diff options
Diffstat (limited to 'com32/modules/kontron_wdt.c')
| -rw-r--r-- | com32/modules/kontron_wdt.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/com32/modules/kontron_wdt.c b/com32/modules/kontron_wdt.c new file mode 100644 index 00000000..4e1d2535 --- /dev/null +++ b/com32/modules/kontron_wdt.c @@ -0,0 +1,414 @@ +/* + * 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; + } +} |