Use an internal copy buffer, worst in terms of performances, but easier to use, preve...

diff --git a/drivers/serial.c b/drivers/serial.c
index ba11e77..53cf5aa 100644 (file)
--- a/drivers/serial.c
+++ b/drivers/serial.c
@@ -29,7 +29,9 @@
 #include "core/lpc_regs_12xx.h"
 #include "core/lpc_core_cm0.h"
 #include "core/system.h"
+#include "lib/string.h"
 
+#define SERIAL_OUT_BUFF_SIZE 64
 struct uart_device
 {
        uint32_t num;
@@ -37,7 +39,7 @@ struct uart_device
        uint32_t baudrate;
 
        /* Output buffer */
-       volatile const char* out_buff;
+       volatile char out_buff[SERIAL_OUT_BUFF_SIZE];
        volatile uint32_t sending; /* Actual sending position in out buffer */
        volatile uint32_t out_lock;
        volatile uint32_t out_length; /* actual position to add in out buffer */
@@ -51,7 +53,7 @@ static struct uart_device uarts[NUM_UARTS] = {
                .num = 0,
                .regs = (struct lpc_uart*)LPC_UART_0,
                .baudrate = 0,
-               .out_buff = NULL,
+               .out_buff = {0},
                .sending = 0,
                .out_lock = 0,
        },
@@ -59,7 +61,7 @@ static struct uart_device uarts[NUM_UARTS] = {
                .num = 1,
                .regs = (struct lpc_uart*)LPC_UART_1,
                .baudrate = 0,
-               .out_buff = NULL,
+               .out_buff = {0},
                .sending = 0,
                .out_lock = 0,
        },
@@ -114,8 +116,16 @@ static void uart_start_sending(uint32_t uart_num)
 
 
 /***************************************************************************** */
-/*    Serial Write    */
-
+/*    Serial Write
+ *
+ * Try to send at most "length" characters from "buf" on the requested uart.
+ * Returns -1 on error, or number of characters copied into output buffer, witch
+ * may be less than requested "length"
+ * Possible errors: requested uart does not exists or unable to acquire uart lock.
+ *
+ * Warning for Real Time : This implementation will block if there's already a
+ * transmission ongoing.
+ */
 int serial_write(uint32_t uart_num, const char *buf, uint32_t length)
 {
        struct uart_device* uart = NULL;
@@ -132,7 +142,10 @@ int serial_write(uint32_t uart_num, const char *buf, uint32_t length)
        /* If UART is sending wait for buffer empty */
        do {} while (uart->sending != 0);
 
-       uart->out_buff = buf;
+       if (length > SERIAL_OUT_BUFF_SIZE) {
+               length = SERIAL_OUT_BUFF_SIZE;
+       }
+       memcpy((char*)uart->out_buff, buf, length);
        uart->out_length = length;
 
        /* Turn output on */

diff --git a/include/drivers/serial.h b/include/drivers/serial.h
index 4ab049c..829dcd3 100644 (file)
--- a/include/drivers/serial.h
+++ b/include/drivers/serial.h
@@ -26,8 +26,16 @@
 
 
 /***************************************************************************** */
-/*    Serial Write    */
-
+/*    Serial Write
+ *
+ * Try to send at most "length" characters from "buf" on the requested uart.
+ * Returns -1 on error, or number of characters copied into output buffer, witch
+ * may be less than requested "length"
+ * Possible errors: requested uart does not exists or unable to acquire uart lock.
+ *
+ * Warning for Real Time : This implementation will block if there's already a
+ * transmission ongoing.
+ */
 int serial_write(uint32_t uart_num, const char *buf, uint32_t length);
 
 
@@ -37,14 +45,11 @@ int serial_write(uint32_t uart_num, const char *buf, uint32_t length);
 /***************************************************************************** */
 /*   Public access to UART setup   */
 
-
 void set_uarts_pins(void);
 
-
 /* Allow any change to the main clock to be forwarded to us */
 void uart_clk_update(void);
 
-
 /* Do we need to allow setting of other parameters ? (Other than 8n1) */
 /* Do we need to allow specifying an interrupt handler ? */
 void uart_on(uint32_t uart_num, uint32_t baudrate);