linux/drivers/input/serio/hp_sdc_mlc.c
Helge Deller 879bc2d279 hil/parisc: Disable HIL driver when it gets stuck
When starting a HP machine with HIL driver but without an HIL keyboard
or HIL mouse attached, it may happen that data written to the HIL loop
gets stuck (e.g. because the transaction queue is full).  Usually one
will then have to reboot the machine because all you see is and endless
output of:
 Transaction add failed: transaction already queued?

In the higher layers hp_sdc_enqueue_transaction() is called to queued up
a HIL packet. This function returns an error code, and this patch adds
the necessary checks for this return code and disables the HIL driver if
further packets can't be sent.

Tested on a HP 730 and a HP 715/64 machine.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
2020-10-22 22:44:35 +02:00

356 lines
9.1 KiB
C

/*
* Access to HP-HIL MLC through HP System Device Controller.
*
* Copyright (c) 2001 Brian S. Julin
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
*
* References:
* HP-HIL Technical Reference Manual. Hewlett Packard Product No. 45918A
* System Device Controller Microprocessor Firmware Theory of Operation
* for Part Number 1820-4784 Revision B. Dwg No. A-1820-4784-2
*
*/
#include <linux/hil_mlc.h>
#include <linux/hp_sdc.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/semaphore.h>
#define PREFIX "HP SDC MLC: "
static hil_mlc hp_sdc_mlc;
MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
MODULE_DESCRIPTION("Glue for onboard HIL MLC in HP-PARISC machines");
MODULE_LICENSE("Dual BSD/GPL");
static struct hp_sdc_mlc_priv_s {
int emtestmode;
hp_sdc_transaction trans;
u8 tseq[16];
int got5x;
} hp_sdc_mlc_priv;
/************************* Interrupt context ******************************/
static void hp_sdc_mlc_isr (int irq, void *dev_id,
uint8_t status, uint8_t data)
{
int idx;
hil_mlc *mlc = &hp_sdc_mlc;
write_lock(&mlc->lock);
if (mlc->icount < 0) {
printk(KERN_WARNING PREFIX "HIL Overflow!\n");
up(&mlc->isem);
goto out;
}
idx = 15 - mlc->icount;
if ((status & HP_SDC_STATUS_IRQMASK) == HP_SDC_STATUS_HILDATA) {
mlc->ipacket[idx] |= data | HIL_ERR_INT;
mlc->icount--;
if (hp_sdc_mlc_priv.got5x || !idx)
goto check;
if ((mlc->ipacket[idx - 1] & HIL_PKT_ADDR_MASK) !=
(mlc->ipacket[idx] & HIL_PKT_ADDR_MASK)) {
mlc->ipacket[idx] &= ~HIL_PKT_ADDR_MASK;
mlc->ipacket[idx] |= (mlc->ipacket[idx - 1]
& HIL_PKT_ADDR_MASK);
}
goto check;
}
/* We know status is 5X */
if (data & HP_SDC_HIL_ISERR)
goto err;
mlc->ipacket[idx] =
(data & HP_SDC_HIL_R1MASK) << HIL_PKT_ADDR_SHIFT;
hp_sdc_mlc_priv.got5x = 1;
goto out;
check:
hp_sdc_mlc_priv.got5x = 0;
if (mlc->imatch == 0)
goto done;
if ((mlc->imatch == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
&& (mlc->ipacket[idx] == (mlc->imatch | idx)))
goto done;
if (mlc->ipacket[idx] == mlc->imatch)
goto done;
goto out;
err:
printk(KERN_DEBUG PREFIX "err code %x\n", data);
switch (data) {
case HP_SDC_HIL_RC_DONE:
printk(KERN_WARNING PREFIX "Bastard SDC reconfigured loop!\n");
break;
case HP_SDC_HIL_ERR:
mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_PERR |
HIL_ERR_FERR | HIL_ERR_FOF;
break;
case HP_SDC_HIL_TO:
mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_LERR;
break;
case HP_SDC_HIL_RC:
printk(KERN_WARNING PREFIX "Bastard SDC decided to reconfigure loop!\n");
break;
default:
printk(KERN_WARNING PREFIX "Unknown HIL Error status (%x)!\n", data);
break;
}
/* No more data will be coming due to an error. */
done:
tasklet_schedule(mlc->tasklet);
up(&mlc->isem);
out:
write_unlock(&mlc->lock);
}
/******************** Tasklet or userspace context functions ****************/
static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)
{
struct hp_sdc_mlc_priv_s *priv;
int rc = 2;
priv = mlc->priv;
/* Try to down the semaphore */
if (down_trylock(&mlc->isem)) {
if (priv->emtestmode) {
mlc->ipacket[0] =
HIL_ERR_INT | (mlc->opacket &
(HIL_PKT_CMD |
HIL_PKT_ADDR_MASK |
HIL_PKT_DATA_MASK));
mlc->icount = 14;
/* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
goto wasup;
}
if (time_after(jiffies, mlc->instart + mlc->intimeout)) {
/* printk("!%i %i",
tv.tv_usec - mlc->instart.tv_usec,
mlc->intimeout);
*/
rc = 1;
up(&mlc->isem);
}
goto done;
}
wasup:
up(&mlc->isem);
rc = 0;
done:
return rc;
}
static int hp_sdc_mlc_cts(hil_mlc *mlc)
{
struct hp_sdc_mlc_priv_s *priv;
priv = mlc->priv;
/* Try to down the semaphores -- they should be up. */
BUG_ON(down_trylock(&mlc->isem));
BUG_ON(down_trylock(&mlc->osem));
up(&mlc->isem);
up(&mlc->osem);
if (down_trylock(&mlc->csem)) {
if (priv->trans.act.semaphore != &mlc->csem)
goto poll;
else
goto busy;
}
if (!(priv->tseq[4] & HP_SDC_USE_LOOP))
goto done;
poll:
priv->trans.act.semaphore = &mlc->csem;
priv->trans.actidx = 0;
priv->trans.idx = 1;
priv->trans.endidx = 5;
priv->tseq[0] =
HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
priv->tseq[1] = HP_SDC_CMD_READ_USE;
priv->tseq[2] = 1;
priv->tseq[3] = 0;
priv->tseq[4] = 0;
return __hp_sdc_enqueue_transaction(&priv->trans);
busy:
return 1;
done:
priv->trans.act.semaphore = &mlc->osem;
up(&mlc->csem);
return 0;
}
static int hp_sdc_mlc_out(hil_mlc *mlc)
{
struct hp_sdc_mlc_priv_s *priv;
priv = mlc->priv;
/* Try to down the semaphore -- it should be up. */
BUG_ON(down_trylock(&mlc->osem));
if (mlc->opacket & HIL_DO_ALTER_CTRL)
goto do_control;
do_data:
if (priv->emtestmode) {
up(&mlc->osem);
return 0;
}
/* Shouldn't be sending commands when loop may be busy */
BUG_ON(down_trylock(&mlc->csem));
up(&mlc->csem);
priv->trans.actidx = 0;
priv->trans.idx = 1;
priv->trans.act.semaphore = &mlc->osem;
priv->trans.endidx = 6;
priv->tseq[0] =
HP_SDC_ACT_DATAREG | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_SEMAPHORE;
priv->tseq[1] = 0x7;
priv->tseq[2] =
(mlc->opacket &
(HIL_PKT_ADDR_MASK | HIL_PKT_CMD))
>> HIL_PKT_ADDR_SHIFT;
priv->tseq[3] =
(mlc->opacket & HIL_PKT_DATA_MASK)
>> HIL_PKT_DATA_SHIFT;
priv->tseq[4] = 0; /* No timeout */
if (priv->tseq[3] == HIL_CMD_DHR)
priv->tseq[4] = 1;
priv->tseq[5] = HP_SDC_CMD_DO_HIL;
goto enqueue;
do_control:
priv->emtestmode = mlc->opacket & HIL_CTRL_TEST;
/* we cannot emulate this, it should not be used. */
BUG_ON((mlc->opacket & (HIL_CTRL_APE | HIL_CTRL_IPF)) == HIL_CTRL_APE);
if ((mlc->opacket & HIL_CTRL_ONLY) == HIL_CTRL_ONLY)
goto control_only;
/* Should not send command/data after engaging APE */
BUG_ON(mlc->opacket & HIL_CTRL_APE);
/* Disengaging APE this way would not be valid either since
* the loop must be allowed to idle.
*
* So, it works out that we really never actually send control
* and data when using SDC, we just send the data.
*/
goto do_data;
control_only:
priv->trans.actidx = 0;
priv->trans.idx = 1;
priv->trans.act.semaphore = &mlc->osem;
priv->trans.endidx = 4;
priv->tseq[0] =
HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
priv->tseq[1] = HP_SDC_CMD_SET_LPC;
priv->tseq[2] = 1;
/* priv->tseq[3] = (mlc->ddc + 1) | HP_SDC_LPS_ACSUCC; */
priv->tseq[3] = 0;
if (mlc->opacket & HIL_CTRL_APE) {
priv->tseq[3] |= HP_SDC_LPC_APE_IPF;
BUG_ON(down_trylock(&mlc->csem));
}
enqueue:
return hp_sdc_enqueue_transaction(&priv->trans);
}
static int __init hp_sdc_mlc_init(void)
{
hil_mlc *mlc = &hp_sdc_mlc;
int err;
#ifdef __mc68000__
if (!MACH_IS_HP300)
return -ENODEV;
#endif
printk(KERN_INFO PREFIX "Registering the System Domain Controller's HIL MLC.\n");
hp_sdc_mlc_priv.emtestmode = 0;
hp_sdc_mlc_priv.trans.seq = hp_sdc_mlc_priv.tseq;
hp_sdc_mlc_priv.trans.act.semaphore = &mlc->osem;
hp_sdc_mlc_priv.got5x = 0;
mlc->cts = &hp_sdc_mlc_cts;
mlc->in = &hp_sdc_mlc_in;
mlc->out = &hp_sdc_mlc_out;
mlc->priv = &hp_sdc_mlc_priv;
err = hil_mlc_register(mlc);
if (err) {
printk(KERN_WARNING PREFIX "Failed to register MLC structure with hil_mlc\n");
return err;
}
if (hp_sdc_request_hil_irq(&hp_sdc_mlc_isr)) {
printk(KERN_WARNING PREFIX "Request for raw HIL ISR hook denied\n");
if (hil_mlc_unregister(mlc))
printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
"This is bad. Could cause an oops.\n");
return -EBUSY;
}
return 0;
}
static void __exit hp_sdc_mlc_exit(void)
{
hil_mlc *mlc = &hp_sdc_mlc;
if (hp_sdc_release_hil_irq(&hp_sdc_mlc_isr))
printk(KERN_ERR PREFIX "Failed to release the raw HIL ISR hook.\n"
"This is bad. Could cause an oops.\n");
if (hil_mlc_unregister(mlc))
printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
"This is bad. Could cause an oops.\n");
}
module_init(hp_sdc_mlc_init);
module_exit(hp_sdc_mlc_exit);