xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 2146cf56)
1 /*
2  * SuperH SCIF device driver.
3  * Copyright (c) 2007 Nobuhiro Iwamatsu
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 
20 #include <common.h>
21 #include <asm/processor.h>
22 
23 #ifdef CFG_SCIF_CONSOLE
24 
25 #if defined (CONFIG_CONS_SCIF0)
26 #define SCIF_BASE	SCIF0_BASE
27 #elif defined (CONFIG_CONS_SCIF1)
28 #define SCIF_BASE	SCIF1_BASE
29 #else
30 #error "Default SCIF doesn't set....."
31 #endif
32 
33 #define SCSMR 	(vu_short *)(SCIF_BASE + 0x0)
34 #define SCBRR 	(vu_char  *)(SCIF_BASE + 0x4)
35 #define SCSCR 	(vu_short *)(SCIF_BASE + 0x8)
36 #define SCFTDR 	(vu_char  *)(SCIF_BASE + 0xC)
37 #define SCFSR 	(vu_short *)(SCIF_BASE + 0x10)
38 #define SCFRDR 	(vu_char  *)(SCIF_BASE + 0x14)
39 #define SCFCR 	(vu_short *)(SCIF_BASE + 0x18)
40 #define SCFDR 	(vu_short *)(SCIF_BASE + 0x1C)
41 #if defined(CONFIG_SH4A)
42 #define SCRFDR	(vu_short *)(SCIF_BASE + 0x20)
43 #define SCSPTR	(vu_short *)(SCIF_BASE + 0x24)
44 #define SCLSR   (vu_short *)(SCIF_BASE + 0x28)
45 #define SCRER	(vu_short *)(SCIF_BASE + 0x2C)
46 #elif defined (CONFIG_SH4)
47 #define SCSPTR 	(vu_short *)(SCIF_BASE + 0x20)
48 #define SCLSR 	(vu_short *)(SCIF_BASE + 0x24)
49 #elif defined (CONFIG_SH3)
50 #define SCLSR 	(vu_short *)(SCIF_BASE + 0x24)
51 #endif
52 
53 #define SCR_RE 		(1 << 4)
54 #define SCR_TE 		(1 << 5)
55 #define FCR_RFRST	(1 << 1) /* RFCL */
56 #define FCR_TFRST	(1 << 2) /* TFCL */
57 #define FSR_DR   	(1 << 0)
58 #define FSR_RDF  	(1 << 1)
59 #define FSR_FER  	(1 << 3)
60 #define FSR_BRK  	(1 << 4)
61 #define FSR_FER  	(1 << 3)
62 #define FSR_TEND 	(1 << 6)
63 #define FSR_ER   	(1 << 7)
64 
65 /*----------------------------------------------------------------------*/
66 
67 void serial_setbrg (void)
68 {
69 	DECLARE_GLOBAL_DATA_PTR;
70 	int divisor = gd->baudrate * 32;
71 
72 	*SCBRR = (CONFIG_SYS_CLK_FREQ + (divisor / 2)) /
73 						(gd->baudrate * 32) - 1;
74 }
75 
76 int serial_init (void)
77 {
78 	*SCSCR = (SCR_RE | SCR_TE);
79 	*SCSMR = 0 ;
80 	*SCSMR = 0;
81 	*SCFCR = (FCR_RFRST | FCR_TFRST);
82 	*SCFCR;
83 	*SCFCR = 0;
84 
85 	serial_setbrg();
86 	return 0;
87 }
88 
89 static int serial_tx_fifo_level (void)
90 {
91 	return (*SCFDR >> 8) & 0x1F;
92 }
93 
94 static int serial_rx_fifo_level (void)
95 {
96 	return (*SCFDR >> 0) & 0x1F;
97 }
98 
99 void serial_raw_putc (const char c)
100 {
101 	unsigned int fsr_bits_to_clear;
102 
103 	while (1) {
104 		if (*SCFSR & FSR_TEND) {		/* Tx fifo is empty */
105 			fsr_bits_to_clear = FSR_TEND;
106 			break;
107 		}
108 	}
109 
110 	*SCFTDR = c;
111 	if (fsr_bits_to_clear != 0)
112 		*SCFSR &= ~fsr_bits_to_clear;
113 }
114 
115 void serial_putc (const char c)
116 {
117 	if (c == '\n')
118 		serial_raw_putc ('\r');
119 	serial_raw_putc (c);
120 }
121 
122 void serial_puts (const char *s)
123 {
124 	char c;
125 	while ((c = *s++) != 0)
126 		serial_putc (c);
127 }
128 
129 int serial_tstc (void)
130 {
131 	return serial_rx_fifo_level() ? 1 : 0;
132 }
133 
134 #define FSR_ERR_CLEAR   0x0063
135 #define RDRF_CLEAR      0x00fc
136 #define LSR_ORER        1
137 void handle_error( void ){
138 
139 	(void)*SCFSR ;
140 	*SCFSR = FSR_ERR_CLEAR ;
141 	(void)*SCLSR ;
142 	*SCLSR = 0x00 ;
143 }
144 
145 int serial_getc_check( void ){
146 	unsigned short status;
147 
148 	status = *SCFSR ;
149 
150 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
151 		handle_error();
152 	if( *SCLSR & LSR_ORER )
153 		handle_error();
154 	return (status & ( FSR_DR | FSR_RDF ));
155 }
156 
157 int serial_getc (void)
158 {
159 	unsigned short status ;
160 	char ch;
161 	while(!serial_getc_check());
162 
163 	ch = *SCFRDR;
164 	status =  *SCFSR ;
165 
166 	*SCFSR = RDRF_CLEAR ;
167 
168 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
169 		handle_error();
170 
171 	if( *SCLSR & LSR_ORER )
172 		handle_error();
173 
174 	return ch ;
175 }
176 
177 #endif	/* CFG_SCIF_CONSOLE */
178