xref: /openbmc/linux/arch/m68k/bvme6000/config.c (revision 59b4412f)
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/clocksource.h>
22 #include <linux/console.h>
23 #include <linux/linkage.h>
24 #include <linux/init.h>
25 #include <linux/major.h>
26 #include <linux/genhd.h>
27 #include <linux/rtc.h>
28 #include <linux/interrupt.h>
29 #include <linux/bcd.h>
30 
31 #include <asm/bootinfo.h>
32 #include <asm/bootinfo-vme.h>
33 #include <asm/byteorder.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 int bvme6000_hwclk (int, struct rtc_time *);
43 extern void bvme6000_reset (void);
44 void bvme6000_set_vectors (void);
45 
46 
47 int __init bvme6000_parse_bootinfo(const struct bi_record *bi)
48 {
49 	if (be16_to_cpu(bi->tag) == BI_VME_TYPE)
50 		return 0;
51 	else
52 		return 1;
53 }
54 
55 void bvme6000_reset(void)
56 {
57 	volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
58 
59 	pr_info("\r\n\nCalled bvme6000_reset\r\n"
60 		"\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r");
61 	/* The string of returns is to delay the reset until the whole
62 	 * message is output. */
63 	/* Enable the watchdog, via PIT port C bit 4 */
64 
65 	pit->pcddr	|= 0x10;	/* WDOG enable */
66 
67 	while(1)
68 		;
69 }
70 
71 static void bvme6000_get_model(char *model)
72 {
73     sprintf(model, "BVME%d000", m68k_cputype == CPU_68060 ? 6 : 4);
74 }
75 
76 /*
77  * This function is called during kernel startup to initialize
78  * the bvme6000 IRQ handling routines.
79  */
80 static void __init bvme6000_init_IRQ(void)
81 {
82 	m68k_setup_user_interrupt(VEC_USER, 192);
83 }
84 
85 void __init config_bvme6000(void)
86 {
87     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
88 
89     /* Board type is only set by newer versions of vmelilo/tftplilo */
90     if (!vme_brdtype) {
91 	if (m68k_cputype == CPU_68060)
92 	    vme_brdtype = VME_TYPE_BVME6000;
93 	else
94 	    vme_brdtype = VME_TYPE_BVME4000;
95     }
96 #if 0
97     /* Call bvme6000_set_vectors() so ABORT will work, along with BVMBug
98      * debugger.  Note trap_init() will splat the abort vector, but
99      * bvme6000_init_IRQ() will put it back again.  Hopefully. */
100 
101     bvme6000_set_vectors();
102 #endif
103 
104     mach_max_dma_address = 0xffffffff;
105     mach_sched_init      = bvme6000_sched_init;
106     mach_init_IRQ        = bvme6000_init_IRQ;
107     mach_hwclk           = bvme6000_hwclk;
108     mach_reset		 = bvme6000_reset;
109     mach_get_model       = bvme6000_get_model;
110 
111     pr_info("Board is %sconfigured as a System Controller\n",
112 	    *config_reg_ptr & BVME_CONFIG_SW1 ? "" : "not ");
113 
114     /* Now do the PIT configuration */
115 
116     pit->pgcr	= 0x00;	/* Unidirectional 8 bit, no handshake for now */
117     pit->psrr	= 0x18;	/* PIACK and PIRQ functions enabled */
118     pit->pacr	= 0x00;	/* Sub Mode 00, H2 i/p, no DMA */
119     pit->padr	= 0x00;	/* Just to be tidy! */
120     pit->paddr	= 0x00;	/* All inputs for now (safest) */
121     pit->pbcr	= 0x80;	/* Sub Mode 1x, H4 i/p, no DMA */
122     pit->pbdr	= 0xbc | (*config_reg_ptr & BVME_CONFIG_SW1 ? 0 : 0x40);
123 			/* PRI, SYSCON?, Level3, SCC clks from xtal */
124     pit->pbddr	= 0xf3;	/* Mostly outputs */
125     pit->pcdr	= 0x01;	/* PA transceiver disabled */
126     pit->pcddr	= 0x03;	/* WDOG disable */
127 
128     /* Disable snooping for Ethernet and VME accesses */
129 
130     bvme_acr_addrctl = 0;
131 }
132 
133 
134 irqreturn_t bvme6000_abort_int (int irq, void *dev_id)
135 {
136         unsigned long *new = (unsigned long *)vectors;
137         unsigned long *old = (unsigned long *)0xf8000000;
138 
139         /* Wait for button release */
140         while (*(volatile unsigned char *)BVME_LOCAL_IRQ_STAT & BVME_ABORT_STATUS)
141                 ;
142 
143         *(new+4) = *(old+4);            /* Illegal instruction */
144         *(new+9) = *(old+9);            /* Trace */
145         *(new+47) = *(old+47);          /* Trap #15 */
146         *(new+0x1f) = *(old+0x1f);      /* ABORT switch */
147 	return IRQ_HANDLED;
148 }
149 
150 static u64 bvme6000_read_clk(struct clocksource *cs);
151 
152 static struct clocksource bvme6000_clk = {
153 	.name   = "rtc",
154 	.rating = 250,
155 	.read   = bvme6000_read_clk,
156 	.mask   = CLOCKSOURCE_MASK(32),
157 	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
158 };
159 
160 static u32 clk_total, clk_offset;
161 
162 #define RTC_TIMER_CLOCK_FREQ 8000000
163 #define RTC_TIMER_CYCLES     (RTC_TIMER_CLOCK_FREQ / HZ)
164 #define RTC_TIMER_COUNT      ((RTC_TIMER_CYCLES / 2) - 1)
165 
166 static irqreturn_t bvme6000_timer_int (int irq, void *dev_id)
167 {
168     irq_handler_t timer_routine = dev_id;
169     unsigned long flags;
170     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
171     unsigned char msr;
172 
173     local_irq_save(flags);
174     msr = rtc->msr & 0xc0;
175     rtc->msr = msr | 0x20;		/* Ack the interrupt */
176     clk_total += RTC_TIMER_CYCLES;
177     clk_offset = 0;
178     timer_routine(0, NULL);
179     local_irq_restore(flags);
180 
181     return IRQ_HANDLED;
182 }
183 
184 /*
185  * Set up the RTC timer 1 to mode 2, so T1 output toggles every 5ms
186  * (40000 x 125ns).  It will interrupt every 10ms, when T1 goes low.
187  * So, when reading the elapsed time, you should read timer1,
188  * subtract it from 39999, and then add 40000 if T1 is high.
189  * That gives you the number of 125ns ticks in to the 10ms period,
190  * so divide by 8 to get the microsecond result.
191  */
192 
193 void bvme6000_sched_init (irq_handler_t timer_routine)
194 {
195     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
196     unsigned char msr = rtc->msr & 0xc0;
197 
198     rtc->msr = 0;	/* Ensure timer registers accessible */
199 
200     if (request_irq(BVME_IRQ_RTC, bvme6000_timer_int, IRQF_TIMER, "timer",
201                     timer_routine))
202 	panic ("Couldn't register timer int");
203 
204     rtc->t1cr_omr = 0x04;	/* Mode 2, ext clk */
205     rtc->t1msb = RTC_TIMER_COUNT >> 8;
206     rtc->t1lsb = RTC_TIMER_COUNT & 0xff;
207     rtc->irr_icr1 &= 0xef;	/* Route timer 1 to INTR pin */
208     rtc->msr = 0x40;		/* Access int.cntrl, etc */
209     rtc->pfr_icr0 = 0x80;	/* Just timer 1 ints enabled */
210     rtc->irr_icr1 = 0;
211     rtc->t1cr_omr = 0x0a;	/* INTR+T1 active lo, push-pull */
212     rtc->t0cr_rtmr &= 0xdf;	/* Stop timers in standby */
213     rtc->msr = 0;		/* Access timer 1 control */
214     rtc->t1cr_omr = 0x05;	/* Mode 2, ext clk, GO */
215 
216     rtc->msr = msr;
217 
218     clocksource_register_hz(&bvme6000_clk, RTC_TIMER_CLOCK_FREQ);
219 
220     if (request_irq(BVME_IRQ_ABORT, bvme6000_abort_int, 0,
221 				"abort", bvme6000_abort_int))
222 	panic ("Couldn't register abort int");
223 }
224 
225 
226 /*
227  * NOTE:  Don't accept any readings within 5us of rollover, as
228  * the T1INT bit may be a little slow getting set.  There is also
229  * a fault in the chip, meaning that reads may produce invalid
230  * results...
231  */
232 
233 static u64 bvme6000_read_clk(struct clocksource *cs)
234 {
235     unsigned long flags;
236     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
237     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
238     unsigned char msr, msb;
239     unsigned char t1int, t1op;
240     u32 v = 800000, ov;
241 
242     local_irq_save(flags);
243 
244     msr = rtc->msr & 0xc0;
245     rtc->msr = 0;	/* Ensure timer registers accessible */
246 
247     do {
248 	ov = v;
249 	t1int = rtc->msr & 0x20;
250 	t1op  = pit->pcdr & 0x04;
251 	rtc->t1cr_omr |= 0x40;		/* Latch timer1 */
252 	msb = rtc->t1msb;		/* Read timer1 */
253 	v = (msb << 8) | rtc->t1lsb;	/* Read timer1 */
254     } while (t1int != (rtc->msr & 0x20) ||
255 		t1op != (pit->pcdr & 0x04) ||
256 			abs(ov-v) > 80 ||
257 				v > RTC_TIMER_COUNT - (RTC_TIMER_COUNT / 100));
258 
259     v = RTC_TIMER_COUNT - v;
260     if (!t1op)				/* If in second half cycle.. */
261 	v += RTC_TIMER_CYCLES / 2;
262     if (msb > 0 && t1int)
263 	clk_offset = RTC_TIMER_CYCLES;
264     rtc->msr = msr;
265 
266     v += clk_offset + clk_total;
267 
268     local_irq_restore(flags);
269 
270     return v;
271 }
272 
273 /*
274  * Looks like op is non-zero for setting the clock, and zero for
275  * reading the clock.
276  *
277  *  struct hwclk_time {
278  *         unsigned        sec;       0..59
279  *         unsigned        min;       0..59
280  *         unsigned        hour;      0..23
281  *         unsigned        day;       1..31
282  *         unsigned        mon;       0..11
283  *         unsigned        year;      00...
284  *         int             wday;      0..6, 0 is Sunday, -1 means unknown/don't set
285  * };
286  */
287 
288 int bvme6000_hwclk(int op, struct rtc_time *t)
289 {
290 	volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
291 	unsigned char msr = rtc->msr & 0xc0;
292 
293 	rtc->msr = 0x40;	/* Ensure clock and real-time-mode-register
294 				 * are accessible */
295 	if (op)
296 	{	/* Write.... */
297 		rtc->t0cr_rtmr = t->tm_year%4;
298 		rtc->bcd_tenms = 0;
299 		rtc->bcd_sec = bin2bcd(t->tm_sec);
300 		rtc->bcd_min = bin2bcd(t->tm_min);
301 		rtc->bcd_hr  = bin2bcd(t->tm_hour);
302 		rtc->bcd_dom = bin2bcd(t->tm_mday);
303 		rtc->bcd_mth = bin2bcd(t->tm_mon + 1);
304 		rtc->bcd_year = bin2bcd(t->tm_year%100);
305 		if (t->tm_wday >= 0)
306 			rtc->bcd_dow = bin2bcd(t->tm_wday+1);
307 		rtc->t0cr_rtmr = t->tm_year%4 | 0x08;
308 	}
309 	else
310 	{	/* Read....  */
311 		do {
312 			t->tm_sec  = bcd2bin(rtc->bcd_sec);
313 			t->tm_min  = bcd2bin(rtc->bcd_min);
314 			t->tm_hour = bcd2bin(rtc->bcd_hr);
315 			t->tm_mday = bcd2bin(rtc->bcd_dom);
316 			t->tm_mon  = bcd2bin(rtc->bcd_mth)-1;
317 			t->tm_year = bcd2bin(rtc->bcd_year);
318 			if (t->tm_year < 70)
319 				t->tm_year += 100;
320 			t->tm_wday = bcd2bin(rtc->bcd_dow)-1;
321 		} while (t->tm_sec != bcd2bin(rtc->bcd_sec));
322 	}
323 
324 	rtc->msr = msr;
325 
326 	return 0;
327 }
328