[U-Boot] PATCH - Added support to YANU Nios2 uart (02)

[Scott McNutt <smcnutt@psyent.com>]

Renato,

Patch applied to the nios2 tree.

I think it's time to consider moving the nios2 header files
into include/asm-nios before the top-level include gets
too polluted.

Regards,
--Scott

Renato Andreola wrote:
>  From d7a79fc4e5a3ebc6a1ca5c23500e3f2f1c3b33c2 Mon Sep 17 00:00:00 2001
> From: Renato Andreola <renato.andreola@imagos.it>
> Date: Mon, 24 Aug 2009 16:03:51 +0200
> Subject: [PATCH] Yanu Support for U-Boot
> 
> with this patch YANU uart (from opencores) support will be added to u-boot.
> Remember to modify properly your board files for defining physical address etc etc
> 
> Sign-off-by: Renato Andreola <renato.andreola@imagos.it>
> ---
>   cpu/nios2/serial.c   |  165 +++++++++++++++++++++++++++++++++++++++++++++++++-
>   include/nios2-yanu.h |  115 +++++++++++++++++++++++++++++++++++
>   2 files changed, 279 insertions(+), 1 deletions(-)
>   create mode 100644 include/nios2-yanu.h
> 
> diff --git a/cpu/nios2/serial.c b/cpu/nios2/serial.c
> index 8bbb803..467df4c 100644
> --- a/cpu/nios2/serial.c
> +++ b/cpu/nios2/serial.c
> @@ -26,6 +26,7 @@
>   #include <watchdog.h>
>   #include <asm/io.h>
>   #include <nios2-io.h>
> +#include <nios2-yanu.h>
> 
>   DECLARE_GLOBAL_DATA_PTR;
> 
> @@ -74,10 +75,172 @@ 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_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 /* CFG_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..e44aa69
> --- /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