[people/ms/u-boot.git] / drivers / serial / opencores_yanu.c

/*
 * Copyright 2010, 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
 */

#include <common.h>
#include <watchdog.h>
#include <asm/io.h>
#include <nios2-yanu.h>

DECLARE_GLOBAL_DATA_PTR;

/*-----------------------------------------------------------------*/
/* 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(baud, &uart->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(baud, &uart->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(action, &uart->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(control, &uart->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((unsigned char)c, &uart->data);
}

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(YANU_ACTION_RFIFO_PULL, &uart->action);

	return(readl(&uart->data) & YANU_DATA_CHAR_MASK);
}
Commit	Line	Data
5c952cf0	1	/*
67c7189d RA	2	* Copyright 2010, Renato Andreola <renato.andreola@imagos.it>
67c7189d RA	3	*
5c952cf0 WD	4	* See file CREDITS for list of people who contributed to this
	5	* project.
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License as
	9	* published by the Free Software Foundation; either version 2 of
	10	* the License, or (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	20	* MA 02111-1307 USA
	21	*/
	22
5c952cf0 WD	23	#include <common.h>
5c952cf0 WD	24	#include <watchdog.h>
c2ced000	25	#include <asm/io.h>
67c7189d	26	#include <nios2-yanu.h>
5c952cf0	27
d87080b7 WD	28	DECLARE_GLOBAL_DATA_PTR;
d87080b7 WD	29
67c7189d RA	30	/-----------------------------------------------------------------/
	31	/* YANU Imagos serial port */
	32	/-----------------------------------------------------------------/
	33
	34	static yanu_uart_t uart = (yanu_uart_t )CONFIG_SYS_NIOS_CONSOLE;
	35
	36	#if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
	37
	38	/* Everything's already setup for fixed-baud PTF assignment*/
	39
	40	void serial_setbrg (void)
	41	{
	42	int n, k;
	43	const unsigned max_uns = 0xFFFFFFFF;
	44	unsigned best_n, best_m, baud;
	45
	46	/* compute best N and M couple */
	47	best_n = YANU_MAX_PRESCALER_N;
	48	for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
	49	if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
	50	(unsigned)CONFIG_BAUDRATE) {
	51	best_n = n;
	52	break;
	53	}
	54	}
	55	for (k = 0;; k++) {
	56	if ((unsigned)CONFIG_BAUDRATE <= (max_uns >> (15+n-k)))
	57	break;
	58	}
	59	best_m =
	60	((unsigned)CONFIG_BAUDRATE * (1 << (15 + n - k))) /
	61	((unsigned)CONFIG_SYS_CLK_FREQ >> k);
	62
	63	baud = best_m + best_n * YANU_BAUDE;
3ea0037f	64	writel(baud, &uart->baud);
67c7189d RA	65
	66	return;
	67	}
	68
	69	#else
	70
	71	void serial_setbrg (void)
c4976807	72	{
67c7189d RA	73	int n, k;
	74	const unsigned max_uns = 0xFFFFFFFF;
	75	unsigned best_n, best_m, baud;
	76
	77	/* compute best N and M couple */
	78	best_n = YANU_MAX_PRESCALER_N;
	79	for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
	80	if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
	81	gd->baudrate) {
	82	best_n = n;
	83	break;
	84	}
	85	}
	86	for (k = 0;; k++) {
	87	if (gd->baudrate <= (max_uns >> (15+n-k)))
	88	break;
	89	}
	90	best_m =
	91	(gd->baudrate * (1 << (15 + n - k))) /
	92	((unsigned)CONFIG_SYS_CLK_FREQ >> k);
	93
	94	baud = best_m + best_n * YANU_BAUDE;
3ea0037f	95	writel(baud, &uart->baud);
67c7189d RA	96
	97	return;
	98	}
	99
	100
	101	#endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
	102
	103	int serial_init (void)
	104	{
	105	unsigned action,control;
	106
	107	/* status register cleanup */
	108	action = YANU_ACTION_RRRDY \|
	109	YANU_ACTION_RTRDY \|
	110	YANU_ACTION_ROE \|
	111	YANU_ACTION_RBRK \|
	112	YANU_ACTION_RFE \|
	113	YANU_ACTION_RPE \|
	114	YANU_ACTION_RFE \| YANU_ACTION_RFIFO_CLEAR \| YANU_ACTION_TFIFO_CLEAR;
	115
3ea0037f	116	writel(action, &uart->action);
c4976807 WD	117
	118	/*
	119	* control register cleanup
	120	* no interrupts enabled
	121	* one stop bit
	122	* hardware flow control disabled
	123	* 8 bits
	124	*/
67c7189d RA	125	control = (0x7 << YANU_CONTROL_BITS_POS);
	126	/* enven parity just to be clean */
	127	control \|= YANU_CONTROL_PAREVEN;
	128	/* we set threshold for fifo */
	129	control \|= YANU_CONTROL_RDYDLY * YANU_RXFIFO_DLY;
	130	control \|= YANU_CONTROL_TXTHR * YANU_TXFIFO_THR;
	131
3ea0037f	132	writel(control, &uart->control);
67c7189d RA	133
	134	/* to set baud rate */
	135	serial_setbrg();
	136
	137	return (0);
	138	}
	139
	140
	141	/*-----------------------------------------------------------------------
	142	* YANU CONSOLE
	143	---------------------------------------------------------------------/
	144	void serial_putc (char c)
	145	{
	146	int tx_chars;
	147	unsigned status;
	148
	149	if (c == '\n')
	150	serial_putc ('\r');
c4976807	151
67c7189d RA	152	while (1) {
	153	status = readl(&uart->status);
	154	tx_chars = (status>>YANU_TFIFO_CHARS_POS)
	155	& ((1<<YANU_TFIFO_CHARS_N)-1);
	156	if (tx_chars < YANU_TXFIFO_SIZE-1)
	157	break;
	158	WATCHDOG_RESET ();
	159	}
	160
3ea0037f	161	writel((unsigned char)c, &uart->data);
67c7189d RA	162	}
	163
	164	void serial_puts (const char *s)
	165	{
	166	while (*s != 0) {
	167	serial_putc (*s++);
	168	}
	169	}
	170
	171
	172	int serial_tstc(void)
	173	{
	174	unsigned status ;
	175
	176	status = readl(&uart->status);
	177	return (((status >> YANU_RFIFO_CHARS_POS) &
	178	((1 << YANU_RFIFO_CHARS_N) - 1)) > 0);
c4976807	179	}
67c7189d RA	180
	181	int serial_getc (void)
	182	{
	183	while (serial_tstc() == 0)
	184	WATCHDOG_RESET ();
c4976807	185
67c7189d	186	/* first we pull the char */
3ea0037f	187	writel(YANU_ACTION_RFIFO_PULL, &uart->action);
67c7189d RA	188
	189	return(readl(&uart->data) & YANU_DATA_CHAR_MASK);
	190	}