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authorRenato Andreola <renato.andreola@imagos.it>2010-03-16 16:01:29 -0400
committerScott McNutt <smcnutt@psyent.com>2010-03-16 16:01:29 -0400
commit67c7189dd35cb368ef665126fd17816581bd2e92 (patch)
tree75db38b613296b94e0dcdaa8ca615583483127e8 /cpu
parent1e67fb32fbdae7949bb423c9e20b3f77c0a61663 (diff)
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nios2: Added support to YANU UART
Signed-off-by: Scott McNutt <smcnutt@psyent.com>
Diffstat (limited to 'cpu')
-rw-r--r--cpu/nios2/serial.c168
1 files changed, 167 insertions, 1 deletions
diff --git a/cpu/nios2/serial.c b/cpu/nios2/serial.c
index 8bbb803..6c835af 100644
--- a/cpu/nios2/serial.c
+++ b/cpu/nios2/serial.c
@@ -2,6 +2,9 @@
* (C) Copyright 2004, Psyent Corporation <www.psyent.com>
* Scott McNutt <smcnutt@psyent.com>
*
+ * YANU Support:
+ * Copyright 2010, Renato Andreola <renato.andreola@imagos.it>
+ *
* See file CREDITS for list of people who contributed to this
* project.
*
@@ -26,6 +29,7 @@
#include <watchdog.h>
#include <asm/io.h>
#include <nios2-io.h>
+#include <nios2-yanu.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -74,10 +78,172 @@ int serial_getc (void)
return (c);
}
+#elif defined(CONFIG_CONSOLE_YANU)
+/*-----------------------------------------------------------------*/
+/* YANU Imagos serial port */
+/*-----------------------------------------------------------------*/
+
+static yanu_uart_t *uart = (yanu_uart_t *)CONFIG_SYS_NIOS_CONSOLE;
+
+#if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
+
+/* Everything's already setup for fixed-baud PTF assignment*/
+
+void serial_setbrg (void)
+{
+ int n, k;
+ const unsigned max_uns = 0xFFFFFFFF;
+ unsigned best_n, best_m, baud;
+
+ /* compute best N and M couple */
+ best_n = YANU_MAX_PRESCALER_N;
+ for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
+ if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
+ (unsigned)CONFIG_BAUDRATE) {
+ best_n = n;
+ break;
+ }
+ }
+ for (k = 0;; k++) {
+ if ((unsigned)CONFIG_BAUDRATE <= (max_uns >> (15+n-k)))
+ break;
+ }
+ best_m =
+ ((unsigned)CONFIG_BAUDRATE * (1 << (15 + n - k))) /
+ ((unsigned)CONFIG_SYS_CLK_FREQ >> k);
+
+ baud = best_m + best_n * YANU_BAUDE;
+ writel(&uart->baud, baud);
+
+ return;
+}
+
+#else
+
+void serial_setbrg (void)
+{
+ int n, k;
+ const unsigned max_uns = 0xFFFFFFFF;
+ unsigned best_n, best_m, baud;
+
+ /* compute best N and M couple */
+ best_n = YANU_MAX_PRESCALER_N;
+ for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
+ if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
+ gd->baudrate) {
+ best_n = n;
+ break;
+ }
+ }
+ for (k = 0;; k++) {
+ if (gd->baudrate <= (max_uns >> (15+n-k)))
+ break;
+ }
+ best_m =
+ (gd->baudrate * (1 << (15 + n - k))) /
+ ((unsigned)CONFIG_SYS_CLK_FREQ >> k);
+
+ baud = best_m + best_n * YANU_BAUDE;
+ writel(&uart->baud, baud);
+
+ return;
+}
+
+
+#endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
+
+int serial_init (void)
+{
+ unsigned action,control;
+
+ /* status register cleanup */
+ action = YANU_ACTION_RRRDY |
+ YANU_ACTION_RTRDY |
+ YANU_ACTION_ROE |
+ YANU_ACTION_RBRK |
+ YANU_ACTION_RFE |
+ YANU_ACTION_RPE |
+ YANU_ACTION_RFE | YANU_ACTION_RFIFO_CLEAR | YANU_ACTION_TFIFO_CLEAR;
+
+ writel(&uart->action, action);
+
+ /* control register cleanup */
+ /* no interrupts enabled */
+ /* one stop bit */
+ /* hardware flow control disabled */
+ /* 8 bits */
+ control = (0x7 << YANU_CONTROL_BITS_POS);
+ /* enven parity just to be clean */
+ control |= YANU_CONTROL_PAREVEN;
+ /* we set threshold for fifo */
+ control |= YANU_CONTROL_RDYDLY * YANU_RXFIFO_DLY;
+ control |= YANU_CONTROL_TXTHR * YANU_TXFIFO_THR;
+
+ writel(&uart->control, control);
+
+ /* to set baud rate */
+ serial_setbrg();
+
+ return (0);
+}
+
+
+/*-----------------------------------------------------------------------
+ * YANU CONSOLE
+ *---------------------------------------------------------------------*/
+void serial_putc (char c)
+{
+ int tx_chars;
+ unsigned status;
+
+ if (c == '\n')
+ serial_putc ('\r');
+
+ while (1) {
+ status = readl(&uart->status);
+ tx_chars = (status>>YANU_TFIFO_CHARS_POS)
+ & ((1<<YANU_TFIFO_CHARS_N)-1);
+ if (tx_chars < YANU_TXFIFO_SIZE-1)
+ break;
+ WATCHDOG_RESET ();
+ }
+
+ writel(&uart->data, (unsigned char)c);
+}
+
+void serial_puts (const char *s)
+{
+ while (*s != 0) {
+ serial_putc (*s++);
+ }
+}
+
+
+int serial_tstc(void)
+{
+ unsigned status ;
+
+ status = readl(&uart->status);
+ return (((status >> YANU_RFIFO_CHARS_POS) &
+ ((1 << YANU_RFIFO_CHARS_N) - 1)) > 0);
+}
+
+int serial_getc (void)
+{
+ while (serial_tstc() == 0)
+ WATCHDOG_RESET ();
+
+ /* first we pull the char */
+ writel(&uart->action, YANU_ACTION_RFIFO_PULL);
+
+ return(readl(&uart->data) & YANU_DATA_CHAR_MASK);
+}
+
+#else /*CONFIG_CONSOLE_YANU*/
+
/*------------------------------------------------------------------
* UART the serial port
*-----------------------------------------------------------------*/
-#else
static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;