xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 7d9b5bae)
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 #if defined(CONFIG_CONS_SCIF0)
24 # define SCIF_BASE	SCIF0_BASE
25 #elif defined(CONFIG_CONS_SCIF1)
26 # define SCIF_BASE	SCIF1_BASE
27 #elif defined(CONFIG_CONS_SCIF2)
28 # define SCIF_BASE	SCIF2_BASE
29 #elif defined(CONFIG_CONS_SCIF3)
30 # define SCIF_BASE	SCIF3_BASE
31 #elif defined(CONFIG_CONS_SCIF4)
32 # define SCIF_BASE	SCIF4_BASE
33 #elif defined(CONFIG_CONS_SCIF5)
34 # define SCIF_BASE	SCIF5_BASE
35 #else
36 # error "Default SCIF doesn't set....."
37 #endif
38 
39 /* Base register */
40 #define SCSMR	(vu_short *)(SCIF_BASE + 0x0)
41 #define SCBRR	(vu_char  *)(SCIF_BASE + 0x4)
42 #define SCSCR	(vu_short *)(SCIF_BASE + 0x8)
43 #define SCFCR	(vu_short *)(SCIF_BASE + 0x18)
44 #define SCFDR	(vu_short *)(SCIF_BASE + 0x1C)
45 #if defined(CONFIG_CPU_SH7720) || \
46 	(defined(CONFIG_CPU_SH7723) && defined(CONFIG_SCIF_A))
47 # define SCFSR	(vu_short *)(SCIF_BASE + 0x14)	/* SCSSR */
48 # define SCFTDR	(vu_char  *)(SCIF_BASE + 0x20)
49 # define SCFRDR	(vu_char  *)(SCIF_BASE + 0x24)
50 #else
51 # define SCFTDR (vu_char  *)(SCIF_BASE + 0xC)
52 # define SCFSR 	(vu_short *)(SCIF_BASE + 0x10)
53 # define SCFRDR (vu_char  *)(SCIF_BASE + 0x14)
54 #endif
55 
56 #if	defined(CONFIG_CPU_SH7780) || \
57 	defined(CONFIG_CPU_SH7785)
58 # define SCRFDR	(vu_short *)(SCIF_BASE + 0x20)
59 # define SCSPTR	(vu_short *)(SCIF_BASE + 0x24)
60 # define SCLSR	(vu_short *)(SCIF_BASE + 0x28)
61 # define SCRER	(vu_short *)(SCIF_BASE + 0x2C)
62 # define LSR_ORER	1
63 # define FIFOLEVEL_MASK	0xFF
64 #elif defined(CONFIG_CPU_SH7763)
65 # if defined(CONFIG_CONS_SCIF2)
66 # define SCSPTR	(vu_short *)(SCIF_BASE + 0x20)
67 # define SCLSR 	(vu_short *)(SCIF_BASE + 0x24)
68 # define LSR_ORER	1
69 # define FIFOLEVEL_MASK	0x1F
70 # else
71 # define SCRFDR	(vu_short *)(SCIF_BASE + 0x20)
72 # define SCSPTR	(vu_short *)(SCIF_BASE + 0x24)
73 # define SCLSR	(vu_short *)(SCIF_BASE + 0x28)
74 # define SCRER	(vu_short *)(SCIF_BASE + 0x2C)
75 # define LSR_ORER	1
76 # define FIFOLEVEL_MASK	0xFF
77 # endif
78 #elif defined(CONFIG_CPU_SH7723)
79 # if defined(CONIFG_SCIF_A)
80 # define SCLSR	SCFSR
81 # define LSR_ORER	0x0200
82 # define FIFOLEVEL_MASK	0x3F
83 #else
84 # define SCLSR	(vu_short *)(SCIF_BASE + 0x24)
85 # define LSR_ORER	1
86 # define FIFOLEVEL_MASK	0x1F
87 #endif
88 #elif defined(CONFIG_CPU_SH7750) || \
89 	defined(CONFIG_CPU_SH7751) || \
90 	defined(CONFIG_CPU_SH7722) || \
91 	defined(CONFIG_CPU_SH7203)
92 # define SCSPTR	(vu_short *)(SCIF_BASE + 0x20)
93 # define SCLSR 	(vu_short *)(SCIF_BASE + 0x24)
94 # define LSR_ORER	1
95 # define FIFOLEVEL_MASK	0x1F
96 #elif defined(CONFIG_CPU_SH7720)
97 # define SCLSR		(vu_short *)(SCIF_BASE + 0x24)
98 # define LSR_ORER	0x0200
99 # define FIFOLEVEL_MASK	0x1F
100 #elif defined(CONFIG_CPU_SH7710) || \
101 	defined(CONFIG_CPU_SH7712)
102 # define SCLSR	SCFSR		/* SCSSR */
103 # define LSR_ORER	1
104 # define FIFOLEVEL_MASK	0x1F
105 #endif
106 
107 /* SCBRR register value setting */
108 #if defined(CONFIG_CPU_SH7720)
109 # define SCBRR_VALUE(bps, clk) (((clk*2)+16*bps)/(32*bps)-1)
110 #elif defined(CONFIG_CPU_SH7723) && defined(CONFIG_SCIF_A)
111 /* SH7723 SCIFA use bus clock. So clock *2 */
112 # define SCBRR_VALUE(bps, clk) (((clk*2*2)+16*bps)/(32*bps)-1)
113 #else /* Generic SuperH */
114 # define SCBRR_VALUE(bps, clk) ((clk+16*bps)/(32*bps)-1)
115 #endif
116 
117 #define SCR_RE 		(1 << 4)
118 #define SCR_TE 		(1 << 5)
119 #define FCR_RFRST	(1 << 1)	/* RFCL */
120 #define FCR_TFRST	(1 << 2)	/* TFCL */
121 #define FSR_DR   	(1 << 0)
122 #define FSR_RDF  	(1 << 1)
123 #define FSR_FER  	(1 << 3)
124 #define FSR_BRK  	(1 << 4)
125 #define FSR_FER  	(1 << 3)
126 #define FSR_TEND 	(1 << 6)
127 #define FSR_ER   	(1 << 7)
128 
129 /*----------------------------------------------------------------------*/
130 
131 void serial_setbrg(void)
132 {
133 	DECLARE_GLOBAL_DATA_PTR;
134 	*SCBRR = SCBRR_VALUE(gd->baudrate, CONFIG_SYS_CLK_FREQ);
135 }
136 
137 int serial_init(void)
138 {
139 	*SCSCR = (SCR_RE | SCR_TE);
140 	*SCSMR = 0;
141 	*SCSMR = 0;
142 	*SCFCR = (FCR_RFRST | FCR_TFRST);
143 	*SCFCR;
144 	*SCFCR = 0;
145 
146 	serial_setbrg();
147 	return 0;
148 }
149 
150 static int serial_rx_fifo_level(void)
151 {
152 #if defined(SCRFDR)
153 	return (*SCRFDR >> 0) & FIFOLEVEL_MASK;
154 #else
155 	return (*SCFDR >> 0) & FIFOLEVEL_MASK;
156 #endif
157 }
158 
159 void serial_raw_putc(const char c)
160 {
161 	unsigned int fsr_bits_to_clear;
162 
163 	while (1) {
164 		if (*SCFSR & FSR_TEND) {	/* Tx fifo is empty */
165 			fsr_bits_to_clear = FSR_TEND;
166 			break;
167 		}
168 	}
169 
170 	*SCFTDR = c;
171 	if (fsr_bits_to_clear != 0)
172 		*SCFSR &= ~fsr_bits_to_clear;
173 }
174 
175 void serial_putc(const char c)
176 {
177 	if (c == '\n')
178 		serial_raw_putc('\r');
179 	serial_raw_putc(c);
180 }
181 
182 void serial_puts(const char *s)
183 {
184 	char c;
185 	while ((c = *s++) != 0)
186 		serial_putc(c);
187 }
188 
189 int serial_tstc(void)
190 {
191 	return serial_rx_fifo_level() ? 1 : 0;
192 }
193 
194 #define FSR_ERR_CLEAR   0x0063
195 #define RDRF_CLEAR      0x00fc
196 void handle_error(void)
197 {
198 
199 	(void)*SCFSR;
200 	*SCFSR = FSR_ERR_CLEAR;
201 	(void)*SCLSR;
202 	*SCLSR = 0x00;
203 }
204 
205 int serial_getc_check(void)
206 {
207 	unsigned short status;
208 
209 	status = *SCFSR;
210 
211 	if (status & (FSR_FER | FSR_ER | FSR_BRK))
212 		handle_error();
213 	if (*SCLSR & LSR_ORER)
214 		handle_error();
215 	return status & (FSR_DR | FSR_RDF);
216 }
217 
218 int serial_getc(void)
219 {
220 	unsigned short status;
221 	char ch;
222 
223 	while (!serial_getc_check())
224 		;
225 
226 	ch = *SCFRDR;
227 	status = *SCFSR;
228 
229 	*SCFSR = RDRF_CLEAR;
230 
231 	if (status & (FSR_FER | FSR_FER | FSR_ER | FSR_BRK))
232 		handle_error();
233 
234 	if (*SCLSR & LSR_ORER)
235 		handle_error();
236 
237 	return ch;
238 }
239