1 /**
2  * \file
3  *
4  * \brief SAM Watchdog Driver for SAMB
5  *
6  * Copyright (C) 2015 Atmel Corporation. All rights reserved.
7  *
8  * \asf_license_start
9  *
10  * \page License
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions are met:
14  *
15  * 1. Redistributions of source code must retain the above copyright notice,
16  *    this list of conditions and the following disclaimer.
17  *
18  * 2. Redistributions in binary form must reproduce the above copyright notice,
19  *    this list of conditions and the following disclaimer in the documentation
20  *    and/or other materials provided with the distribution.
21  *
22  * 3. The name of Atmel may not be used to endorse or promote products derived
23  *    from this software without specific prior written permission.
24  *
25  * 4. This software may only be redistributed and used in connection with an
26  *    Atmel microcontroller product.
27  *
28  * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
29  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
30  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
31  * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
32  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
36  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38  * POSSIBILITY OF SUCH DAMAGE.
39  *
40  * \asf_license_stop
41  *
42  */
43 /*
44  * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
45  */
46 #include "wdt_sam_b.h"
47 
48 struct wdt_module *_wdt_instances[WDT_INST_NUM];
49 
wdt_isr_handler(void)50 static void wdt_isr_handler(void)
51 {
52 	struct wdt_module *module = NULL;
53 
54 	if (WDT0->WDOGMIS.reg) {
55 		module = _wdt_instances[0];
56 		if (!(module->hw->WDOGCONTROL.reg & WDT_WDOGCONTROL_RESEN)) {
57 			module->hw->WDOGINTCLR.reg = 0x01;
58 		}
59 		if ((module->callback_enable_mask & (1 << WDT_CALLBACK_EARLY_WARNING)) &&
60 			(module->callback_reg_mask & (1 << WDT_CALLBACK_EARLY_WARNING))) {
61 			(module->callback[WDT_CALLBACK_EARLY_WARNING])();
62 		}
63 	}
64 	if (WDT1->WDOGMIS.reg) {
65 		module = _wdt_instances[1];
66 		if (!(module->hw->WDOGCONTROL.reg & WDT_WDOGCONTROL_RESEN)) {
67 			module->hw->WDOGINTCLR.reg = 0x01;
68 		}
69 		if ((module->callback_enable_mask & (1 << WDT_CALLBACK_EARLY_WARNING)) &&
70 			(module->callback_reg_mask & (1 << WDT_CALLBACK_EARLY_WARNING))) {
71 			(module->callback[WDT_CALLBACK_EARLY_WARNING])();
72 		}
73 	}
74 }
75 
76 /**
77  * \brief Initializes a Watchdog Timer configuration structure to defaults.
78  *
79  *  Initializes a given Watchdog Timer configuration structure to a set of
80  *  known default values. This function should be called on all new
81  *  instances of these configuration structures before being modified by the
82  *  user application.
83  *
84  *  The default configuration is as follows:
85  *   \li Load register value
86  *   \li Enable reset output
87  *   \li Open write access
88  *
89  *  \param[out] config  Configuration structure to initialize to default values
90  */
wdt_get_config_defaults(struct wdt_config * const config)91 void wdt_get_config_defaults(struct wdt_config *const config)
92 {
93 	/* Sanity check arguments */
94 	Assert(config);
95 
96 	config->load_value = 0xFFFFFFFF;
97 	config->enable_reset = true;
98 	config->write_access = true;
99 }
100 
101 /**
102  * \brief Sets up the WDT hardware module based on the configuration.
103  *
104  * Writes a given configuration of a WDT configuration to the
105  * hardware module, and initializes the internal device struct.
106  *
107  * \param[in]  module  Pointer to the software instance struct
108  * \param[in]  hw      Pointer to WDT hardware instance
109  * \param[in]  config  Pointer to configuration struct
110  *
111  * \return Status of the initialization.
112  *
113  * \retval STATUS_OK            The initialization was successful
114  * \retval STATUS_ERR_BAD_DATA  If the value isn't available
115  */
wdt_set_config(struct wdt_module * const module,Wdt * const hw,const struct wdt_config * const config)116 enum status_code wdt_set_config(struct wdt_module *const module, Wdt * const hw,
117 		const struct wdt_config *const config)
118 {
119 	/* Sanity check arguments */
120 	Assert(module);
121 	Assert(hw);
122 	Assert(config);
123 
124 	/* Assign module pointer to software instance struct */
125 	module->hw = hw;
126 
127 	if (config->load_value == 0) {
128 		return STATUS_ERR_BAD_DATA;
129 	}
130 
131 	if (module->hw == WDT0) {
132 		system_clock_peripheral_disable(PERIPHERAL_WDT0);
133 	} else if (module->hw ==WDT1) {
134 		system_clock_peripheral_disable(PERIPHERAL_WDT1);
135 	}
136 
137 	/* Unlock register */
138 	module->hw->WDOGLOCK.reg = WDT_WRITE_ACCESS_KEY;
139 
140 	module->hw->WDOGLOAD.reg = config->load_value;
141 
142 	if (config->enable_reset) {
143 		module->hw->WDOGCONTROL.reg |= WDT_WDOGCONTROL_RESEN;
144 	}
145 	module->hw->WDOGCONTROL.reg |= WDT_WDOGCONTROL_INTEN;
146 
147 	/* Lock register */
148 	if (config->write_access == false) {
149 		module->hw->WDOGLOCK.reg = WDT_WDOGLOCK_ENABLE_STATUS;
150 	}
151 
152 	system_register_isr(RAM_ISR_TABLE_NMI_INDEX, (uint32_t)wdt_isr_handler);
153 
154 	/* Enable WDT clock */
155 	if (module->hw == WDT0) {
156 		_wdt_instances[0] = module;
157 		system_clock_peripheral_enable(PERIPHERAL_WDT0);
158 	} else if (module->hw == WDT1) {
159 		_wdt_instances[1] = module;
160 		system_clock_peripheral_enable(PERIPHERAL_WDT1);
161 	}
162 
163 	return STATUS_OK;
164 }
165 
166 /**
167  * \brief Reset WDT module.
168  *
169  * Reset WDT module.
170  *
171  * \param[in]  module  Pointer to the software instance struct
172  */
wdt_reset(struct wdt_module * const module)173 void wdt_reset(struct wdt_module *const module)
174 {
175 	if (module->hw == WDT0) {
176 		system_peripheral_reset(PERIPHERAL_WDT0);
177 	} else if (module->hw == WDT1) {
178 		system_peripheral_reset(PERIPHERAL_WDT1);
179 	}
180 }
181 
182 /**
183  * \brief Get WDT interrupt status.
184  *
185  * Get WDT interrupt status.
186  *
187  * \param[in]  module  Pointer to the software instance struct
188  */
wdt_get_interrupt_status(struct wdt_module * const module)189 uint8_t wdt_get_interrupt_status(struct wdt_module *const module)
190 {
191 	return module->hw->WDOGMIS.reg;
192 }
193 
194 /**
195  * \brief Get WDT raw interrupt status.
196  *
197  * Get WDT raw interrupt status.
198  *
199  * \param[in]  module  Pointer to the software instance struct
200  */
wdt_get_status(struct wdt_module * const module)201 uint8_t wdt_get_status(struct wdt_module *const module)
202 {
203 	return module->hw->WDOGRIS.reg;
204 }
205 
206 /**
207  * \brief Clear WDT interrupt status.
208  *
209  * Clear WDT interrupt status.
210  *
211  * \param[in]  module  Pointer to the software instance struct
212  */
wdt_clear_status(struct wdt_module * const module)213 void wdt_clear_status(struct wdt_module *const module)
214 {
215 	module->hw->WDOGINTCLR.reg = 0x01;
216 }
217 
218 /**
219  * \brief Reload the count of the running Watchdog Timer.
220  *
221  * Reload the value of WDT Load register. When this register is written to,
222  * the count is immediately restarted from the new value.
223  *
224  * \param[in]  module      Pointer to the software instance struct
225  * \param[in]  load_value  Reload value
226  *
227  * \return Status of the operation.
228  * \retval STATUS_OK            If the operation was completed
229  * \retval STATUS_ERR_BAD_DATA  If the value isn't available
230  */
wdt_set_reload_count(struct wdt_module * const module,uint32_t load_value)231 enum status_code wdt_set_reload_count(struct wdt_module *const module, uint32_t load_value)
232 {
233 	if (load_value == 0) {
234 		return STATUS_ERR_BAD_DATA;
235 	} else {
236 		if (module->hw->WDOGLOCK.bit.ENABLE_STATUS) {
237 			module->hw->WDOGLOCK.reg = WDT_WRITE_ACCESS_KEY;
238 			module->hw->WDOGLOAD.reg = load_value;
239 			module->hw->WDOGLOCK.reg = WDT_WDOGLOCK_ENABLE_STATUS;
240 		} else {
241 			module->hw->WDOGLOAD.reg = load_value;
242 		}
243 	}
244 
245 	return STATUS_OK;
246 }
247 
248 /**
249  * \brief Get the current count value of the running Watchdog Timer.
250  *
251  * Get the current count value of the running Watchdog Timer.
252  *
253  * \param[in]      module       Pointer to the software instance struct
254  * \param[in,out]  count_value  Pointer to store the current count value
255  *
256  */
wdt_get_current_count(struct wdt_module * const module,uint32_t * count_value)257 void wdt_get_current_count(struct wdt_module *const module, \
258 			uint32_t * count_value)
259 {
260 	*count_value = module->hw->WDOGVALUE.reg;
261 }
262 
263 /**
264  * \brief Registers a callback
265  *
266  * Registers a callback function which is implemented by the user.
267  *
268  * \note The callback must be enabled by \ref wdt_enable_callback,
269  *       in order for the interrupt handler to call it when the conditions for
270  *       the callback type are met.
271  *
272  * \param[in]  module         Pointer to WDT software instance struct
273  * \param[in]  callback_func  Pointer to callback function
274  * \param[in]  callback_type  Callback type given by an enum
275  *
276  */
wdt_register_callback(struct wdt_module * const module,wdt_callback_t callback_func,enum wdt_callback callback_type)277 void wdt_register_callback(struct wdt_module *const module,
278 		wdt_callback_t callback_func,
279 		enum wdt_callback callback_type)
280 {
281 	/* Sanity check arguments */
282 	Assert(module);
283 	Assert(callback_func);
284 
285 	/* Register callback function */
286 	module->callback[callback_type] = callback_func;
287 	/* Set the bit corresponding to the callback_type */
288 	module->callback_reg_mask |= (1 << callback_type);
289 }
290 
291 /**
292  * \brief Unregisters a callback
293  *
294  * Unregisters a callback function which is implemented by the user.
295  *
296  * \param[in,out]  module         Pointer to WDT software instance struct
297  * \param[in]      callback_type  Callback type given by an enum
298  *
299  */
wdt_unregister_callback(struct wdt_module * module,enum wdt_callback callback_type)300 void wdt_unregister_callback(struct wdt_module *module,
301 		enum wdt_callback callback_type)
302 {
303 	/* Sanity check arguments */
304 	Assert(module);
305 
306 	/* Unregister callback function */
307 	module->callback[callback_type] = NULL;
308 	/* Clear the bit corresponding to the callback_type */
309 	module->callback_reg_mask &= ~(1 << callback_type);
310 }
311 
312 /**
313  * \brief Enables callback
314  *
315  * Enables the callback function registered by the \ref usart_register_callback.
316  * The callback function will be called from the interrupt handler when the
317  * conditions for the callback type are met.
318  *
319  * \param[in]  module         Pointer to WDT software instance struct
320  * \param[in]  callback_type  Callback type given by an enum
321  */
wdt_enable_callback(struct wdt_module * const module,enum wdt_callback callback_type)322 void wdt_enable_callback(struct wdt_module *const module,
323 		enum wdt_callback callback_type)
324 {
325 	/* Sanity check arguments */
326 	Assert(module);
327 
328 	/* Enable callback */
329 	module->callback_enable_mask |= (1 << callback_type);
330 }
331 
332 /**
333  * \brief Disable callback
334  *
335  * Disables the callback function registered by the \ref usart_register_callback,
336  * and the callback will not be called from the interrupt routine.
337  *
338  * \param[in]  module         Pointer to WDT software instance struct
339  * \param[in]  callback_type  Callback type given by an enum
340  */
wdt_disable_callback(struct wdt_module * const module,enum wdt_callback callback_type)341 void wdt_disable_callback(struct wdt_module *const module,
342 		enum wdt_callback callback_type)
343 {
344 	/* Sanity check arguments */
345 	Assert(module);
346 
347 	/* Disable callback */
348 	module->callback_enable_mask &= ~(1 << callback_type);
349 }