xref: /netbsd-src/sys/arch/evbarm/stand/board/sscom.c (revision 355f6c61dce0706278148e6a3462763827326b7c)
1 /*	$NetBSD: sscom.c,v 1.7 2022/09/05 14:14:42 tsutsui Exp $ */
2 
3 
4 /*
5  * Copyright (c) 2002, 2003 Fujitsu Component Limited
6  * Copyright (c) 2002, 2003 Genetec Corporation
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of The Fujitsu Component Limited nor the name of
18  *    Genetec corporation may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY FUJITSU COMPONENT LIMITED AND GENETEC
22  * CORPORATION ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25  * DISCLAIMED.  IN NO EVENT SHALL FUJITSU COMPONENT LIMITED OR GENETEC
26  * CORPORATION BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 /* derived from ns16550.c */
36 /*
37  * Copyright (c) 2002 Wasabi Systems, Inc.
38  * All rights reserved.
39  *
40  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
41  *
42  * Redistribution and use in source and binary forms, with or without
43  * modification, are permitted provided that the following conditions
44  * are met:
45  * 1. Redistributions of source code must retain the above copyright
46  *    notice, this list of conditions and the following disclaimer.
47  * 2. Redistributions in binary form must reproduce the above copyright
48  *    notice, this list of conditions and the following disclaimer in the
49  *    documentation and/or other materials provided with the distribution.
50  * 3. All advertising materials mentioning features or use of this software
51  *    must display the following acknowledgement:
52  *	This product includes software developed for the NetBSD Project by
53  *	Wasabi Systems, Inc.
54  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
55  *    or promote products derived from this software without specific prior
56  *    written permission.
57  *
58  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
60  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
61  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
62  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
63  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
64  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
65  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
66  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
67  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
68  * POSSIBILITY OF SUCH DAMAGE.
69  */
70 /*
71  * This file provides the cons_init() function and console I/O routines
72  * for boards that use built-in UART of Samsung's S3C2xx0 CPUs.
73  */
74 
75 #include <sys/types.h>
76 #include <arch/arm/s3c2xx0/s3c2xx0reg.h>
77 #ifdef	CPU_S3C2410
78 #include <arch/arm/s3c2xx0/s3c2410reg.h>
79 #endif
80 #ifdef	CPU_S3C2800
81 #include <arch/arm/s3c2xx0/s3c2800reg.h>
82 #endif
83 #include <lib/libsa/stand.h>
84 
85 #include "board.h"
86 
87 #ifndef SSCOM_TOLERANCE
88 #define	SSCOM_TOLERANCE	30	/* XXX: baud rate tolerance, in 0.1% units */
89 #endif
90 
91 #define	INB(x)		*((volatile uint8_t *) ((CONADDR) + (x)))
92 #define	INW(x)		*((volatile uint32_t *) ((CONADDR) + (x)))
93 #define	OUTB(x, v)	(*((volatile uint8_t *) ((CONADDR) + (x))) = (v))
94 #define	OUTW(x, v)	(*((volatile uint32_t *) ((CONADDR) + (x))) = (v))
95 
96 static long get_com_freq(void);
97 
98 static int
sscomspeed(long speed)99 sscomspeed(long speed)
100 {
101 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
102 
103 	int x, err;
104 	long pclk = get_com_freq();
105 
106 	if (speed <= 0)
107 		return -1;
108 	x = divrnd(pclk / 16, speed);
109 	if (x <= 0)
110 		return -1;
111 	err = divrnd(((quad_t)pclk) * 1000 / 16, speed * x) - 1000;
112 	if (err < 0)
113 		err = -err;
114 	if (err > SSCOM_TOLERANCE)
115 		return -1;
116 	return x-1;
117 
118 #undef	divrnd
119 }
120 
121 void
cons_init(void)122 cons_init(void)
123 {
124 	int rate;
125 
126 	OUTW(SSCOM_UCON, 0);
127 	OUTB(SSCOM_UFCON, UFCON_TXTRIGGER_8 | UFCON_RXTRIGGER_8 |
128 	    UFCON_TXFIFO_RESET | UFCON_RXFIFO_RESET |
129 	    UFCON_FIFO_ENABLE);
130 
131 	rate = sscomspeed(CONSPEED);
132 	OUTW(SSCOM_UBRDIV, rate);
133 	OUTW(SSCOM_ULCON, ULCON_PARITY_NONE|ULCON_LENGTH_8);
134 
135 	/* enable UART */
136 	OUTW(SSCOM_UCON, UCON_TXMODE_INT|UCON_RXMODE_INT);
137 	OUTW(SSCOM_UMCON, UMCON_RTS);
138 }
139 
140 #define sscom_rxrdy() (INB(SSCOM_UTRSTAT) & UTRSTAT_RXREADY)
141 
142 int
getchar(void)143 getchar(void)
144 {
145 	uint8_t stat __unused;
146 	int c;
147 
148 	while (!sscom_rxrdy())
149 		/* spin */ ;
150 	c = INB(SSCOM_URXH);
151 	stat = INB(SSCOM_UERSTAT);	/* XXX */
152 
153 	return c;
154 }
155 
156 static void
iputchar(int c)157 iputchar(int c)
158 {
159 	uint32_t stat;
160 	int timo;
161 
162 	/* Wait for any pending transmission to finish. */
163 	timo = 50000;
164 	while (ISSET(stat = INW(SSCOM_UFSTAT), UFSTAT_TXFULL) && --timo)
165 		/* spin */ ;
166 
167 	OUTB(SSCOM_UTXH, c);
168 
169 #if 0
170 	/* Wait for this transmission to complete. */
171 	timo = 1500000;
172 	while (!ISSET(stat = INW(SSCOM_UFSTAT), UFSTAT_TXFULL) && --timo)
173 		/* spin */ ;
174 #endif
175 }
176 
177 void
putchar(int c)178 putchar(int c)
179 {
180 
181 	if (c == '\n')
182 		iputchar('\r');
183 	iputchar(c);
184 }
185 
186 
187 #define read_reg(addr)	(*(volatile uint32_t *)(addr))
188 
189 static long
get_com_freq(void)190 get_com_freq(void)
191 {
192 	long clk;
193 #ifdef	CPU_S3C2800
194 	uint32_t pllcon = read_reg(S3C2800_CLKMAN_BASE+CLKMAN_PLLCON);
195 	uint32_t div = read_reg(S3C2800_CLKMAN_BASE+CLKMAN_CLKCON);
196 #define	HDIV	CLKCON_HCLK
197 #define PDIV	CLKCON_PCLK
198 #endif
199 #ifdef	CPU_S3C2410
200 	uint32_t pllcon = read_reg(S3C2410_CLKMAN_BASE+CLKMAN_MPLLCON);
201 	uint32_t div = read_reg(S3C2410_CLKMAN_BASE+CLKMAN_CLKDIVN);
202 #define	HDIV	CLKDIVN_HDIVN
203 #define PDIV	CLKDIVN_PDIVN
204 #endif
205 
206 	int mdiv = (pllcon & PLLCON_MDIV_MASK) >> PLLCON_MDIV_SHIFT;
207 	int pdiv = (pllcon & PLLCON_PDIV_MASK) >> PLLCON_PDIV_SHIFT;
208 	int sdiv = (pllcon & PLLCON_SDIV_MASK) >> PLLCON_SDIV_SHIFT;
209 
210 #if XTAL_CLK < 1000   /* in MHz */
211 	clk = (XTAL_CLK * 1000000 * (8 + mdiv)) / ((pdiv + 2) << sdiv);
212 #else /* in Hz */
213 	clk = (XTAL_CLK * (8 + mdiv)) / ((pdiv + 2) << sdiv);
214 #endif
215 
216 	/*printf( "M=%d P=%d S=%d\n", mdiv, pdiv, sdiv);*/
217 
218 	if (div & HDIV)
219 		clk /= 2;
220 	if (div & PDIV)
221 		clk /= 2;
222 
223 	return clk;
224 }
225