xref: /openbmc/linux/arch/m68k/bvme6000/config.c (revision f519f0be)
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/pgtable.h>
35 #include <asm/setup.h>
36 #include <asm/irq.h>
37 #include <asm/traps.h>
38 #include <asm/machdep.h>
39 #include <asm/bvme6000hw.h>
40 
41 static void bvme6000_get_model(char *model);
42 extern void bvme6000_sched_init(irq_handler_t handler);
43 extern int bvme6000_hwclk (int, struct rtc_time *);
44 extern void bvme6000_reset (void);
45 void bvme6000_set_vectors (void);
46 
47 
48 int __init bvme6000_parse_bootinfo(const struct bi_record *bi)
49 {
50 	if (be16_to_cpu(bi->tag) == BI_VME_TYPE)
51 		return 0;
52 	else
53 		return 1;
54 }
55 
56 void bvme6000_reset(void)
57 {
58 	volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
59 
60 	pr_info("\r\n\nCalled bvme6000_reset\r\n"
61 		"\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r");
62 	/* The string of returns is to delay the reset until the whole
63 	 * message is output. */
64 	/* Enable the watchdog, via PIT port C bit 4 */
65 
66 	pit->pcddr	|= 0x10;	/* WDOG enable */
67 
68 	while(1)
69 		;
70 }
71 
72 static void bvme6000_get_model(char *model)
73 {
74     sprintf(model, "BVME%d000", m68k_cputype == CPU_68060 ? 6 : 4);
75 }
76 
77 /*
78  * This function is called during kernel startup to initialize
79  * the bvme6000 IRQ handling routines.
80  */
81 static void __init bvme6000_init_IRQ(void)
82 {
83 	m68k_setup_user_interrupt(VEC_USER, 192);
84 }
85 
86 void __init config_bvme6000(void)
87 {
88     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
89 
90     /* Board type is only set by newer versions of vmelilo/tftplilo */
91     if (!vme_brdtype) {
92 	if (m68k_cputype == CPU_68060)
93 	    vme_brdtype = VME_TYPE_BVME6000;
94 	else
95 	    vme_brdtype = VME_TYPE_BVME4000;
96     }
97 #if 0
98     /* Call bvme6000_set_vectors() so ABORT will work, along with BVMBug
99      * debugger.  Note trap_init() will splat the abort vector, but
100      * bvme6000_init_IRQ() will put it back again.  Hopefully. */
101 
102     bvme6000_set_vectors();
103 #endif
104 
105     mach_max_dma_address = 0xffffffff;
106     mach_sched_init      = bvme6000_sched_init;
107     mach_init_IRQ        = bvme6000_init_IRQ;
108     mach_hwclk           = bvme6000_hwclk;
109     mach_reset		 = bvme6000_reset;
110     mach_get_model       = bvme6000_get_model;
111 
112     pr_info("Board is %sconfigured as a System Controller\n",
113 	    *config_reg_ptr & BVME_CONFIG_SW1 ? "" : "not ");
114 
115     /* Now do the PIT configuration */
116 
117     pit->pgcr	= 0x00;	/* Unidirectional 8 bit, no handshake for now */
118     pit->psrr	= 0x18;	/* PIACK and PIRQ functions enabled */
119     pit->pacr	= 0x00;	/* Sub Mode 00, H2 i/p, no DMA */
120     pit->padr	= 0x00;	/* Just to be tidy! */
121     pit->paddr	= 0x00;	/* All inputs for now (safest) */
122     pit->pbcr	= 0x80;	/* Sub Mode 1x, H4 i/p, no DMA */
123     pit->pbdr	= 0xbc | (*config_reg_ptr & BVME_CONFIG_SW1 ? 0 : 0x40);
124 			/* PRI, SYSCON?, Level3, SCC clks from xtal */
125     pit->pbddr	= 0xf3;	/* Mostly outputs */
126     pit->pcdr	= 0x01;	/* PA transceiver disabled */
127     pit->pcddr	= 0x03;	/* WDOG disable */
128 
129     /* Disable snooping for Ethernet and VME accesses */
130 
131     bvme_acr_addrctl = 0;
132 }
133 
134 
135 irqreturn_t bvme6000_abort_int (int irq, void *dev_id)
136 {
137         unsigned long *new = (unsigned long *)vectors;
138         unsigned long *old = (unsigned long *)0xf8000000;
139 
140         /* Wait for button release */
141         while (*(volatile unsigned char *)BVME_LOCAL_IRQ_STAT & BVME_ABORT_STATUS)
142                 ;
143 
144         *(new+4) = *(old+4);            /* Illegal instruction */
145         *(new+9) = *(old+9);            /* Trace */
146         *(new+47) = *(old+47);          /* Trap #15 */
147         *(new+0x1f) = *(old+0x1f);      /* ABORT switch */
148 	return IRQ_HANDLED;
149 }
150 
151 static u64 bvme6000_read_clk(struct clocksource *cs);
152 
153 static struct clocksource bvme6000_clk = {
154 	.name   = "rtc",
155 	.rating = 250,
156 	.read   = bvme6000_read_clk,
157 	.mask   = CLOCKSOURCE_MASK(32),
158 	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
159 };
160 
161 static u32 clk_total, clk_offset;
162 
163 #define RTC_TIMER_CLOCK_FREQ 8000000
164 #define RTC_TIMER_CYCLES     (RTC_TIMER_CLOCK_FREQ / HZ)
165 #define RTC_TIMER_COUNT      ((RTC_TIMER_CYCLES / 2) - 1)
166 
167 static irqreturn_t bvme6000_timer_int (int irq, void *dev_id)
168 {
169     irq_handler_t timer_routine = dev_id;
170     unsigned long flags;
171     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
172     unsigned char msr;
173 
174     local_irq_save(flags);
175     msr = rtc->msr & 0xc0;
176     rtc->msr = msr | 0x20;		/* Ack the interrupt */
177     clk_total += RTC_TIMER_CYCLES;
178     clk_offset = 0;
179     timer_routine(0, NULL);
180     local_irq_restore(flags);
181 
182     return IRQ_HANDLED;
183 }
184 
185 /*
186  * Set up the RTC timer 1 to mode 2, so T1 output toggles every 5ms
187  * (40000 x 125ns).  It will interrupt every 10ms, when T1 goes low.
188  * So, when reading the elapsed time, you should read timer1,
189  * subtract it from 39999, and then add 40000 if T1 is high.
190  * That gives you the number of 125ns ticks in to the 10ms period,
191  * so divide by 8 to get the microsecond result.
192  */
193 
194 void bvme6000_sched_init (irq_handler_t timer_routine)
195 {
196     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
197     unsigned char msr = rtc->msr & 0xc0;
198 
199     rtc->msr = 0;	/* Ensure timer registers accessible */
200 
201     if (request_irq(BVME_IRQ_RTC, bvme6000_timer_int, IRQF_TIMER, "timer",
202                     timer_routine))
203 	panic ("Couldn't register timer int");
204 
205     rtc->t1cr_omr = 0x04;	/* Mode 2, ext clk */
206     rtc->t1msb = RTC_TIMER_COUNT >> 8;
207     rtc->t1lsb = RTC_TIMER_COUNT & 0xff;
208     rtc->irr_icr1 &= 0xef;	/* Route timer 1 to INTR pin */
209     rtc->msr = 0x40;		/* Access int.cntrl, etc */
210     rtc->pfr_icr0 = 0x80;	/* Just timer 1 ints enabled */
211     rtc->irr_icr1 = 0;
212     rtc->t1cr_omr = 0x0a;	/* INTR+T1 active lo, push-pull */
213     rtc->t0cr_rtmr &= 0xdf;	/* Stop timers in standby */
214     rtc->msr = 0;		/* Access timer 1 control */
215     rtc->t1cr_omr = 0x05;	/* Mode 2, ext clk, GO */
216 
217     rtc->msr = msr;
218 
219     clocksource_register_hz(&bvme6000_clk, RTC_TIMER_CLOCK_FREQ);
220 
221     if (request_irq(BVME_IRQ_ABORT, bvme6000_abort_int, 0,
222 				"abort", bvme6000_abort_int))
223 	panic ("Couldn't register abort int");
224 }
225 
226 
227 /*
228  * NOTE:  Don't accept any readings within 5us of rollover, as
229  * the T1INT bit may be a little slow getting set.  There is also
230  * a fault in the chip, meaning that reads may produce invalid
231  * results...
232  */
233 
234 static u64 bvme6000_read_clk(struct clocksource *cs)
235 {
236     unsigned long flags;
237     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
238     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
239     unsigned char msr, msb;
240     unsigned char t1int, t1op;
241     u32 v = 800000, ov;
242 
243     local_irq_save(flags);
244 
245     msr = rtc->msr & 0xc0;
246     rtc->msr = 0;	/* Ensure timer registers accessible */
247 
248     do {
249 	ov = v;
250 	t1int = rtc->msr & 0x20;
251 	t1op  = pit->pcdr & 0x04;
252 	rtc->t1cr_omr |= 0x40;		/* Latch timer1 */
253 	msb = rtc->t1msb;		/* Read timer1 */
254 	v = (msb << 8) | rtc->t1lsb;	/* Read timer1 */
255     } while (t1int != (rtc->msr & 0x20) ||
256 		t1op != (pit->pcdr & 0x04) ||
257 			abs(ov-v) > 80 ||
258 				v > RTC_TIMER_COUNT - (RTC_TIMER_COUNT / 100));
259 
260     v = RTC_TIMER_COUNT - v;
261     if (!t1op)				/* If in second half cycle.. */
262 	v += RTC_TIMER_CYCLES / 2;
263     if (msb > 0 && t1int)
264 	clk_offset = RTC_TIMER_CYCLES;
265     rtc->msr = msr;
266 
267     v += clk_offset + clk_total;
268 
269     local_irq_restore(flags);
270 
271     return v;
272 }
273 
274 /*
275  * Looks like op is non-zero for setting the clock, and zero for
276  * reading the clock.
277  *
278  *  struct hwclk_time {
279  *         unsigned        sec;       0..59
280  *         unsigned        min;       0..59
281  *         unsigned        hour;      0..23
282  *         unsigned        day;       1..31
283  *         unsigned        mon;       0..11
284  *         unsigned        year;      00...
285  *         int             wday;      0..6, 0 is Sunday, -1 means unknown/don't set
286  * };
287  */
288 
289 int bvme6000_hwclk(int op, struct rtc_time *t)
290 {
291 	volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
292 	unsigned char msr = rtc->msr & 0xc0;
293 
294 	rtc->msr = 0x40;	/* Ensure clock and real-time-mode-register
295 				 * are accessible */
296 	if (op)
297 	{	/* Write.... */
298 		rtc->t0cr_rtmr = t->tm_year%4;
299 		rtc->bcd_tenms = 0;
300 		rtc->bcd_sec = bin2bcd(t->tm_sec);
301 		rtc->bcd_min = bin2bcd(t->tm_min);
302 		rtc->bcd_hr  = bin2bcd(t->tm_hour);
303 		rtc->bcd_dom = bin2bcd(t->tm_mday);
304 		rtc->bcd_mth = bin2bcd(t->tm_mon + 1);
305 		rtc->bcd_year = bin2bcd(t->tm_year%100);
306 		if (t->tm_wday >= 0)
307 			rtc->bcd_dow = bin2bcd(t->tm_wday+1);
308 		rtc->t0cr_rtmr = t->tm_year%4 | 0x08;
309 	}
310 	else
311 	{	/* Read....  */
312 		do {
313 			t->tm_sec  = bcd2bin(rtc->bcd_sec);
314 			t->tm_min  = bcd2bin(rtc->bcd_min);
315 			t->tm_hour = bcd2bin(rtc->bcd_hr);
316 			t->tm_mday = bcd2bin(rtc->bcd_dom);
317 			t->tm_mon  = bcd2bin(rtc->bcd_mth)-1;
318 			t->tm_year = bcd2bin(rtc->bcd_year);
319 			if (t->tm_year < 70)
320 				t->tm_year += 100;
321 			t->tm_wday = bcd2bin(rtc->bcd_dow)-1;
322 		} while (t->tm_sec != bcd2bin(rtc->bcd_sec));
323 	}
324 
325 	rtc->msr = msr;
326 
327 	return 0;
328 }
329