| /* |
| * kempld_wdt.c - Kontron PLD watchdog driver |
| * |
| * Copyright (c) 2010 Kontron Embedded Modules GmbH |
| * Author: Michael Brunner <[email protected]> |
| * Author: Erwan Velu <[email protected]> |
| * |
| * 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; |
| } |
| } |
