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 */
25int atari_SCC_reset_done;
26EXPORT_SYMBOL(atari_SCC_reset_done);
27
28static struct console atari_console_driver = {
29	.name	= "debug",
30	.flags	= CON_PRINTBUFFER,
31	.index	= -1,
32};
33
34
35static inline void ata_mfp_out(char c)
36{
37	while (!(st_mfp.trn_stat & 0x80))	/* wait for tx buf empty */
38		barrier();
39	st_mfp.usart_dta = c;
40}
41
42static 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
52static inline void ata_scc_out(char c)
53{
54	do {
55		MFPDELAY();
56	} while (!(atari_scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
57	MFPDELAY();
58	atari_scc.cha_b_data = c;
59}
60
61static 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
71static 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
78static 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
88static 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 ((st_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
109static 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
132int atari_mfp_console_wait_key(struct console *co)
133{
134	while (!(st_mfp.rcv_stat & 0x80))	/* wait for rx buf filled */
135		barrier();
136	return st_mfp.usart_dta;
137}
138
139int atari_scc_console_wait_key(struct console *co)
140{
141	do {
142		MFPDELAY();
143	} while (!(atari_scc.cha_b_ctrl & 0x01)); /* wait for rx buf filled */
144	MFPDELAY();
145	return atari_scc.cha_b_data;
146}
147
148int 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 */
161static 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	st_mfp.trn_stat &= ~0x01;	/* disable TX */
179	st_mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
180	st_mfp.tim_ct_cd &= 0x70;	/* stop timer D */
181	st_mfp.tim_dt_d = baud_table[baud];
182	st_mfp.tim_ct_cd |= 0x01;	/* start timer D, 1:4 */
183	st_mfp.trn_stat |= 0x01;	/* enable TX */
184}
185
186#define SCC_WRITE(reg, val)				\
187	do {						\
188		atari_scc.cha_b_ctrl = (reg);		\
189		MFPDELAY();				\
190		atari_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
203static void __init atari_init_scc_port(int cflag)
204{
205	static int clksrc_table[9] =
206		/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
207		{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
208	static int brgsrc_table[9] =
209		/* reg 14: 0 = RTxC, 2 = PCLK */
210		{ 2, 2, 2, 2, 2, 2, 0, 2, 2 };
211	static int clkmode_table[9] =
212		/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
213		{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
214	static int div_table[9] =
215		/* reg12 (BRG low) */
216		{ 208, 138, 103, 50, 24, 11, 1, 0, 0 };
217
218	int baud = cflag & CBAUD;
219	int clksrc, clkmode, div, reg3, reg5;
220
221	if (cflag & CBAUDEX)
222		baud += B38400;
223	if (baud < B1200 || baud > B38400+2)
224		baud = B9600;		/* use default 9600bps for non-implemented rates */
225	baud -= B1200;			/* tables starts at 1200bps */
226
227	clksrc  = clksrc_table[baud];
228	clkmode = clkmode_table[baud];
229	div     = div_table[baud];
230	if (ATARIHW_PRESENT(TT_MFP) && baud >= 6) {
231		/* special treatment for TT, where rates >= 38400 are done via TRxC */
232		clksrc = 0x28;		/* TRxC */
233		clkmode = baud == 6 ? 0xc0 :
234			  baud == 7 ? 0x80 : /* really 76800bps */
235				      0x40;  /* really 153600bps */
236		div = 0;
237	}
238
239	reg3 = (cflag & CSIZE) == CS8 ? 0xc0 : 0x40;
240	reg5 = (cflag & CSIZE) == CS8 ? 0x60 : 0x20 | 0x82 /* assert DTR/RTS */;
241
242	(void)atari_scc.cha_b_ctrl;	/* reset reg pointer */
243	SCC_WRITE(9, 0xc0);		/* reset */
244	LONG_DELAY();			/* extra delay after WR9 access */
245	SCC_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03)
246				      : 0 | 0x04 /* 1 stopbit */ | clkmode);
247	SCC_WRITE(3, reg3);
248	SCC_WRITE(5, reg5);
249	SCC_WRITE(9, 0);		/* no interrupts */
250	LONG_DELAY();			/* extra delay after WR9 access */
251	SCC_WRITE(10, 0);		/* NRZ mode */
252	SCC_WRITE(11, clksrc);		/* main clock source */
253	SCC_WRITE(12, div);		/* BRG value */
254	SCC_WRITE(13, 0);		/* BRG high byte */
255	SCC_WRITE(14, brgsrc_table[baud]);
256	SCC_WRITE(14, brgsrc_table[baud] | (div ? 1 : 0));
257	SCC_WRITE(3, reg3 | 1);
258	SCC_WRITE(5, reg5 | 8);
259
260	atari_SCC_reset_done = 1;
261}
262
263static void __init atari_init_midi_port(int cflag)
264{
265	int baud = cflag & CBAUD;
266	int csize = ((cflag & CSIZE) == CS8) ? 0x10 : 0x00;
267	/* warning 7N1 isn't possible! (instead 7O2 is used...) */
268	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x0c : 0x08) : 0x04;
269	int div;
270
271	/* 4800 selects 7812.5, 115200 selects 500000, all other (incl. 9600 as
272	 * default) the standard MIDI speed 31250. */
273	if (cflag & CBAUDEX)
274		baud += B38400;
275	if (baud == B4800)
276		div = ACIA_DIV64;	/* really 7812.5 bps */
277	else if (baud == B38400+2 /* 115200 */)
278		div = ACIA_DIV1;	/* really 500 kbps (does that work??) */
279	else
280		div = ACIA_DIV16;	/* 31250 bps, standard for MIDI */
281
282	/* RTS low, ints disabled */
283	acia.mid_ctrl = div | csize | parity |
284		    ((atari_switches & ATARI_SWITCH_MIDI) ?
285		     ACIA_RHTID : ACIA_RLTID);
286}
287
288static int __init atari_debug_setup(char *arg)
289{
290	bool registered;
291
292	if (!MACH_IS_ATARI)
293		return 0;
294
295	if (!strcmp(arg, "ser"))
296		/* defaults to ser2 for a Falcon and ser1 otherwise */
297		arg = MACH_IS_FALCON ? "ser2" : "ser1";
298
299	registered = !!atari_console_driver.write;
300	if (!strcmp(arg, "ser1")) {
301		/* ST-MFP Modem1 serial port */
302		atari_init_mfp_port(B9600|CS8);
303		atari_console_driver.write = atari_mfp_console_write;
304	} else if (!strcmp(arg, "ser2")) {
305		/* SCC Modem2 serial port */
306		atari_init_scc_port(B9600|CS8);
307		atari_console_driver.write = atari_scc_console_write;
308	} else if (!strcmp(arg, "midi")) {
309		/* MIDI port */
310		atari_init_midi_port(B9600|CS8);
311		atari_console_driver.write = atari_midi_console_write;
312	} else if (!strcmp(arg, "par")) {
313		/* parallel printer */
314		atari_turnoff_irq(IRQ_MFP_BUSY); /* avoid ints */
315		sound_ym.rd_data_reg_sel = 7;	/* select mixer control */
316		sound_ym.wd_data = 0xff;	/* sound off, ports are output */
317		sound_ym.rd_data_reg_sel = 15;	/* select port B */
318		sound_ym.wd_data = 0;		/* no char */
319		sound_ym.rd_data_reg_sel = 14;	/* select port A */
320		sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
321		atari_console_driver.write = atari_par_console_write;
322	}
323	if (atari_console_driver.write && !registered)
324		register_console(&atari_console_driver);
325
326	return 0;
327}
328
329early_param("debug", atari_debug_setup);
330