1 /*
2  *  Copyright (C) 2006-2009  Anders Gavare.  All rights reserved.
3  *
4  *  Redistribution and use in source and binary forms, with or without
5  *  modification, are permitted provided that the following conditions are met:
6  *
7  *  1. Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. The name of the author may not be used to endorse or promote products
13  *     derived from this software without specific prior written permission.
14  *
15  *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  *  SUCH DAMAGE.
26  *
27  *
28  *  COMMENT: A generic Real-Time Clock device, for the test machines
29  *
30  *  It can be used to retrieve the current system time, and to cause periodic
31  *  interrupts.
32  */
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <sys/time.h>
38 
39 #include "cpu.h"
40 #include "device.h"
41 #include "emul.h"
42 #include "machine.h"
43 #include "memory.h"
44 #include "misc.h"
45 #include "timer.h"
46 
47 #include "testmachine/dev_rtc.h"
48 
49 
50 #define	DEV_RTC_TICK_SHIFT	14
51 
52 struct rtc_data {
53 	struct interrupt	irq;
54 	int			pending_interrupts;
55 
56 	int			hz;
57 	struct timer		*timer;
58 
59 	struct timeval		cur_time;
60 };
61 
62 
63 /*
64  *  timer_tick():
65  *
66  *  This function is called d->hz times per second.
67  */
timer_tick(struct timer * t,void * extra)68 static void timer_tick(struct timer *t, void *extra)
69 {
70         struct rtc_data *d = (struct rtc_data *) extra;
71         d->pending_interrupts ++;
72 }
73 
74 
DEVICE_TICK(rtc)75 DEVICE_TICK(rtc)
76 {
77 	struct rtc_data *d = (struct rtc_data *) extra;
78 
79 	if (d->pending_interrupts > 0)
80 		INTERRUPT_ASSERT(d->irq);
81 	else
82 		INTERRUPT_DEASSERT(d->irq);
83 }
84 
85 
DEVICE_ACCESS(rtc)86 DEVICE_ACCESS(rtc)
87 {
88 	struct rtc_data *d = (struct rtc_data *) extra;
89 	uint64_t idata = 0, odata = 0;
90 
91 	if (writeflag == MEM_WRITE)
92 		idata = memory_readmax64(cpu, data, len);
93 
94 	switch (relative_addr) {
95 
96 	case DEV_RTC_TRIGGER_READ:
97 		gettimeofday(&d->cur_time, NULL);
98 		break;
99 
100 	case DEV_RTC_SEC:
101 		odata = d->cur_time.tv_sec;
102 		break;
103 
104 	case DEV_RTC_USEC:
105 		odata = d->cur_time.tv_usec;
106 		break;
107 
108 	case DEV_RTC_HZ:
109 		if (writeflag == MEM_READ) {
110 			odata = d->hz;
111 		} else {
112 			d->hz = idata;
113 
114 			if (d->hz == 0) {
115 				/*  Remove the timer, if any:  */
116 				if (d->timer != NULL)
117 					timer_remove(d->timer);
118 
119 				d->timer = NULL;
120 				d->pending_interrupts = 0;
121 			} else {
122 				/*  Add a timer, or update the existing one:  */
123 				if (d->timer == NULL)
124 					d->timer = timer_add(d->hz,
125 					    timer_tick, d);
126 				else
127 					timer_update_frequency(d->timer, d->hz);
128 			}
129 		}
130 		break;
131 
132 	case DEV_RTC_INTERRUPT_ACK:
133 		if (d->pending_interrupts > 0)
134 			d->pending_interrupts --;
135 
136 		INTERRUPT_DEASSERT(d->irq);
137 
138 		/*  TODO: Reassert the interrupt here, if
139 		    d->pending_interrupts is still above zero?  */
140 
141 		break;
142 
143 	default:if (writeflag == MEM_WRITE) {
144 			fatal("[ rtc: unimplemented write to "
145 			    "offset 0x%x: data=0x%x ]\n", (int)
146 			    relative_addr, (int)idata);
147 		} else {
148 			fatal("[ rtc: unimplemented read from "
149 			    "offset 0x%x ]\n", (int)relative_addr);
150 		}
151 	}
152 
153 	if (writeflag == MEM_READ)
154 		memory_writemax64(cpu, data, len, odata);
155 
156 	return 1;
157 }
158 
159 
DEVINIT(rtc)160 DEVINIT(rtc)
161 {
162 	struct rtc_data *d;
163 
164 	CHECK_ALLOCATION(d = (struct rtc_data *) malloc(sizeof(struct rtc_data)));
165 	memset(d, 0, sizeof(struct rtc_data));
166 
167 	INTERRUPT_CONNECT(devinit->interrupt_path, d->irq);
168 
169 	memory_device_register(devinit->machine->memory, devinit->name,
170 	    devinit->addr, DEV_RTC_LENGTH, dev_rtc_access, (void *)d,
171 	    DM_DEFAULT, NULL);
172 
173 	machine_add_tickfunction(devinit->machine,
174 	    dev_rtc_tick, d, DEV_RTC_TICK_SHIFT);
175 
176 	return 1;
177 }
178 
179