xref: /openbmc/linux/arch/m68k/bvme6000/config.c (revision 045f77ba)
1 /*
2  *  arch/m68k/bvme6000/config.c
3  *
4  *  Copyright (C) 1997 Richard Hirst [richard@sleepie.demon.co.uk]
5  *
6  * Based on:
7  *
8  *  linux/amiga/config.c
9  *
10  *  Copyright (C) 1993 Hamish Macdonald
11  *
12  * This file is subject to the terms and conditions of the GNU General Public
13  * License.  See the file README.legal in the main directory of this archive
14  * for more details.
15  */
16 
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/tty.h>
21 #include <linux/console.h>
22 #include <linux/linkage.h>
23 #include <linux/init.h>
24 #include <linux/major.h>
25 #include <linux/genhd.h>
26 #include <linux/rtc.h>
27 #include <linux/interrupt.h>
28 #include <linux/bcd.h>
29 
30 #include <asm/bootinfo.h>
31 #include <asm/bootinfo-vme.h>
32 #include <asm/byteorder.h>
33 #include <asm/pgtable.h>
34 #include <asm/setup.h>
35 #include <asm/irq.h>
36 #include <asm/traps.h>
37 #include <asm/machdep.h>
38 #include <asm/bvme6000hw.h>
39 
40 static void bvme6000_get_model(char *model);
41 extern void bvme6000_sched_init(irq_handler_t handler);
42 extern u32 bvme6000_gettimeoffset(void);
43 extern int bvme6000_hwclk (int, struct rtc_time *);
44 extern void bvme6000_reset (void);
45 void bvme6000_set_vectors (void);
46 
47 /* Save tick handler routine pointer, will point to xtime_update() in
48  * kernel/timer/timekeeping.c, called via bvme6000_process_int() */
49 
50 static irq_handler_t tick_handler;
51 
52 
53 int __init bvme6000_parse_bootinfo(const struct bi_record *bi)
54 {
55 	if (be16_to_cpu(bi->tag) == BI_VME_TYPE)
56 		return 0;
57 	else
58 		return 1;
59 }
60 
61 void bvme6000_reset(void)
62 {
63 	volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
64 
65 	pr_info("\r\n\nCalled bvme6000_reset\r\n"
66 		"\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r");
67 	/* The string of returns is to delay the reset until the whole
68 	 * message is output. */
69 	/* Enable the watchdog, via PIT port C bit 4 */
70 
71 	pit->pcddr	|= 0x10;	/* WDOG enable */
72 
73 	while(1)
74 		;
75 }
76 
77 static void bvme6000_get_model(char *model)
78 {
79     sprintf(model, "BVME%d000", m68k_cputype == CPU_68060 ? 6 : 4);
80 }
81 
82 /*
83  * This function is called during kernel startup to initialize
84  * the bvme6000 IRQ handling routines.
85  */
86 static void __init bvme6000_init_IRQ(void)
87 {
88 	m68k_setup_user_interrupt(VEC_USER, 192);
89 }
90 
91 void __init config_bvme6000(void)
92 {
93     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
94 
95     /* Board type is only set by newer versions of vmelilo/tftplilo */
96     if (!vme_brdtype) {
97 	if (m68k_cputype == CPU_68060)
98 	    vme_brdtype = VME_TYPE_BVME6000;
99 	else
100 	    vme_brdtype = VME_TYPE_BVME4000;
101     }
102 #if 0
103     /* Call bvme6000_set_vectors() so ABORT will work, along with BVMBug
104      * debugger.  Note trap_init() will splat the abort vector, but
105      * bvme6000_init_IRQ() will put it back again.  Hopefully. */
106 
107     bvme6000_set_vectors();
108 #endif
109 
110     mach_max_dma_address = 0xffffffff;
111     mach_sched_init      = bvme6000_sched_init;
112     mach_init_IRQ        = bvme6000_init_IRQ;
113     arch_gettimeoffset   = bvme6000_gettimeoffset;
114     mach_hwclk           = bvme6000_hwclk;
115     mach_reset		 = bvme6000_reset;
116     mach_get_model       = bvme6000_get_model;
117 
118     pr_info("Board is %sconfigured as a System Controller\n",
119 	    *config_reg_ptr & BVME_CONFIG_SW1 ? "" : "not ");
120 
121     /* Now do the PIT configuration */
122 
123     pit->pgcr	= 0x00;	/* Unidirectional 8 bit, no handshake for now */
124     pit->psrr	= 0x18;	/* PIACK and PIRQ functions enabled */
125     pit->pacr	= 0x00;	/* Sub Mode 00, H2 i/p, no DMA */
126     pit->padr	= 0x00;	/* Just to be tidy! */
127     pit->paddr	= 0x00;	/* All inputs for now (safest) */
128     pit->pbcr	= 0x80;	/* Sub Mode 1x, H4 i/p, no DMA */
129     pit->pbdr	= 0xbc | (*config_reg_ptr & BVME_CONFIG_SW1 ? 0 : 0x40);
130 			/* PRI, SYSCON?, Level3, SCC clks from xtal */
131     pit->pbddr	= 0xf3;	/* Mostly outputs */
132     pit->pcdr	= 0x01;	/* PA transceiver disabled */
133     pit->pcddr	= 0x03;	/* WDOG disable */
134 
135     /* Disable snooping for Ethernet and VME accesses */
136 
137     bvme_acr_addrctl = 0;
138 }
139 
140 
141 irqreturn_t bvme6000_abort_int (int irq, void *dev_id)
142 {
143         unsigned long *new = (unsigned long *)vectors;
144         unsigned long *old = (unsigned long *)0xf8000000;
145 
146         /* Wait for button release */
147         while (*(volatile unsigned char *)BVME_LOCAL_IRQ_STAT & BVME_ABORT_STATUS)
148                 ;
149 
150         *(new+4) = *(old+4);            /* Illegal instruction */
151         *(new+9) = *(old+9);            /* Trace */
152         *(new+47) = *(old+47);          /* Trap #15 */
153         *(new+0x1f) = *(old+0x1f);      /* ABORT switch */
154 	return IRQ_HANDLED;
155 }
156 
157 
158 static irqreturn_t bvme6000_timer_int (int irq, void *dev_id)
159 {
160     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
161     unsigned char msr = rtc->msr & 0xc0;
162 
163     rtc->msr = msr | 0x20;		/* Ack the interrupt */
164 
165     return tick_handler(irq, dev_id);
166 }
167 
168 /*
169  * Set up the RTC timer 1 to mode 2, so T1 output toggles every 5ms
170  * (40000 x 125ns).  It will interrupt every 10ms, when T1 goes low.
171  * So, when reading the elapsed time, you should read timer1,
172  * subtract it from 39999, and then add 40000 if T1 is high.
173  * That gives you the number of 125ns ticks in to the 10ms period,
174  * so divide by 8 to get the microsecond result.
175  */
176 
177 void bvme6000_sched_init (irq_handler_t timer_routine)
178 {
179     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
180     unsigned char msr = rtc->msr & 0xc0;
181 
182     rtc->msr = 0;	/* Ensure timer registers accessible */
183 
184     tick_handler = timer_routine;
185     if (request_irq(BVME_IRQ_RTC, bvme6000_timer_int, 0,
186 				"timer", bvme6000_timer_int))
187 	panic ("Couldn't register timer int");
188 
189     rtc->t1cr_omr = 0x04;	/* Mode 2, ext clk */
190     rtc->t1msb = 39999 >> 8;
191     rtc->t1lsb = 39999 & 0xff;
192     rtc->irr_icr1 &= 0xef;	/* Route timer 1 to INTR pin */
193     rtc->msr = 0x40;		/* Access int.cntrl, etc */
194     rtc->pfr_icr0 = 0x80;	/* Just timer 1 ints enabled */
195     rtc->irr_icr1 = 0;
196     rtc->t1cr_omr = 0x0a;	/* INTR+T1 active lo, push-pull */
197     rtc->t0cr_rtmr &= 0xdf;	/* Stop timers in standby */
198     rtc->msr = 0;		/* Access timer 1 control */
199     rtc->t1cr_omr = 0x05;	/* Mode 2, ext clk, GO */
200 
201     rtc->msr = msr;
202 
203     if (request_irq(BVME_IRQ_ABORT, bvme6000_abort_int, 0,
204 				"abort", bvme6000_abort_int))
205 	panic ("Couldn't register abort int");
206 }
207 
208 
209 /* This is always executed with interrupts disabled.  */
210 
211 /*
212  * NOTE:  Don't accept any readings within 5us of rollover, as
213  * the T1INT bit may be a little slow getting set.  There is also
214  * a fault in the chip, meaning that reads may produce invalid
215  * results...
216  */
217 
218 u32 bvme6000_gettimeoffset(void)
219 {
220     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
221     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
222     unsigned char msr = rtc->msr & 0xc0;
223     unsigned char t1int, t1op;
224     u32 v = 800000, ov;
225 
226     rtc->msr = 0;	/* Ensure timer registers accessible */
227 
228     do {
229 	ov = v;
230 	t1int = rtc->msr & 0x20;
231 	t1op  = pit->pcdr & 0x04;
232 	rtc->t1cr_omr |= 0x40;		/* Latch timer1 */
233 	v = rtc->t1msb << 8;		/* Read timer1 */
234 	v |= rtc->t1lsb;		/* Read timer1 */
235     } while (t1int != (rtc->msr & 0x20) ||
236 		t1op != (pit->pcdr & 0x04) ||
237 			abs(ov-v) > 80 ||
238 				v > 39960);
239 
240     v = 39999 - v;
241     if (!t1op)				/* If in second half cycle.. */
242 	v += 40000;
243     v /= 8;				/* Convert ticks to microseconds */
244     if (t1int)
245 	v += 10000;			/* Int pending, + 10ms */
246     rtc->msr = msr;
247 
248     return v * 1000;
249 }
250 
251 /*
252  * Looks like op is non-zero for setting the clock, and zero for
253  * reading the clock.
254  *
255  *  struct hwclk_time {
256  *         unsigned        sec;       0..59
257  *         unsigned        min;       0..59
258  *         unsigned        hour;      0..23
259  *         unsigned        day;       1..31
260  *         unsigned        mon;       0..11
261  *         unsigned        year;      00...
262  *         int             wday;      0..6, 0 is Sunday, -1 means unknown/don't set
263  * };
264  */
265 
266 int bvme6000_hwclk(int op, struct rtc_time *t)
267 {
268 	volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
269 	unsigned char msr = rtc->msr & 0xc0;
270 
271 	rtc->msr = 0x40;	/* Ensure clock and real-time-mode-register
272 				 * are accessible */
273 	if (op)
274 	{	/* Write.... */
275 		rtc->t0cr_rtmr = t->tm_year%4;
276 		rtc->bcd_tenms = 0;
277 		rtc->bcd_sec = bin2bcd(t->tm_sec);
278 		rtc->bcd_min = bin2bcd(t->tm_min);
279 		rtc->bcd_hr  = bin2bcd(t->tm_hour);
280 		rtc->bcd_dom = bin2bcd(t->tm_mday);
281 		rtc->bcd_mth = bin2bcd(t->tm_mon + 1);
282 		rtc->bcd_year = bin2bcd(t->tm_year%100);
283 		if (t->tm_wday >= 0)
284 			rtc->bcd_dow = bin2bcd(t->tm_wday+1);
285 		rtc->t0cr_rtmr = t->tm_year%4 | 0x08;
286 	}
287 	else
288 	{	/* Read....  */
289 		do {
290 			t->tm_sec  = bcd2bin(rtc->bcd_sec);
291 			t->tm_min  = bcd2bin(rtc->bcd_min);
292 			t->tm_hour = bcd2bin(rtc->bcd_hr);
293 			t->tm_mday = bcd2bin(rtc->bcd_dom);
294 			t->tm_mon  = bcd2bin(rtc->bcd_mth)-1;
295 			t->tm_year = bcd2bin(rtc->bcd_year);
296 			if (t->tm_year < 70)
297 				t->tm_year += 100;
298 			t->tm_wday = bcd2bin(rtc->bcd_dow)-1;
299 		} while (t->tm_sec != bcd2bin(rtc->bcd_sec));
300 	}
301 
302 	rtc->msr = msr;
303 
304 	return 0;
305 }
306