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authorDrashna Jaelre <drashna@live.com>2020-02-21 02:32:30 -0800
committerDrashna Jael're <drashna@live.com>2020-03-26 00:42:12 -0700
commit283b18f3e0e4b56f5abff33934bfce1f7649220f (patch)
tree2f5583ef7c14a621e0abf5fea05ae1dd77617a43 /tmk_core
parent87ece02fa956119b73b4c64153403719e8baa3e1 (diff)
uart.c fix from TMK (#7628)
* uart.c fix from TMK Backport from tmk/tmk_keyboard@c41e48a0ab0712d2667feb6b5dd8a4d5491cfcc5 * Avoid deadlock when uart.c is usind in ISR Backport from tmk/tmk_keyboard@55443fabb731459e21b45781c6d951edac5d75f4 format code according to conventions [skip ci]
Diffstat (limited to 'tmk_core')
-rw-r--r--tmk_core/common/uart.c54
1 files changed, 44 insertions, 10 deletions
diff --git a/tmk_core/common/uart.c b/tmk_core/common/uart.c
index f2e4bc4f34..ccf7f7ff01 100644
--- a/tmk_core/common/uart.c
+++ b/tmk_core/common/uart.c
@@ -31,9 +31,41 @@
#include "uart.h"
+#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega168P__) || defined(__AVR_ATmega328P__)
+# define UDRn UDR0
+# define UBRRn UBRR0
+# define UCSRnA UCSR0A
+# define UCSRnB UCSR0B
+# define UCSRnC UCSR0C
+# define U2Xn U2X0
+# define RXENn RXEN0
+# define TXENn TXEN0
+# define RXCIEn RXCIE0
+# define UCSZn1 UCSZ01
+# define UCSZn0 UCSZ00
+# define UDRIEn UDRIE0
+# define UDRE_vect USART_UDRE_vect
+# define RX_vect USART_RX_vect
+#elif defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega32U2__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__)
+# define UDRn UDR1
+# define UBRRn UBRR1
+# define UCSRnA UCSR1A
+# define UCSRnB UCSR1B
+# define UCSRnC UCSR1C
+# define U2Xn U2X1
+# define RXENn RXEN1
+# define TXENn TXEN1
+# define RXCIEn RXCIE1
+# define UCSZn1 UCSZ11
+# define UCSZn0 UCSZ10
+# define UDRIEn UDRIE1
+# define UDRE_vect USART1_UDRE_vect
+# define RX_vect USART1_RX_vect
+#endif
+
// These buffers may be any size from 2 to 256 bytes.
#define RX_BUFFER_SIZE 64
-#define TX_BUFFER_SIZE 40
+#define TX_BUFFER_SIZE 256
static volatile uint8_t tx_buffer[TX_BUFFER_SIZE];
static volatile uint8_t tx_buffer_head;
@@ -45,10 +77,10 @@ static volatile uint8_t rx_buffer_tail;
// Initialize the UART
void uart_init(uint32_t baud) {
cli();
- UBRR0 = (F_CPU / 4 / baud - 1) / 2;
- UCSR0A = (1 << U2X0);
- UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0);
- UCSR0C = (1 << UCSZ01) | (1 << UCSZ00);
+ UBRRn = (F_CPU / 4 / baud - 1) / 2;
+ UCSRnA = (1 << U2Xn);
+ UCSRnB = (1 << RXENn) | (1 << TXENn) | (1 << RXCIEn);
+ UCSRnC = (1 << UCSZn1) | (1 << UCSZn0);
tx_buffer_head = tx_buffer_tail = 0;
rx_buffer_head = rx_buffer_tail = 0;
sei();
@@ -60,12 +92,14 @@ void uart_putchar(uint8_t c) {
i = tx_buffer_head + 1;
if (i >= TX_BUFFER_SIZE) i = 0;
+ // return immediately to avoid deadlock when interrupt is disabled(called from ISR)
+ if (tx_buffer_tail == i && (SREG & (1 << SREG_I)) == 0) return;
while (tx_buffer_tail == i)
; // wait until space in buffer
// cli();
tx_buffer[i] = c;
tx_buffer_head = i;
- UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0) | (1 << UDRIE0);
+ UCSRB = (1 << RXENn) | (1 << TXENn) | (1 << RXCIEn) | (1 << UDRIEn);
// sei();
}
@@ -95,12 +129,12 @@ uint8_t uart_available(void) {
}
// Transmit Interrupt
-ISR(USART_UDRE_vect) {
+ISR(UDRE_vect) {
uint8_t i;
if (tx_buffer_head == tx_buffer_tail) {
// buffer is empty, disable transmit interrupt
- UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0);
+ UCSRnB = (1 << RXENn) | (1 << TXENn) | (1 << RXCIEn);
} else {
i = tx_buffer_tail + 1;
if (i >= TX_BUFFER_SIZE) i = 0;
@@ -110,10 +144,10 @@ ISR(USART_UDRE_vect) {
}
// Receive Interrupt
-ISR(USART_RX_vect) {
+ISR(RX_vect) {
uint8_t c, i;
- c = UDR0;
+ c = UDRn;
i = rx_buffer_head + 1;
if (i >= RX_BUFFER_SIZE) i = 0;
if (i != rx_buffer_tail) {