xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision b97a2a0a)
1 /*
2  * SuperH SCIF device driver.
3  * Copyright (c) 2007,2008 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_CPU_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_CPU_SH7720 /* SH7720 specific */
61 #define SCLSR   (vu_short *)(SCIF_BASE + 0x24)
62 #define LSR_ORER	0x0200
63 #else
64 #define SCLSR	SCFSR	/* SCSSR */
65 #define LSR_ORER	1
66 #endif
67 #endif
68 
69 #if defined(CONFIG_CPU_SH7720)
70 #define SCBRR_VALUE(bps, clk) (((clk*2)+16*bps)/(32*bps)-1)
71 #else	/* Generic SuperH */
72 #define SCBRR_VALUE(bps, clk) ((clk+16*bps)/(32*bps)-1)
73 #endif
74 
75 #define SCR_RE 		(1 << 4)
76 #define SCR_TE 		(1 << 5)
77 #define FCR_RFRST	(1 << 1) /* RFCL */
78 #define FCR_TFRST	(1 << 2) /* TFCL */
79 #define FSR_DR   	(1 << 0)
80 #define FSR_RDF  	(1 << 1)
81 #define FSR_FER  	(1 << 3)
82 #define FSR_BRK  	(1 << 4)
83 #define FSR_FER  	(1 << 3)
84 #define FSR_TEND 	(1 << 6)
85 #define FSR_ER   	(1 << 7)
86 
87 /*----------------------------------------------------------------------*/
88 
89 void serial_setbrg (void)
90 {
91 	DECLARE_GLOBAL_DATA_PTR;
92 	*SCBRR = SCBRR_VALUE(gd->baudrate,CONFIG_SYS_CLK_FREQ);
93 }
94 
95 int serial_init (void)
96 {
97 	*SCSCR = (SCR_RE | SCR_TE);
98 	*SCSMR = 0 ;
99 	*SCSMR = 0;
100 	*SCFCR = (FCR_RFRST | FCR_TFRST);
101 	*SCFCR;
102 	*SCFCR = 0;
103 
104 	serial_setbrg();
105 	return 0;
106 }
107 
108 static int serial_tx_fifo_level (void)
109 {
110 	return (*SCFDR >> 8) & 0x1F;
111 }
112 
113 static int serial_rx_fifo_level (void)
114 {
115 	return (*SCFDR >> 0) & 0x1F;
116 }
117 
118 void serial_raw_putc (const char c)
119 {
120 	unsigned int fsr_bits_to_clear;
121 
122 	while (1) {
123 		if (*SCFSR & FSR_TEND) {		/* Tx fifo is empty */
124 			fsr_bits_to_clear = FSR_TEND;
125 			break;
126 		}
127 	}
128 
129 	*SCFTDR = c;
130 	if (fsr_bits_to_clear != 0)
131 		*SCFSR &= ~fsr_bits_to_clear;
132 }
133 
134 void serial_putc (const char c)
135 {
136 	if (c == '\n')
137 		serial_raw_putc ('\r');
138 	serial_raw_putc (c);
139 }
140 
141 void serial_puts (const char *s)
142 {
143 	char c;
144 	while ((c = *s++) != 0)
145 		serial_putc (c);
146 }
147 
148 int serial_tstc (void)
149 {
150 	return serial_rx_fifo_level() ? 1 : 0;
151 }
152 
153 #define FSR_ERR_CLEAR   0x0063
154 #define RDRF_CLEAR      0x00fc
155 void handle_error( void ){
156 
157 	(void)*SCFSR ;
158 	*SCFSR = FSR_ERR_CLEAR ;
159 	(void)*SCLSR ;
160 	*SCLSR = 0x00 ;
161 }
162 
163 int serial_getc_check( void ){
164 	unsigned short status;
165 
166 	status = *SCFSR ;
167 
168 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
169 		handle_error();
170 	if( *SCLSR & LSR_ORER )
171 		handle_error();
172 	return (status & ( FSR_DR | FSR_RDF ));
173 }
174 
175 int serial_getc (void)
176 {
177 	unsigned short status ;
178 	char ch;
179 	while(!serial_getc_check());
180 
181 	ch = *SCFRDR;
182 	status =  *SCFSR ;
183 
184 	*SCFSR = RDRF_CLEAR ;
185 
186 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
187 		handle_error();
188 
189 	if( *SCLSR & LSR_ORER )
190 		handle_error();
191 
192 	return ch ;
193 }
194 
195 #endif	/* CFG_SCIF_CONSOLE */
196