1 /*
2 * Copyright (c) 2021 ITE Corporation. All Rights Reserved.
3 * SPDX-License-Identifier: Apache-2.0
4 */
5
6 #define DT_DRV_COMPAT ite_it8xxx2_watchdog
7
8 #include <zephyr/drivers/watchdog.h>
9 #include <zephyr/irq.h>
10 #include <errno.h>
11 #include <soc.h>
12
13 #include <zephyr/logging/log.h>
14 #define LOG_LEVEL CONFIG_WDT_LOG_LEVEL
15 LOG_MODULE_REGISTER(wdt_ite_it8xxx2);
16
17 #define IT8XXX2_WATCHDOG_MAGIC_BYTE 0x5c
18 #define WARNING_TIMER_PERIOD_MS_TO_1024HZ_COUNT(ms) ((ms) * 1024 / 1000)
19
20 /* enter critical period or not */
21 static int wdt_warning_fired;
22
23 /* device config */
24 struct wdt_it8xxx2_config {
25 /* wdt register base address */
26 struct wdt_it8xxx2_regs *base;
27 };
28
29 /* driver data */
30 struct wdt_it8xxx2_data {
31 /* timeout callback used to handle watchdog event */
32 wdt_callback_t callback;
33 /* indicate whether a watchdog timeout is installed */
34 bool timeout_installed;
35 /* watchdog feed timeout in milliseconds */
36 uint32_t timeout;
37 };
38
wdt_it8xxx2_install_timeout(const struct device * dev,const struct wdt_timeout_cfg * config)39 static int wdt_it8xxx2_install_timeout(const struct device *dev,
40 const struct wdt_timeout_cfg *config)
41 {
42 const struct wdt_it8xxx2_config *const wdt_config = dev->config;
43 struct wdt_it8xxx2_data *data = dev->data;
44 struct wdt_it8xxx2_regs *const inst = wdt_config->base;
45
46 /* if watchdog is already running */
47 if ((inst->ETWCFG) & IT8XXX2_WDT_LEWDCNTL) {
48 return -EBUSY;
49 }
50
51 /*
52 * Not support lower limit window timeouts (min value must be equal to
53 * 0). Upper limit window timeouts can't be 0 when we install timeout.
54 */
55 if ((config->window.min != 0) || (config->window.max == 0)) {
56 data->timeout_installed = false;
57 return -EINVAL;
58 }
59
60 /* save watchdog timeout */
61 data->timeout = config->window.max;
62
63 /* install user timeout isr */
64 data->callback = config->callback;
65
66 /* mark installed */
67 data->timeout_installed = true;
68
69 return 0;
70 }
71
wdt_it8xxx2_setup(const struct device * dev,uint8_t options)72 static int wdt_it8xxx2_setup(const struct device *dev, uint8_t options)
73 {
74 const struct wdt_it8xxx2_config *const wdt_config = dev->config;
75 struct wdt_it8xxx2_data *data = dev->data;
76 struct wdt_it8xxx2_regs *const inst = wdt_config->base;
77 uint16_t cnt0 = WARNING_TIMER_PERIOD_MS_TO_1024HZ_COUNT(data->timeout);
78 uint16_t cnt1 = WARNING_TIMER_PERIOD_MS_TO_1024HZ_COUNT((data->timeout
79 + CONFIG_WDT_ITE_WARNING_LEADING_TIME_MS));
80
81 /* disable pre-warning timer1 interrupt */
82 irq_disable(DT_INST_IRQN(0));
83
84 if (!data->timeout_installed) {
85 LOG_ERR("No valid WDT timeout installed");
86 return -EINVAL;
87 }
88
89 if ((inst->ETWCFG) & IT8XXX2_WDT_LEWDCNTL) {
90 LOG_ERR("WDT is already running");
91 return -EBUSY;
92 }
93
94 if ((options & WDT_OPT_PAUSE_IN_SLEEP) != 0) {
95 LOG_ERR("WDT_OPT_PAUSE_IN_SLEEP is not supported");
96 return -ENOTSUP;
97 }
98
99 /* pre-warning timer1 is 16-bit counter down timer */
100 inst->ET1CNTLHR = (cnt0 >> 8) & 0xff;
101 inst->ET1CNTLLR = cnt0 & 0xff;
102
103 /* clear pre-warning timer1 interrupt status */
104 ite_intc_isr_clear(DT_INST_IRQN(0));
105
106 /* enable pre-warning timer1 interrupt */
107 irq_enable(DT_INST_IRQN(0));
108
109 /* don't stop watchdog timer counting */
110 inst->ETWCTRL &= ~IT8XXX2_WDT_EWDSCEN;
111
112 /* set watchdog timer count */
113 inst->EWDCNTHR = (cnt1 >> 8) & 0xff;
114 inst->EWDCNTLR = cnt1 & 0xff;
115
116 /* allow to write timer1 count register */
117 inst->ETWCFG &= ~IT8XXX2_WDT_LET1CNTL;
118
119 /*
120 * bit5 = 1: enable key match function to touch watchdog
121 * bit4 = 1: select watchdog clock source from prescaler
122 * bit3 = 1: lock watchdog count register (also mark as watchdog running)
123 * bit1 = 1: lock timer1 prescaler register
124 */
125 inst->ETWCFG = (IT8XXX2_WDT_EWDKEYEN |
126 IT8XXX2_WDT_EWDSRC |
127 IT8XXX2_WDT_LEWDCNTL |
128 IT8XXX2_WDT_LET1PS);
129
130 LOG_DBG("WDT Setup and enabled");
131
132 return 0;
133 }
134
135 /*
136 * reload the WDT and pre-warning timer1 counter
137 *
138 * @param dev Pointer to the device structure for the driver instance.
139 * @param channel_id Index of the fed channel, and we only support
140 * channel_id = 0 now.
141 */
wdt_it8xxx2_feed(const struct device * dev,int channel_id)142 static int wdt_it8xxx2_feed(const struct device *dev, int channel_id)
143 {
144 const struct wdt_it8xxx2_config *const wdt_config = dev->config;
145 struct wdt_it8xxx2_data *data = dev->data;
146 struct wdt_it8xxx2_regs *const inst = wdt_config->base;
147 uint16_t cnt0 = WARNING_TIMER_PERIOD_MS_TO_1024HZ_COUNT(data->timeout);
148
149 ARG_UNUSED(channel_id);
150
151 /* reset pre-warning timer1 */
152 inst->ETWCTRL |= IT8XXX2_WDT_ET1RST;
153
154 /* restart watchdog timer */
155 inst->EWDKEYR = IT8XXX2_WATCHDOG_MAGIC_BYTE;
156
157 /* reset pre-warning timer1 to default if time is touched */
158 if (wdt_warning_fired) {
159 wdt_warning_fired = 0;
160
161 /* pre-warning timer1 is 16-bit counter down timer */
162 inst->ET1CNTLHR = (cnt0 >> 8) & 0xff;
163 inst->ET1CNTLLR = cnt0 & 0xff;
164
165 /* clear timer1 interrupt status */
166 ite_intc_isr_clear(DT_INST_IRQN(0));
167
168 /* enable timer1 interrupt */
169 irq_enable(DT_INST_IRQN(0));
170 }
171
172 LOG_DBG("WDT Kicking");
173
174 return 0;
175 }
176
wdt_it8xxx2_disable(const struct device * dev)177 static int wdt_it8xxx2_disable(const struct device *dev)
178 {
179 const struct wdt_it8xxx2_config *const wdt_config = dev->config;
180 struct wdt_it8xxx2_data *data = dev->data;
181 struct wdt_it8xxx2_regs *const inst = wdt_config->base;
182
183 /* stop watchdog timer counting */
184 inst->ETWCTRL |= IT8XXX2_WDT_EWDSCEN;
185
186 /* unlock watchdog count register (also mark as watchdog not running) */
187 inst->ETWCFG &= ~IT8XXX2_WDT_LEWDCNTL;
188
189 /* disable pre-warning timer1 interrupt */
190 irq_disable(DT_INST_IRQN(0));
191
192 /* mark uninstalled */
193 data->timeout_installed = false;
194
195 LOG_DBG("WDT Disabled");
196
197 return 0;
198 }
199
wdt_it8xxx2_isr(const struct device * dev)200 static void wdt_it8xxx2_isr(const struct device *dev)
201 {
202 const struct wdt_it8xxx2_config *const wdt_config = dev->config;
203 struct wdt_it8xxx2_data *data = dev->data;
204 struct wdt_it8xxx2_regs *const inst = wdt_config->base;
205
206 /* clear pre-warning timer1 interrupt status */
207 ite_intc_isr_clear(DT_INST_IRQN(0));
208
209 /* reset pre-warning timer1 */
210 inst->ETWCTRL |= IT8XXX2_WDT_ET1RST;
211
212 /* callback function, ex. print warning message */
213 if (data->callback) {
214 data->callback(dev, 0);
215 }
216
217 if (IS_ENABLED(CONFIG_WDT_ITE_REDUCE_WARNING_LEADING_TIME)) {
218 /*
219 * Once warning timer triggered: if watchdog timer isn't reloaded,
220 * then we will reduce interval of warning timer to 30ms to print
221 * more warning messages before watchdog reset.
222 */
223 if (!wdt_warning_fired) {
224 uint16_t cnt0 = WARNING_TIMER_PERIOD_MS_TO_1024HZ_COUNT(30);
225
226 /* pre-warning timer1 is 16-bit counter down timer */
227 inst->ET1CNTLHR = (cnt0 >> 8) & 0xff;
228 inst->ET1CNTLLR = cnt0 & 0xff;
229
230 /* clear pre-warning timer1 interrupt status */
231 ite_intc_isr_clear(DT_INST_IRQN(0));
232 }
233 }
234 wdt_warning_fired++;
235
236 LOG_DBG("WDT ISR");
237 }
238
239 static const struct wdt_driver_api wdt_it8xxx2_api = {
240 .setup = wdt_it8xxx2_setup,
241 .disable = wdt_it8xxx2_disable,
242 .install_timeout = wdt_it8xxx2_install_timeout,
243 .feed = wdt_it8xxx2_feed,
244 };
245
wdt_it8xxx2_init(const struct device * dev)246 static int wdt_it8xxx2_init(const struct device *dev)
247 {
248 const struct wdt_it8xxx2_config *const wdt_config = dev->config;
249 struct wdt_it8xxx2_regs *const inst = wdt_config->base;
250
251 if (IS_ENABLED(CONFIG_WDT_DISABLE_AT_BOOT)) {
252 wdt_it8xxx2_disable(dev);
253 }
254
255 /* unlock access to watchdog registers */
256 inst->ETWCFG = 0x00;
257
258 /* set WDT and timer1 to use 1.024kHz clock */
259 inst->ET1PSR = IT8XXX2_WDT_ETPS_1P024_KHZ;
260
261 /* set WDT key match enabled and WDT clock to use ET1PSR */
262 inst->ETWCFG = (IT8XXX2_WDT_EWDKEYEN |
263 IT8XXX2_WDT_EWDSRC);
264
265 /*
266 * select the mode that watchdog can be stopped, this is needed for
267 * wdt_it8xxx2_disable() api and WDT_OPT_PAUSE_HALTED_BY_DBG flag
268 */
269 inst->ETWCTRL |= IT8XXX2_WDT_EWDSCMS;
270
271 IRQ_CONNECT(DT_INST_IRQN(0), 0, wdt_it8xxx2_isr,
272 DEVICE_DT_INST_GET(0), 0);
273 return 0;
274 }
275
276 static const struct wdt_it8xxx2_config wdt_it8xxx2_cfg_0 = {
277 .base = (struct wdt_it8xxx2_regs *)DT_INST_REG_ADDR(0),
278 };
279
280 static struct wdt_it8xxx2_data wdt_it8xxx2_dev_data;
281
282 DEVICE_DT_INST_DEFINE(0, wdt_it8xxx2_init, NULL,
283 &wdt_it8xxx2_dev_data, &wdt_it8xxx2_cfg_0,
284 PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT,
285 &wdt_it8xxx2_api);
286
