xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 32c81ea6)
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 #ifdef CONFIG_SCIF_USE_EXT_CLK
53 	unsigned short dl = DL_VALUE(gd->baudrate, CONFIG_SH_SCIF_CLK_FREQ);
54 	sci_out(&sh_sci, DL, dl);
55 	/* Need wait: Clock * 1/dl $B!_(B 1/16 */
56 	udelay((1000000 * dl * 16 / CONFIG_SYS_CLK_FREQ) * 1000 + 1);
57 #else
58 	sci_out(&sh_sci, SCBRR,
59 		SCBRR_VALUE(gd->baudrate, CONFIG_SH_SCIF_CLK_FREQ));
60 #endif
61 }
62 
63 static int sh_serial_init(void)
64 {
65 	sci_out(&sh_sci, SCSCR , SCSCR_INIT(&sh_sci));
66 	sci_out(&sh_sci, SCSCR , SCSCR_INIT(&sh_sci));
67 	sci_out(&sh_sci, SCSMR, 0);
68 	sci_out(&sh_sci, SCSMR, 0);
69 	sci_out(&sh_sci, SCFCR, SCFCR_RFRST|SCFCR_TFRST);
70 	sci_in(&sh_sci, SCFCR);
71 	sci_out(&sh_sci, SCFCR, 0);
72 
73 	serial_setbrg();
74 	return 0;
75 }
76 
77 #if defined(CONFIG_CPU_SH7760) || \
78 	defined(CONFIG_CPU_SH7780) || \
79 	defined(CONFIG_CPU_SH7785) || \
80 	defined(CONFIG_CPU_SH7786)
81 static int scif_rxfill(struct uart_port *port)
82 {
83 	return sci_in(port, SCRFDR) & 0xff;
84 }
85 #elif defined(CONFIG_CPU_SH7763)
86 static int scif_rxfill(struct uart_port *port)
87 {
88 	if ((port->mapbase == 0xffe00000) ||
89 		(port->mapbase == 0xffe08000)) {
90 		/* SCIF0/1*/
91 		return sci_in(port, SCRFDR) & 0xff;
92 	} else {
93 		/* SCIF2 */
94 		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
95 	}
96 }
97 #elif defined(CONFIG_ARCH_SH7372)
98 static int scif_rxfill(struct uart_port *port)
99 {
100 	if (port->type == PORT_SCIFA)
101 		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
102 	else
103 		return sci_in(port, SCRFDR);
104 }
105 #else
106 static int scif_rxfill(struct uart_port *port)
107 {
108 	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
109 }
110 #endif
111 
112 static int serial_rx_fifo_level(void)
113 {
114 	return scif_rxfill(&sh_sci);
115 }
116 
117 static void handle_error(void)
118 {
119 	sci_in(&sh_sci, SCxSR);
120 	sci_out(&sh_sci, SCxSR, SCxSR_ERROR_CLEAR(&sh_sci));
121 	sci_in(&sh_sci, SCLSR);
122 	sci_out(&sh_sci, SCLSR, 0x00);
123 }
124 
125 static void serial_raw_putc(const char c)
126 {
127 	while (1) {
128 		/* Tx fifo is empty */
129 		if (sci_in(&sh_sci, SCxSR) & SCxSR_TEND(&sh_sci))
130 			break;
131 	}
132 
133 	sci_out(&sh_sci, SCxTDR, c);
134 	sci_out(&sh_sci, SCxSR, sci_in(&sh_sci, SCxSR) & ~SCxSR_TEND(&sh_sci));
135 }
136 
137 static void sh_serial_putc(const char c)
138 {
139 	if (c == '\n')
140 		serial_raw_putc('\r');
141 	serial_raw_putc(c);
142 }
143 
144 static int sh_serial_tstc(void)
145 {
146 	if (sci_in(&sh_sci, SCxSR) & SCIF_ERRORS) {
147 		handle_error();
148 		return 0;
149 	}
150 
151 	return serial_rx_fifo_level() ? 1 : 0;
152 }
153 
154 
155 static int serial_getc_check(void)
156 {
157 	unsigned short status;
158 
159 	status = sci_in(&sh_sci, SCxSR);
160 
161 	if (status & SCIF_ERRORS)
162 		handle_error();
163 	if (sci_in(&sh_sci, SCLSR) & SCxSR_ORER(&sh_sci))
164 		handle_error();
165 	return status & (SCIF_DR | SCxSR_RDxF(&sh_sci));
166 }
167 
168 static int sh_serial_getc(void)
169 {
170 	unsigned short status;
171 	char ch;
172 
173 	while (!serial_getc_check())
174 		;
175 
176 	ch = sci_in(&sh_sci, SCxRDR);
177 	status = sci_in(&sh_sci, SCxSR);
178 
179 	sci_out(&sh_sci, SCxSR, SCxSR_RDxF_CLEAR(&sh_sci));
180 
181 	if (status & SCIF_ERRORS)
182 			handle_error();
183 
184 	if (sci_in(&sh_sci, SCLSR) & SCxSR_ORER(&sh_sci))
185 		handle_error();
186 	return ch;
187 }
188 
189 static struct serial_device sh_serial_drv = {
190 	.name	= "sh_serial",
191 	.start	= sh_serial_init,
192 	.stop	= NULL,
193 	.setbrg	= sh_serial_setbrg,
194 	.putc	= sh_serial_putc,
195 	.puts	= default_serial_puts,
196 	.getc	= sh_serial_getc,
197 	.tstc	= sh_serial_tstc,
198 };
199 
200 void sh_serial_initialize(void)
201 {
202 	serial_register(&sh_serial_drv);
203 }
204 
205 __weak struct serial_device *default_serial_console(void)
206 {
207 	return &sh_serial_drv;
208 }
209