/* not here if both > 0 */
>> +}
>> +
>> +static int pi_test_proto(PIA * pi, char *scratch, int verbose)
>> +{
>> +	int res;
>> +
>> +	pi_claim(pi);
>> +	if (pi->proto->test_proto)
>> +		res = pi->proto->test_proto(pi, scratch, verbose);
>> +	else
>> +		res = default_test_proto(pi, scratch, verbose);
>> +	pi_unclaim(pi);
>> +
>> +	return res;
>> +}
>> +
>> +static int pi_register_parport(PIA *pi, int verbose, int unit)
>> +{
>> +	struct parport *port;
>> +	struct pardev_cb par_cb;
>> +
>> +	port = parport_find_base(pi->port);
>> +	if (!port)
>> +		return 0;
>> +	memset(&par_cb, 0, sizeof(par_cb));
>> +	par_cb.wakeup = pi_wake_up;
>> +	par_cb.private = (void *)pi;
>> +	pi->pardev = parport_register_dev_model(port, pi->device, &par_cb,
>> +						unit);
>> +	parport_put_port(port);
>> +	if (!pi->pardev)
>> +		return 0;
>> +
>> +	init_waitqueue_head(&pi->parq);
>> +
>> +	if (verbose)
>> +		printk("%s: 0x%x is %s\n", pi->device, pi->port, port->name);
>> +
>> +	pi->parname = (char *) port->name;
>> +
>> +	return 1;
>> +}
>> +
>> +static int pi_probe_mode(PIA * pi, int max, char *scratch, int verbose)
>> +{
>> +	int best, range;
>> +
>> +	if (pi->mode != -1) {
>> +		if (pi->mode >= max)
>> +			return 0;
>> +		range = 3;
>> +		if (pi->mode >= pi->proto->epp_first)
>> +			range = 8;
>> +		if ((range == 8) && (pi->port % 8))
>> +			return 0;
>> +		pi->reserved = range;
>> +		return (!pi_test_proto(pi, scratch, verbose));
>> +	}
>> +	best = -1;
>> +	for (pi->mode = 0; pi->mode < max; pi->mode++) {
>> +		range = 3;
>> +		if (pi->mode >= pi->proto->epp_first)
>> +			range = 8;
>> +		if ((range == 8) && (pi->port % 8))
>> +			break;
>> +		pi->reserved = range;
>> +		if (!pi_test_proto(pi, scratch, verbose))
>> +			best = pi->mode;
>> +	}
>> +	pi->mode = best;
>> +	return (best > -1);
>> +}
>> +
>> +
>> +static int pi_probe_unit(PIA * pi, int unit, char *scratch, int verbose)
>> +{
>> +	int max, s, e;
>> +
>> +	s = unit;
>> +	e = s + 1;
>> +
>> +	if (s == -1) {
>> +		s = 0;
>> +		e = pi->proto->max_units;
>> +	}
>> +
>> +	if (!pi_register_parport(pi, verbose, s))
>> +		return 0;
>> +
>> +	if (pi->proto->test_port) {
>> +		pi_claim(pi);
>> +		max = pi->proto->test_port(pi);
>> +		pi_unclaim(pi);
>> +	} else
>> +		max = pi->proto->max_mode;
>> +
>> +	if (pi->proto->probe_unit) {
>> +		pi_claim(pi);
>> +		for (pi->unit = s; pi->unit < e; pi->unit++)
>> +			if (pi->proto->probe_unit(pi)) {
>> +				pi_unclaim(pi);
>> +				if (pi_probe_mode(pi, max, scratch, verbose))
>> +					return 1;
>> +				pi_unregister_parport(pi);
>> +				return 0;
>> +			}
>> +		pi_unclaim(pi);
>> +		pi_unregister_parport(pi);
>> +		return 0;
>> +	}
>> +
>> +	if (!pi_probe_mode(pi, max, scratch, verbose)) {
>> +		pi_unregister_parport(pi);
>> +		return 0;
>> +	}
>> +	return 1;
>> +
>> +}
>> +
>> +int pi_init(PIA * pi, int autoprobe, int port, int mode,
>> +	int unit, int protocol, int delay, char *scratch,
>> +	int devtype, int verbose, char *device)
>> +{
>> +	int p, k, s, e;
>> +	int lpts[7] = { 0x3bc, 0x378, 0x278, 0x268, 0x27c, 0x26c, 0 };
>> +
>> +	s = protocol;
>> +	e = s + 1;
>> +
>> +	if (!protocols[0])
>> +		request_module("paride_protocol");
>> +
>> +	if (autoprobe) {
>> +		s = 0;
>> +		e = MAX_PROTOS;
>> +	} else if ((s < 0) || (s >= MAX_PROTOS) || (port <= 0) ||
>> +		   (!protocols[s]) || (unit < 0) ||
>> +		   (unit >= protocols[s]->max_units)) {
>> +		printk("%s: Invalid parameters\n", device);
>> +		return 0;
>> +	}
>> +
>> +	for (p = s; p < e; p++) {
>> +		struct pi_protocol *proto = protocols[p];
>> +		if (!proto)
>> +			continue;
>> +		/* still racy */
>> +		if (!try_module_get(proto->owner))
>> +			continue;
>> +		pi->proto = proto;
>> +		pi->private = 0;
>> +		if (proto->init_proto && proto->init_proto(pi) < 0) {
>> +			pi->proto = NULL;
>> +			module_put(proto->owner);
>> +			continue;
>> +		}
>> +		if (delay == -1)
>> +			pi->delay = pi->proto->default_delay;
>> +		else
>> +			pi->delay = delay;
>> +		pi->devtype = devtype;
>> +		pi->device = device;
>> +
>> +		pi->parname = NULL;
>> +		pi->pardev = NULL;
>> +		init_waitqueue_head(&pi->parq);
>> +		pi->claimed = 0;
>> +		pi->claim_cont = NULL;
>> +
>> +		pi->mode = mode;
>> +		if (port != -1) {
>> +			pi->port = port;
>> +			if (pi_probe_unit(pi, unit, scratch, verbose))
>> +				break;
>> +			pi->port = 0;
>> +		} else {
>> +			k = 0;
>> +			while ((pi->port = lpts[k++]))
>> +				if (pi_probe_unit
>> +				    (pi, unit, scratch, verbose))
>> +					break;
>> +			if (pi->port)
>> +				break;
>> +		}
>> +		if (pi->proto->release_proto)
>> +			pi->proto->release_proto(pi);
>> +		module_put(proto->owner);
>> +	}
>> +
>> +	if (!pi->port) {
>> +		if (autoprobe)
>> +			printk("%s: Autoprobe failed\n", device);
>> +		else
>> +			printk("%s: Adapter not found\n", device);
>> +		return 0;
>> +	}
>> +
>> +	if (pi->parname)
>> +		printk("%s: Sharing %s at 0x%x\n", pi->device,
>> +		       pi->parname, pi->port);
>> +
>> +	pi->proto->log_adapter(pi, scratch, verbose);
>> +
>> +	return 1;
>> +}
>> +
>> +static struct scsi_host_template pata_parport_sht = {
>> +	ATA_PIO_SHT(DRV_NAME),
>> +};
>> +
>> +static ssize_t new_device_store(struct bus_type *bus, const char *buf, size_t count)
>> +{
>> +	struct pi_adapter *pi;
>> +	int retval;
>> +	int autoprobe, port, mode, unit, protocol, delay;
>> +	int fields = 0;
>> +	struct device dev;
>> +	const struct ata_port_info *ppi[] = { &pata_parport_port_info };
>> +	struct ata_host *host;
>> +	char scratch[512];
>> +
>> +	fields = sscanf(buf, "%x %d %d %d %d",
>> +			&port, &mode, &unit, &protocol, &delay);
>> +	if (fields < 5)
>> +		return -EINVAL;
>> +
>> +	memset(&dev, 0, sizeof(dev));
>> +	dev.parent = bus->dev_root;
>> +	dev.bus = bus;
>> +	dev_set_name(&dev, "pata_parport%d", 0);////
>> +	retval = device_register(&dev);
>> +	if (retval) {
>> +		printk("register failed\n");
>> +		return retval;
>> +	}
>> +
>> +	pi = devm_kzalloc(&dev, sizeof(struct pi_adapter), GFP_KERNEL);
>> +	if (!pi) {
>> +		//device_unregister
>> +		return -ENOMEM;
>> +	}
>> +
>> +	if (!pi_init(pi, autoprobe, port, mode, unit, protocol, delay, scratch, PI_PD, 2, "xxx"))
>> +		return -ENODEV;
>> +
>> +	printk("pi_init ok!\n");
>> +	pi_claim(pi);
>> +	pi->proto->connect(pi);
>> +	host = ata_host_alloc_pinfo(&dev, ppi, 1);
>> +	if (!host) {
>> +		/* pi_deinit??? */
>> +		return -ENOMEM;
>> +	}
>> +	host->private_data = pi;
>> +	printk("alloc_ok!\n");
>> +	if (ata_host_activate(host, 0, NULL, 0, &pata_parport_sht)) {
>> +		/* dealloc, pi_deinit??? */
>> +		return -EIO;
>> +	}
>> +
>> +	return count;
>> +}
>> +static BUS_ATTR_WO(new_device);
>> +
>> +static struct bus_type pata_parport_bus = {
>> +	.name = "pata_parport",
>> +};
>> +
>> +static __init int pata_parport_init(void)
>> +{
>> +	int error;
>> +
>> +	error = bus_register(&pata_parport_bus);
>> +	if (error) {
>> +		pr_err("failed to register pata_parport bus, error: %d\n", error);
>> +		return error;
>> +	}
>> +	error = bus_create_file(&pata_parport_bus, &bus_attr_new_device);
>> +	if (error) {
>> +		pr_err("unable to create sysfs file, error: %d\n", error);
>> +		return error;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static __exit void pata_parport_exit(void)
>> +{
>> +	bus_remove_file(&pata_parport_bus, &bus_attr_new_device);
>> +	bus_unregister(&pata_parport_bus);
>> +}
>> +
>> +MODULE_AUTHOR("Ondrej Zary");
>> +MODULE_DESCRIPTION("driver for parallel port ATA adapters");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("paride");
>> +
>> +module_init(pata_parport_init);
>> +module_exit(pata_parport_exit);
>> -- 
>> Ondrej Zary
> ---end quoted text---
> 


-- 
Damien Le Moal
Western Digital Research