pwm.c
3.76 KB
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
/*
* Copyright (C) 2014 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup lpc2387
* @{
*
* @file
* @brief CPU specific low-level PWM driver implementation for the LPC2387
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*
* @}
*/
#include "bitarithm.h"
#include "lpc2387.h"
#include "periph_conf.h"
/* guard file in case no PWM device is defined */
#if (PWM_0_EN || PWM_1_EN)
/* pull the PWM header inside the guards for now. Guards will be removed on
* adapting this driver implementation... */
#include "periph/pwm.h"
/**
* @note The PWM is always initialized with left-aligned mode.
*
* TODO: add center and right aligned modes
*/
uint32_t pwm_init(pwm_t dev, pwm_mode_t mode, uint32_t freq, uint16_t res)
{
(void) mode; /* unused */
switch (dev) {
#if PWM_0_EN
case PWM_0:
/* select function PWM[3] for pins */
PWM_0_PORT &= ~((3 << PWM_0_CH0_PIN * 2) |
(3 << PWM_0_CH1_PIN * 2) |
(3 << PWM_0_CH2_PIN * 2));
PWM_0_PORT |= (PWM_0_FUNC << PWM_0_CH0_PIN * 2) |
(PWM_0_FUNC << PWM_0_CH1_PIN * 2) |
(PWM_0_FUNC << PWM_0_CH2_PIN * 2);
/* power on PWM1 */
pwm_poweron(dev);
/* select PWM1 clock */
PCLKSEL0 &= ~(BIT13);
PCLKSEL0 |= (BIT12);
/* reset PWM1s counter */
PWM1TCR = BIT1;
/* set prescaler */
PWM1PR = (CLOCK_CORECLOCK / (freq * res)) - 1;
/* set match register */
PWM1MR0 = res;
PWM_0_CH0_MR = 0;
PWM_0_CH1_MR = 0;
PWM_0_CH2_MR = 0;
/* reset timer counter on MR0 match */
PWM1MCR = BIT1;
/* enable PWM1 channel 3, 4 and 5 */
PWM1PCR = (1 << (8 + PWM_0_CH0)) | (1 << (8 + PWM_0_CH1)) | (1 << (8 + PWM_0_CH2));
/* enable PWM1 timer in PWM mode */
PWM1TCR = BIT0 + BIT3;
/* update match registers */
PWM1LER = BIT0 | (1 << PWM_0_CH0) | (1 << PWM_0_CH1) | (1 << PWM_0_CH2);
break;
#endif
default:
return 0;
}
return freq;
}
uint8_t pwm_channels(pwm_t dev)
{
if (dev == PWM_0) {
return PWM_0_CHANNELS;
}
return 0;
}
void pwm_set(pwm_t dev, uint8_t channel, uint16_t value)
{
switch (dev) {
#if PWM_0_EN
case PWM_0:
switch (channel) {
case 0:
PWM_0_CH0_MR = value;
PWM1LER |= (1 << PWM_0_CH0);
break;
case 1:
PWM_0_CH1_MR = value;
PWM1LER |= (1 << PWM_0_CH1);
break;
case 2:
PWM_0_CH2_MR = value;
PWM1LER |= (1 << PWM_0_CH2);
break;
default:
return;
break;
}
break;
#endif
}
}
void pwm_start(pwm_t dev)
{
switch (dev) {
#if PWM_0_EN
case PWM_0:
PWM1TCR |= BIT0;
break;
#endif
}
}
void pwm_stop(pwm_t dev)
{
switch (dev) {
#if PWM_0_EN
case PWM_0:
PWM1TCR &= ~(BIT0);
break;
#endif
}
}
void pwm_poweron(pwm_t dev)
{
switch (dev) {
#if PWM_0_EN
case PWM_0:
PCONP |= PCPWM1;
break;
#endif
}
}
void pwm_poweroff(pwm_t dev)
{
switch (dev) {
#if PWM_0_EN
case PWM_0:
PCONP &= ~(PCPWM1);
break;
#endif
}
}
#endif /* (PWM_0_EN || PWM_1_EN) */