xref: /openbmc/linux/arch/m68k/bvme6000/config.c (revision 89b15863)
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_sched_init      = bvme6000_sched_init;
105     mach_init_IRQ        = bvme6000_init_IRQ;
106     mach_hwclk           = bvme6000_hwclk;
107     mach_reset		 = bvme6000_reset;
108     mach_get_model       = bvme6000_get_model;
109 
110     pr_info("Board is %sconfigured as a System Controller\n",
111 	    *config_reg_ptr & BVME_CONFIG_SW1 ? "" : "not ");
112 
113     /* Now do the PIT configuration */
114 
115     pit->pgcr	= 0x00;	/* Unidirectional 8 bit, no handshake for now */
116     pit->psrr	= 0x18;	/* PIACK and PIRQ functions enabled */
117     pit->pacr	= 0x00;	/* Sub Mode 00, H2 i/p, no DMA */
118     pit->padr	= 0x00;	/* Just to be tidy! */
119     pit->paddr	= 0x00;	/* All inputs for now (safest) */
120     pit->pbcr	= 0x80;	/* Sub Mode 1x, H4 i/p, no DMA */
121     pit->pbdr	= 0xbc | (*config_reg_ptr & BVME_CONFIG_SW1 ? 0 : 0x40);
122 			/* PRI, SYSCON?, Level3, SCC clks from xtal */
123     pit->pbddr	= 0xf3;	/* Mostly outputs */
124     pit->pcdr	= 0x01;	/* PA transceiver disabled */
125     pit->pcddr	= 0x03;	/* WDOG disable */
126 
127     /* Disable snooping for Ethernet and VME accesses */
128 
129     bvme_acr_addrctl = 0;
130 }
131 
132 
133 irqreturn_t bvme6000_abort_int (int irq, void *dev_id)
134 {
135         unsigned long *new = (unsigned long *)vectors;
136         unsigned long *old = (unsigned long *)0xf8000000;
137 
138         /* Wait for button release */
139         while (*(volatile unsigned char *)BVME_LOCAL_IRQ_STAT & BVME_ABORT_STATUS)
140                 ;
141 
142         *(new+4) = *(old+4);            /* Illegal instruction */
143         *(new+9) = *(old+9);            /* Trace */
144         *(new+47) = *(old+47);          /* Trap #15 */
145         *(new+0x1f) = *(old+0x1f);      /* ABORT switch */
146 	return IRQ_HANDLED;
147 }
148 
149 static u64 bvme6000_read_clk(struct clocksource *cs);
150 
151 static struct clocksource bvme6000_clk = {
152 	.name   = "rtc",
153 	.rating = 250,
154 	.read   = bvme6000_read_clk,
155 	.mask   = CLOCKSOURCE_MASK(32),
156 	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
157 };
158 
159 static u32 clk_total, clk_offset;
160 
161 #define RTC_TIMER_CLOCK_FREQ 8000000
162 #define RTC_TIMER_CYCLES     (RTC_TIMER_CLOCK_FREQ / HZ)
163 #define RTC_TIMER_COUNT      ((RTC_TIMER_CYCLES / 2) - 1)
164 
165 static irqreturn_t bvme6000_timer_int (int irq, void *dev_id)
166 {
167     irq_handler_t timer_routine = dev_id;
168     unsigned long flags;
169     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
170     unsigned char msr;
171 
172     local_irq_save(flags);
173     msr = rtc->msr & 0xc0;
174     rtc->msr = msr | 0x20;		/* Ack the interrupt */
175     clk_total += RTC_TIMER_CYCLES;
176     clk_offset = 0;
177     timer_routine(0, NULL);
178     local_irq_restore(flags);
179 
180     return IRQ_HANDLED;
181 }
182 
183 /*
184  * Set up the RTC timer 1 to mode 2, so T1 output toggles every 5ms
185  * (40000 x 125ns).  It will interrupt every 10ms, when T1 goes low.
186  * So, when reading the elapsed time, you should read timer1,
187  * subtract it from 39999, and then add 40000 if T1 is high.
188  * That gives you the number of 125ns ticks in to the 10ms period,
189  * so divide by 8 to get the microsecond result.
190  */
191 
192 void bvme6000_sched_init (irq_handler_t timer_routine)
193 {
194     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
195     unsigned char msr = rtc->msr & 0xc0;
196 
197     rtc->msr = 0;	/* Ensure timer registers accessible */
198 
199     if (request_irq(BVME_IRQ_RTC, bvme6000_timer_int, IRQF_TIMER, "timer",
200                     timer_routine))
201 	panic ("Couldn't register timer int");
202 
203     rtc->t1cr_omr = 0x04;	/* Mode 2, ext clk */
204     rtc->t1msb = RTC_TIMER_COUNT >> 8;
205     rtc->t1lsb = RTC_TIMER_COUNT & 0xff;
206     rtc->irr_icr1 &= 0xef;	/* Route timer 1 to INTR pin */
207     rtc->msr = 0x40;		/* Access int.cntrl, etc */
208     rtc->pfr_icr0 = 0x80;	/* Just timer 1 ints enabled */
209     rtc->irr_icr1 = 0;
210     rtc->t1cr_omr = 0x0a;	/* INTR+T1 active lo, push-pull */
211     rtc->t0cr_rtmr &= 0xdf;	/* Stop timers in standby */
212     rtc->msr = 0;		/* Access timer 1 control */
213     rtc->t1cr_omr = 0x05;	/* Mode 2, ext clk, GO */
214 
215     rtc->msr = msr;
216 
217     clocksource_register_hz(&bvme6000_clk, RTC_TIMER_CLOCK_FREQ);
218 
219     if (request_irq(BVME_IRQ_ABORT, bvme6000_abort_int, 0,
220 				"abort", bvme6000_abort_int))
221 	panic ("Couldn't register abort int");
222 }
223 
224 
225 /*
226  * NOTE:  Don't accept any readings within 5us of rollover, as
227  * the T1INT bit may be a little slow getting set.  There is also
228  * a fault in the chip, meaning that reads may produce invalid
229  * results...
230  */
231 
232 static u64 bvme6000_read_clk(struct clocksource *cs)
233 {
234     unsigned long flags;
235     volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
236     volatile PitRegsPtr pit = (PitRegsPtr)BVME_PIT_BASE;
237     unsigned char msr, msb;
238     unsigned char t1int, t1op;
239     u32 v = 800000, ov;
240 
241     local_irq_save(flags);
242 
243     msr = rtc->msr & 0xc0;
244     rtc->msr = 0;	/* Ensure timer registers accessible */
245 
246     do {
247 	ov = v;
248 	t1int = rtc->msr & 0x20;
249 	t1op  = pit->pcdr & 0x04;
250 	rtc->t1cr_omr |= 0x40;		/* Latch timer1 */
251 	msb = rtc->t1msb;		/* Read timer1 */
252 	v = (msb << 8) | rtc->t1lsb;	/* Read timer1 */
253     } while (t1int != (rtc->msr & 0x20) ||
254 		t1op != (pit->pcdr & 0x04) ||
255 			abs(ov-v) > 80 ||
256 				v > RTC_TIMER_COUNT - (RTC_TIMER_COUNT / 100));
257 
258     v = RTC_TIMER_COUNT - v;
259     if (!t1op)				/* If in second half cycle.. */
260 	v += RTC_TIMER_CYCLES / 2;
261     if (msb > 0 && t1int)
262 	clk_offset = RTC_TIMER_CYCLES;
263     rtc->msr = msr;
264 
265     v += clk_offset + clk_total;
266 
267     local_irq_restore(flags);
268 
269     return v;
270 }
271 
272 /*
273  * Looks like op is non-zero for setting the clock, and zero for
274  * reading the clock.
275  *
276  *  struct hwclk_time {
277  *         unsigned        sec;       0..59
278  *         unsigned        min;       0..59
279  *         unsigned        hour;      0..23
280  *         unsigned        day;       1..31
281  *         unsigned        mon;       0..11
282  *         unsigned        year;      00...
283  *         int             wday;      0..6, 0 is Sunday, -1 means unknown/don't set
284  * };
285  */
286 
287 int bvme6000_hwclk(int op, struct rtc_time *t)
288 {
289 	volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
290 	unsigned char msr = rtc->msr & 0xc0;
291 
292 	rtc->msr = 0x40;	/* Ensure clock and real-time-mode-register
293 				 * are accessible */
294 	if (op)
295 	{	/* Write.... */
296 		rtc->t0cr_rtmr = t->tm_year%4;
297 		rtc->bcd_tenms = 0;
298 		rtc->bcd_sec = bin2bcd(t->tm_sec);
299 		rtc->bcd_min = bin2bcd(t->tm_min);
300 		rtc->bcd_hr  = bin2bcd(t->tm_hour);
301 		rtc->bcd_dom = bin2bcd(t->tm_mday);
302 		rtc->bcd_mth = bin2bcd(t->tm_mon + 1);
303 		rtc->bcd_year = bin2bcd(t->tm_year%100);
304 		if (t->tm_wday >= 0)
305 			rtc->bcd_dow = bin2bcd(t->tm_wday+1);
306 		rtc->t0cr_rtmr = t->tm_year%4 | 0x08;
307 	}
308 	else
309 	{	/* Read....  */
310 		do {
311 			t->tm_sec  = bcd2bin(rtc->bcd_sec);
312 			t->tm_min  = bcd2bin(rtc->bcd_min);
313 			t->tm_hour = bcd2bin(rtc->bcd_hr);
314 			t->tm_mday = bcd2bin(rtc->bcd_dom);
315 			t->tm_mon  = bcd2bin(rtc->bcd_mth)-1;
316 			t->tm_year = bcd2bin(rtc->bcd_year);
317 			if (t->tm_year < 70)
318 				t->tm_year += 100;
319 			t->tm_wday = bcd2bin(rtc->bcd_dow)-1;
320 		} while (t->tm_sec != bcd2bin(rtc->bcd_sec));
321 	}
322 
323 	rtc->msr = msr;
324 
325 	return 0;
326 }
327