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/*
* Copyright (c) 2022 TOKITA Hiroshi
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT gd_gd32_wwdgt
#include <zephyr/drivers/clock_control.h>
#include <zephyr/drivers/clock_control/gd32.h>
#include <zephyr/drivers/reset.h>
#include <zephyr/drivers/watchdog.h>
#include <zephyr/irq.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys_clock.h>
#include <gd32_wwdgt.h>
LOG_MODULE_REGISTER(wdt_wwdgt_gd32, CONFIG_WDT_LOG_LEVEL);
#define WWDGT_PRESCALER_EXP_MAX (3U)
#define WWDGT_COUNTER_MIN (0x40U)
#define WWDGT_COUNTER_MAX (0x7fU)
#define WWDGT_INTERNAL_DIVIDER (4096ULL)
struct gd32_wwdgt_config {
uint16_t clkid;
struct reset_dt_spec reset;
};
/* mutable driver data */
struct gd32_wwdgt_data {
/* counter update value*/
uint8_t counter;
/* user defined callback */
wdt_callback_t callback;
};
static void gd32_wwdgt_irq_config(const struct device *dev);
/**
* @param timeout Timeout value in milliseconds.
* @param exp exponent part of prescaler
*
* @return ticks count calculated by this formula.
*
* timeout = pclk * INTERNAL_DIVIDER * (2^prescaler_exp) * (count + 1)
* transform as
* count = (timeout * pclk / INTERNAL_DIVIDER * (2^prescaler_exp) ) - 1
*
* and add WWDGT_COUNTER_MIN to this as a offset value.
*/
static inline uint32_t gd32_wwdgt_calc_ticks(const struct device *dev,
uint32_t timeout, uint32_t exp)
{
const struct gd32_wwdgt_config *config = dev->config;
uint32_t pclk;
(void)clock_control_get_rate(GD32_CLOCK_CONTROLLER,
(clock_control_subsys_t)&config->clkid,
&pclk);
return ((timeout * pclk)
/ (WWDGT_INTERNAL_DIVIDER * (1 << exp) * MSEC_PER_SEC) - 1)
+ WWDGT_COUNTER_MIN;
}
/**
* @brief Calculates WWDGT config value from timeout window.
*
* @param win Pointer to timeout window struct.
* @param counter Pointer to the storage of counter value.
* @param wval Pointer to the storage of window value.
* @param prescaler Pointer to the storage of prescaler value.
*
* @return 0 on success, -EINVAL if the window-max is out of range
*/
static int gd32_wwdgt_calc_window(const struct device *dev,
const struct wdt_window *win,
uint32_t *counter, uint32_t *wval,
uint32_t *prescaler)
{
for (uint32_t shift = 0U; shift <= WWDGT_PRESCALER_EXP_MAX; shift++) {
uint32_t max_count = gd32_wwdgt_calc_ticks(dev, win->max, shift);
if (max_count <= WWDGT_COUNTER_MAX) {
*counter = max_count;
*prescaler = CFG_PSC(shift);
if (win->min == 0U) {
*wval = max_count;
} else {
*wval = gd32_wwdgt_calc_ticks(dev, win->min, shift);
}
return 0;
}
}
return -EINVAL;
}
static int gd32_wwdgt_setup(const struct device *dev, uint8_t options)
{
ARG_UNUSED(dev);
if (options & WDT_OPT_PAUSE_HALTED_BY_DBG) {
#if CONFIG_GD32_DBG_SUPPORT
dbg_periph_enable(DBG_WWDGT_HOLD);
#else
LOG_ERR("Debug support not enabled");
return -ENOTSUP;
#endif
}
if (options & WDT_OPT_PAUSE_IN_SLEEP) {
LOG_ERR("WDT_OPT_PAUSE_IN_SLEEP not supported");
return -ENOTSUP;
}
wwdgt_enable();
wwdgt_flag_clear();
wwdgt_interrupt_enable();
return 0;
}
static int gd32_wwdgt_disable(const struct device *dev)
{
/* watchdog cannot be stopped once started */
ARG_UNUSED(dev);
return -EPERM;
}
static int gd32_wwdgt_install_timeout(const struct device *dev,
const struct wdt_timeout_cfg *config)
{
uint32_t prescaler = 0U;
uint32_t counter = 0U;
uint32_t window = 0U;
struct gd32_wwdgt_data *data = dev->data;
if (config->window.max == 0U) {
LOG_ERR("window.max must be non-zero");
return -EINVAL;
}
if (gd32_wwdgt_calc_window(dev, &config->window, &counter, &window,
&prescaler) != 0) {
LOG_ERR("window.max in out of range");
return -EINVAL;
}
data->callback = config->callback;
data->counter = counter;
wwdgt_config(counter, window, prescaler);
return 0;
}
static int gd32_wwdgt_feed(const struct device *dev, int channel_id)
{
struct gd32_wwdgt_data *data = dev->data;
ARG_UNUSED(channel_id);
wwdgt_counter_update(data->counter);
return 0;
}
static void gd32_wwdgt_isr(const struct device *dev)
{
struct gd32_wwdgt_data *data = dev->data;
if (wwdgt_flag_get() != 0) {
wwdgt_flag_clear();
if (data->callback != NULL) {
data->callback(dev, 0);
}
}
}
static void gd32_wwdgt_irq_config(const struct device *dev)
{
ARG_UNUSED(dev);
IRQ_CONNECT(DT_INST_IRQN(0), DT_INST_IRQ(0, priority), gd32_wwdgt_isr,
DEVICE_DT_INST_GET(0), 0);
irq_enable(DT_INST_IRQN(0));
}
static const struct wdt_driver_api wwdgt_gd32_api = {
.setup = gd32_wwdgt_setup,
.disable = gd32_wwdgt_disable,
.install_timeout = gd32_wwdgt_install_timeout,
.feed = gd32_wwdgt_feed,
};
static int gd32_wwdgt_init(const struct device *dev)
{
const struct gd32_wwdgt_config *config = dev->config;
(void)clock_control_on(GD32_CLOCK_CONTROLLER,
(clock_control_subsys_t)&config->clkid);
(void)reset_line_toggle_dt(&config->reset);
gd32_wwdgt_irq_config(dev);
return 0;
}
static const struct gd32_wwdgt_config wwdgt_cfg = {
.clkid = DT_INST_CLOCKS_CELL(0, id),
.reset = RESET_DT_SPEC_INST_GET(0),
};
static struct gd32_wwdgt_data wwdgt_data = {
.counter = WWDGT_COUNTER_MIN,
.callback = NULL
};
DEVICE_DT_INST_DEFINE(0, gd32_wwdgt_init, NULL, &wwdgt_data, &wwdgt_cfg, POST_KERNEL,
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &wwdgt_gd32_api);