blob: ea1b4a4c6ace15d5da990ed3d769932d80fcf702 (
plain)
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
|
/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Interrupt based USART RX driver for STM32 */
#include "usart.h"
#include "atomic.h"
#include "common.h"
#include "queue.h"
#include "registers.h"
static void usart_rx_init(struct usart_config const *config)
{
intptr_t base = config->hw->base;
STM32_USART_CR1(base) |= STM32_USART_CR1_RXNEIE;
STM32_USART_CR1(base) |= STM32_USART_CR1_RE;
}
static void usart_rx_interrupt_handler(struct usart_config const *config)
{
intptr_t base = config->hw->base;
uint8_t byte;
if (!(STM32_USART_SR(base) & STM32_USART_SR_RXNE))
return;
byte = STM32_USART_RDR(base);
if (!queue_add_unit(config->producer.queue, &byte))
atomic_add(&config->state->rx_dropped, 1);
}
struct usart_rx const usart_rx_interrupt = {
.producer_ops = {
/*
* Nothing to do here, we either had enough space in the queue
* when a character came in or we dropped it already.
*/
.read = NULL,
},
.init = usart_rx_init,
.interrupt = usart_rx_interrupt_handler,
};
|
