nios2: Added support to YANU UART

[karo-tx-uboot.git] / cpu / nios2 / serial.c

diff --git a/cpu/nios2/serial.c b/cpu/nios2/serial.c
index 8bbb803a6893c319cce8a7706affb1ee5dd66b8a..6c835af4b1b18ce95d723e23b8be41ec5a452ad6 100644 (file)
--- 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;