xref: /openbmc/linux/arch/m68k/atari/debug.c (revision 22246614)
1 /*
2  * linux/arch/m68k/atari/debug.c
3  *
4  * Atari debugging and serial console stuff
5  *
6  * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file COPYING in the main directory of this archive
10  * for more details.
11  */
12 
13 #include <linux/types.h>
14 #include <linux/tty.h>
15 #include <linux/console.h>
16 #include <linux/init.h>
17 #include <linux/delay.h>
18 #include <linux/module.h>
19 
20 #include <asm/atarihw.h>
21 #include <asm/atariints.h>
22 
23 /* Flag that Modem1 port is already initialized and used */
24 int atari_MFP_init_done;
25 EXPORT_SYMBOL(atari_MFP_init_done);
26 
27 /* Flag that Modem1 port is already initialized and used */
28 int atari_SCC_init_done;
29 EXPORT_SYMBOL(atari_SCC_init_done);
30 
31 /* Can be set somewhere, if a SCC master reset has already be done and should
32  * not be repeated; used by kgdb */
33 int atari_SCC_reset_done;
34 EXPORT_SYMBOL(atari_SCC_reset_done);
35 
36 static struct console atari_console_driver = {
37 	.name	= "debug",
38 	.flags	= CON_PRINTBUFFER,
39 	.index	= -1,
40 };
41 
42 
43 static inline void ata_mfp_out(char c)
44 {
45 	while (!(mfp.trn_stat & 0x80))	/* wait for tx buf empty */
46 		barrier();
47 	mfp.usart_dta = c;
48 }
49 
50 void atari_mfp_console_write(struct console *co, const char *str,
51 			     unsigned int count)
52 {
53 	while (count--) {
54 		if (*str == '\n')
55 			ata_mfp_out('\r');
56 		ata_mfp_out(*str++);
57 	}
58 }
59 
60 static inline void ata_scc_out(char c)
61 {
62 	do {
63 		MFPDELAY();
64 	} while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
65 	MFPDELAY();
66 	scc.cha_b_data = c;
67 }
68 
69 void atari_scc_console_write(struct console *co, const char *str,
70 			     unsigned int count)
71 {
72 	while (count--) {
73 		if (*str == '\n')
74 			ata_scc_out('\r');
75 		ata_scc_out(*str++);
76 	}
77 }
78 
79 static inline void ata_midi_out(char c)
80 {
81 	while (!(acia.mid_ctrl & ACIA_TDRE))	/* wait for tx buf empty */
82 		barrier();
83 	acia.mid_data = c;
84 }
85 
86 void atari_midi_console_write(struct console *co, const char *str,
87 			      unsigned int count)
88 {
89 	while (count--) {
90 		if (*str == '\n')
91 			ata_midi_out('\r');
92 		ata_midi_out(*str++);
93 	}
94 }
95 
96 static int ata_par_out(char c)
97 {
98 	unsigned char tmp;
99 	/* This a some-seconds timeout in case no printer is connected */
100 	unsigned long i = loops_per_jiffy > 1 ? loops_per_jiffy : 10000000/HZ;
101 
102 	while ((mfp.par_dt_reg & 1) && --i) /* wait for BUSY == L */
103 		;
104 	if (!i)
105 		return 0;
106 
107 	sound_ym.rd_data_reg_sel = 15;	/* select port B */
108 	sound_ym.wd_data = c;		/* put char onto port */
109 	sound_ym.rd_data_reg_sel = 14;	/* select port A */
110 	tmp = sound_ym.rd_data_reg_sel;
111 	sound_ym.wd_data = tmp & ~0x20;	/* set strobe L */
112 	MFPDELAY();			/* wait a bit */
113 	sound_ym.wd_data = tmp | 0x20;	/* set strobe H */
114 	return 1;
115 }
116 
117 static void atari_par_console_write(struct console *co, const char *str,
118 				    unsigned int count)
119 {
120 	static int printer_present = 1;
121 
122 	if (!printer_present)
123 		return;
124 
125 	while (count--) {
126 		if (*str == '\n') {
127 			if (!ata_par_out('\r')) {
128 				printer_present = 0;
129 				return;
130 			}
131 		}
132 		if (!ata_par_out(*str++)) {
133 			printer_present = 0;
134 			return;
135 		}
136 	}
137 }
138 
139 #ifdef CONFIG_SERIAL_CONSOLE
140 int atari_mfp_console_wait_key(struct console *co)
141 {
142 	while (!(mfp.rcv_stat & 0x80))	/* wait for rx buf filled */
143 		barrier();
144 	return mfp.usart_dta;
145 }
146 
147 int atari_scc_console_wait_key(struct console *co)
148 {
149 	do {
150 		MFPDELAY();
151 	} while (!(scc.cha_b_ctrl & 0x01)); /* wait for rx buf filled */
152 	MFPDELAY();
153 	return scc.cha_b_data;
154 }
155 
156 int atari_midi_console_wait_key(struct console *co)
157 {
158 	while (!(acia.mid_ctrl & ACIA_RDRF)) /* wait for rx buf filled */
159 		barrier();
160 	return acia.mid_data;
161 }
162 #endif
163 
164 /*
165  * The following two functions do a quick'n'dirty initialization of the MFP or
166  * SCC serial ports. They're used by the debugging interface, kgdb, and the
167  * serial console code.
168  */
169 #ifndef CONFIG_SERIAL_CONSOLE
170 static void __init atari_init_mfp_port(int cflag)
171 #else
172 void atari_init_mfp_port(int cflag)
173 #endif
174 {
175 	/*
176 	 * timer values for 1200...115200 bps; > 38400 select 110, 134, or 150
177 	 * bps, resp., and work only correct if there's a RSVE or RSSPEED
178 	 */
179 	static int baud_table[9] = { 16, 11, 8, 4, 2, 1, 175, 143, 128 };
180 	int baud = cflag & CBAUD;
181 	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x04 : 0x06) : 0;
182 	int csize = ((cflag & CSIZE) == CS7) ? 0x20 : 0x00;
183 
184 	if (cflag & CBAUDEX)
185 		baud += B38400;
186 	if (baud < B1200 || baud > B38400+2)
187 		baud = B9600;		/* use default 9600bps for non-implemented rates */
188 	baud -= B1200;			/* baud_table[] starts at 1200bps */
189 
190 	mfp.trn_stat &= ~0x01;		/* disable TX */
191 	mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
192 	mfp.tim_ct_cd &= 0x70;		/* stop timer D */
193 	mfp.tim_dt_d = baud_table[baud];
194 	mfp.tim_ct_cd |= 0x01;		/* start timer D, 1:4 */
195 	mfp.trn_stat |= 0x01;		/* enable TX */
196 
197 	atari_MFP_init_done = 1;
198 }
199 
200 #define SCC_WRITE(reg, val)				\
201 	do {						\
202 		scc.cha_b_ctrl = (reg);			\
203 		MFPDELAY();				\
204 		scc.cha_b_ctrl = (val);			\
205 		MFPDELAY();				\
206 	} while (0)
207 
208 /* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
209  * delay of ~ 60us. */
210 #define LONG_DELAY()					\
211 	do {						\
212 		int i;					\
213 		for (i = 100; i > 0; --i)		\
214 			MFPDELAY();			\
215 	} while (0)
216 
217 #ifndef CONFIG_SERIAL_CONSOLE
218 static void __init atari_init_scc_port(int cflag)
219 #else
220 void atari_init_scc_port(int cflag)
221 #endif
222 {
223 	extern int atari_SCC_reset_done;
224 	static int clksrc_table[9] =
225 		/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
226 		{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
227 	static int brgsrc_table[9] =
228 		/* reg 14: 0 = RTxC, 2 = PCLK */
229 		{ 2, 2, 2, 2, 2, 2, 0, 2, 2 };
230 	static int clkmode_table[9] =
231 		/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
232 		{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
233 	static int div_table[9] =
234 		/* reg12 (BRG low) */
235 		{ 208, 138, 103, 50, 24, 11, 1, 0, 0 };
236 
237 	int baud = cflag & CBAUD;
238 	int clksrc, clkmode, div, reg3, reg5;
239 
240 	if (cflag & CBAUDEX)
241 		baud += B38400;
242 	if (baud < B1200 || baud > B38400+2)
243 		baud = B9600;		/* use default 9600bps for non-implemented rates */
244 	baud -= B1200;			/* tables starts at 1200bps */
245 
246 	clksrc  = clksrc_table[baud];
247 	clkmode = clkmode_table[baud];
248 	div     = div_table[baud];
249 	if (ATARIHW_PRESENT(TT_MFP) && baud >= 6) {
250 		/* special treatment for TT, where rates >= 38400 are done via TRxC */
251 		clksrc = 0x28;		/* TRxC */
252 		clkmode = baud == 6 ? 0xc0 :
253 			  baud == 7 ? 0x80 : /* really 76800bps */
254 				      0x40;  /* really 153600bps */
255 		div = 0;
256 	}
257 
258 	reg3 = (cflag & CSIZE) == CS8 ? 0xc0 : 0x40;
259 	reg5 = (cflag & CSIZE) == CS8 ? 0x60 : 0x20 | 0x82 /* assert DTR/RTS */;
260 
261 	(void)scc.cha_b_ctrl;		/* reset reg pointer */
262 	SCC_WRITE(9, 0xc0);		/* reset */
263 	LONG_DELAY();			/* extra delay after WR9 access */
264 	SCC_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03)
265 				      : 0 | 0x04 /* 1 stopbit */ | clkmode);
266 	SCC_WRITE(3, reg3);
267 	SCC_WRITE(5, reg5);
268 	SCC_WRITE(9, 0);		/* no interrupts */
269 	LONG_DELAY();			/* extra delay after WR9 access */
270 	SCC_WRITE(10, 0);		/* NRZ mode */
271 	SCC_WRITE(11, clksrc);		/* main clock source */
272 	SCC_WRITE(12, div);		/* BRG value */
273 	SCC_WRITE(13, 0);		/* BRG high byte */
274 	SCC_WRITE(14, brgsrc_table[baud]);
275 	SCC_WRITE(14, brgsrc_table[baud] | (div ? 1 : 0));
276 	SCC_WRITE(3, reg3 | 1);
277 	SCC_WRITE(5, reg5 | 8);
278 
279 	atari_SCC_reset_done = 1;
280 	atari_SCC_init_done = 1;
281 }
282 
283 #ifndef CONFIG_SERIAL_CONSOLE
284 static void __init atari_init_midi_port(int cflag)
285 #else
286 void atari_init_midi_port(int cflag)
287 #endif
288 {
289 	int baud = cflag & CBAUD;
290 	int csize = ((cflag & CSIZE) == CS8) ? 0x10 : 0x00;
291 	/* warning 7N1 isn't possible! (instead 7O2 is used...) */
292 	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x0c : 0x08) : 0x04;
293 	int div;
294 
295 	/* 4800 selects 7812.5, 115200 selects 500000, all other (incl. 9600 as
296 	 * default) the standard MIDI speed 31250. */
297 	if (cflag & CBAUDEX)
298 		baud += B38400;
299 	if (baud == B4800)
300 		div = ACIA_DIV64;	/* really 7812.5 bps */
301 	else if (baud == B38400+2 /* 115200 */)
302 		div = ACIA_DIV1;	/* really 500 kbps (does that work??) */
303 	else
304 		div = ACIA_DIV16;	/* 31250 bps, standard for MIDI */
305 
306 	/* RTS low, ints disabled */
307 	acia.mid_ctrl = div | csize | parity |
308 		    ((atari_switches & ATARI_SWITCH_MIDI) ?
309 		     ACIA_RHTID : ACIA_RLTID);
310 }
311 
312 static int __init atari_debug_setup(char *arg)
313 {
314 	if (!MACH_IS_ATARI)
315 		return 0;
316 
317 	if (!strcmp(arg, "ser"))
318 		/* defaults to ser2 for a Falcon and ser1 otherwise */
319 		arg = MACH_IS_FALCON ? "ser2" : "ser1";
320 
321 	if (!strcmp(arg, "ser1")) {
322 		/* ST-MFP Modem1 serial port */
323 		atari_init_mfp_port(B9600|CS8);
324 		atari_console_driver.write = atari_mfp_console_write;
325 	} else if (!strcmp(arg, "ser2")) {
326 		/* SCC Modem2 serial port */
327 		atari_init_scc_port(B9600|CS8);
328 		atari_console_driver.write = atari_scc_console_write;
329 	} else if (!strcmp(arg, "midi")) {
330 		/* MIDI port */
331 		atari_init_midi_port(B9600|CS8);
332 		atari_console_driver.write = atari_midi_console_write;
333 	} else if (!strcmp(arg, "par")) {
334 		/* parallel printer */
335 		atari_turnoff_irq(IRQ_MFP_BUSY); /* avoid ints */
336 		sound_ym.rd_data_reg_sel = 7;	/* select mixer control */
337 		sound_ym.wd_data = 0xff;	/* sound off, ports are output */
338 		sound_ym.rd_data_reg_sel = 15;	/* select port B */
339 		sound_ym.wd_data = 0;		/* no char */
340 		sound_ym.rd_data_reg_sel = 14;	/* select port A */
341 		sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
342 		atari_console_driver.write = atari_par_console_write;
343 	}
344 	if (atari_console_driver.write)
345 		register_console(&atari_console_driver);
346 
347 	return 0;
348 }
349 
350 early_param("debug", atari_debug_setup);
351