cpu/nrf51: adapted UART driver

cpu/nrf51/periph/uart.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014 Freie Universität Berlin
+ * Copyright (C) 2014-2015 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
@@ -25,58 +25,25 @@
 #include "cpu.h"
 #include "thread.h"
 #include "sched.h"
-#include "periph_conf.h"
 #include "periph/uart.h"
-#include "board.h"
-
-/* guard file in case no UART device was specified */
-#if UART_0_EN
-
-/**
- * @brief Each UART device has to store two callbacks.
- */
-typedef struct {
-    uart_rx_cb_t rx_cb;
-    uart_tx_cb_t tx_cb;
-    void *arg;
-} uart_conf_t;
 
 /**
  * @brief Data structure holding the callbacks and argument for each UART device
  */
-static uart_conf_t uart_config;
+static uart_isr_ctx_t uart_config;
 
 /**
  * @brief Allocate memory to store the callback functions.
  */
-int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, uart_tx_cb_t tx_cb, void *arg)
+int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
 {
-
-    int res;
-
-    /* initialize UART in blocking mode fist */
-    res = uart_init_blocking(uart, baudrate);
-    if (res != 0) {
-        return res;
+    if (uart != 0) {
+        return -1;
     }
 
     /* remember callback addresses and argument */
     uart_config.rx_cb = rx_cb;
-    uart_config.tx_cb = tx_cb;
     uart_config.arg = arg;
-    /* enable global and receiving interrupt */
-    NVIC_SetPriority(UART0_IRQn, UART_IRQ_PRIO);
-    NVIC_EnableIRQ(UART0_IRQn);
-    NRF_UART0->INTENSET = UART_INTENSET_RXDRDY_Msk;
-    return 0;
-}
-
-int uart_init_blocking(uart_t uart, uint32_t baudrate)
-{
-    /* the NRF only supports 1 UART device, so we don't need a switch statement here */
-    if (uart != UART_0) {
-        return -1;
-    }
 
     /* power on the UART device */
     NRF_UART0->POWER = 1;
@@ -150,7 +117,7 @@ int uart_init_blocking(uart_t uart, uint32_t baudrate)
             NRF_UART0->BAUDRATE = UART_BAUDRATE_BAUDRATE_Baud921600;
             break;
         default:
-            return -1;
+            return -2;
     }
 
     /* enable the UART device */
@@ -158,67 +125,36 @@ int uart_init_blocking(uart_t uart, uint32_t baudrate)
     /* enable TX and RX */
     NRF_UART0->TASKS_STARTTX = 1;
     NRF_UART0->TASKS_STARTRX = 1;
-
+    /* enable global and receiving interrupt */
+    NVIC_EnableIRQ(UART0_IRQn);
+    NRF_UART0->INTENSET = UART_INTENSET_RXDRDY_Msk;
     return 0;
 }
 
-void uart_tx_begin(uart_t uart)
+void uart_write(uart_t uart, const uint8_t *data, size_t len)
 {
-    if (uart == UART_0) {
-        if (uart_config.tx_cb(uart_config.arg) != 0) {
-            NRF_UART0->INTENSET = UART_INTENSET_TXDRDY_Msk;
+    if (uart == 0) {
+        for (size_t i = 0; i < len; i++) {
+            /* write data into transmit register */
+            NRF_UART0->TXD = data[i];
+            /* wait for any transmission to be done */
+            while (NRF_UART0->EVENTS_TXDRDY == 0);
+            /* reset ready flag */
+            NRF_UART0->EVENTS_TXDRDY = 0;
         }
     }
 }
 
-int uart_write(uart_t uart, char data)
-{
-    if (uart == UART_0) {
-        NRF_UART0->TXD = (uint8_t)data;
-        NRF_UART0->EVENTS_TXDRDY = 0;
-        return 1;
-    }
-    return 0;
-}
-
-int uart_read_blocking(uart_t uart, char *data)
-{
-    if (uart == UART_0) {
-        /* wait for until data was received (RXDRDY == 1) */
-        while (NRF_UART0->EVENTS_RXDRDY != 1);
-        /* reset RXDRDY flag */
-        NRF_UART0->EVENTS_RXDRDY = 0;
-        /* read new byte from receive data register */
-        *data = (char)(NRF_UART0->RXD & 0xff);
-        return 1;
-    }
-    return 0;
-}
-
-int uart_write_blocking(uart_t uart, char data)
-{
-    if (uart == UART_0) {
-        /* write data into transmit register */
-        NRF_UART0->TXD = (uint8_t)data;
-        /* wait for any transmission to be done */
-        while (NRF_UART0->EVENTS_TXDRDY == 0);
-        /* reset ready flag */
-        NRF_UART0->EVENTS_TXDRDY = 0;
-        return 1;
-    }
-    return 0;
-}
-
 void uart_poweron(uart_t uart)
 {
-    if (uart == UART_0) {
+    if (uart == 0) {
         NRF_UART0->POWER = 1;
     }
 }
 
 void uart_poweroff(uart_t uart)
 {
-    if (uart == UART_0) {
+    if (uart == 0) {
         NRF_UART0->POWER = 0;
     }
 }
@@ -230,15 +166,7 @@ void isr_uart0(void)
         char byte = (char)(NRF_UART0->RXD & 0xff);
         uart_config.rx_cb(uart_config.arg, byte);
     }
-    if (NRF_UART0->EVENTS_TXDRDY == 1) {
-        NRF_UART0->EVENTS_TXDRDY = 0;
-        if (uart_config.tx_cb(uart_config.arg) == 0) {
-            NRF_UART0->INTENCLR = UART_INTENSET_TXDRDY_Msk;
-        }
-    }
     if (sched_context_switch_request) {
         thread_yield();
     }
 }
-
-#endif /* UART_0_EN */