1 /**
2  * \file
3  *
4  * \brief Sleep manager
5  *
6  * Copyright (c) 2010-2016 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 #ifndef SLEEPMGR_H
47 #define SLEEPMGR_H
48 
49 #include <compiler.h>
50 #include <parts.h>
51 
52 #if (SAM3S || SAM3U || SAM3N || SAM3XA || SAM4S || SAM4E || SAM4N || SAM4C || SAMG || SAM4CP || SAM4CM || SAMV71 || SAMV70 || SAMS70 || SAME70)
53 # include "sam/sleepmgr.h"
54 #elif XMEGA
55 # include "xmega/sleepmgr.h"
56 #elif UC3
57 # include "uc3/sleepmgr.h"
58 #elif SAM4L
59 # include "sam4l/sleepmgr.h"
60 #elif MEGA
61 # include "mega/sleepmgr.h"
62 #elif (SAMD20 || SAMD21 || SAMR21 || SAMD11 || SAMDA1)
63 # include "samd/sleepmgr.h"
64 #elif (SAML21 || SAML22 || SAMR30)
65 # include "saml/sleepmgr.h"
66 #elif (SAMC21)
67 # include "samc/sleepmgr.h"
68 #else
69 # error Unsupported device.
70 #endif
71 
72 #ifdef __cplusplus
73 extern "C" {
74 #endif
75 
76 /**
77  * \defgroup sleepmgr_group Sleep manager
78  *
79  * The sleep manager is a service for ensuring that the device is not put to
80  * sleep in deeper sleep modes than the system (e.g., peripheral drivers,
81  * services or the application) allows at any given time.
82  *
83  * It is based on the use of lock counting for the individual sleep modes, and
84  * will put the device to sleep in the shallowest sleep mode that has a non-zero
85  * lock count. The drivers/services/application can change these counts by use
86  * of \ref sleepmgr_lock_mode and \ref sleepmgr_unlock_mode.
87  * Refer to \ref sleepmgr_mode for a list of the sleep modes available for
88  * locking, and the device datasheet for information on their effect.
89  *
90  * The application must supply the file \ref conf_sleepmgr.h.
91  *
92  * For the sleep manager to be enabled, the symbol \ref CONFIG_SLEEPMGR_ENABLE
93  * must be defined, e.g., in \ref conf_sleepmgr.h. If this symbol is not
94  * defined, the functions are replaced with dummy functions and no RAM is used.
95  *
96  * @{
97  */
98 
99 /**
100  * \def CONFIG_SLEEPMGR_ENABLE
101  * \brief Configuration symbol for enabling the sleep manager
102  *
103  * If this symbol is not defined, the functions of this service are replaced
104  * with dummy functions. This is useful for reducing code size and execution
105  * time if the sleep manager is not needed in the application.
106  *
107  * This symbol may be defined in \ref conf_sleepmgr.h.
108  */
109 #if defined(__DOXYGEN__) && !defined(CONFIG_SLEEPMGR_ENABLE)
110 #  define CONFIG_SLEEPMGR_ENABLE
111 #endif
112 
113 /**
114  * \enum sleepmgr_mode
115  * \brief Sleep mode locks
116  *
117  * Identifiers for the different sleep mode locks.
118  */
119 
120 /**
121  * \brief Initialize the lock counts
122  *
123  * Sets all lock counts to 0, except the very last one, which is set to 1. This
124  * is done to simplify the algorithm for finding the deepest allowable sleep
125  * mode in \ref sleepmgr_enter_sleep.
126  */
sleepmgr_init(void)127 static inline void sleepmgr_init(void)
128 {
129 #ifdef CONFIG_SLEEPMGR_ENABLE
130 	uint8_t i;
131 
132 	for (i = 0; i < SLEEPMGR_NR_OF_MODES - 1; i++) {
133 		sleepmgr_locks[i] = 0;
134 	}
135 	sleepmgr_locks[SLEEPMGR_NR_OF_MODES - 1] = 1;
136 #endif /* CONFIG_SLEEPMGR_ENABLE */
137 }
138 
139 /**
140  * \brief Increase lock count for a sleep mode
141  *
142  * Increases the lock count for \a mode to ensure that the sleep manager does
143  * not put the device to sleep in the deeper sleep modes.
144  *
145  * \param mode Sleep mode to lock.
146  */
sleepmgr_lock_mode(enum sleepmgr_mode mode)147 static inline void sleepmgr_lock_mode(enum sleepmgr_mode mode)
148 {
149 #ifdef CONFIG_SLEEPMGR_ENABLE
150 	irqflags_t flags;
151 
152 	if(sleepmgr_locks[mode] >= 0xff) {
153 		while (true) {
154 			// Warning: maximum value of sleepmgr_locks buffer is no more than 255.
155 			// Check APP or change the data type to uint16_t.
156 		}
157 	}
158 
159 	// Enter a critical section
160 	flags = cpu_irq_save();
161 
162 	++sleepmgr_locks[mode];
163 
164 	// Leave the critical section
165 	cpu_irq_restore(flags);
166 #else
167 	UNUSED(mode);
168 #endif /* CONFIG_SLEEPMGR_ENABLE */
169 }
170 
171 /**
172  * \brief Decrease lock count for a sleep mode
173  *
174  * Decreases the lock count for \a mode. If the lock count reaches 0, the sleep
175  * manager can put the device to sleep in the deeper sleep modes.
176  *
177  * \param mode Sleep mode to unlock.
178  */
sleepmgr_unlock_mode(enum sleepmgr_mode mode)179 static inline void sleepmgr_unlock_mode(enum sleepmgr_mode mode)
180 {
181 #ifdef CONFIG_SLEEPMGR_ENABLE
182 	irqflags_t flags;
183 
184 	if(sleepmgr_locks[mode] == 0) {
185 		while (true) {
186 			// Warning: minimum value of sleepmgr_locks buffer is no less than 0.
187 			// Check APP.
188 		}
189 	}
190 
191 	// Enter a critical section
192 	flags = cpu_irq_save();
193 
194 	--sleepmgr_locks[mode];
195 
196 	// Leave the critical section
197 	cpu_irq_restore(flags);
198 #else
199 	UNUSED(mode);
200 #endif /* CONFIG_SLEEPMGR_ENABLE */
201 }
202 
203  /**
204  * \brief Retrieves the deepest allowable sleep mode
205  *
206  * Searches through the sleep mode lock counts, starting at the shallowest sleep
207  * mode, until the first non-zero lock count is found. The deepest allowable
208  * sleep mode is then returned.
209  */
sleepmgr_get_sleep_mode(void)210 static inline enum sleepmgr_mode sleepmgr_get_sleep_mode(void)
211 {
212 	enum sleepmgr_mode sleep_mode = SLEEPMGR_ACTIVE;
213 
214 #ifdef CONFIG_SLEEPMGR_ENABLE
215 	uint8_t *lock_ptr = sleepmgr_locks;
216 
217 	// Find first non-zero lock count, starting with the shallowest modes.
218 	while (!(*lock_ptr)) {
219 		lock_ptr++;
220 		sleep_mode = (enum sleepmgr_mode)(sleep_mode + 1);
221 	}
222 
223 	// Catch the case where one too many sleepmgr_unlock_mode() call has been
224 	// performed on the deepest sleep mode.
225 	Assert((uintptr_t)(lock_ptr - sleepmgr_locks) < SLEEPMGR_NR_OF_MODES);
226 
227 #endif /* CONFIG_SLEEPMGR_ENABLE */
228 
229 	return sleep_mode;
230 }
231 
232 /**
233  * \fn sleepmgr_enter_sleep
234  * \brief Go to sleep in the deepest allowed mode
235  *
236  * Searches through the sleep mode lock counts, starting at the shallowest sleep
237  * mode, until the first non-zero lock count is found. The device is then put to
238  * sleep in the sleep mode that corresponds to the lock.
239  *
240  * \note This function enables interrupts before going to sleep, and will leave
241  * them enabled upon return. This also applies if sleep is skipped due to ACTIVE
242  * mode being locked.
243  */
244 
sleepmgr_enter_sleep(void)245 static inline void sleepmgr_enter_sleep(void)
246 {
247 #ifdef CONFIG_SLEEPMGR_ENABLE
248 	enum sleepmgr_mode sleep_mode;
249 
250 	cpu_irq_disable();
251 
252 	// Find the deepest allowable sleep mode
253 	sleep_mode = sleepmgr_get_sleep_mode();
254 	// Return right away if first mode (ACTIVE) is locked.
255 	if (sleep_mode==SLEEPMGR_ACTIVE) {
256 		cpu_irq_enable();
257 		return;
258 	}
259 	// Enter the deepest allowable sleep mode with interrupts enabled
260 	sleepmgr_sleep(sleep_mode);
261 #else
262 	cpu_irq_enable();
263 #endif /* CONFIG_SLEEPMGR_ENABLE */
264 }
265 
266 
267 //! @}
268 
269 #ifdef __cplusplus
270 }
271 #endif
272 
273 #endif /* SLEEPMGR_H */
274