xref: /openbmc/u-boot/drivers/serial/serial_ns16550.c (revision 841977df21e5f2c1276ae5a33cca3ac4fb976ad9)
1 /*
2  * (C) Copyright 2000
3  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <linux/compiler.h>
10 
11 #include <ns16550.h>
12 #ifdef CONFIG_NS87308
13 #include <ns87308.h>
14 #endif
15 
16 #include <serial.h>
17 
18 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
19 
20 DECLARE_GLOBAL_DATA_PTR;
21 
22 #if !defined(CONFIG_CONS_INDEX)
23 #elif (CONFIG_CONS_INDEX < 1) || (CONFIG_CONS_INDEX > 6)
24 #error	"Invalid console index value."
25 #endif
26 
27 #if CONFIG_CONS_INDEX == 1 && !defined(CONFIG_SYS_NS16550_COM1)
28 #error	"Console port 1 defined but not configured."
29 #elif CONFIG_CONS_INDEX == 2 && !defined(CONFIG_SYS_NS16550_COM2)
30 #error	"Console port 2 defined but not configured."
31 #elif CONFIG_CONS_INDEX == 3 && !defined(CONFIG_SYS_NS16550_COM3)
32 #error	"Console port 3 defined but not configured."
33 #elif CONFIG_CONS_INDEX == 4 && !defined(CONFIG_SYS_NS16550_COM4)
34 #error	"Console port 4 defined but not configured."
35 #elif CONFIG_CONS_INDEX == 5 && !defined(CONFIG_SYS_NS16550_COM5)
36 #error	"Console port 5 defined but not configured."
37 #elif CONFIG_CONS_INDEX == 6 && !defined(CONFIG_SYS_NS16550_COM6)
38 #error	"Console port 6 defined but not configured."
39 #endif
40 
41 /* Note: The port number specified in the functions is 1 based.
42  *	 the array is 0 based.
43  */
44 static NS16550_t serial_ports[6] = {
45 #ifdef CONFIG_SYS_NS16550_COM1
46 	(NS16550_t)CONFIG_SYS_NS16550_COM1,
47 #else
48 	NULL,
49 #endif
50 #ifdef CONFIG_SYS_NS16550_COM2
51 	(NS16550_t)CONFIG_SYS_NS16550_COM2,
52 #else
53 	NULL,
54 #endif
55 #ifdef CONFIG_SYS_NS16550_COM3
56 	(NS16550_t)CONFIG_SYS_NS16550_COM3,
57 #else
58 	NULL,
59 #endif
60 #ifdef CONFIG_SYS_NS16550_COM4
61 	(NS16550_t)CONFIG_SYS_NS16550_COM4,
62 #else
63 	NULL,
64 #endif
65 #ifdef CONFIG_SYS_NS16550_COM5
66 	(NS16550_t)CONFIG_SYS_NS16550_COM5,
67 #else
68 	NULL,
69 #endif
70 #ifdef CONFIG_SYS_NS16550_COM6
71 	(NS16550_t)CONFIG_SYS_NS16550_COM6
72 #else
73 	NULL
74 #endif
75 };
76 
77 #define PORT	serial_ports[port-1]
78 
79 /* Multi serial device functions */
80 #define DECLARE_ESERIAL_FUNCTIONS(port) \
81 	static int  eserial##port##_init(void) \
82 	{ \
83 		int clock_divisor; \
84 		clock_divisor = calc_divisor(serial_ports[port-1]); \
85 		NS16550_init(serial_ports[port-1], clock_divisor); \
86 		return 0 ; \
87 	} \
88 	static void eserial##port##_setbrg(void) \
89 	{ \
90 		serial_setbrg_dev(port); \
91 	} \
92 	static int  eserial##port##_getc(void) \
93 	{ \
94 		return serial_getc_dev(port); \
95 	} \
96 	static int  eserial##port##_tstc(void) \
97 	{ \
98 		return serial_tstc_dev(port); \
99 	} \
100 	static void eserial##port##_putc(const char c) \
101 	{ \
102 		serial_putc_dev(port, c); \
103 	} \
104 	static void eserial##port##_puts(const char *s) \
105 	{ \
106 		serial_puts_dev(port, s); \
107 	}
108 
109 /* Serial device descriptor */
110 #define INIT_ESERIAL_STRUCTURE(port, __name) {	\
111 	.name	= __name,			\
112 	.start	= eserial##port##_init,		\
113 	.stop	= NULL,				\
114 	.setbrg	= eserial##port##_setbrg,	\
115 	.getc	= eserial##port##_getc,		\
116 	.tstc	= eserial##port##_tstc,		\
117 	.putc	= eserial##port##_putc,		\
118 	.puts	= eserial##port##_puts,		\
119 }
120 
121 static int calc_divisor (NS16550_t port)
122 {
123 #ifdef CONFIG_OMAP1510
124 	/* If can't cleanly clock 115200 set div to 1 */
125 	if ((CONFIG_SYS_NS16550_CLK == 12000000) && (gd->baudrate == 115200)) {
126 		port->osc_12m_sel = OSC_12M_SEL;	/* enable 6.5 * divisor */
127 		return (1);				/* return 1 for base divisor */
128 	}
129 	port->osc_12m_sel = 0;			/* clear if previsouly set */
130 #endif
131 
132 #define MODE_X_DIV 16
133 	/* Compute divisor value. Normally, we should simply return:
134 	 *   CONFIG_SYS_NS16550_CLK) / MODE_X_DIV / gd->baudrate
135 	 * but we need to round that value by adding 0.5.
136 	 * Rounding is especially important at high baud rates.
137 	 */
138 	return (CONFIG_SYS_NS16550_CLK + (gd->baudrate * (MODE_X_DIV / 2))) /
139 		(MODE_X_DIV * gd->baudrate);
140 }
141 
142 void
143 _serial_putc(const char c,const int port)
144 {
145 	if (c == '\n')
146 		NS16550_putc(PORT, '\r');
147 
148 	NS16550_putc(PORT, c);
149 }
150 
151 void
152 _serial_putc_raw(const char c,const int port)
153 {
154 	NS16550_putc(PORT, c);
155 }
156 
157 void
158 _serial_puts (const char *s,const int port)
159 {
160 	while (*s) {
161 		_serial_putc (*s++,port);
162 	}
163 }
164 
165 
166 int
167 _serial_getc(const int port)
168 {
169 	return NS16550_getc(PORT);
170 }
171 
172 int
173 _serial_tstc(const int port)
174 {
175 	return NS16550_tstc(PORT);
176 }
177 
178 void
179 _serial_setbrg (const int port)
180 {
181 	int clock_divisor;
182 
183 	clock_divisor = calc_divisor(PORT);
184 	NS16550_reinit(PORT, clock_divisor);
185 }
186 
187 static inline void
188 serial_putc_dev(unsigned int dev_index,const char c)
189 {
190 	_serial_putc(c,dev_index);
191 }
192 
193 static inline void
194 serial_putc_raw_dev(unsigned int dev_index,const char c)
195 {
196 	_serial_putc_raw(c,dev_index);
197 }
198 
199 static inline void
200 serial_puts_dev(unsigned int dev_index,const char *s)
201 {
202 	_serial_puts(s,dev_index);
203 }
204 
205 static inline int
206 serial_getc_dev(unsigned int dev_index)
207 {
208 	return _serial_getc(dev_index);
209 }
210 
211 static inline int
212 serial_tstc_dev(unsigned int dev_index)
213 {
214 	return _serial_tstc(dev_index);
215 }
216 
217 static inline void
218 serial_setbrg_dev(unsigned int dev_index)
219 {
220 	_serial_setbrg(dev_index);
221 }
222 
223 #if defined(CONFIG_SYS_NS16550_COM1)
224 DECLARE_ESERIAL_FUNCTIONS(1);
225 struct serial_device eserial1_device =
226 	INIT_ESERIAL_STRUCTURE(1, "eserial0");
227 #endif
228 #if defined(CONFIG_SYS_NS16550_COM2)
229 DECLARE_ESERIAL_FUNCTIONS(2);
230 struct serial_device eserial2_device =
231 	INIT_ESERIAL_STRUCTURE(2, "eserial1");
232 #endif
233 #if defined(CONFIG_SYS_NS16550_COM3)
234 DECLARE_ESERIAL_FUNCTIONS(3);
235 struct serial_device eserial3_device =
236 	INIT_ESERIAL_STRUCTURE(3, "eserial2");
237 #endif
238 #if defined(CONFIG_SYS_NS16550_COM4)
239 DECLARE_ESERIAL_FUNCTIONS(4);
240 struct serial_device eserial4_device =
241 	INIT_ESERIAL_STRUCTURE(4, "eserial3");
242 #endif
243 #if defined(CONFIG_SYS_NS16550_COM5)
244 DECLARE_ESERIAL_FUNCTIONS(5);
245 struct serial_device eserial5_device =
246 	INIT_ESERIAL_STRUCTURE(5, "eserial4");
247 #endif
248 #if defined(CONFIG_SYS_NS16550_COM6)
249 DECLARE_ESERIAL_FUNCTIONS(6);
250 struct serial_device eserial6_device =
251 	INIT_ESERIAL_STRUCTURE(6, "eserial5");
252 #endif
253 
254 __weak struct serial_device *default_serial_console(void)
255 {
256 #if CONFIG_CONS_INDEX == 1
257 	return &eserial1_device;
258 #elif CONFIG_CONS_INDEX == 2
259 	return &eserial2_device;
260 #elif CONFIG_CONS_INDEX == 3
261 	return &eserial3_device;
262 #elif CONFIG_CONS_INDEX == 4
263 	return &eserial4_device;
264 #elif CONFIG_CONS_INDEX == 5
265 	return &eserial5_device;
266 #elif CONFIG_CONS_INDEX == 6
267 	return &eserial6_device;
268 #else
269 #error "Bad CONFIG_CONS_INDEX."
270 #endif
271 }
272 
273 void ns16550_serial_initialize(void)
274 {
275 #if defined(CONFIG_SYS_NS16550_COM1)
276 	serial_register(&eserial1_device);
277 #endif
278 #if defined(CONFIG_SYS_NS16550_COM2)
279 	serial_register(&eserial2_device);
280 #endif
281 #if defined(CONFIG_SYS_NS16550_COM3)
282 	serial_register(&eserial3_device);
283 #endif
284 #if defined(CONFIG_SYS_NS16550_COM4)
285 	serial_register(&eserial4_device);
286 #endif
287 #if defined(CONFIG_SYS_NS16550_COM5)
288 	serial_register(&eserial5_device);
289 #endif
290 #if defined(CONFIG_SYS_NS16550_COM6)
291 	serial_register(&eserial6_device);
292 #endif
293 }
294 
295 #endif /* !CONFIG_NS16550_MIN_FUNCTIONS */
296