/*
* kempld_wdt.c - Kontron PLD watchdog driver
*
* Copyright (c) 2010 Kontron Embedded Modules GmbH
* Author: Michael Brunner <michael.brunner@kontron.com>
* Author: Erwan Velu <erwan.velu@zodiacaerospace.com>
*
* Note: From the PLD watchdog point of view timeout and pretimeout are
* defined differently than in the kernel.
* First the pretimeout stage runs out before the timeout stage gets
* active. This has to be kept in mind.
*
* Kernel/API: P-----| pretimeout
* |-----------------------T timeout
* Watchdog: |-----------------P pretimeout_stage
* |-----T timeout_stage
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <string.h>
#include <sys/io.h>
#include <unistd.h>
#include <syslinux/boot.h>
#include <stdio.h>
#include <stdlib.h>
#include <console.h>
#include "kontron_wdt.h"
struct kempld_device_data pld;
struct kempld_watchdog_data wdt;
uint8_t status;
char default_label[255];
/* Default Timeout is 60sec */
#define TIMEOUT 60
#define PRETIMEOUT 0
#define do_div(n,base) ({ \
int __res; \
__res = ((unsigned long) n) % (unsigned) base; \
n = ((unsigned long) n) / (unsigned) base; \
__res; })
/* Basic Wrappers to get code as less changed as possible */
void iowrite8(uint8_t val, uint16_t addr) { outb(val,addr); }
void iowrite16(uint16_t val, uint16_t addr) { outw(val,addr); }
void iowrite32(uint32_t val, uint16_t addr) { outl(val,addr);}
uint8_t ioread8(uint16_t addr) { return inb(addr);}
uint16_t ioread16(uint16_t addr) { return inw(addr);}
uint32_t ioread32(uint32_t addr) { return inl(addr);}
/**
* kempld_set_index - change the current register index of the PLD
* @pld: kempld_device_data structure describing the PLD
* @index: register index on the chip
*
* This function changes the register index of the PLD.
*/
void kempld_set_index(struct kempld_device_data *pld, uint8_t index)
{
if (pld->last_index != index) {
iowrite8(index, pld->io_index);
pld->last_index = index;
}
}
uint8_t kempld_read8(struct kempld_device_data *pld, uint8_t index) {
kempld_set_index(pld, index);
return ioread8(pld->io_data);
}
void kempld_write8(struct kempld_device_data *pld, uint8_t index, uint8_t data) {
kempld_set_index(pld, index);
iowrite8(data, pld->io_data);
}
uint16_t kempld_read16(struct kempld_device_data *pld, uint8_t index)
{
return kempld_read8(pld, index) | kempld_read8(pld, index+1) << 8;
}
void kempld_write16(struct kempld_device_data *pld, uint8_t index, uint16_t data)
{
kempld_write8(pld, index, (uint8_t)data);
kempld_write8(pld, index+1, (uint8_t)(data>>8));
}
uint32_t kempld_read32(struct kempld_device_data *pld, uint8_t index)
{
return kempld_read16(pld, index) | kempld_read16(pld, index+2) << 16;
}
void kempld_write32(struct kempld_device_data *pld, uint8_t index, uint32_t data)
{
kempld_write16(pld, index, (uint16_t)data);
kempld_write16(pld, index+2, (uint16_t)(data>>16));
}
static void kempld_release_mutex(struct kempld_device_data *pld)
{
iowrite8(pld->last_index | KEMPLD_MUTEX_KEY, pld->io_index);
}
void init_structure(void) {
/* set default values for the case we start the watchdog or change
* the configuration */
memset(&wdt,0,sizeof(wdt));
memset(&pld,0,sizeof(pld));
memset(&default_label,0,sizeof(default_label));
wdt.timeout = TIMEOUT;
wdt.pretimeout = PRETIMEOUT;
wdt.pld = &pld;
pld.io_base=KEMPLD_IOPORT;
pld.io_index=KEMPLD_IOPORT;
pld.io_data=KEMPLD_IODATA;
pld.pld_clock=33333333;
}
static int kempld_probe(void) {
/* Check for empty IO space */
int ret=0;
uint8_t index_reg = ioread8(pld.io_index);
if ((index_reg == 0xff) && (ioread8(pld.io_data) == 0xff)) {
ret = 1;
goto err_empty_io;
}
printf("Kempld structure found at 0x%X (data @ 0x%X)\n",pld.io_base,pld.io_data);
return 0;
err_empty_io:
printf("No IO Found !\n");
return ret;
}
static int kempld_wdt_probe_stages(struct kempld_watchdog_data *wdt)
{
struct kempld_device_data *pld = wdt->pld;
int i, ret;
uint32_t timeout;
uint32_t timeout_mask;
struct kempld_watchdog_stage *stage;
wdt->stages = 0;
wdt->timeout_stage = NULL;
wdt->pretimeout_stage = NULL;
for (i = 0; i < KEMPLD_WDT_MAX_STAGES; i++) {
timeout = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(i));
kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(i), 0x00000000);
timeout_mask = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(i));
kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(i), timeout);
if (timeout_mask != 0xffffffff) {
stage = malloc(sizeof(struct kempld_watchdog_stage));
if (stage == NULL) {
ret = -1;
goto err_alloc_stages;
}
stage->num = i;
stage->timeout_mask = ~timeout_mask;
wdt->stage[i] = stage;
wdt->stages++;
/* assign available stages to timeout and pretimeout */
if (wdt->stages == 1)
wdt->timeout_stage = stage;
else if (wdt->stages == 2) {
wdt->pretimeout_stage = wdt->timeout_stage;
wdt->timeout_stage = stage;
}
} else {
wdt->stage[i] = NULL;
}
}
return 0;
err_alloc_stages:
kempld_release_mutex(pld);
printf("Cannot allocate stages\n");
return ret;
}
static int kempld_wdt_keepalive(struct kempld_watchdog_data *wdt)
{
struct kempld_device_data *pld = wdt->pld;
kempld_write8(pld, KEMPLD_WDT_KICK, 'K');
return 0;
}
static int kempld_wdt_setstageaction(struct kempld_watchdog_data *wdt,
struct kempld_watchdog_stage *stage,
int action)
{
struct kempld_device_data *pld = wdt->pld;
uint8_t stage_cfg;
if (stage == NULL)
return -1;
stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->num));
stage_cfg &= ~KEMPLD_WDT_STAGE_CFG_ACTION_MASK;
stage_cfg |= (action & KEMPLD_WDT_STAGE_CFG_ACTION_MASK);
if (action == KEMPLD_WDT_ACTION_RESET)
stage_cfg |= KEMPLD_WDT_STAGE_CFG_ASSERT;
else
stage_cfg &= ~KEMPLD_WDT_STAGE_CFG_ASSERT;
kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->num), stage_cfg);
stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->num));
return 0;
}
static int kempld_wdt_setstagetimeout(struct kempld_watchdog_data *wdt,
struct kempld_watchdog_stage *stage,
int timeout)
{
struct kempld_device_data *pld = wdt->pld;
uint8_t stage_cfg;
uint8_t prescaler;
uint64_t stage_timeout64;
uint32_t stage_timeout;
if (stage == NULL)
return -1;
prescaler = KEMPLD_WDT_PRESCALER_21BIT;
stage_timeout64 = ((uint64_t)timeout*pld->pld_clock);
do_div(stage_timeout64, KEMPLD_PRESCALER(prescaler));
stage_timeout = stage_timeout64 & stage->timeout_mask;
if (stage_timeout64 != (uint64_t)stage_timeout)
return -1;
stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->num));
stage_cfg &= ~KEMPLD_WDT_STAGE_CFG_PRESCALER_MASK;
stage_cfg |= KEMPLD_WDT_STAGE_CFG_SET_PRESCALER(prescaler);
kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->num), stage_cfg);
kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->num),
stage_timeout);
return 0;
}
static int kempld_wdt_settimeout(struct kempld_watchdog_data *wdt)
{
int stage_timeout;
int stage_pretimeout;
int ret;
if ((wdt->timeout <= 0) ||
(wdt->pretimeout < 0) ||
(wdt->pretimeout > wdt->timeout)) {
ret = -1;
goto err_check_values;
}
if ((wdt->pretimeout == 0) || (wdt->pretimeout_stage == NULL)) {
if (wdt->pretimeout != 0)
printf("No pretimeout stage available, only enabling reset!\n");
stage_pretimeout = 0;
stage_timeout = wdt->timeout;
} else {
stage_pretimeout = wdt->timeout - wdt->pretimeout;
stage_timeout = wdt->pretimeout;
}
if (stage_pretimeout != 0) {
ret = kempld_wdt_setstageaction(wdt, wdt->pretimeout_stage,
KEMPLD_WDT_ACTION_NMI);
} else if ((stage_pretimeout == 0)
&& (wdt->pretimeout_stage != NULL)) {
ret = kempld_wdt_setstageaction(wdt, wdt->pretimeout_stage,
KEMPLD_WDT_ACTION_NONE);
} else
ret = 0;
if (ret)
goto err_setstage;
if (stage_pretimeout != 0) {
ret = kempld_wdt_setstagetimeout(wdt, wdt->pretimeout_stage,
stage_pretimeout);
if (ret)
goto err_setstage;
}
ret = kempld_wdt_setstageaction(wdt, wdt->timeout_stage,
KEMPLD_WDT_ACTION_RESET);
if (ret)
goto err_setstage;
ret = kempld_wdt_setstagetimeout(wdt, wdt->timeout_stage,
stage_timeout);
if (ret)
goto err_setstage;
return 0;
err_setstage:
err_check_values:
return ret;
}
static int kempld_wdt_start(struct kempld_watchdog_data *wdt)
{
struct kempld_device_data *pld = wdt->pld;
uint8_t status;
status = kempld_read8(pld, KEMPLD_WDT_CFG);
status |= KEMPLD_WDT_CFG_ENABLE;
kempld_write8(pld, KEMPLD_WDT_CFG, status);
status = kempld_read8(pld, KEMPLD_WDT_CFG);
/* check if the watchdog was enabled */
if (!(status & KEMPLD_WDT_CFG_ENABLE))
return -1;
return 0;
}
/* A regular configuration file looks like
LABEL WDT
COM32 wdt.c32
APPEND timeout=120 default_label=local
*/
void detect_parameters(const int argc, const char *argv[]) {
for (int i = 1; i < argc; i++) {
/* Override the timeout if specified on the cmdline */
if (!strncmp(argv[i], "timeout=", 8)) {
wdt.timeout=atoi(argv[i]+8);
} else
/* Define which boot entry shall be used */
if (!strncmp(argv[i], "default_label=", 14)) {
strlcpy(default_label, argv[i] + 14, sizeof(default_label));
}
}
}
int main(int argc, const char *argv[]) {
int ret=0;
openconsole(&dev_rawcon_r, &dev_stdcon_w);
init_structure();
detect_parameters(argc,argv);
kempld_probe();
/* probe how many usable stages we have */
if (kempld_wdt_probe_stages(&wdt)) {
printf("Cannot Probe Stages\n");
return -1;
}
/* Useless but who knows */
wdt.ident.firmware_version = KEMPLD_WDT_REV_GET(kempld_read8(&pld, KEMPLD_WDT_REV));
status = kempld_read8(&pld, KEMPLD_WDT_CFG);
/* kick the watchdog if it is already enabled, otherwise start it */
if (status & KEMPLD_WDT_CFG_ENABLE) {
/* Maybye the BIOS did setup a first timer
* in this case, let's enforce the timeout
* to be sure we do have the proper value */
kempld_wdt_settimeout(&wdt);
kempld_wdt_keepalive(&wdt);
} else {
ret = kempld_wdt_settimeout(&wdt);
if (ret) {
printf("Unable to setup timeout !\n");
goto booting;
}
ret = kempld_wdt_start(&wdt);
if (ret) {
printf("Unable to start watchdog !\n");
goto booting;
}
}
printf("Watchog armed ! Rebooting in %d seconds if no feed occurs !\n",wdt.timeout);
booting:
/* Release Mutex to let Linux's Driver taking control */
kempld_release_mutex(&pld);
/* Let's boot the default entry if specified */
if (strlen(default_label)>0) {
printf("Executing default label = '%s'\n",default_label);
syslinux_run_command(default_label);
} else {
return ret;
}
}