1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/*
* Copyright (c) 2011-2012, Freescale Semiconductor, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* o Neither the name of Freescale Semiconductor, Inc. nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
//! @addtogroup diag_gpt
//! @{
/*!
* @file gpt.h
* @brief GPT driver public interface.
*/
#ifndef __GPT_H__
#define __GPT_H__
#include "imx_timer.h"
#include "sdk.h"
////////////////////////////////////////////////////////////////////////////////
// Definitions
////////////////////////////////////////////////////////////////////////////////
//! @brief Possible events for the GPT.
//!
//! These constants are intended to be combined together to form a bitmask. Several
//! of the GPT driver APIs use such a bitmask. For instance, gpt_counter_enable()
//! accepts a bitmask that selects the events for which interrupts should be enabled.
//!
//! Note that the values of these enums happen to be the bitmasks for the respective
//! fields in the HW_GPT_SR and HW_GPT_IR registers, so a mask constructed from them
//! can be used directly with register values.
enum _gpt_events
{
kGPTNoEvent = 0, //!< No events enabled.
kGPTRollover = 1 << 5, //!< Rollover event.
kGPTInputCapture1 = 1 << 3, //!< Input capture 1 event.
kGPTInputCapture2 = 1 << 4, //!< Input capture 2 event.
kGPTOutputCompare1 = 1 << 0, //!< Output compare 1 event.
kGPTOutputCompare2 = 1 << 1, //!< Output compare 2 event.
kGPTOutputCompare3 = 1 << 2, //!< Output compare 3 event.
//! Combined mask of all GPT events.
kGPTAllEvents = kGPTRollover | kGPTInputCapture1 | kGPTInputCapture2
| kGPTOutputCompare1 | kGPTOutputCompare2 | kGPTOutputCompare3
};
//! @brief GPT counter modes.
enum _gpt_counter_mode
{
RESTART_MODE = 0,
FREE_RUN_MODE = 1
};
//! @brief Supported input capture modes.
enum _gpt_capture_modes
{
INPUT_CAP_DISABLE = 0, //!< input capture event disabled
INPUT_CAP_RISING_EDGE = 1, //!< input capture event on a rising edge
INPUT_CAP_FALLING_EDGE = 2, //!< input capture event on a falling edge
INPUT_CAP_BOTH_EDGE = 3 //!< input capture event on a both edge
};
//! @brief Supported output modes.
enum _gpt_compare_modes
{
OUTPUT_CMP_DISABLE = 0, //!< output disconnected from pad
OUTPUT_CMP_TOGGLE = 1, //!< output toggle mode
OUTPUT_CMP_CLEAR = 2, //!< output set low mode
OUTPUT_CMP_SET = 3, //!< output set high mode
OUTPUT_CMP_LOWPULSE = 4 //!< output set high mode
};
////////////////////////////////////////////////////////////////////////////////
// API
////////////////////////////////////////////////////////////////////////////////
#if defined(__cplusplus)
extern "C" {
#endif
/*!
* @brief Initialize the GPT timer.
*
* @param clock_src Source clock of the counter: CLKSRC_OFF, CLKSRC_IPG_CLK,
* CLKSRC_PER_CLK, CLKSRC_CKIL, CLKSRC_CLKIN.
* @param prescaler Prescaler of the source clock from 1 to 4096.
* @param counter_mode Counter mode: FREE_RUN_MODE or RESTART_MODE.
* @param low_power_mode Low power during which the timer is enabled:
* WAIT_MODE_EN and/or STOP_MODE_EN.
*/
void gpt_init(uint32_t clock_src, uint32_t prescaler, uint32_t counter_mode, uint32_t low_power_mode);
/*!
* @brief Setup GPT interrupt.
*
* It enables or disables the related HW module interrupt, and attached the
* related sub-routine into the vector table.
*
* @param irq_subroutine the GPT interrupt interrupt routine.
* @param enableIt Pass true to enable the interrupt.
*/
void gpt_setup_interrupt(void (*irq_subroutine)(void), bool enableIt);
/*!
* @brief Enable the GPT module.
*
* Used typically when the gpt_init is done, and other interrupt related settings are ready.
*
* If a value of #kGPTNoEvent is passed for @a irq_mode, then no interrupts will be enabled.
* This effectively puts the timer into polling mode, where you must call gpt_get_x_event()
* to check for an event having occurred.
*
* @param irq_mode Mask of events to enable interrupts for, such as #kGPTRollover or
* #kGPTOutputCompare1. See the #_gpt_events enum for the complete list. Pass
* #kGPTNoEvent to prevent any interrupts from being enabled, which effectively puts
* the timer into polling mode.
*/
void gpt_counter_enable(uint32_t irq_mode);
/*!
* @brief Disable the counter.
*
* It saves power when not used.
*
*/
void gpt_counter_disable(void);
/*!
* @brief Get rollover event flag and clear it if set.
*
* This function can typically be used for polling method, but
* is also used to clear the status compare flag in IRQ mode.
*
* @return Either 0 of kGPTRollover.
*/
uint32_t gpt_get_rollover_event(void);
/*!
* @brief Get a captured value when an event occured, and clear the flag if set.
*
* Use this function to check for an input capture event having occurred, either in
* the event ISR or to check manually in polling mode. Pass the input channel to check
* in the @a flag parameter. If that channel fired, its captured timer value will be
* read and placed in @a capture_val (if not NULL). The event that fired will be cleared
* and its event mask returned as the return value from the function. If no event
* occurred, the function returns 0.
*
* @param flag Which channel to check, either #kGPTInputCapture1 or #kGPTInputCapture2.
* Only one channel may be specified.
* @param capture_val The capture register value is returned through this parameter if
* the specified event occurred. May be NULL if not required.
* @return Mask of input specified capture event that occurred, or 0 if no event occurred.
*/
uint32_t gpt_get_capture_event(uint8_t flag, uint32_t * capture_val);
/*!
* @brief Set the input capture mode.
*
* @param cap_input The input capture channel to configure, either #kGPTInputCapture1
* or #kGPTInputCapture2.
* @param cap_input_mode Capture input mode: #INPUT_CAP_DISABLE, #INPUT_CAP_BOTH_EDGE,
* #INPUT_CAP_FALLING_EDGE, #INPUT_CAP_RISING_EDGE.
*/
void gpt_set_capture_event(uint8_t cap_input, uint8_t cap_input_mode);
/*!
* @brief Get a compare event flag and clear it if set.
*
* This function can typically be used for polling method, but
* is also used to clear the status compare flag in IRQ mode.
*
* @param flag Checked compare event flag such GPTSR_OF1, GPTSR_OF2, GPTSR_OF3.
* @return The value of the compare event flag.
*/
uint32_t gpt_get_compare_event(uint8_t flag);
/*!
* @brief Set a compare event by programming the compare register and
* compare output mode.
*
* @param cmp_output The channel to configure. Must be one of #kGPTOutputCompare1,
* #kGPTOutputCompare2, or #kGPTOutputCompare3.
* @param cmp_output_mode Compare output mode: #OUTPUT_CMP_DISABLE, #OUTPUT_CMP_TOGGLE,
* #OUTPUT_CMP_CLEAR, #OUTPUT_CMP_SET, #OUTPUT_CMP_LOWPULSE.
* @param cmp_value Compare value for the compare register.
*/
void gpt_set_compare_event(uint8_t cmp_output, uint8_t cmp_output_mode, uint32_t cmp_value);
#if defined(__cplusplus)
}
#endif
//! @}
#endif //__GPT_H__
////////////////////////////////////////////////////////////////////////////////
// EOF
////////////////////////////////////////////////////////////////////////////////
|
