1 /*
2  * linux/arch/m68k/mac/debug.c
3  *
4  * Shamelessly stolen (SCC code and general framework) from:
5  *
6  * linux/arch/m68k/atari/debug.c
7  *
8  * Atari debugging and serial console stuff
9  *
10  * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
11  *
12  * This file is subject to the terms and conditions of the GNU General Public
13  * License.  See the file COPYING in the main directory of this archive
14  * for more details.
15  */
16 
17 #include <linux/config.h>
18 #include <linux/types.h>
19 #include <linux/sched.h>
20 #include <linux/tty.h>
21 #include <linux/console.h>
22 #include <linux/init.h>
23 #include <linux/delay.h>
24 
25 #define BOOTINFO_COMPAT_1_0
26 #include <asm/setup.h>
27 #include <asm/bootinfo.h>
28 #include <asm/machw.h>
29 #include <asm/macints.h>
30 
31 extern char m68k_debug_device[];
32 
33 extern struct compat_bootinfo compat_boot_info;
34 
35 extern unsigned long mac_videobase;
36 extern unsigned long mac_videodepth;
37 extern unsigned long mac_rowbytes;
38 
39 extern void mac_serial_print(const char *);
40 
41 #define DEBUG_HEADS
42 #undef DEBUG_SCREEN
43 #define DEBUG_SERIAL
44 
45 /*
46  * These two auxiliary debug functions should go away ASAP. Only usage:
47  * before the console output is up (after head.S come some other crucial
48  * setup routines :-) it permits writing 'data' to the screen as bit patterns
49  * (good luck reading those). Helped to figure that the bootinfo contained
50  * garbage data on the amount and size of memory chunks ...
51  *
52  * The 'pos' argument now simply means 'linefeed after print' ...
53  */
54 
55 #ifdef DEBUG_SCREEN
56 static int peng=0, line=0;
57 #endif
58 
mac_debugging_short(int pos,short num)59 void mac_debugging_short(int pos, short num)
60 {
61 #ifdef DEBUG_SCREEN
62 	unsigned char *pengoffset;
63 	unsigned char *pptr;
64 	int i;
65 #endif
66 
67 #ifdef DEBUG_SERIAL
68 	printk("debug: %d !\n", num);
69 #endif
70 
71 #ifdef DEBUG_SCREEN
72 	if (!MACH_IS_MAC) {
73 		/* printk("debug: %d !\n", num); */
74 		return;
75 	}
76 
77 	/* calculate current offset */
78 	pengoffset=(unsigned char *)(mac_videobase+(150+line*2)*mac_rowbytes)
79 		    +80*peng;
80 
81 	pptr=pengoffset;
82 
83 	for(i=0;i<8*sizeof(short);i++) /* # of bits */
84 	{
85 		/*        value        mask for bit i, reverse order */
86 		*pptr++ = (num & ( 1 << (8*sizeof(short)-i-1) ) ? 0xFF : 0x00);
87 	}
88 
89 	peng++;
90 
91 	if (pos) {
92 		line++;
93 		peng = 0;
94 	}
95 #endif
96 }
97 
mac_debugging_long(int pos,long addr)98 void mac_debugging_long(int pos, long addr)
99 {
100 #ifdef DEBUG_SCREEN
101 	unsigned char *pengoffset;
102 	unsigned char *pptr;
103 	int i;
104 #endif
105 
106 #ifdef DEBUG_SERIAL
107 	printk("debug: #%ld !\n", addr);
108 #endif
109 
110 #ifdef DEBUG_SCREEN
111 	if (!MACH_IS_MAC) {
112 		/* printk("debug: #%ld !\n", addr); */
113 		return;
114 	}
115 
116 	pengoffset=(unsigned char *)(mac_videobase+(150+line*2)*mac_rowbytes)
117 		    +80*peng;
118 
119 	pptr=pengoffset;
120 
121 	for(i=0;i<8*sizeof(long);i++) /* # of bits */
122 	{
123 		*pptr++ = (addr & ( 1 << (8*sizeof(long)-i-1) ) ? 0xFF : 0x00);
124 	}
125 
126 	peng++;
127 
128 	if (pos) {
129 		line++;
130 		peng = 0;
131 	}
132 #endif
133 }
134 
135 #ifdef DEBUG_SERIAL
136 /*
137  * TODO: serial debug code
138  */
139 
140 struct mac_SCC
141  {
142   u_char cha_b_ctrl;
143   u_char char_dummy1;
144   u_char cha_a_ctrl;
145   u_char char_dummy2;
146   u_char cha_b_data;
147   u_char char_dummy3;
148   u_char cha_a_data;
149  };
150 
151 # define scc (*((volatile struct mac_SCC*)mac_bi_data.sccbase))
152 
153 /* Flag that serial port is already initialized and used */
154 int mac_SCC_init_done = 0;
155 /* Can be set somewhere, if a SCC master reset has already be done and should
156  * not be repeated; used by kgdb */
157 int mac_SCC_reset_done = 0;
158 
159 static int scc_port = -1;
160 
161 static struct console mac_console_driver = {
162 	name:		"debug",
163 	flags:		CON_PRINTBUFFER,
164 	index:		-1,
165 };
166 
167 /*
168  * Crude hack to get console output to the screen before the framebuffer
169  * is initialized (happens a lot later in 2.1!).
170  * We just use the console routines declared in head.S, this will interfere
171  * with regular framebuffer console output and should be used exclusively
172  * to debug kernel problems manifesting before framebuffer init (aka WSOD)
173  *
174  * To keep this hack from interfering with the regular console driver, either
175  * deregister this driver before/on framebuffer console init, or silence this
176  * function after the fbcon driver is running (will lose console messages!?).
177  * To debug real early bugs, need to write a 'mac_register_console_hack()'
178  * that is called from start_kernel() before setup_arch() and just registers
179  * this driver if Mac.
180  */
181 
mac_debug_console_write(struct console * co,const char * str,unsigned int count)182 void mac_debug_console_write (struct console *co, const char *str,
183 			      unsigned int count)
184 {
185 	mac_serial_print(str);
186 }
187 
188 
189 
190 /* Mac: loops_per_jiffy min. 19000 ^= .5 us; MFPDELAY was 0.6 us*/
191 
192 #define uSEC 1
193 
mac_sccb_out(char c)194 static inline void mac_sccb_out (char c)
195 {
196     int i;
197     do {
198 	for( i = uSEC; i > 0; --i )
199 		barrier();
200     } while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
201     for( i = uSEC; i > 0; --i )
202 	barrier();
203     scc.cha_b_data = c;
204 }
205 
mac_scca_out(char c)206 static inline void mac_scca_out (char c)
207 {
208     int i;
209     do {
210 	for( i = uSEC; i > 0; --i )
211 		barrier();
212     } while (!(scc.cha_a_ctrl & 0x04)); /* wait for tx buf empty */
213     for( i = uSEC; i > 0; --i )
214 	barrier();
215     scc.cha_a_data = c;
216 }
217 
mac_sccb_console_write(struct console * co,const char * str,unsigned int count)218 void mac_sccb_console_write (struct console *co, const char *str,
219 			      unsigned int count)
220 {
221     while (count--) {
222 	if (*str == '\n')
223 	    mac_sccb_out( '\r' );
224 	mac_sccb_out( *str++ );
225     }
226 }
227 
mac_scca_console_write(struct console * co,const char * str,unsigned int count)228 void mac_scca_console_write (struct console *co, const char *str,
229 			      unsigned int count)
230 {
231     while (count--) {
232 	if (*str == '\n')
233 	    mac_scca_out( '\r' );
234 	mac_scca_out( *str++ );
235     }
236 }
237 
238 /* The following two functions do a quick'n'dirty initialization of the MFP or
239  * SCC serial ports. They're used by the debugging interface, kgdb, and the
240  * serial console code. */
241 #define SCCB_WRITE(reg,val)				\
242     do {						\
243 	int i;						\
244 	scc.cha_b_ctrl = (reg);				\
245 	for( i = uSEC; i > 0; --i )			\
246 		barrier();				\
247 	scc.cha_b_ctrl = (val);				\
248 	for( i = uSEC; i > 0; --i )			\
249 		barrier();				\
250     } while(0)
251 
252 #define SCCA_WRITE(reg,val)				\
253     do {						\
254 	int i;						\
255 	scc.cha_a_ctrl = (reg);				\
256 	for( i = uSEC; i > 0; --i )			\
257 		barrier();				\
258 	scc.cha_a_ctrl = (val);				\
259 	for( i = uSEC; i > 0; --i )			\
260 		barrier();				\
261     } while(0)
262 
263 /* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
264  * delay of ~ 60us. */
265 /* Mac: loops_per_jiffy min. 19000 ^= .5 us; MFPDELAY was 0.6 us*/
266 #define LONG_DELAY()				\
267     do {					\
268 	int i;					\
269 	for( i = 60*uSEC; i > 0; --i )		\
270 	    barrier();				\
271     } while(0)
272 
273 #ifndef CONFIG_SERIAL_CONSOLE
mac_init_scc_port(int cflag,int port)274 static void __init mac_init_scc_port( int cflag, int port )
275 #else
276 void mac_init_scc_port( int cflag, int port )
277 #endif
278 {
279 	extern int mac_SCC_reset_done;
280 
281 	/*
282 	 * baud rates: 1200, 1800, 2400, 4800, 9600, 19.2k, 38.4k, 57.6k, 115.2k
283 	 */
284 
285 	static int clksrc_table[9] =
286 		/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
287     		{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
288 	static int clkmode_table[9] =
289 		/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
290     		{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
291 	static int div_table[9] =
292 		/* reg12 (BRG low) */
293     		{ 94, 62, 46, 22, 10, 4, 1, 0, 0 };
294 
295     int baud = cflag & CBAUD;
296     int clksrc, clkmode, div, reg3, reg5;
297 
298     if (cflag & CBAUDEX)
299 	baud += B38400;
300     if (baud < B1200 || baud > B38400+2)
301 	baud = B9600; /* use default 9600bps for non-implemented rates */
302     baud -= B1200; /* tables starts at 1200bps */
303 
304     clksrc  = clksrc_table[baud];
305     clkmode = clkmode_table[baud];
306     div     = div_table[baud];
307 
308     reg3 = (((cflag & CSIZE) == CS8) ? 0xc0 : 0x40);
309     reg5 = (((cflag & CSIZE) == CS8) ? 0x60 : 0x20) | 0x82 /* assert DTR/RTS */;
310 
311     if (port == 1) {
312 	    (void)scc.cha_b_ctrl;	/* reset reg pointer */
313 	    SCCB_WRITE( 9, 0xc0 );	/* reset */
314 	    LONG_DELAY();		/* extra delay after WR9 access */
315 	    SCCB_WRITE( 4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
316 			  0x04 /* 1 stopbit */ |
317 			  clkmode );
318 	    SCCB_WRITE( 3, reg3 );
319 	    SCCB_WRITE( 5, reg5 );
320 	    SCCB_WRITE( 9, 0 );		/* no interrupts */
321 	    LONG_DELAY();		/* extra delay after WR9 access */
322 	    SCCB_WRITE( 10, 0 );	/* NRZ mode */
323 	    SCCB_WRITE( 11, clksrc );	/* main clock source */
324 	    SCCB_WRITE( 12, div );	/* BRG value */
325 	    SCCB_WRITE( 13, 0 );		/* BRG high byte */
326 	    SCCB_WRITE( 14, 1 );
327 	    SCCB_WRITE( 3, reg3 | 1 );
328 	    SCCB_WRITE( 5, reg5 | 8 );
329     } else if (port == 0) {
330 	    (void)scc.cha_a_ctrl;	/* reset reg pointer */
331 	    SCCA_WRITE( 9, 0xc0 );	/* reset */
332 	    LONG_DELAY();		/* extra delay after WR9 access */
333 	    SCCA_WRITE( 4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
334 			  0x04 /* 1 stopbit */ |
335 			  clkmode );
336 	    SCCA_WRITE( 3, reg3 );
337 	    SCCA_WRITE( 5, reg5 );
338 	    SCCA_WRITE( 9, 0 );		/* no interrupts */
339 	    LONG_DELAY();		/* extra delay after WR9 access */
340 	    SCCA_WRITE( 10, 0 );	/* NRZ mode */
341 	    SCCA_WRITE( 11, clksrc );	/* main clock source */
342 	    SCCA_WRITE( 12, div );	/* BRG value */
343 	    SCCA_WRITE( 13, 0 );		/* BRG high byte */
344 	    SCCA_WRITE( 14, 1 );
345 	    SCCA_WRITE( 3, reg3 | 1 );
346 	    SCCA_WRITE( 5, reg5 | 8 );
347     }
348 
349     mac_SCC_reset_done = 1;
350     mac_SCC_init_done = 1;
351 }
352 #endif /* DEBUG_SERIAL */
353 
mac_init_scca_port(int cflag)354 void mac_init_scca_port( int cflag )
355 {
356 	mac_init_scc_port(cflag, 0);
357 }
358 
mac_init_sccb_port(int cflag)359 void mac_init_sccb_port( int cflag )
360 {
361 	mac_init_scc_port(cflag, 1);
362 }
363 
mac_debug_init(void)364 void __init mac_debug_init(void)
365 {
366 #ifdef DEBUG_SERIAL
367     if (   !strcmp( m68k_debug_device, "ser"  )
368         || !strcmp( m68k_debug_device, "ser1" )) {
369 	/* Mac modem port */
370 	mac_init_scc_port( B9600|CS8, 0 );
371 	mac_console_driver.write = mac_scca_console_write;
372 	scc_port = 0;
373     }
374     else if (!strcmp( m68k_debug_device, "ser2" )) {
375 	/* Mac printer port */
376 	mac_init_scc_port( B9600|CS8, 1 );
377 	mac_console_driver.write = mac_sccb_console_write;
378 	scc_port = 1;
379     }
380 #endif
381 #ifdef DEBUG_HEADS
382     if (   !strcmp( m68k_debug_device, "scn"  )
383         || !strcmp( m68k_debug_device, "con" )) {
384 	/* display, using head.S console routines */
385 	mac_console_driver.write = mac_debug_console_write;
386     }
387 #endif
388     if (mac_console_driver.write)
389 	register_console(&mac_console_driver);
390 }
391 
392 /*
393  * Local variables:
394  *  c-indent-level: 4
395  *  tab-width: 8
396  * End:
397  */
398