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
|
/******************************************************************************
* The MIT License
*
* Copyright (c) 2012 LeafLabs, LLC.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*****************************************************************************/
/**
* @file libmaple/stm32f2-f4/usart.c
* @author Marti Bolivar <mbolivar@leaflabs.com>
* @brief STM32F2 USART.
*/
#include <libmaple/usart.h>
#include <libmaple/gpio.h>
#include "usart_private.h"
/*
* Devices
*/
static ring_buffer usart1_rb;
static usart_dev usart1 = {
.regs = USART1_BASE,
.rb = &usart1_rb,
.max_baud = 4500000UL, /* TODO: are these correct? 5250000UL for STM32F4? */
.clk_id = RCC_USART1,
.irq_num = NVIC_USART1,
};
/** USART1 device */
usart_dev *USART1 = &usart1;
static ring_buffer usart2_rb;
static usart_dev usart2 = {
.regs = USART2_BASE,
.rb = &usart2_rb,
.max_baud = 2250000UL, /* TODO: are these correct? 2620000UL for STM32F4? */
.clk_id = RCC_USART2,
.irq_num = NVIC_USART2,
};
/** USART2 device */
usart_dev *USART2 = &usart2;
static ring_buffer usart3_rb;
static usart_dev usart3 = {
.regs = USART3_BASE,
.rb = &usart3_rb,
.max_baud = 2250000UL, /* TODO: are these correct? */
.clk_id = RCC_USART3,
.irq_num = NVIC_USART3,
};
/** USART3 device */
usart_dev *USART3 = &usart3;
static ring_buffer uart4_rb;
static usart_dev uart4 = {
.regs = UART4_BASE,
.rb = &uart4_rb,
.max_baud = 2250000UL, /* TODO: are these correct? */
.clk_id = RCC_UART4,
.irq_num = NVIC_UART4,
};
/** UART4 device */
usart_dev *UART4 = &uart4;
static ring_buffer uart5_rb;
static usart_dev uart5 = {
.regs = UART5_BASE,
.rb = &uart5_rb,
.max_baud = 2250000UL, /* TODO: are these correct? */
.clk_id = RCC_UART5,
.irq_num = NVIC_UART5,
};
/** UART5 device */
usart_dev *UART5 = &uart5;
static ring_buffer usart6_rb;
static usart_dev usart6 = {
.regs = USART6_BASE,
.rb = &usart6_rb,
.max_baud = 4500000UL, /* TODO: are these correct? 5250000UL for STM32F4? */
.clk_id = RCC_USART6,
.irq_num = NVIC_USART6,
};
usart_dev *USART6 = &usart6;
/*
* Routines
*/
void usart_config_gpios_async(usart_dev *udev,
gpio_dev *rx_dev, uint8 rx,
gpio_dev *tx_dev, uint8 tx,
unsigned flags) {
gpio_af af = usart_get_af(udev);
gpio_set_modef(rx_dev, rx, GPIO_MODE_AF, 0);
gpio_set_modef(tx_dev, tx, GPIO_MODE_AF, 0);
gpio_set_af(rx_dev, rx, af);
gpio_set_af(tx_dev, tx, af);
}
void usart_set_baud_rate(usart_dev *dev, uint32 clock_speed, uint32 baud) {
uint32 integer_part;
uint32 fractional_part;
uint32 tmp;
uint32 over8 = !!(dev->regs->CR1 & USART_CR1_OVER8);
ASSERT(!over8); /* OVER8 is currently unsupported. */
/* Figure out the clock speed, if the user doesn't give one. */
if (clock_speed == 0) {
clock_speed = _usart_clock_freq(dev);
}
ASSERT(clock_speed);
/* Convert desired baud rate to baud rate register setting. */
integer_part = (25 * clock_speed) / (2 * (2 - over8) * baud);
tmp = (integer_part / 100) << 4;
fractional_part = integer_part - (100 * (tmp >> 4));
tmp |= ((fractional_part * 16 + 50) / 100) & (uint8)0x0F;
dev->regs->BRR = tmp;
}
/**
* @brief Call a function on each USART.
* @param fn Function to call.
*/
void usart_foreach(void (*fn)(usart_dev*)) {
fn(USART1);
fn(USART2);
fn(USART3);
fn(UART4);
fn(UART5);
fn(USART6);
}
/**
* @brief Get GPIO alternate function mode for a USART.
* @param dev USART whose gpio_af to get.
* @return gpio_af corresponding to dev.
*/
gpio_af usart_get_af(usart_dev *dev) {
switch (dev->clk_id) {
case RCC_USART1:
case RCC_USART2:
case RCC_USART3:
return GPIO_AF_USART_1_2_3;
case RCC_UART4:
case RCC_UART5:
case RCC_USART6:
return GPIO_AF_USART_4_5_6;
default:
ASSERT(0); /* Can't happen */
return (gpio_af)-1;
}
}
/*
* Interrupt handlers.
*/
void __irq_usart1(void) {
usart_irq(&usart1_rb, USART1_BASE);
}
void __irq_usart2(void) {
usart_irq(&usart2_rb, USART2_BASE);
}
void __irq_usart3(void) {
usart_irq(&usart3_rb, USART3_BASE);
}
void __irq_uart4(void) {
usart_irq(&uart4_rb, UART4_BASE);
}
void __irq_uart5(void) {
usart_irq(&uart5_rb, UART5_BASE);
}
void __irq_usart6(void) {
usart_irq(&usart6_rb, USART6_BASE);
}
|
