xref: /openbmc/linux/arch/m68k/atari/debug.c (revision 384740dc)
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 /* Can be set somewhere, if a SCC master reset has already be done and should
24  * not be repeated; used by kgdb */
25 int atari_SCC_reset_done;
26 EXPORT_SYMBOL(atari_SCC_reset_done);
27 
28 static struct console atari_console_driver = {
29 	.name	= "debug",
30 	.flags	= CON_PRINTBUFFER,
31 	.index	= -1,
32 };
33 
34 
35 static inline void ata_mfp_out(char c)
36 {
37 	while (!(mfp.trn_stat & 0x80))	/* wait for tx buf empty */
38 		barrier();
39 	mfp.usart_dta = c;
40 }
41 
42 static void atari_mfp_console_write(struct console *co, const char *str,
43 				    unsigned int count)
44 {
45 	while (count--) {
46 		if (*str == '\n')
47 			ata_mfp_out('\r');
48 		ata_mfp_out(*str++);
49 	}
50 }
51 
52 static inline void ata_scc_out(char c)
53 {
54 	do {
55 		MFPDELAY();
56 	} while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
57 	MFPDELAY();
58 	scc.cha_b_data = c;
59 }
60 
61 static void atari_scc_console_write(struct console *co, const char *str,
62 				    unsigned int count)
63 {
64 	while (count--) {
65 		if (*str == '\n')
66 			ata_scc_out('\r');
67 		ata_scc_out(*str++);
68 	}
69 }
70 
71 static inline void ata_midi_out(char c)
72 {
73 	while (!(acia.mid_ctrl & ACIA_TDRE))	/* wait for tx buf empty */
74 		barrier();
75 	acia.mid_data = c;
76 }
77 
78 static void atari_midi_console_write(struct console *co, const char *str,
79 				     unsigned int count)
80 {
81 	while (count--) {
82 		if (*str == '\n')
83 			ata_midi_out('\r');
84 		ata_midi_out(*str++);
85 	}
86 }
87 
88 static int ata_par_out(char c)
89 {
90 	unsigned char tmp;
91 	/* This a some-seconds timeout in case no printer is connected */
92 	unsigned long i = loops_per_jiffy > 1 ? loops_per_jiffy : 10000000/HZ;
93 
94 	while ((mfp.par_dt_reg & 1) && --i) /* wait for BUSY == L */
95 		;
96 	if (!i)
97 		return 0;
98 
99 	sound_ym.rd_data_reg_sel = 15;	/* select port B */
100 	sound_ym.wd_data = c;		/* put char onto port */
101 	sound_ym.rd_data_reg_sel = 14;	/* select port A */
102 	tmp = sound_ym.rd_data_reg_sel;
103 	sound_ym.wd_data = tmp & ~0x20;	/* set strobe L */
104 	MFPDELAY();			/* wait a bit */
105 	sound_ym.wd_data = tmp | 0x20;	/* set strobe H */
106 	return 1;
107 }
108 
109 static void atari_par_console_write(struct console *co, const char *str,
110 				    unsigned int count)
111 {
112 	static int printer_present = 1;
113 
114 	if (!printer_present)
115 		return;
116 
117 	while (count--) {
118 		if (*str == '\n') {
119 			if (!ata_par_out('\r')) {
120 				printer_present = 0;
121 				return;
122 			}
123 		}
124 		if (!ata_par_out(*str++)) {
125 			printer_present = 0;
126 			return;
127 		}
128 	}
129 }
130 
131 #if 0
132 int atari_mfp_console_wait_key(struct console *co)
133 {
134 	while (!(mfp.rcv_stat & 0x80))	/* wait for rx buf filled */
135 		barrier();
136 	return mfp.usart_dta;
137 }
138 
139 int atari_scc_console_wait_key(struct console *co)
140 {
141 	do {
142 		MFPDELAY();
143 	} while (!(scc.cha_b_ctrl & 0x01)); /* wait for rx buf filled */
144 	MFPDELAY();
145 	return scc.cha_b_data;
146 }
147 
148 int atari_midi_console_wait_key(struct console *co)
149 {
150 	while (!(acia.mid_ctrl & ACIA_RDRF)) /* wait for rx buf filled */
151 		barrier();
152 	return acia.mid_data;
153 }
154 #endif
155 
156 /*
157  * The following two functions do a quick'n'dirty initialization of the MFP or
158  * SCC serial ports. They're used by the debugging interface, kgdb, and the
159  * serial console code.
160  */
161 static void __init atari_init_mfp_port(int cflag)
162 {
163 	/*
164 	 * timer values for 1200...115200 bps; > 38400 select 110, 134, or 150
165 	 * bps, resp., and work only correct if there's a RSVE or RSSPEED
166 	 */
167 	static int baud_table[9] = { 16, 11, 8, 4, 2, 1, 175, 143, 128 };
168 	int baud = cflag & CBAUD;
169 	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x04 : 0x06) : 0;
170 	int csize = ((cflag & CSIZE) == CS7) ? 0x20 : 0x00;
171 
172 	if (cflag & CBAUDEX)
173 		baud += B38400;
174 	if (baud < B1200 || baud > B38400+2)
175 		baud = B9600;		/* use default 9600bps for non-implemented rates */
176 	baud -= B1200;			/* baud_table[] starts at 1200bps */
177 
178 	mfp.trn_stat &= ~0x01;		/* disable TX */
179 	mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
180 	mfp.tim_ct_cd &= 0x70;		/* stop timer D */
181 	mfp.tim_dt_d = baud_table[baud];
182 	mfp.tim_ct_cd |= 0x01;		/* start timer D, 1:4 */
183 	mfp.trn_stat |= 0x01;		/* enable TX */
184 }
185 
186 #define SCC_WRITE(reg, val)				\
187 	do {						\
188 		scc.cha_b_ctrl = (reg);			\
189 		MFPDELAY();				\
190 		scc.cha_b_ctrl = (val);			\
191 		MFPDELAY();				\
192 	} while (0)
193 
194 /* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
195  * delay of ~ 60us. */
196 #define LONG_DELAY()					\
197 	do {						\
198 		int i;					\
199 		for (i = 100; i > 0; --i)		\
200 			MFPDELAY();			\
201 	} while (0)
202 
203 static void __init atari_init_scc_port(int cflag)
204 {
205 	extern int atari_SCC_reset_done;
206 	static int clksrc_table[9] =
207 		/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
208 		{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
209 	static int brgsrc_table[9] =
210 		/* reg 14: 0 = RTxC, 2 = PCLK */
211 		{ 2, 2, 2, 2, 2, 2, 0, 2, 2 };
212 	static int clkmode_table[9] =
213 		/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
214 		{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
215 	static int div_table[9] =
216 		/* reg12 (BRG low) */
217 		{ 208, 138, 103, 50, 24, 11, 1, 0, 0 };
218 
219 	int baud = cflag & CBAUD;
220 	int clksrc, clkmode, div, reg3, reg5;
221 
222 	if (cflag & CBAUDEX)
223 		baud += B38400;
224 	if (baud < B1200 || baud > B38400+2)
225 		baud = B9600;		/* use default 9600bps for non-implemented rates */
226 	baud -= B1200;			/* tables starts at 1200bps */
227 
228 	clksrc  = clksrc_table[baud];
229 	clkmode = clkmode_table[baud];
230 	div     = div_table[baud];
231 	if (ATARIHW_PRESENT(TT_MFP) && baud >= 6) {
232 		/* special treatment for TT, where rates >= 38400 are done via TRxC */
233 		clksrc = 0x28;		/* TRxC */
234 		clkmode = baud == 6 ? 0xc0 :
235 			  baud == 7 ? 0x80 : /* really 76800bps */
236 				      0x40;  /* really 153600bps */
237 		div = 0;
238 	}
239 
240 	reg3 = (cflag & CSIZE) == CS8 ? 0xc0 : 0x40;
241 	reg5 = (cflag & CSIZE) == CS8 ? 0x60 : 0x20 | 0x82 /* assert DTR/RTS */;
242 
243 	(void)scc.cha_b_ctrl;		/* reset reg pointer */
244 	SCC_WRITE(9, 0xc0);		/* reset */
245 	LONG_DELAY();			/* extra delay after WR9 access */
246 	SCC_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03)
247 				      : 0 | 0x04 /* 1 stopbit */ | clkmode);
248 	SCC_WRITE(3, reg3);
249 	SCC_WRITE(5, reg5);
250 	SCC_WRITE(9, 0);		/* no interrupts */
251 	LONG_DELAY();			/* extra delay after WR9 access */
252 	SCC_WRITE(10, 0);		/* NRZ mode */
253 	SCC_WRITE(11, clksrc);		/* main clock source */
254 	SCC_WRITE(12, div);		/* BRG value */
255 	SCC_WRITE(13, 0);		/* BRG high byte */
256 	SCC_WRITE(14, brgsrc_table[baud]);
257 	SCC_WRITE(14, brgsrc_table[baud] | (div ? 1 : 0));
258 	SCC_WRITE(3, reg3 | 1);
259 	SCC_WRITE(5, reg5 | 8);
260 
261 	atari_SCC_reset_done = 1;
262 }
263 
264 static void __init atari_init_midi_port(int cflag)
265 {
266 	int baud = cflag & CBAUD;
267 	int csize = ((cflag & CSIZE) == CS8) ? 0x10 : 0x00;
268 	/* warning 7N1 isn't possible! (instead 7O2 is used...) */
269 	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x0c : 0x08) : 0x04;
270 	int div;
271 
272 	/* 4800 selects 7812.5, 115200 selects 500000, all other (incl. 9600 as
273 	 * default) the standard MIDI speed 31250. */
274 	if (cflag & CBAUDEX)
275 		baud += B38400;
276 	if (baud == B4800)
277 		div = ACIA_DIV64;	/* really 7812.5 bps */
278 	else if (baud == B38400+2 /* 115200 */)
279 		div = ACIA_DIV1;	/* really 500 kbps (does that work??) */
280 	else
281 		div = ACIA_DIV16;	/* 31250 bps, standard for MIDI */
282 
283 	/* RTS low, ints disabled */
284 	acia.mid_ctrl = div | csize | parity |
285 		    ((atari_switches & ATARI_SWITCH_MIDI) ?
286 		     ACIA_RHTID : ACIA_RLTID);
287 }
288 
289 static int __init atari_debug_setup(char *arg)
290 {
291 	if (!MACH_IS_ATARI)
292 		return 0;
293 
294 	if (!strcmp(arg, "ser"))
295 		/* defaults to ser2 for a Falcon and ser1 otherwise */
296 		arg = MACH_IS_FALCON ? "ser2" : "ser1";
297 
298 	if (!strcmp(arg, "ser1")) {
299 		/* ST-MFP Modem1 serial port */
300 		atari_init_mfp_port(B9600|CS8);
301 		atari_console_driver.write = atari_mfp_console_write;
302 	} else if (!strcmp(arg, "ser2")) {
303 		/* SCC Modem2 serial port */
304 		atari_init_scc_port(B9600|CS8);
305 		atari_console_driver.write = atari_scc_console_write;
306 	} else if (!strcmp(arg, "midi")) {
307 		/* MIDI port */
308 		atari_init_midi_port(B9600|CS8);
309 		atari_console_driver.write = atari_midi_console_write;
310 	} else if (!strcmp(arg, "par")) {
311 		/* parallel printer */
312 		atari_turnoff_irq(IRQ_MFP_BUSY); /* avoid ints */
313 		sound_ym.rd_data_reg_sel = 7;	/* select mixer control */
314 		sound_ym.wd_data = 0xff;	/* sound off, ports are output */
315 		sound_ym.rd_data_reg_sel = 15;	/* select port B */
316 		sound_ym.wd_data = 0;		/* no char */
317 		sound_ym.rd_data_reg_sel = 14;	/* select port A */
318 		sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
319 		atari_console_driver.write = atari_par_console_write;
320 	}
321 	if (atari_console_driver.write)
322 		register_console(&atari_console_driver);
323 
324 	return 0;
325 }
326 
327 early_param("debug", atari_debug_setup);
328