blob: 2dec616b0ce286e604d9d445c6222bf63e71a765 [file] [log] [blame] [edit]
/*
* Copyright (c) 2022 TOKITA Hiroshi
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT gd_gd32_fwdgt
#include <zephyr/drivers/watchdog.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys_clock.h>
#include <gd32_fwdgt.h>
LOG_MODULE_REGISTER(wdt_fwdgt_gd32, CONFIG_WDT_LOG_LEVEL);
#define FWDGT_RELOAD_MAX (0xFFFU)
#define FWDGT_PRESCALER_MAX (256U)
#if defined(CONFIG_GD32_HAS_IRC_32K)
#define RCU_IRC_LOW_SPEED RCU_IRC32K
#elif defined(CONFIG_GD32_HAS_IRC_40K)
#define RCU_IRC_LOW_SPEED RCU_IRC40K
#else
#error IRC frequency was not configured
#endif
#define IS_VALID_FWDGT_PRESCALER(psc) \
(((psc) == FWDGT_PSC_DIV4) || ((psc) == FWDGT_PSC_DIV8) || \
((psc) == FWDGT_PSC_DIV16) || ((psc) == FWDGT_PSC_DIV32) || \
((psc) == FWDGT_PSC_DIV64) || ((psc) == FWDGT_PSC_DIV128) || \
((psc) == FWDGT_PSC_DIV256))
#define FWDGT_INITIAL_TIMEOUT DT_INST_PROP(0, initial_timeout_ms)
#if (FWDGT_INITIAL_TIMEOUT <= 0)
#error Must be initial-timeout > 0
#elif (FWDGT_INITIAL_TIMEOUT > \
(FWDGT_PRESCALER_MAX * FWDGT_RELOAD_MAX * MSEC_PER_SEC / \
CONFIG_GD32_LOW_SPEED_IRC_FREQUENCY))
#error Must be initial-timeout <= (256 * 4095 * 1000 / GD32_LOW_SPEED_IRC_FREQUENCY)
#endif
/**
* @brief Calculates FWDGT config value from timeout.
*
* @param timeout Timeout value in milliseconds.
* @param prescaler Pointer to the storage of prescaler value.
* @param reload Pointer to the storage of reload value.
*
* @return 0 on success, -EINVAL if the timeout is out of range
*/
static int gd32_fwdgt_calc_timeout(uint32_t timeout, uint32_t *prescaler,
uint32_t *reload)
{
uint16_t divider = 4U;
uint8_t shift = 0U;
uint32_t ticks = (uint64_t)CONFIG_GD32_LOW_SPEED_IRC_FREQUENCY *
timeout / MSEC_PER_SEC;
while ((ticks / divider) > FWDGT_RELOAD_MAX) {
shift++;
divider = 4U << shift;
}
if (!IS_VALID_FWDGT_PRESCALER(PSC_PSC(shift)) || timeout == 0U) {
return -EINVAL;
}
/* convert the 'shift' to prescaler value */
*prescaler = PSC_PSC(shift);
*reload = (ticks / divider) - 1U;
return 0;
}
static int gd32_fwdgt_setup(const struct device *dev, uint8_t options)
{
ARG_UNUSED(dev);
if ((options & WDT_OPT_PAUSE_HALTED_BY_DBG) != 0U) {
#if CONFIG_GD32_DBG_SUPPORT
dbg_periph_enable(DBG_FWDGT_HOLD);
#else
LOG_ERR("Debug support not enabled");
return -ENOTSUP;
#endif
}
if ((options & WDT_OPT_PAUSE_IN_SLEEP) != 0U) {
LOG_ERR("WDT_OPT_PAUSE_IN_SLEEP not supported");
return -ENOTSUP;
}
fwdgt_enable();
return 0;
}
static int gd32_fwdgt_disable(const struct device *dev)
{
/* watchdog cannot be stopped once started */
ARG_UNUSED(dev);
return -EPERM;
}
static int gd32_fwdgt_install_timeout(const struct device *dev,
const struct wdt_timeout_cfg *config)
{
uint32_t prescaler = 0U;
uint32_t reload = 0U;
ErrStatus errstat = ERROR;
/* Callback is not supported by FWDGT */
if (config->callback != NULL) {
LOG_ERR("callback not supported by FWDGT");
return -ENOTSUP;
}
/* Calculate prescaler and reload value from timeout value */
if (gd32_fwdgt_calc_timeout(config->window.max, &prescaler,
&reload) != 0) {
LOG_ERR("window max is out of range");
return -EINVAL;
}
/* Configure and run FWDGT */
fwdgt_write_enable();
errstat = fwdgt_config(reload, prescaler);
if (errstat != SUCCESS) {
LOG_ERR("fwdgt_config() failed: %d", errstat);
return -EINVAL;
}
fwdgt_write_disable();
return 0;
}
static int gd32_fwdgt_feed(const struct device *dev, int channel_id)
{
ARG_UNUSED(channel_id);
fwdgt_counter_reload();
return 0;
}
static const struct wdt_driver_api fwdgt_gd32_api = {
.setup = gd32_fwdgt_setup,
.disable = gd32_fwdgt_disable,
.install_timeout = gd32_fwdgt_install_timeout,
.feed = gd32_fwdgt_feed,
};
static int gd32_fwdgt_init(const struct device *dev)
{
int ret = 0;
/* Turn on and wait stabilize system clock oscillator. */
rcu_osci_on(RCU_IRC_LOW_SPEED);
while (!rcu_osci_stab_wait(RCU_IRC_LOW_SPEED)) {
}
#if !defined(CONFIG_WDT_DISABLE_AT_BOOT)
const struct wdt_timeout_cfg config = {
.window.max = FWDGT_INITIAL_TIMEOUT
};
ret = gd32_fwdgt_install_timeout(dev, &config);
#endif
return ret;
}
DEVICE_DT_INST_DEFINE(0, gd32_fwdgt_init, NULL, NULL, NULL, POST_KERNEL,
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &fwdgt_gd32_api);