xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision afea2c96)
1 /*
2  * SuperH SCIF device driver.
3  * Copyright (C) 2013  Renesas Electronics Corporation
4  * Copyright (C) 2007,2008,2010 Nobuhiro Iwamatsu
5  * Copyright (C) 2002 - 2008  Paul Mundt
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 #include <asm/io.h>
12 #include <asm/processor.h>
13 #include "serial_sh.h"
14 #include <serial.h>
15 #include <linux/compiler.h>
16 
17 #if defined(CONFIG_CONS_SCIF0)
18 # define SCIF_BASE	SCIF0_BASE
19 #elif defined(CONFIG_CONS_SCIF1)
20 # define SCIF_BASE	SCIF1_BASE
21 #elif defined(CONFIG_CONS_SCIF2)
22 # define SCIF_BASE	SCIF2_BASE
23 #elif defined(CONFIG_CONS_SCIF3)
24 # define SCIF_BASE	SCIF3_BASE
25 #elif defined(CONFIG_CONS_SCIF4)
26 # define SCIF_BASE	SCIF4_BASE
27 #elif defined(CONFIG_CONS_SCIF5)
28 # define SCIF_BASE	SCIF5_BASE
29 #elif defined(CONFIG_CONS_SCIF6)
30 # define SCIF_BASE	SCIF6_BASE
31 #elif defined(CONFIG_CONS_SCIF7)
32 # define SCIF_BASE	SCIF7_BASE
33 #else
34 # error "Default SCIF doesn't set....."
35 #endif
36 
37 #if defined(CONFIG_SCIF_A)
38 	#define SCIF_BASE_PORT	PORT_SCIFA
39 #else
40 	#define SCIF_BASE_PORT	PORT_SCIF
41 #endif
42 
43 static struct uart_port sh_sci = {
44 	.membase	= (unsigned char*)SCIF_BASE,
45 	.mapbase	= SCIF_BASE,
46 	.type		= SCIF_BASE_PORT,
47 };
48 
49 static void sh_serial_setbrg(void)
50 {
51 	DECLARE_GLOBAL_DATA_PTR;
52 
53 	sci_out(&sh_sci, SCBRR,
54 		SCBRR_VALUE(gd->baudrate, CONFIG_SH_SCIF_CLK_FREQ));
55 }
56 
57 static int sh_serial_init(void)
58 {
59 	sci_out(&sh_sci, SCSCR , SCSCR_INIT(&sh_sci));
60 	sci_out(&sh_sci, SCSCR , SCSCR_INIT(&sh_sci));
61 	sci_out(&sh_sci, SCSMR, 0);
62 	sci_out(&sh_sci, SCSMR, 0);
63 	sci_out(&sh_sci, SCFCR, SCFCR_RFRST|SCFCR_TFRST);
64 	sci_in(&sh_sci, SCFCR);
65 	sci_out(&sh_sci, SCFCR, 0);
66 
67 	serial_setbrg();
68 	return 0;
69 }
70 
71 #if defined(CONFIG_CPU_SH7760) || \
72 	defined(CONFIG_CPU_SH7780) || \
73 	defined(CONFIG_CPU_SH7785) || \
74 	defined(CONFIG_CPU_SH7786)
75 static int scif_rxfill(struct uart_port *port)
76 {
77 	return sci_in(port, SCRFDR) & 0xff;
78 }
79 #elif defined(CONFIG_CPU_SH7763)
80 static int scif_rxfill(struct uart_port *port)
81 {
82 	if ((port->mapbase == 0xffe00000) ||
83 		(port->mapbase == 0xffe08000)) {
84 		/* SCIF0/1*/
85 		return sci_in(port, SCRFDR) & 0xff;
86 	} else {
87 		/* SCIF2 */
88 		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
89 	}
90 }
91 #elif defined(CONFIG_ARCH_SH7372)
92 static int scif_rxfill(struct uart_port *port)
93 {
94 	if (port->type == PORT_SCIFA)
95 		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
96 	else
97 		return sci_in(port, SCRFDR);
98 }
99 #else
100 static int scif_rxfill(struct uart_port *port)
101 {
102 	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
103 }
104 #endif
105 
106 static int serial_rx_fifo_level(void)
107 {
108 	return scif_rxfill(&sh_sci);
109 }
110 
111 static void handle_error(void)
112 {
113 	sci_in(&sh_sci, SCxSR);
114 	sci_out(&sh_sci, SCxSR, SCxSR_ERROR_CLEAR(&sh_sci));
115 	sci_in(&sh_sci, SCLSR);
116 	sci_out(&sh_sci, SCLSR, 0x00);
117 }
118 
119 void serial_raw_putc(const char c)
120 {
121 	while (1) {
122 		/* Tx fifo is empty */
123 		if (sci_in(&sh_sci, SCxSR) & SCxSR_TEND(&sh_sci))
124 			break;
125 	}
126 
127 	sci_out(&sh_sci, SCxTDR, c);
128 	sci_out(&sh_sci, SCxSR, sci_in(&sh_sci, SCxSR) & ~SCxSR_TEND(&sh_sci));
129 }
130 
131 static void sh_serial_putc(const char c)
132 {
133 	if (c == '\n')
134 		serial_raw_putc('\r');
135 	serial_raw_putc(c);
136 }
137 
138 static int sh_serial_tstc(void)
139 {
140 	if (sci_in(&sh_sci, SCxSR) & SCIF_ERRORS) {
141 		handle_error();
142 		return 0;
143 	}
144 
145 	return serial_rx_fifo_level() ? 1 : 0;
146 }
147 
148 
149 int serial_getc_check(void)
150 {
151 	unsigned short status;
152 
153 	status = sci_in(&sh_sci, SCxSR);
154 
155 	if (status & SCIF_ERRORS)
156 		handle_error();
157 	if (sci_in(&sh_sci, SCLSR) & SCxSR_ORER(&sh_sci))
158 		handle_error();
159 	return status & (SCIF_DR | SCxSR_RDxF(&sh_sci));
160 }
161 
162 static int sh_serial_getc(void)
163 {
164 	unsigned short status;
165 	char ch;
166 
167 	while (!serial_getc_check())
168 		;
169 
170 	ch = sci_in(&sh_sci, SCxRDR);
171 	status = sci_in(&sh_sci, SCxSR);
172 
173 	sci_out(&sh_sci, SCxSR, SCxSR_RDxF_CLEAR(&sh_sci));
174 
175 	if (status & SCIF_ERRORS)
176 			handle_error();
177 
178 	if (sci_in(&sh_sci, SCLSR) & SCxSR_ORER(&sh_sci))
179 		handle_error();
180 	return ch;
181 }
182 
183 static struct serial_device sh_serial_drv = {
184 	.name	= "sh_serial",
185 	.start	= sh_serial_init,
186 	.stop	= NULL,
187 	.setbrg	= sh_serial_setbrg,
188 	.putc	= sh_serial_putc,
189 	.puts	= default_serial_puts,
190 	.getc	= sh_serial_getc,
191 	.tstc	= sh_serial_tstc,
192 };
193 
194 void sh_serial_initialize(void)
195 {
196 	serial_register(&sh_serial_drv);
197 }
198 
199 __weak struct serial_device *default_serial_console(void)
200 {
201 	return &sh_serial_drv;
202 }
203