nios2: Added support to YANU UART

Signed-off-by: Scott McNutt <smcnutt@psyent.com>

2 files changed, 282 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;
 
diff --git a/include/nios2-yanu.h b/include/nios2-yanu.h
new file mode 100644
index 0000000..1c9a967
--- /dev/null
+++ b/include/nios2-yanu.h
@@ -0,0 +1,115 @@
+/*
+ * (C) Copyright 2006, Imagos S.a.s <www.imagos.it>
+ * Renato Andreola <renato.andreola@imagos.it>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*************************************************************************
+ * Altera NiosII YANU serial interface by Imagos
+ * please see  http://www.opencores.org/project,yanu for
+ * information/downloads
+ ************************************************************************/
+
+#ifndef __NIOS2_YANU_H__
+#define __NIOS2_YANU_H__
+
+#define YANU_MAX_PRESCALER_N   ((1 << 4) - 1)	/* 15 */
+#define YANU_MAX_PRESCALER_M   ((1 << 11) -1)	/* 2047 */
+#define YANU_FIFO_SIZE         (16)
+#define YANU_RXFIFO_SIZE       (YANU_FIFO_SIZE)
+#define YANU_TXFIFO_SIZE       (YANU_FIFO_SIZE)
+
+#define YANU_RXFIFO_DLY        (10*11)
+#define YANU_TXFIFO_THR        (10)
+#define YANU_DATA_CHAR_MASK    (0xFF)
+
+/* data register */
+#define YANU_DATA_OFFSET       (0)	/* data register offset */
+
+#define YANU_CONTROL_OFFSET    (4)	/* control register offset */
+/* interrupt enable */
+#define YANU_CONTROL_IE_RRDY   (1<<0)	/* ie on received character ready */
+#define YANU_CONTROL_IE_OE     (1<<1)	/* ie on rx overrun    */
+#define YANU_CONTROL_IE_BRK    (1<<2)	/* ie on break detect  */
+#define YANU_CONTROL_IE_FE     (1<<3)	/* ie on framing error */
+#define YANU_CONTROL_IE_PE     (1<<4)	/* ie on parity error  */
+#define YANU_CONTROL_IE_TRDY   (1<<5)	/* ie interrupt on tranmitter ready */
+/* control bits */
+#define YANU_CONTROL_BITS_POS  (6)	/* bits number pos */
+#define YANU_CONTROL_BITS      (1<<YANU_CONTROL_BITS_POS)	/* number of rx/tx bits per word. 3 bit unsigned integer */
+#define YANU_CONTROL_BITS_N    (3)	/* ... its bit filed length */
+#define YANU_CONTROL_PARENA    (1<<9)	/*  enable parity bit transmission/reception */
+#define YANU_CONTROL_PAREVEN   (1<<10)	/* parity even */
+#define YANU_CONTROL_STOPS     (1<<11)	/* number of stop bits */
+#define YANU_CONTROL_HHENA     (1<<12)	/* Harware Handshake enable... */
+#define YANU_CONTROL_FORCEBRK  (1<<13)	/* if set than txd = active (0) */
+/* tuning part */
+#define YANU_CONTROL_RDYDLY    (1<<14)	/* delay from "first" before setting rrdy (in bit) */
+#define YANU_CONTROL_RDYDLY_N  (8)	/* ... its bit filed length */
+#define YANU_CONTROL_TXTHR     (1<<22)	/* tx interrupt threshold: the trdy set if txfifo_chars<= txthr (chars) */
+#define YANU_CONTROL_TXTHR_N   (4)	/* ... its bit field length */
+
+#define YANU_BAUD_OFFSET  (8)	/* baud register offset */
+#define YANU_BAUDM        (1<<0)	/* baud mantissa lsb */
+#define YANU_BAUDM_N      (12)	/* ...its bit filed length */
+#define YANU_BAUDE        (1<<12)	/* baud exponent lsb */
+#define YANU_BAUDE_N      (4)	/* ...its bit field length */
+
+#define YANU_ACTION_OFFSET   (12)	/* action register... write only */
+#define YANU_ACTION_RRRDY    (1<<0)	/* reset rrdy */
+#define YANU_ACTION_ROE      (1<<1)	/* reset oe */
+#define YANU_ACTION_RBRK     (1<<2)	/* reset brk */
+#define YANU_ACTION_RFE      (1<<3)	/* reset fe  */
+#define YANU_ACTION_RPE      (1<<4)	/* reset pe  */
+#define YANU_ACTION_SRRDY    (1<<5)	/* set rrdy  */
+#define YANU_ACTION_SOE      (1<<6)	/* set oe    */
+#define YANU_ACTION_SBRK     (1<<7)	/* set brk   */
+#define YANU_ACTION_SFE      (1<<8)	/* set fe    */
+#define YANU_ACTION_SPE      (1<<9)	/* set pe    */
+#define YANU_ACTION_RFIFO_PULL  (1<<10)	/* pull a char from rx fifo we MUST do it before taking a char */
+#define YANU_ACTION_RFIFO_CLEAR (1<<11)	/* clear rx fifo */
+#define YANU_ACTION_TFIFO_CLEAR (1<<12)	/* clear tx fifo */
+#define YANU_ACTION_RTRDY       (1<<13)	/* clear trdy    */
+#define YANU_ACTION_STRDY       (1<<14)	/* set trdy      */
+
+#define YANU_STATUS_OFFSET   (16)
+#define YANU_STATUS_RRDY     (1<<0)	/* rxrdy flag */
+#define YANU_STATUS_TRDY     (1<<1)	/* txrdy flag */
+#define YANU_STATUS_OE       (1<<2)	/* rx overrun error */
+#define YANU_STATUS_BRK      (1<<3)	/* rx break detect flag */
+#define YANU_STATUS_FE       (1<<4)	/* rx framing error flag */
+#define YANU_STATUS_PE       (1<<5)	/* rx parity erro flag */
+#define YANU_RFIFO_CHARS_POS (6)
+#define YANU_RFIFO_CHARS     (1<<RFIFO_CHAR_POS)	/* number of chars into rx fifo */
+#define YANU_RFIFO_CHARS_N   (5)	/* ...its bit field length: 32 chars */
+#define YANU_TFIFO_CHARS_POS (11)
+#define YANU_TFIFO_CHARS     (1<<TFIFO_CHAR_POS)	/* number of chars into tx fifo */
+#define YANU_TFIFO_CHARS_N   (5)	/* ...its bit field length: 32 chars */
+
+typedef volatile struct yanu_uart_t {
+	volatile unsigned data;
+	volatile unsigned control;	/* control register (RW) 32-bit   */
+	volatile unsigned baud;	/* baud/prescaler register (RW) 32-bit */
+	volatile unsigned action;	/* action register (W) 32-bit */
+	volatile unsigned status;	/* status register (R) 32-bit */
+	volatile unsigned magic;	/* magic register (R) 32-bit */
+} yanu_uart_t;
+
+#endif