Merge tag 'isdn-removal' of https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

Arnd Bergmann says:

====================
isdn: deprecate non-mISDN drivers

When isdn4linux came up in the context of another patch series, I
remembered that we had discussed removing it a while ago.

It turns out that the suggestion from Karsten Keil wa to remove I4L
in 2018 after the last public ISDN networks are shut down. This has
happened now (with a very small number of exceptions), so I guess it's
time to try again.

We currently have three ISDN stacks in the kernel: the original
isdn4linux (with the hisax driver), the newer CAPI (with four drivers),
and finally the mISDN stack (supporting roughly the same hardware as
hisax).

As far as I can tell, anyone using ISDN with mainline kernel drivers in
the past few years uses mISDN, and this is typically used for voice-only
PBX installations that don't require a public network.

The older stacks support additional features for data networks, but those
typically make no sense any more if there is no network to connect to.

My proposal for this time is to kill off isdn4linux entirely, as it seems
to have been unusable for quite a while. This code has been abandoned
for many years and it does cause problems for treewide maintenance as
it tends to do everything that we try to stop doing.
Birger Harzenetter mentioned that is is still using i4l in order to
make use of the 'divert' feature that is not part of mISDN, but has
otherwise moved on to mISDN for normal operation, like apparently
everyone else.

CAPI in turn is not quite as obsolete, but two of the drivers (avm
and hysdn) don't seem to be used at all, while another one (gigaset)
will stop being maintained as Paul Bolle is no longer able to
test it after the network gets shut down in September.
All three are now moved into drivers/staging to let others speak
up in case there are remaining users.
This leaves Bluetooth CMTP as the only remaining user of CAPI, but
Marcel Holtmann wishes to keep maintaining it.

For the discussion on version 1, see [2]
Unfortunately, Karsten Keil as the maintainer has not participated in
the discussion.

      Arnd

[1] https://patchwork.kernel.org/patch/8484861/#17900371
[2] https://listserv.isdn4linux.de/pipermail/isdn4linux/2019-April/thread.html
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 445 insertions, 0 deletions

diff --git a/drivers/staging/isdn/hysdn/boardergo.c b/drivers/staging/isdn/hysdn/boardergo.c
new file mode 100644
index 000000000000..2aa2a0e08247
--- /dev/null
+++ b/drivers/staging/isdn/hysdn/boardergo.c
@@ -0,0 +1,445 @@
+/* $Id: boardergo.c,v 1.5.6.7 2001/11/06 21:58:19 kai Exp $
+ *
+ * Linux driver for HYSDN cards, specific routines for ergo type boards.
+ *
+ * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
+ * Copyright 1999 by Werner Cornelius (werner@titro.de)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ * As all Linux supported cards Champ2, Ergo and Metro2/4 use the same
+ * DPRAM interface and layout with only minor differences all related
+ * stuff is done here, not in separate modules.
+ *
+ */
+
+#include <linux/signal.h>
+#include <linux/kernel.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+
+#include "hysdn_defs.h"
+#include "boardergo.h"
+
+#define byteout(addr, val) outb(val, addr)
+#define bytein(addr) inb(addr)
+
+/***************************************************/
+/* The cards interrupt handler. Called from system */
+/***************************************************/
+static irqreturn_t
+ergo_interrupt(int intno, void *dev_id)
+{
+	hysdn_card *card = dev_id;	/* parameter from irq */
+	tErgDpram *dpr;
+	unsigned long flags;
+	unsigned char volatile b;
+
+	if (!card)
+		return IRQ_NONE;		/* error -> spurious interrupt */
+	if (!card->irq_enabled)
+		return IRQ_NONE;		/* other device interrupting or irq switched off */
+
+	spin_lock_irqsave(&card->hysdn_lock, flags); /* no further irqs allowed */
+
+	if (!(bytein(card->iobase + PCI9050_INTR_REG) & PCI9050_INTR_REG_STAT1)) {
+		spin_unlock_irqrestore(&card->hysdn_lock, flags);	/* restore old state */
+		return IRQ_NONE;		/* no interrupt requested by E1 */
+	}
+	/* clear any pending ints on the board */
+	dpr = card->dpram;
+	b = dpr->ToPcInt;	/* clear for ergo */
+	b |= dpr->ToPcIntMetro;	/* same for metro */
+	b |= dpr->ToHyInt;	/* and for champ */
+
+	/* start kernel task immediately after leaving all interrupts */
+	if (!card->hw_lock)
+		schedule_work(&card->irq_queue);
+	spin_unlock_irqrestore(&card->hysdn_lock, flags);
+	return IRQ_HANDLED;
+}				/* ergo_interrupt */
+
+/******************************************************************************/
+/* ergo_irq_bh will be called as part of the kernel clearing its shared work  */
+/* queue sometime after a call to schedule_work has been made passing our     */
+/* work_struct. This task is the only one handling data transfer from or to   */
+/* the card after booting. The task may be queued from everywhere             */
+/* (interrupts included).                                                     */
+/******************************************************************************/
+static void
+ergo_irq_bh(struct work_struct *ugli_api)
+{
+	hysdn_card *card = container_of(ugli_api, hysdn_card, irq_queue);
+	tErgDpram *dpr;
+	int again;
+	unsigned long flags;
+
+	if (card->state != CARD_STATE_RUN)
+		return;		/* invalid call */
+
+	dpr = card->dpram;	/* point to DPRAM */
+
+	spin_lock_irqsave(&card->hysdn_lock, flags);
+	if (card->hw_lock) {
+		spin_unlock_irqrestore(&card->hysdn_lock, flags);	/* hardware currently unavailable */
+		return;
+	}
+	card->hw_lock = 1;	/* we now lock the hardware */
+
+	do {
+		again = 0;	/* assume loop not to be repeated */
+
+		if (!dpr->ToHyFlag) {
+			/* we are able to send a buffer */
+
+			if (hysdn_sched_tx(card, dpr->ToHyBuf, &dpr->ToHySize, &dpr->ToHyChannel,
+					   ERG_TO_HY_BUF_SIZE)) {
+				dpr->ToHyFlag = 1;	/* enable tx */
+				again = 1;	/* restart loop */
+			}
+		}		/* we are able to send a buffer */
+		if (dpr->ToPcFlag) {
+			/* a message has arrived for us, handle it */
+
+			if (hysdn_sched_rx(card, dpr->ToPcBuf, dpr->ToPcSize, dpr->ToPcChannel)) {
+				dpr->ToPcFlag = 0;	/* we worked the data */
+				again = 1;	/* restart loop */
+			}
+		}		/* a message has arrived for us */
+		if (again) {
+			dpr->ToHyInt = 1;
+			dpr->ToPcInt = 1;	/* interrupt to E1 for all cards */
+		} else
+			card->hw_lock = 0;	/* free hardware again */
+	} while (again);	/* until nothing more to do */
+
+	spin_unlock_irqrestore(&card->hysdn_lock, flags);
+}				/* ergo_irq_bh */
+
+
+/*********************************************************/
+/* stop the card (hardware reset) and disable interrupts */
+/*********************************************************/
+static void
+ergo_stopcard(hysdn_card *card)
+{
+	unsigned long flags;
+	unsigned char val;
+
+	hysdn_net_release(card);	/* first release the net device if existing */
+#ifdef CONFIG_HYSDN_CAPI
+	hycapi_capi_stop(card);
+#endif /* CONFIG_HYSDN_CAPI */
+	spin_lock_irqsave(&card->hysdn_lock, flags);
+	val = bytein(card->iobase + PCI9050_INTR_REG);	/* get actual value */
+	val &= ~(PCI9050_INTR_REG_ENPCI | PCI9050_INTR_REG_EN1);	/* mask irq */
+	byteout(card->iobase + PCI9050_INTR_REG, val);
+	card->irq_enabled = 0;
+	byteout(card->iobase + PCI9050_USER_IO, PCI9050_E1_RESET);	/* reset E1 processor */
+	card->state = CARD_STATE_UNUSED;
+	card->err_log_state = ERRLOG_STATE_OFF;		/* currently no log active */
+
+	spin_unlock_irqrestore(&card->hysdn_lock, flags);
+}				/* ergo_stopcard */
+
+/**************************************************************************/
+/* enable or disable the cards error log. The event is queued if possible */
+/**************************************************************************/
+static void
+ergo_set_errlog_state(hysdn_card *card, int on)
+{
+	unsigned long flags;
+
+	if (card->state != CARD_STATE_RUN) {
+		card->err_log_state = ERRLOG_STATE_OFF;		/* must be off */
+		return;
+	}
+	spin_lock_irqsave(&card->hysdn_lock, flags);
+
+	if (((card->err_log_state == ERRLOG_STATE_OFF) && !on) ||
+	    ((card->err_log_state == ERRLOG_STATE_ON) && on)) {
+		spin_unlock_irqrestore(&card->hysdn_lock, flags);
+		return;		/* nothing to do */
+	}
+	if (on)
+		card->err_log_state = ERRLOG_STATE_START;	/* request start */
+	else
+		card->err_log_state = ERRLOG_STATE_STOP;	/* request stop */
+
+	spin_unlock_irqrestore(&card->hysdn_lock, flags);
+	schedule_work(&card->irq_queue);
+}				/* ergo_set_errlog_state */
+
+/******************************************/
+/* test the cards RAM and return 0 if ok. */
+/******************************************/
+static const char TestText[36] = "This Message is filler, why read it";
+
+static int
+ergo_testram(hysdn_card *card)
+{
+	tErgDpram *dpr = card->dpram;
+
+	memset(dpr->TrapTable, 0, sizeof(dpr->TrapTable));	/* clear all Traps */
+	dpr->ToHyInt = 1;	/* E1 INTR state forced */
+
+	memcpy(&dpr->ToHyBuf[ERG_TO_HY_BUF_SIZE - sizeof(TestText)], TestText,
+	       sizeof(TestText));
+	if (memcmp(&dpr->ToHyBuf[ERG_TO_HY_BUF_SIZE - sizeof(TestText)], TestText,
+		   sizeof(TestText)))
+		return (-1);
+
+	memcpy(&dpr->ToPcBuf[ERG_TO_PC_BUF_SIZE - sizeof(TestText)], TestText,
+	       sizeof(TestText));
+	if (memcmp(&dpr->ToPcBuf[ERG_TO_PC_BUF_SIZE - sizeof(TestText)], TestText,
+		   sizeof(TestText)))
+		return (-1);
+
+	return (0);
+}				/* ergo_testram */
+
+/*****************************************************************************/
+/* this function is intended to write stage 1 boot image to the cards buffer */
+/* this is done in two steps. First the 1024 hi-words are written (offs=0),  */
+/* then the 1024 lo-bytes are written. The remaining DPRAM is cleared, the   */
+/* PCI-write-buffers flushed and the card is taken out of reset.             */
+/* The function then waits for a reaction of the E1 processor or a timeout.  */
+/* Negative return values are interpreted as errors.                         */
+/*****************************************************************************/
+static int
+ergo_writebootimg(struct HYSDN_CARD *card, unsigned char *buf,
+		  unsigned long offs)
+{
+	unsigned char *dst;
+	tErgDpram *dpram;
+	int cnt = (BOOT_IMG_SIZE >> 2);		/* number of words to move and swap (byte order!) */
+
+	if (card->debug_flags & LOG_POF_CARD)
+		hysdn_addlog(card, "ERGO: write bootldr offs=0x%lx ", offs);
+
+	dst = card->dpram;	/* pointer to start of DPRAM */
+	dst += (offs + ERG_DPRAM_FILL_SIZE);	/* offset in the DPRAM */
+	while (cnt--) {
+		*dst++ = *(buf + 1);	/* high byte */
+		*dst++ = *buf;	/* low byte */
+		dst += 2;	/* point to next longword */
+		buf += 2;	/* buffer only filled with words */
+	}
+
+	/* if low words (offs = 2) have been written, clear the rest of the DPRAM, */
+	/* flush the PCI-write-buffer and take the E1 out of reset */
+	if (offs) {
+		memset(card->dpram, 0, ERG_DPRAM_FILL_SIZE);	/* fill the DPRAM still not cleared */
+		dpram = card->dpram;	/* get pointer to dpram structure */
+		dpram->ToHyNoDpramErrLog = 0xFF;	/* write a dpram register */
+		while (!dpram->ToHyNoDpramErrLog);	/* reread volatile register to flush PCI */
+
+		byteout(card->iobase + PCI9050_USER_IO, PCI9050_E1_RUN);	/* start E1 processor */
+		/* the interrupts are still masked */
+
+		msleep_interruptible(20);		/* Timeout 20ms */
+
+		if (((tDpramBootSpooler *) card->dpram)->Len != DPRAM_SPOOLER_DATA_SIZE) {
+			if (card->debug_flags & LOG_POF_CARD)
+				hysdn_addlog(card, "ERGO: write bootldr no answer");
+			return (-ERR_BOOTIMG_FAIL);
+		}
+	}			/* start_boot_img */
+	return (0);		/* successful */
+}				/* ergo_writebootimg */
+
+/********************************************************************************/
+/* ergo_writebootseq writes the buffer containing len bytes to the E1 processor */
+/* using the boot spool mechanism. If everything works fine 0 is returned. In   */
+/* case of errors a negative error value is returned.                           */
+/********************************************************************************/
+static int
+ergo_writebootseq(struct HYSDN_CARD *card, unsigned char *buf, int len)
+{
+	tDpramBootSpooler *sp = (tDpramBootSpooler *) card->dpram;
+	unsigned char *dst;
+	unsigned char buflen;
+	int nr_write;
+	unsigned char tmp_rdptr;
+	unsigned char wr_mirror;
+	int i;
+
+	if (card->debug_flags & LOG_POF_CARD)
+		hysdn_addlog(card, "ERGO: write boot seq len=%d ", len);
+
+	dst = sp->Data;		/* point to data in spool structure */
+	buflen = sp->Len;	/* maximum len of spooled data */
+	wr_mirror = sp->WrPtr;	/* only once read */
+
+	/* try until all bytes written or error */
+	i = 0x1000;		/* timeout value */
+	while (len) {
+
+		/* first determine the number of bytes that may be buffered */
+		do {
+			tmp_rdptr = sp->RdPtr;	/* first read the pointer */
+			i--;	/* decrement timeout */
+		} while (i && (tmp_rdptr != sp->RdPtr));	/* wait for stable pointer */
+
+		if (!i) {
+			if (card->debug_flags & LOG_POF_CARD)
+				hysdn_addlog(card, "ERGO: write boot seq timeout");
+			return (-ERR_BOOTSEQ_FAIL);	/* value not stable -> timeout */
+		}
+		if ((nr_write = tmp_rdptr - wr_mirror - 1) < 0)
+			nr_write += buflen;	/* now we got number of free bytes - 1 in buffer */
+
+		if (!nr_write)
+			continue;	/* no free bytes in buffer */
+
+		if (nr_write > len)
+			nr_write = len;		/* limit if last few bytes */
+		i = 0x1000;	/* reset timeout value */
+
+		/* now we know how much bytes we may put in the puffer */
+		len -= nr_write;	/* we savely could adjust len before output */
+		while (nr_write--) {
+			*(dst + wr_mirror) = *buf++;	/* output one byte */
+			if (++wr_mirror >= buflen)
+				wr_mirror = 0;
+			sp->WrPtr = wr_mirror;	/* announce the next byte to E1 */
+		}		/* while (nr_write) */
+
+	}			/* while (len) */
+	return (0);
+}				/* ergo_writebootseq */
+
+/***********************************************************************************/
+/* ergo_waitpofready waits for a maximum of 10 seconds for the completition of the */
+/* boot process. If the process has been successful 0 is returned otherwise a     */
+/* negative error code is returned.                                                */
+/***********************************************************************************/
+static int
+ergo_waitpofready(struct HYSDN_CARD *card)
+{
+	tErgDpram *dpr = card->dpram;	/* pointer to DPRAM structure */
+	int timecnt = 10000 / 50;	/* timeout is 10 secs max. */
+	unsigned long flags;
+	int msg_size;
+	int i;
+
+	if (card->debug_flags & LOG_POF_CARD)
+		hysdn_addlog(card, "ERGO: waiting for pof ready");
+	while (timecnt--) {
+		/* wait until timeout  */
+
+		if (dpr->ToPcFlag) {
+			/* data has arrived */
+
+			if ((dpr->ToPcChannel != CHAN_SYSTEM) ||
+			    (dpr->ToPcSize < MIN_RDY_MSG_SIZE) ||
+			    (dpr->ToPcSize > MAX_RDY_MSG_SIZE) ||
+			    ((*(unsigned long *) dpr->ToPcBuf) != RDY_MAGIC))
+				break;	/* an error occurred */
+
+			/* Check for additional data delivered during SysReady */
+			msg_size = dpr->ToPcSize - RDY_MAGIC_SIZE;
+			if (msg_size > 0)
+				if (EvalSysrTokData(card, dpr->ToPcBuf + RDY_MAGIC_SIZE, msg_size))
+					break;
+
+			if (card->debug_flags & LOG_POF_RECORD)
+				hysdn_addlog(card, "ERGO: pof boot success");
+			spin_lock_irqsave(&card->hysdn_lock, flags);
+
+			card->state = CARD_STATE_RUN;	/* now card is running */
+			/* enable the cards interrupt */
+			byteout(card->iobase + PCI9050_INTR_REG,
+				bytein(card->iobase + PCI9050_INTR_REG) |
+				(PCI9050_INTR_REG_ENPCI | PCI9050_INTR_REG_EN1));
+			card->irq_enabled = 1;	/* we are ready to receive interrupts */
+
+			dpr->ToPcFlag = 0;	/* reset data indicator */
+			dpr->ToHyInt = 1;
+			dpr->ToPcInt = 1;	/* interrupt to E1 for all cards */
+
+			spin_unlock_irqrestore(&card->hysdn_lock, flags);
+			if ((hynet_enable & (1 << card->myid))
+			    && (i = hysdn_net_create(card)))
+			{
+				ergo_stopcard(card);
+				card->state = CARD_STATE_BOOTERR;
+				return (i);
+			}
+#ifdef CONFIG_HYSDN_CAPI
+			if ((i = hycapi_capi_create(card))) {
+				printk(KERN_WARNING "HYSDN: failed to create capi-interface.\n");
+			}
+#endif /* CONFIG_HYSDN_CAPI */
+			return (0);	/* success */
+		}		/* data has arrived */
+		msleep_interruptible(50);		/* Timeout 50ms */
+	}			/* wait until timeout */
+
+	if (card->debug_flags & LOG_POF_CARD)
+		hysdn_addlog(card, "ERGO: pof boot ready timeout");
+	return (-ERR_POF_TIMEOUT);
+}				/* ergo_waitpofready */
+
+
+
+/************************************************************************************/
+/* release the cards hardware. Before releasing do a interrupt disable and hardware */
+/* reset. Also unmap dpram.                                                         */
+/* Use only during module release.                                                  */
+/************************************************************************************/
+static void
+ergo_releasehardware(hysdn_card *card)
+{
+	ergo_stopcard(card);	/* first stop the card if not already done */
+	free_irq(card->irq, card);	/* release interrupt */
+	release_region(card->iobase + PCI9050_INTR_REG, 1);	/* release all io ports */
+	release_region(card->iobase + PCI9050_USER_IO, 1);
+	iounmap(card->dpram);
+	card->dpram = NULL;	/* release shared mem */
+}				/* ergo_releasehardware */
+
+
+/*********************************************************************************/
+/* acquire the needed hardware ports and map dpram. If an error occurs a nonzero */
+/* value is returned.                                                            */
+/* Use only during module init.                                                  */
+/*********************************************************************************/
+int
+ergo_inithardware(hysdn_card *card)
+{
+	if (!request_region(card->iobase + PCI9050_INTR_REG, 1, "HYSDN"))
+		return (-1);
+	if (!request_region(card->iobase + PCI9050_USER_IO, 1, "HYSDN")) {
+		release_region(card->iobase + PCI9050_INTR_REG, 1);
+		return (-1);	/* ports already in use */
+	}
+	card->memend = card->membase + ERG_DPRAM_PAGE_SIZE - 1;
+	if (!(card->dpram = ioremap(card->membase, ERG_DPRAM_PAGE_SIZE))) {
+		release_region(card->iobase + PCI9050_INTR_REG, 1);
+		release_region(card->iobase + PCI9050_USER_IO, 1);
+		return (-1);
+	}
+
+	ergo_stopcard(card);	/* disable interrupts */
+	if (request_irq(card->irq, ergo_interrupt, IRQF_SHARED, "HYSDN", card)) {
+		ergo_releasehardware(card); /* return the acquired hardware */
+		return (-1);
+	}
+	/* success, now setup the function pointers */
+	card->stopcard = ergo_stopcard;
+	card->releasehardware = ergo_releasehardware;
+	card->testram = ergo_testram;
+	card->writebootimg = ergo_writebootimg;
+	card->writebootseq = ergo_writebootseq;
+	card->waitpofready = ergo_waitpofready;
+	card->set_errlog_state = ergo_set_errlog_state;
+	INIT_WORK(&card->irq_queue, ergo_irq_bh);
+	spin_lock_init(&card->hysdn_lock);
+
+	return (0);
+}				/* ergo_inithardware */