xref: /openbmc/linux/arch/m68k/atari/debug.c (revision 643d1f7f)
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 
19 #include <asm/atarihw.h>
20 #include <asm/atariints.h>
21 
22 /* Flag that Modem1 port is already initialized and used */
23 int atari_MFP_init_done;
24 /* Flag that Modem1 port is already initialized and used */
25 int atari_SCC_init_done;
26 /* Can be set somewhere, if a SCC master reset has already be done and should
27  * not be repeated; used by kgdb */
28 int atari_SCC_reset_done;
29 
30 static struct console atari_console_driver = {
31 	.name	= "debug",
32 	.flags	= CON_PRINTBUFFER,
33 	.index	= -1,
34 };
35 
36 
37 static inline void ata_mfp_out(char c)
38 {
39 	while (!(mfp.trn_stat & 0x80))	/* wait for tx buf empty */
40 		barrier();
41 	mfp.usart_dta = c;
42 }
43 
44 void atari_mfp_console_write(struct console *co, const char *str,
45 			     unsigned int count)
46 {
47 	while (count--) {
48 		if (*str == '\n')
49 			ata_mfp_out('\r');
50 		ata_mfp_out(*str++);
51 	}
52 }
53 
54 static inline void ata_scc_out(char c)
55 {
56 	do {
57 		MFPDELAY();
58 	} while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
59 	MFPDELAY();
60 	scc.cha_b_data = c;
61 }
62 
63 void atari_scc_console_write(struct console *co, const char *str,
64 			     unsigned int count)
65 {
66 	while (count--) {
67 		if (*str == '\n')
68 			ata_scc_out('\r');
69 		ata_scc_out(*str++);
70 	}
71 }
72 
73 static inline void ata_midi_out(char c)
74 {
75 	while (!(acia.mid_ctrl & ACIA_TDRE))	/* wait for tx buf empty */
76 		barrier();
77 	acia.mid_data = c;
78 }
79 
80 void atari_midi_console_write(struct console *co, const char *str,
81 			      unsigned int count)
82 {
83 	while (count--) {
84 		if (*str == '\n')
85 			ata_midi_out('\r');
86 		ata_midi_out(*str++);
87 	}
88 }
89 
90 static int ata_par_out(char c)
91 {
92 	unsigned char tmp;
93 	/* This a some-seconds timeout in case no printer is connected */
94 	unsigned long i = loops_per_jiffy > 1 ? loops_per_jiffy : 10000000/HZ;
95 
96 	while ((mfp.par_dt_reg & 1) && --i) /* wait for BUSY == L */
97 		;
98 	if (!i)
99 		return 0;
100 
101 	sound_ym.rd_data_reg_sel = 15;	/* select port B */
102 	sound_ym.wd_data = c;		/* put char onto port */
103 	sound_ym.rd_data_reg_sel = 14;	/* select port A */
104 	tmp = sound_ym.rd_data_reg_sel;
105 	sound_ym.wd_data = tmp & ~0x20;	/* set strobe L */
106 	MFPDELAY();			/* wait a bit */
107 	sound_ym.wd_data = tmp | 0x20;	/* set strobe H */
108 	return 1;
109 }
110 
111 static void atari_par_console_write(struct console *co, const char *str,
112 				    unsigned int count)
113 {
114 	static int printer_present = 1;
115 
116 	if (!printer_present)
117 		return;
118 
119 	while (count--) {
120 		if (*str == '\n') {
121 			if (!ata_par_out('\r')) {
122 				printer_present = 0;
123 				return;
124 			}
125 		}
126 		if (!ata_par_out(*str++)) {
127 			printer_present = 0;
128 			return;
129 		}
130 	}
131 }
132 
133 #ifdef CONFIG_SERIAL_CONSOLE
134 int atari_mfp_console_wait_key(struct console *co)
135 {
136 	while (!(mfp.rcv_stat & 0x80))	/* wait for rx buf filled */
137 		barrier();
138 	return mfp.usart_dta;
139 }
140 
141 int atari_scc_console_wait_key(struct console *co)
142 {
143 	do {
144 		MFPDELAY();
145 	} while (!(scc.cha_b_ctrl & 0x01)); /* wait for rx buf filled */
146 	MFPDELAY();
147 	return scc.cha_b_data;
148 }
149 
150 int atari_midi_console_wait_key(struct console *co)
151 {
152 	while (!(acia.mid_ctrl & ACIA_RDRF)) /* wait for rx buf filled */
153 		barrier();
154 	return acia.mid_data;
155 }
156 #endif
157 
158 /*
159  * The following two functions do a quick'n'dirty initialization of the MFP or
160  * SCC serial ports. They're used by the debugging interface, kgdb, and the
161  * serial console code.
162  */
163 #ifndef CONFIG_SERIAL_CONSOLE
164 static void __init atari_init_mfp_port(int cflag)
165 #else
166 void atari_init_mfp_port(int cflag)
167 #endif
168 {
169 	/*
170 	 * timer values for 1200...115200 bps; > 38400 select 110, 134, or 150
171 	 * bps, resp., and work only correct if there's a RSVE or RSSPEED
172 	 */
173 	static int baud_table[9] = { 16, 11, 8, 4, 2, 1, 175, 143, 128 };
174 	int baud = cflag & CBAUD;
175 	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x04 : 0x06) : 0;
176 	int csize = ((cflag & CSIZE) == CS7) ? 0x20 : 0x00;
177 
178 	if (cflag & CBAUDEX)
179 		baud += B38400;
180 	if (baud < B1200 || baud > B38400+2)
181 		baud = B9600;		/* use default 9600bps for non-implemented rates */
182 	baud -= B1200;			/* baud_table[] starts at 1200bps */
183 
184 	mfp.trn_stat &= ~0x01;		/* disable TX */
185 	mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
186 	mfp.tim_ct_cd &= 0x70;		/* stop timer D */
187 	mfp.tim_dt_d = baud_table[baud];
188 	mfp.tim_ct_cd |= 0x01;		/* start timer D, 1:4 */
189 	mfp.trn_stat |= 0x01;		/* enable TX */
190 
191 	atari_MFP_init_done = 1;
192 }
193 
194 #define SCC_WRITE(reg, val)				\
195 	do {						\
196 		scc.cha_b_ctrl = (reg);			\
197 		MFPDELAY();				\
198 		scc.cha_b_ctrl = (val);			\
199 		MFPDELAY();				\
200 	} while (0)
201 
202 /* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
203  * delay of ~ 60us. */
204 #define LONG_DELAY()					\
205 	do {						\
206 		int i;					\
207 		for (i = 100; i > 0; --i)		\
208 			MFPDELAY();			\
209 	} while (0)
210 
211 #ifndef CONFIG_SERIAL_CONSOLE
212 static void __init atari_init_scc_port(int cflag)
213 #else
214 void atari_init_scc_port(int cflag)
215 #endif
216 {
217 	extern int atari_SCC_reset_done;
218 	static int clksrc_table[9] =
219 		/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
220 		{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
221 	static int brgsrc_table[9] =
222 		/* reg 14: 0 = RTxC, 2 = PCLK */
223 		{ 2, 2, 2, 2, 2, 2, 0, 2, 2 };
224 	static int clkmode_table[9] =
225 		/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
226 		{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
227 	static int div_table[9] =
228 		/* reg12 (BRG low) */
229 		{ 208, 138, 103, 50, 24, 11, 1, 0, 0 };
230 
231 	int baud = cflag & CBAUD;
232 	int clksrc, clkmode, div, reg3, reg5;
233 
234 	if (cflag & CBAUDEX)
235 		baud += B38400;
236 	if (baud < B1200 || baud > B38400+2)
237 		baud = B9600;		/* use default 9600bps for non-implemented rates */
238 	baud -= B1200;			/* tables starts at 1200bps */
239 
240 	clksrc  = clksrc_table[baud];
241 	clkmode = clkmode_table[baud];
242 	div     = div_table[baud];
243 	if (ATARIHW_PRESENT(TT_MFP) && baud >= 6) {
244 		/* special treatment for TT, where rates >= 38400 are done via TRxC */
245 		clksrc = 0x28;		/* TRxC */
246 		clkmode = baud == 6 ? 0xc0 :
247 			  baud == 7 ? 0x80 : /* really 76800bps */
248 				      0x40;  /* really 153600bps */
249 		div = 0;
250 	}
251 
252 	reg3 = (cflag & CSIZE) == CS8 ? 0xc0 : 0x40;
253 	reg5 = (cflag & CSIZE) == CS8 ? 0x60 : 0x20 | 0x82 /* assert DTR/RTS */;
254 
255 	(void)scc.cha_b_ctrl;		/* reset reg pointer */
256 	SCC_WRITE(9, 0xc0);		/* reset */
257 	LONG_DELAY();			/* extra delay after WR9 access */
258 	SCC_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03)
259 				      : 0 | 0x04 /* 1 stopbit */ | clkmode);
260 	SCC_WRITE(3, reg3);
261 	SCC_WRITE(5, reg5);
262 	SCC_WRITE(9, 0);		/* no interrupts */
263 	LONG_DELAY();			/* extra delay after WR9 access */
264 	SCC_WRITE(10, 0);		/* NRZ mode */
265 	SCC_WRITE(11, clksrc);		/* main clock source */
266 	SCC_WRITE(12, div);		/* BRG value */
267 	SCC_WRITE(13, 0);		/* BRG high byte */
268 	SCC_WRITE(14, brgsrc_table[baud]);
269 	SCC_WRITE(14, brgsrc_table[baud] | (div ? 1 : 0));
270 	SCC_WRITE(3, reg3 | 1);
271 	SCC_WRITE(5, reg5 | 8);
272 
273 	atari_SCC_reset_done = 1;
274 	atari_SCC_init_done = 1;
275 }
276 
277 #ifndef CONFIG_SERIAL_CONSOLE
278 static void __init atari_init_midi_port(int cflag)
279 #else
280 void atari_init_midi_port(int cflag)
281 #endif
282 {
283 	int baud = cflag & CBAUD;
284 	int csize = ((cflag & CSIZE) == CS8) ? 0x10 : 0x00;
285 	/* warning 7N1 isn't possible! (instead 7O2 is used...) */
286 	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x0c : 0x08) : 0x04;
287 	int div;
288 
289 	/* 4800 selects 7812.5, 115200 selects 500000, all other (incl. 9600 as
290 	 * default) the standard MIDI speed 31250. */
291 	if (cflag & CBAUDEX)
292 		baud += B38400;
293 	if (baud == B4800)
294 		div = ACIA_DIV64;	/* really 7812.5 bps */
295 	else if (baud == B38400+2 /* 115200 */)
296 		div = ACIA_DIV1;	/* really 500 kbps (does that work??) */
297 	else
298 		div = ACIA_DIV16;	/* 31250 bps, standard for MIDI */
299 
300 	/* RTS low, ints disabled */
301 	acia.mid_ctrl = div | csize | parity |
302 		    ((atari_switches & ATARI_SWITCH_MIDI) ?
303 		     ACIA_RHTID : ACIA_RLTID);
304 }
305 
306 static int __init atari_debug_setup(char *arg)
307 {
308 	if (!MACH_IS_ATARI)
309 		return 0;
310 
311 	if (!strcmp(arg, "ser"))
312 		/* defaults to ser2 for a Falcon and ser1 otherwise */
313 		arg = MACH_IS_FALCON ? "ser2" : "ser1";
314 
315 	if (!strcmp(arg, "ser1")) {
316 		/* ST-MFP Modem1 serial port */
317 		atari_init_mfp_port(B9600|CS8);
318 		atari_console_driver.write = atari_mfp_console_write;
319 	} else if (!strcmp(arg, "ser2")) {
320 		/* SCC Modem2 serial port */
321 		atari_init_scc_port(B9600|CS8);
322 		atari_console_driver.write = atari_scc_console_write;
323 	} else if (!strcmp(arg, "midi")) {
324 		/* MIDI port */
325 		atari_init_midi_port(B9600|CS8);
326 		atari_console_driver.write = atari_midi_console_write;
327 	} else if (!strcmp(arg, "par")) {
328 		/* parallel printer */
329 		atari_turnoff_irq(IRQ_MFP_BUSY); /* avoid ints */
330 		sound_ym.rd_data_reg_sel = 7;	/* select mixer control */
331 		sound_ym.wd_data = 0xff;	/* sound off, ports are output */
332 		sound_ym.rd_data_reg_sel = 15;	/* select port B */
333 		sound_ym.wd_data = 0;		/* no char */
334 		sound_ym.rd_data_reg_sel = 14;	/* select port A */
335 		sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
336 		atari_console_driver.write = atari_par_console_write;
337 	}
338 	if (atari_console_driver.write)
339 		register_console(&atari_console_driver);
340 
341 	return 0;
342 }
343 
344 early_param("debug", atari_debug_setup);
345