blob: ac94f6342e4376ff57eebb195c777f9bcedeba8d [file] [log] [blame]
/*
* Copyright (c) 2018 Henrik Brix Andersen <henrik@brixandersen.dk>
* Copyright (c) 2017 Google LLC.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT atmel_sam0_watchdog
#include <soc.h>
#include <drivers/watchdog.h>
#define LOG_LEVEL CONFIG_WDT_LOG_LEVEL
#include <logging/log.h>
LOG_MODULE_REGISTER(wdt_sam0);
#define WDT_REGS ((Wdt *)DT_INST_REG_ADDR(0))
#ifndef WDT_CONFIG_PER_8_Val
#define WDT_CONFIG_PER_8_Val WDT_CONFIG_PER_CYC8_Val
#endif
#ifndef WDT_CONFIG_PER_8K_Val
#define WDT_CONFIG_PER_8K_Val WDT_CONFIG_PER_CYC8192_Val
#endif
#ifndef WDT_CONFIG_PER_16K_Val
#define WDT_CONFIG_PER_16K_Val WDT_CONFIG_PER_CYC16384_Val
#endif
/* syncbusy check is different for SAM D/E */
#ifdef WDT_STATUS_SYNCBUSY
#define WDT_SYNCBUSY WDT_REGS->STATUS.bit.SYNCBUSY
#else
#define WDT_SYNCBUSY WDT_REGS->SYNCBUSY.reg
#endif
struct wdt_sam0_dev_data {
wdt_callback_t cb;
bool timeout_valid;
};
static struct wdt_sam0_dev_data wdt_sam0_data = { 0 };
static void wdt_sam0_wait_synchronization(void)
{
while (WDT_SYNCBUSY) {
/* wait for SYNCBUSY */
}
}
static inline void wdt_sam0_set_enable(bool on)
{
#ifdef WDT_CTRLA_ENABLE
WDT_REGS->CTRLA.bit.ENABLE = on;
#else
WDT_REGS->CTRL.bit.ENABLE = on;
#endif
}
static inline bool wdt_sam0_is_enabled(void)
{
#ifdef WDT_CTRLA_ENABLE
return WDT_REGS->CTRLA.bit.ENABLE;
#else
return WDT_REGS->CTRL.bit.ENABLE;
#endif
}
static uint32_t wdt_sam0_timeout_to_wdt_period(uint32_t timeout_ms)
{
uint32_t next_pow2;
uint32_t cycles;
/* Calculate number of clock cycles @ 1.024 kHz input clock */
cycles = (timeout_ms * 1024U) / 1000;
/* Minimum wdt period is 8 clock cycles (register value 0) */
if (cycles <= 8U) {
return 0;
}
/* Round up to next pow2 and calculate the register value */
next_pow2 = (1ULL << 32) >> __builtin_clz(cycles - 1);
return find_msb_set(next_pow2 >> 4);
}
static void wdt_sam0_isr(const struct device *dev)
{
struct wdt_sam0_dev_data *data = dev->data;
WDT_REGS->INTFLAG.reg = WDT_INTFLAG_EW;
if (data->cb != NULL) {
data->cb(dev, 0);
}
}
static int wdt_sam0_setup(const struct device *dev, uint8_t options)
{
struct wdt_sam0_dev_data *data = dev->data;
if (wdt_sam0_is_enabled()) {
LOG_ERR("Watchdog already setup");
return -EBUSY;
}
if (!data->timeout_valid) {
LOG_ERR("No valid timeout installed");
return -EINVAL;
}
if (options & WDT_OPT_PAUSE_IN_SLEEP) {
LOG_ERR("Pause in sleep not supported");
return -ENOTSUP;
}
if (options & WDT_OPT_PAUSE_HALTED_BY_DBG) {
LOG_ERR("Pause when halted by debugger not supported");
return -ENOTSUP;
}
/* Enable watchdog */
wdt_sam0_set_enable(1);
wdt_sam0_wait_synchronization();
return 0;
}
static int wdt_sam0_disable(const struct device *dev)
{
if (!wdt_sam0_is_enabled()) {
return -EFAULT;
}
wdt_sam0_set_enable(0);
wdt_sam0_wait_synchronization();
return 0;
}
static int wdt_sam0_install_timeout(const struct device *dev,
const struct wdt_timeout_cfg *cfg)
{
struct wdt_sam0_dev_data *data = dev->data;
uint32_t window, per;
/* CONFIG is enable protected, error out if already enabled */
if (wdt_sam0_is_enabled()) {
LOG_ERR("Watchdog already setup");
return -EBUSY;
}
if (cfg->flags != WDT_FLAG_RESET_SOC) {
LOG_ERR("Only SoC reset supported");
return -ENOTSUP;
}
if (cfg->window.max == 0) {
LOG_ERR("Upper limit timeout out of range");
return -EINVAL;
}
per = wdt_sam0_timeout_to_wdt_period(cfg->window.max);
if (per > WDT_CONFIG_PER_16K_Val) {
LOG_ERR("Upper limit timeout out of range");
goto timeout_invalid;
}
if (cfg->window.min) {
/* Window mode */
window = wdt_sam0_timeout_to_wdt_period(cfg->window.min);
if (window > WDT_CONFIG_PER_8K_Val) {
LOG_ERR("Lower limit timeout out of range");
goto timeout_invalid;
}
if (per <= window) {
/* Ensure we have a window */
per = window + 1;
}
#ifdef WDT_CTRLA_WEN
WDT_REGS->CTRLA.bit.WEN = 1;
#else
WDT_REGS->CTRL.bit.WEN = 1;
#endif
wdt_sam0_wait_synchronization();
} else {
/* Normal mode */
if (cfg->callback) {
if (per == WDT_CONFIG_PER_8_Val) {
/* Ensure we have time for the early warning */
per += 1U;
}
WDT_REGS->EWCTRL.bit.EWOFFSET = per - 1U;
}
window = WDT_CONFIG_PER_8_Val;
#ifdef WDT_CTRLA_WEN
WDT_REGS->CTRLA.bit.WEN = 0;
#else
WDT_REGS->CTRL.bit.WEN = 0;
#endif
wdt_sam0_wait_synchronization();
}
WDT_REGS->CONFIG.reg = WDT_CONFIG_WINDOW(window) | WDT_CONFIG_PER(per);
wdt_sam0_wait_synchronization();
/* Only enable IRQ if a callback was provided */
data->cb = cfg->callback;
if (data->cb) {
WDT_REGS->INTENSET.reg = WDT_INTENSET_EW;
} else {
WDT_REGS->INTENCLR.reg = WDT_INTENCLR_EW;
WDT_REGS->INTFLAG.reg = WDT_INTFLAG_EW;
}
data->timeout_valid = true;
return 0;
timeout_invalid:
data->timeout_valid = false;
data->cb = NULL;
return -EINVAL;
}
static int wdt_sam0_feed(const struct device *dev, int channel_id)
{
struct wdt_sam0_dev_data *data = dev->data;
if (!data->timeout_valid) {
LOG_ERR("No valid timeout installed");
return -EINVAL;
}
if (WDT_SYNCBUSY) {
return -EAGAIN;
}
WDT_REGS->CLEAR.reg = WDT_CLEAR_CLEAR_KEY_Val;
return 0;
}
static const struct wdt_driver_api wdt_sam0_api = {
.setup = wdt_sam0_setup,
.disable = wdt_sam0_disable,
.install_timeout = wdt_sam0_install_timeout,
.feed = wdt_sam0_feed,
};
static int wdt_sam0_init(const struct device *dev)
{
#ifdef CONFIG_WDT_DISABLE_AT_BOOT
/* Ignore any errors */
wdt_sam0_disable(dev);
#endif
/* Enable APB clock */
#ifdef MCLK
MCLK->APBAMASK.bit.WDT_ = 1;
/* watchdog clock is fed by OSCULP32K */
#else
PM->APBAMASK.bit.WDT_ = 1;
/* Connect to GCLK2 (~1.024 kHz) */
GCLK->CLKCTRL.reg = GCLK_CLKCTRL_ID_WDT
| GCLK_CLKCTRL_GEN_GCLK2
| GCLK_CLKCTRL_CLKEN;
#endif
IRQ_CONNECT(DT_INST_IRQN(0),
DT_INST_IRQ(0, priority), wdt_sam0_isr,
DEVICE_DT_INST_GET(0), 0);
irq_enable(DT_INST_IRQN(0));
return 0;
}
static struct wdt_sam0_dev_data wdt_sam0_data;
DEVICE_DT_INST_DEFINE(0, wdt_sam0_init, NULL,
&wdt_sam0_data, NULL, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &wdt_sam0_api);