xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 1ac559d4)
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 /* Base register */
34 #define SCSMR	(vu_short *)(SCIF_BASE + 0x0)
35 #define SCBRR	(vu_char  *)(SCIF_BASE + 0x4)
36 #define SCSCR	(vu_short *)(SCIF_BASE + 0x8)
37 #define SCFCR	(vu_short *)(SCIF_BASE + 0x18)
38 #define SCFDR	(vu_short *)(SCIF_BASE + 0x1C)
39 #ifdef CONFIG_SH7720 /* SH7720 specific */
40 #define SCFSR	(vu_short *)(SCIF_BASE + 0x14)   /* SCSSR */
41 #define SCFTDR	(vu_char  *)(SCIF_BASE + 0x20)
42 #define SCFRDR	(vu_char  *)(SCIF_BASE + 0x24)
43 #else
44 #define SCFTDR 	(vu_char  *)(SCIF_BASE + 0xC)
45 #define SCFSR 	(vu_short *)(SCIF_BASE + 0x10)
46 #define SCFRDR 	(vu_char  *)(SCIF_BASE + 0x14)
47 #endif
48 
49 #if defined(CONFIG_SH4A)
50 #define SCRFDR	(vu_short *)(SCIF_BASE + 0x20)
51 #define SCSPTR	(vu_short *)(SCIF_BASE + 0x24)
52 #define SCLSR   (vu_short *)(SCIF_BASE + 0x28)
53 #define SCRER	(vu_short *)(SCIF_BASE + 0x2C)
54 #define LSR_ORER	1
55 #elif defined (CONFIG_SH4)
56 #define SCSPTR 	(vu_short *)(SCIF_BASE + 0x20)
57 #define SCLSR 	(vu_short *)(SCIF_BASE + 0x24)
58 #define LSR_ORER	1
59 #elif defined (CONFIG_SH3)
60 #ifdef CONFIG_SH7720 /* SH7720 specific */
61 # define SCLSR	SCFSR	/* SCSSR */
62 #else
63 # define SCLSR   (vu_short *)(SCIF_BASE + 0x24)
64 #endif
65 #define LSR_ORER	0x0200
66 #endif
67 
68 #define SCR_RE 		(1 << 4)
69 #define SCR_TE 		(1 << 5)
70 #define FCR_RFRST	(1 << 1) /* RFCL */
71 #define FCR_TFRST	(1 << 2) /* TFCL */
72 #define FSR_DR   	(1 << 0)
73 #define FSR_RDF  	(1 << 1)
74 #define FSR_FER  	(1 << 3)
75 #define FSR_BRK  	(1 << 4)
76 #define FSR_FER  	(1 << 3)
77 #define FSR_TEND 	(1 << 6)
78 #define FSR_ER   	(1 << 7)
79 
80 /*----------------------------------------------------------------------*/
81 
82 void serial_setbrg (void)
83 {
84 	DECLARE_GLOBAL_DATA_PTR;
85 
86 #if defined(CONFIG_CPU_SH7720)
87 	int divisor = gd->baudrate * 16;
88 
89 	*SCBRR = (CONFIG_SYS_CLK_FREQ * 2 + (divisor / 2)) /
90 						(gd->baudrate * 32) - 1;
91 #else
92 	int divisor = gd->baudrate * 32;
93 
94 	*SCBRR = (CONFIG_SYS_CLK_FREQ + (divisor / 2)) /
95 						(gd->baudrate * 32) - 1;
96 #endif
97 }
98 
99 int serial_init (void)
100 {
101 	*SCSCR = (SCR_RE | SCR_TE);
102 	*SCSMR = 0 ;
103 	*SCSMR = 0;
104 	*SCFCR = (FCR_RFRST | FCR_TFRST);
105 	*SCFCR;
106 	*SCFCR = 0;
107 
108 	serial_setbrg();
109 	return 0;
110 }
111 
112 static int serial_tx_fifo_level (void)
113 {
114 	return (*SCFDR >> 8) & 0x1F;
115 }
116 
117 static int serial_rx_fifo_level (void)
118 {
119 	return (*SCFDR >> 0) & 0x1F;
120 }
121 
122 void serial_raw_putc (const char c)
123 {
124 	unsigned int fsr_bits_to_clear;
125 
126 	while (1) {
127 		if (*SCFSR & FSR_TEND) {		/* Tx fifo is empty */
128 			fsr_bits_to_clear = FSR_TEND;
129 			break;
130 		}
131 	}
132 
133 	*SCFTDR = c;
134 	if (fsr_bits_to_clear != 0)
135 		*SCFSR &= ~fsr_bits_to_clear;
136 }
137 
138 void serial_putc (const char c)
139 {
140 	if (c == '\n')
141 		serial_raw_putc ('\r');
142 	serial_raw_putc (c);
143 }
144 
145 void serial_puts (const char *s)
146 {
147 	char c;
148 	while ((c = *s++) != 0)
149 		serial_putc (c);
150 }
151 
152 int serial_tstc (void)
153 {
154 	return serial_rx_fifo_level() ? 1 : 0;
155 }
156 
157 #define FSR_ERR_CLEAR   0x0063
158 #define RDRF_CLEAR      0x00fc
159 void handle_error( void ){
160 
161 	(void)*SCFSR ;
162 	*SCFSR = FSR_ERR_CLEAR ;
163 	(void)*SCLSR ;
164 	*SCLSR = 0x00 ;
165 }
166 
167 int serial_getc_check( void ){
168 	unsigned short status;
169 
170 	status = *SCFSR ;
171 
172 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
173 		handle_error();
174 	if( *SCLSR & LSR_ORER )
175 		handle_error();
176 	return (status & ( FSR_DR | FSR_RDF ));
177 }
178 
179 int serial_getc (void)
180 {
181 	unsigned short status ;
182 	char ch;
183 	while(!serial_getc_check());
184 
185 	ch = *SCFRDR;
186 	status =  *SCFSR ;
187 
188 	*SCFSR = RDRF_CLEAR ;
189 
190 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
191 		handle_error();
192 
193 	if( *SCLSR & LSR_ORER )
194 		handle_error();
195 
196 	return ch ;
197 }
198 
199 #endif	/* CFG_SCIF_CONSOLE */
200