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[pohmelfs.git] / arch / powerpc / kernel / udbg_16550.c
blob6837f839ab78714dd435c3c70fe06215fd77835b
1 /*
2 * udbg for NS16550 compatible serial ports
4 * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 #include <linux/types.h>
12 #include <asm/udbg.h>
13 #include <asm/io.h>
14 #include <asm/reg_a2.h>
16 extern u8 real_readb(volatile u8 __iomem *addr);
17 extern void real_writeb(u8 data, volatile u8 __iomem *addr);
18 extern u8 real_205_readb(volatile u8 __iomem *addr);
19 extern void real_205_writeb(u8 data, volatile u8 __iomem *addr);
21 struct NS16550 {
22 /* this struct must be packed */
23 unsigned char rbr; /* 0 */
24 unsigned char ier; /* 1 */
25 unsigned char fcr; /* 2 */
26 unsigned char lcr; /* 3 */
27 unsigned char mcr; /* 4 */
28 unsigned char lsr; /* 5 */
29 unsigned char msr; /* 6 */
30 unsigned char scr; /* 7 */
33 #define thr rbr
34 #define iir fcr
35 #define dll rbr
36 #define dlm ier
37 #define dlab lcr
39 #define LSR_DR 0x01 /* Data ready */
40 #define LSR_OE 0x02 /* Overrun */
41 #define LSR_PE 0x04 /* Parity error */
42 #define LSR_FE 0x08 /* Framing error */
43 #define LSR_BI 0x10 /* Break */
44 #define LSR_THRE 0x20 /* Xmit holding register empty */
45 #define LSR_TEMT 0x40 /* Xmitter empty */
46 #define LSR_ERR 0x80 /* Error */
48 #define LCR_DLAB 0x80
50 static struct NS16550 __iomem *udbg_comport;
52 static void udbg_550_flush(void)
54 if (udbg_comport) {
55 while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)
56 /* wait for idle */;
60 static void udbg_550_putc(char c)
62 if (udbg_comport) {
63 if (c == '\n')
64 udbg_550_putc('\r');
65 udbg_550_flush();
66 out_8(&udbg_comport->thr, c);
70 static int udbg_550_getc_poll(void)
72 if (udbg_comport) {
73 if ((in_8(&udbg_comport->lsr) & LSR_DR) != 0)
74 return in_8(&udbg_comport->rbr);
75 else
76 return -1;
78 return -1;
81 static int udbg_550_getc(void)
83 if (udbg_comport) {
84 while ((in_8(&udbg_comport->lsr) & LSR_DR) == 0)
85 /* wait for char */;
86 return in_8(&udbg_comport->rbr);
88 return -1;
91 void udbg_init_uart(void __iomem *comport, unsigned int speed,
92 unsigned int clock)
94 unsigned int dll, base_bauds;
96 if (clock == 0)
97 clock = 1843200;
98 if (speed == 0)
99 speed = 9600;
101 base_bauds = clock / 16;
102 dll = base_bauds / speed;
104 if (comport) {
105 udbg_comport = (struct NS16550 __iomem *)comport;
106 out_8(&udbg_comport->lcr, 0x00);
107 out_8(&udbg_comport->ier, 0xff);
108 out_8(&udbg_comport->ier, 0x00);
109 out_8(&udbg_comport->lcr, LCR_DLAB);
110 out_8(&udbg_comport->dll, dll & 0xff);
111 out_8(&udbg_comport->dlm, dll >> 8);
112 /* 8 data, 1 stop, no parity */
113 out_8(&udbg_comport->lcr, 0x03);
114 /* RTS/DTR */
115 out_8(&udbg_comport->mcr, 0x03);
116 /* Clear & enable FIFOs */
117 out_8(&udbg_comport->fcr ,0x07);
118 udbg_putc = udbg_550_putc;
119 udbg_flush = udbg_550_flush;
120 udbg_getc = udbg_550_getc;
121 udbg_getc_poll = udbg_550_getc_poll;
125 unsigned int udbg_probe_uart_speed(void __iomem *comport, unsigned int clock)
127 unsigned int dll, dlm, divisor, prescaler, speed;
128 u8 old_lcr;
129 struct NS16550 __iomem *port = comport;
131 old_lcr = in_8(&port->lcr);
133 /* select divisor latch registers. */
134 out_8(&port->lcr, LCR_DLAB);
136 /* now, read the divisor */
137 dll = in_8(&port->dll);
138 dlm = in_8(&port->dlm);
139 divisor = dlm << 8 | dll;
141 /* check prescaling */
142 if (in_8(&port->mcr) & 0x80)
143 prescaler = 4;
144 else
145 prescaler = 1;
147 /* restore the LCR */
148 out_8(&port->lcr, old_lcr);
150 /* calculate speed */
151 speed = (clock / prescaler) / (divisor * 16);
153 /* sanity check */
154 if (speed > (clock / 16))
155 speed = 9600;
157 return speed;
160 #ifdef CONFIG_PPC_MAPLE
161 void udbg_maple_real_flush(void)
163 if (udbg_comport) {
164 while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
165 /* wait for idle */;
169 void udbg_maple_real_putc(char c)
171 if (udbg_comport) {
172 if (c == '\n')
173 udbg_maple_real_putc('\r');
174 udbg_maple_real_flush();
175 real_writeb(c, &udbg_comport->thr); eieio();
179 void __init udbg_init_maple_realmode(void)
181 udbg_comport = (struct NS16550 __iomem *)0xf40003f8;
183 udbg_putc = udbg_maple_real_putc;
184 udbg_flush = udbg_maple_real_flush;
185 udbg_getc = NULL;
186 udbg_getc_poll = NULL;
188 #endif /* CONFIG_PPC_MAPLE */
190 #ifdef CONFIG_PPC_PASEMI
191 void udbg_pas_real_flush(void)
193 if (udbg_comport) {
194 while ((real_205_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
195 /* wait for idle */;
199 void udbg_pas_real_putc(char c)
201 if (udbg_comport) {
202 if (c == '\n')
203 udbg_pas_real_putc('\r');
204 udbg_pas_real_flush();
205 real_205_writeb(c, &udbg_comport->thr); eieio();
209 void udbg_init_pas_realmode(void)
211 udbg_comport = (struct NS16550 __iomem *)0xfcff03f8UL;
213 udbg_putc = udbg_pas_real_putc;
214 udbg_flush = udbg_pas_real_flush;
215 udbg_getc = NULL;
216 udbg_getc_poll = NULL;
218 #endif /* CONFIG_PPC_MAPLE */
220 #ifdef CONFIG_PPC_EARLY_DEBUG_44x
221 #include <platforms/44x/44x.h>
223 static void udbg_44x_as1_flush(void)
225 if (udbg_comport) {
226 while ((as1_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
227 /* wait for idle */;
231 static void udbg_44x_as1_putc(char c)
233 if (udbg_comport) {
234 if (c == '\n')
235 udbg_44x_as1_putc('\r');
236 udbg_44x_as1_flush();
237 as1_writeb(c, &udbg_comport->thr); eieio();
241 static int udbg_44x_as1_getc(void)
243 if (udbg_comport) {
244 while ((as1_readb(&udbg_comport->lsr) & LSR_DR) == 0)
245 ; /* wait for char */
246 return as1_readb(&udbg_comport->rbr);
248 return -1;
251 void __init udbg_init_44x_as1(void)
253 udbg_comport =
254 (struct NS16550 __iomem *)PPC44x_EARLY_DEBUG_VIRTADDR;
256 udbg_putc = udbg_44x_as1_putc;
257 udbg_flush = udbg_44x_as1_flush;
258 udbg_getc = udbg_44x_as1_getc;
260 #endif /* CONFIG_PPC_EARLY_DEBUG_44x */
262 #ifdef CONFIG_PPC_EARLY_DEBUG_40x
263 static void udbg_40x_real_flush(void)
265 if (udbg_comport) {
266 while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
267 /* wait for idle */;
271 static void udbg_40x_real_putc(char c)
273 if (udbg_comport) {
274 if (c == '\n')
275 udbg_40x_real_putc('\r');
276 udbg_40x_real_flush();
277 real_writeb(c, &udbg_comport->thr); eieio();
281 static int udbg_40x_real_getc(void)
283 if (udbg_comport) {
284 while ((real_readb(&udbg_comport->lsr) & LSR_DR) == 0)
285 ; /* wait for char */
286 return real_readb(&udbg_comport->rbr);
288 return -1;
291 void __init udbg_init_40x_realmode(void)
293 udbg_comport = (struct NS16550 __iomem *)
294 CONFIG_PPC_EARLY_DEBUG_40x_PHYSADDR;
296 udbg_putc = udbg_40x_real_putc;
297 udbg_flush = udbg_40x_real_flush;
298 udbg_getc = udbg_40x_real_getc;
299 udbg_getc_poll = NULL;
301 #endif /* CONFIG_PPC_EARLY_DEBUG_40x */
303 #ifdef CONFIG_PPC_EARLY_DEBUG_WSP
304 static void udbg_wsp_flush(void)
306 if (udbg_comport) {
307 while ((readb(&udbg_comport->lsr) & LSR_THRE) == 0)
308 /* wait for idle */;
312 static void udbg_wsp_putc(char c)
314 if (udbg_comport) {
315 if (c == '\n')
316 udbg_wsp_putc('\r');
317 udbg_wsp_flush();
318 writeb(c, &udbg_comport->thr); eieio();
322 static int udbg_wsp_getc(void)
324 if (udbg_comport) {
325 while ((readb(&udbg_comport->lsr) & LSR_DR) == 0)
326 ; /* wait for char */
327 return readb(&udbg_comport->rbr);
329 return -1;
332 static int udbg_wsp_getc_poll(void)
334 if (udbg_comport)
335 if (readb(&udbg_comport->lsr) & LSR_DR)
336 return readb(&udbg_comport->rbr);
337 return -1;
340 void __init udbg_init_wsp(void)
342 udbg_comport = (struct NS16550 __iomem *)WSP_UART_VIRT;
344 udbg_init_uart(udbg_comport, 57600, 50000000);
346 udbg_putc = udbg_wsp_putc;
347 udbg_flush = udbg_wsp_flush;
348 udbg_getc = udbg_wsp_getc;
349 udbg_getc_poll = udbg_wsp_getc_poll;
351 #endif /* CONFIG_PPC_EARLY_DEBUG_WSP */