From 65673663b51d8b449a0c169e1e8c00237cbb2183 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 20 Oct 2015 16:27:05 +0200
Subject: [PATCH] cpu/saml21: adapted UART driver

---
 cpu/saml21/periph/uart.c | 130 ++++++++++-----------------------------
 1 file changed, 32 insertions(+), 98 deletions(-)

diff --git a/cpu/saml21/periph/uart.c b/cpu/saml21/periph/uart.c
index 480f64fb7f..5897f2fdb1 100644
--- a/cpu/saml21/periph/uart.c
+++ b/cpu/saml21/periph/uart.c
@@ -21,53 +21,30 @@
  * @}
  */
 
-#include "board.h"
 #include "cpu.h"
-
-#include "periph/uart.h"
-#include "periph_conf.h"
-
 #include "sched.h"
 #include "thread.h"
-
-/* guard file in case no UART device was specified */
-#if UART_NUMOF
-
-/**
- * @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 Unified interrupt handler for all UART devices
- *
- * @param uartnum       the number of the UART that triggered the ISR
- * @param uart          the UART device that triggered the ISR
- */
-static inline void irq_handler(uart_t uartnum, SercomUsart *uart);
+#include "periph/uart.h"
 
 /**
  * @brief Allocate memory to store the callback functions.
  */
-static uart_conf_t uart_config[UART_NUMOF];
+static uart_isr_ctx_t uart_config[UART_NUMOF];
 
 static uint64_t _long_division(uint64_t n, uint64_t d);
 
-int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, uart_tx_cb_t tx_cb, void *arg)
+static int init_base(uart_t uart, uint32_t baudrate);
+
+int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
 {
     /* initialize basic functionality */
-    int res = uart_init_blocking(uart, baudrate);
+    int res = init_base(uart, baudrate);
     if (res != 0) {
         return res;
     }
 
     /* register callbacks */
     uart_config[uart].rx_cb = rx_cb;
-    uart_config[uart].tx_cb = tx_cb;
     uart_config[uart].arg = arg;
 
     /* configure interrupts and enable RX interrupt */
@@ -81,7 +58,7 @@ int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, uart_tx_cb_t t
     return 0;
 }
 
-int uart_init_blocking(uart_t uart, uint32_t baudrate)
+static int init_base(uart_t uart, uint32_t baudrate)
 {
     /* Calculate the BAUD value */
     uint64_t temp1 = ((16 * ((uint64_t)baudrate)) << 32);
@@ -134,54 +111,42 @@ int uart_init_blocking(uart_t uart, uint32_t baudrate)
 
             break;
 #endif
+        default:
+            (void)baud_calculated;
+            return -1;
     }
 
     uart_poweron(uart);
     return 0;
 }
 
-void uart_tx_begin(uart_t uart)
+void uart_write(uart_t uart, const uint8_t *data, size_t len)
 {
-
-}
-
-void uart_tx_end(uart_t uart)
-{
-
-}
-
-int uart_write(uart_t uart, char data)
-{
-    switch (uart) {
-        case UART_0:
-            UART_0_DEV.DATA.reg = (uint8_t)data;
-            break;
-    }
-    return 1;
-}
-
-int uart_read_blocking(uart_t uart, char *data)
-{
-    switch (uart) {
-        case UART_0:
-            while (UART_0_DEV.INTFLAG.bit.RXC == 0);
-            *data = (char)(0x00ff & UART_0_DEV.DATA.reg);
-            break;
-    }
-    return 1;
-}
-
-int uart_write_blocking(uart_t uart, char data)
-{
-    switch (uart) {
-        case UART_0:
+    if (uart == UART_0) {
+        for (size_t i = 0; i < len; i++) {
             while (UART_0_DEV.INTFLAG.bit.DRE == 0);
             while(UART_0_DEV.SYNCBUSY.bit.ENABLE);
-            UART_0_DEV.DATA.reg = (uint8_t)data;
+            UART_0_DEV.DATA.reg = data[i];
             while (UART_0_DEV.INTFLAG.reg & SERCOM_USART_INTFLAG_TXC);
-            break;
+        }
+    }
+}
+
+static inline void irq_handler(uint8_t uartnum, SercomUsart *dev)
+{
+    if (dev->INTFLAG.bit.RXC) {
+        /* cleared by reading DATA regiser */
+        char data = (char)dev->DATA.reg;
+        uart_config[uartnum].rx_cb(uart_config[uartnum].arg, data);
+    }
+    else if (dev->INTFLAG.bit.ERROR) {
+        /* clear error flag */
+        dev->INTFLAG.bit.ERROR = 1;
+    }
+
+    if (sched_context_switch_request) {
+        thread_yield();
     }
-    return 1;
 }
 
 void uart_poweron(uart_t uart)
@@ -203,35 +168,6 @@ void UART_0_ISR(void)
 }
 #endif
 
-static inline void irq_handler(uint8_t uartnum, SercomUsart *dev)
-{
-    if (dev->INTFLAG.bit.RXC) {
-        /* cleared by reading DATA regiser */
-        char data = (char)dev->DATA.reg;
-        uart_config[uartnum].rx_cb(uart_config[uartnum].arg, data);
-    }
-    else if (dev->INTFLAG.bit.TXC) {
-        if (uart_config[uartnum].tx_cb(uart_config[uartnum].arg) == 0) {
-            /* TXC flag is also cleared by writing data to DATA register */
-            if (dev->INTFLAG.bit.TXC) {
-                /* cleared by writing 1 to TXC */
-                dev->INTFLAG.bit.TXC = 1;
-            }
-        }
-    }
-    else if (dev->INTFLAG.bit.ERROR) {
-        /* clear error flag */
-        dev->INTFLAG.bit.ERROR = 1;
-    }
-
-    if (sched_context_switch_request) {
-        thread_yield();
-    }
-}
-
-
-
-
 static uint64_t _long_division(uint64_t n, uint64_t d)
 {
     int32_t i;
@@ -253,5 +189,3 @@ static uint64_t _long_division(uint64_t n, uint64_t d)
 
     return q;
 }
-
-#endif /* UART_NUMOF */