xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision 9884abee)
1 /*
2  * QEMU ETRAX Timers
3  *
4  * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qemu/osdep.h"
25 #include "hw/sysbus.h"
26 #include "sysemu/sysemu.h"
27 #include "qemu/timer.h"
28 #include "hw/ptimer.h"
29 
30 #define D(x)
31 
32 #define RW_TMR0_DIV   0x00
33 #define R_TMR0_DATA   0x04
34 #define RW_TMR0_CTRL  0x08
35 #define RW_TMR1_DIV   0x10
36 #define R_TMR1_DATA   0x14
37 #define RW_TMR1_CTRL  0x18
38 #define R_TIME        0x38
39 #define RW_WD_CTRL    0x40
40 #define R_WD_STAT     0x44
41 #define RW_INTR_MASK  0x48
42 #define RW_ACK_INTR   0x4c
43 #define R_INTR        0x50
44 #define R_MASKED_INTR 0x54
45 
46 #define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
47 #define ETRAX_TIMER(obj) \
48     OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
49 
50 typedef struct ETRAXTimerState {
51     SysBusDevice parent_obj;
52 
53     MemoryRegion mmio;
54     qemu_irq irq;
55     qemu_irq nmi;
56 
57     QEMUBH *bh_t0;
58     QEMUBH *bh_t1;
59     QEMUBH *bh_wd;
60     ptimer_state *ptimer_t0;
61     ptimer_state *ptimer_t1;
62     ptimer_state *ptimer_wd;
63 
64     int wd_hits;
65 
66     /* Control registers.  */
67     uint32_t rw_tmr0_div;
68     uint32_t r_tmr0_data;
69     uint32_t rw_tmr0_ctrl;
70 
71     uint32_t rw_tmr1_div;
72     uint32_t r_tmr1_data;
73     uint32_t rw_tmr1_ctrl;
74 
75     uint32_t rw_wd_ctrl;
76 
77     uint32_t rw_intr_mask;
78     uint32_t rw_ack_intr;
79     uint32_t r_intr;
80     uint32_t r_masked_intr;
81 } ETRAXTimerState;
82 
83 static uint64_t
84 timer_read(void *opaque, hwaddr addr, unsigned int size)
85 {
86     ETRAXTimerState *t = opaque;
87     uint32_t r = 0;
88 
89     switch (addr) {
90     case R_TMR0_DATA:
91         r = ptimer_get_count(t->ptimer_t0);
92         break;
93     case R_TMR1_DATA:
94         r = ptimer_get_count(t->ptimer_t1);
95         break;
96     case R_TIME:
97         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
98         break;
99     case RW_INTR_MASK:
100         r = t->rw_intr_mask;
101         break;
102     case R_MASKED_INTR:
103         r = t->r_intr & t->rw_intr_mask;
104         break;
105     default:
106         D(printf ("%s %x\n", __func__, addr));
107         break;
108     }
109     return r;
110 }
111 
112 static void update_ctrl(ETRAXTimerState *t, int tnum)
113 {
114     unsigned int op;
115     unsigned int freq;
116     unsigned int freq_hz;
117     unsigned int div;
118     uint32_t ctrl;
119 
120     ptimer_state *timer;
121 
122     if (tnum == 0) {
123         ctrl = t->rw_tmr0_ctrl;
124         div = t->rw_tmr0_div;
125         timer = t->ptimer_t0;
126     } else {
127         ctrl = t->rw_tmr1_ctrl;
128         div = t->rw_tmr1_div;
129         timer = t->ptimer_t1;
130     }
131 
132 
133     op = ctrl & 3;
134     freq = ctrl >> 2;
135     freq_hz = 32000000;
136 
137     switch (freq)
138     {
139     case 0:
140     case 1:
141         D(printf ("extern or disabled timer clock?\n"));
142         break;
143     case 4: freq_hz =  29493000; break;
144     case 5: freq_hz =  32000000; break;
145     case 6: freq_hz =  32768000; break;
146     case 7: freq_hz = 100000000; break;
147     default:
148         abort();
149         break;
150     }
151 
152     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
153     ptimer_set_freq(timer, freq_hz);
154     ptimer_set_limit(timer, div, 0);
155 
156     switch (op)
157     {
158         case 0:
159             /* Load.  */
160             ptimer_set_limit(timer, div, 1);
161             break;
162         case 1:
163             /* Hold.  */
164             ptimer_stop(timer);
165             break;
166         case 2:
167             /* Run.  */
168             ptimer_run(timer, 0);
169             break;
170         default:
171             abort();
172             break;
173     }
174 }
175 
176 static void timer_update_irq(ETRAXTimerState *t)
177 {
178     t->r_intr &= ~(t->rw_ack_intr);
179     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
180 
181     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
182     qemu_set_irq(t->irq, !!t->r_masked_intr);
183 }
184 
185 static void timer0_hit(void *opaque)
186 {
187     ETRAXTimerState *t = opaque;
188     t->r_intr |= 1;
189     timer_update_irq(t);
190 }
191 
192 static void timer1_hit(void *opaque)
193 {
194     ETRAXTimerState *t = opaque;
195     t->r_intr |= 2;
196     timer_update_irq(t);
197 }
198 
199 static void watchdog_hit(void *opaque)
200 {
201     ETRAXTimerState *t = opaque;
202     if (t->wd_hits == 0) {
203         /* real hw gives a single tick before reseting but we are
204            a bit friendlier to compensate for our slower execution.  */
205         ptimer_set_count(t->ptimer_wd, 10);
206         ptimer_run(t->ptimer_wd, 1);
207         qemu_irq_raise(t->nmi);
208     }
209     else
210         qemu_system_reset_request();
211 
212     t->wd_hits++;
213 }
214 
215 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
216 {
217     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
218     unsigned int wd_key = t->rw_wd_ctrl >> 9;
219     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
220     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
221     unsigned int new_cmd = (value >> 8) & 1;
222 
223     /* If the watchdog is enabled, they written key must match the
224        complement of the previous.  */
225     wd_key = ~wd_key & ((1 << 7) - 1);
226 
227     if (wd_en && wd_key != new_key)
228         return;
229 
230     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
231          wd_en, new_key, wd_key, new_cmd, wd_cnt));
232 
233     if (t->wd_hits)
234         qemu_irq_lower(t->nmi);
235 
236     t->wd_hits = 0;
237 
238     ptimer_set_freq(t->ptimer_wd, 760);
239     if (wd_cnt == 0)
240         wd_cnt = 256;
241     ptimer_set_count(t->ptimer_wd, wd_cnt);
242     if (new_cmd)
243         ptimer_run(t->ptimer_wd, 1);
244     else
245         ptimer_stop(t->ptimer_wd);
246 
247     t->rw_wd_ctrl = value;
248 }
249 
250 static void
251 timer_write(void *opaque, hwaddr addr,
252             uint64_t val64, unsigned int size)
253 {
254     ETRAXTimerState *t = opaque;
255     uint32_t value = val64;
256 
257     switch (addr)
258     {
259         case RW_TMR0_DIV:
260             t->rw_tmr0_div = value;
261             break;
262         case RW_TMR0_CTRL:
263             D(printf ("RW_TMR0_CTRL=%x\n", value));
264             t->rw_tmr0_ctrl = value;
265             update_ctrl(t, 0);
266             break;
267         case RW_TMR1_DIV:
268             t->rw_tmr1_div = value;
269             break;
270         case RW_TMR1_CTRL:
271             D(printf ("RW_TMR1_CTRL=%x\n", value));
272             t->rw_tmr1_ctrl = value;
273             update_ctrl(t, 1);
274             break;
275         case RW_INTR_MASK:
276             D(printf ("RW_INTR_MASK=%x\n", value));
277             t->rw_intr_mask = value;
278             timer_update_irq(t);
279             break;
280         case RW_WD_CTRL:
281             timer_watchdog_update(t, value);
282             break;
283         case RW_ACK_INTR:
284             t->rw_ack_intr = value;
285             timer_update_irq(t);
286             t->rw_ack_intr = 0;
287             break;
288         default:
289             printf ("%s " TARGET_FMT_plx " %x\n",
290                 __func__, addr, value);
291             break;
292     }
293 }
294 
295 static const MemoryRegionOps timer_ops = {
296     .read = timer_read,
297     .write = timer_write,
298     .endianness = DEVICE_LITTLE_ENDIAN,
299     .valid = {
300         .min_access_size = 4,
301         .max_access_size = 4
302     }
303 };
304 
305 static void etraxfs_timer_reset(void *opaque)
306 {
307     ETRAXTimerState *t = opaque;
308 
309     ptimer_stop(t->ptimer_t0);
310     ptimer_stop(t->ptimer_t1);
311     ptimer_stop(t->ptimer_wd);
312     t->rw_wd_ctrl = 0;
313     t->r_intr = 0;
314     t->rw_intr_mask = 0;
315     qemu_irq_lower(t->irq);
316 }
317 
318 static int etraxfs_timer_init(SysBusDevice *dev)
319 {
320     ETRAXTimerState *t = ETRAX_TIMER(dev);
321 
322     t->bh_t0 = qemu_bh_new(timer0_hit, t);
323     t->bh_t1 = qemu_bh_new(timer1_hit, t);
324     t->bh_wd = qemu_bh_new(watchdog_hit, t);
325     t->ptimer_t0 = ptimer_init(t->bh_t0);
326     t->ptimer_t1 = ptimer_init(t->bh_t1);
327     t->ptimer_wd = ptimer_init(t->bh_wd);
328 
329     sysbus_init_irq(dev, &t->irq);
330     sysbus_init_irq(dev, &t->nmi);
331 
332     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
333                           "etraxfs-timer", 0x5c);
334     sysbus_init_mmio(dev, &t->mmio);
335     qemu_register_reset(etraxfs_timer_reset, t);
336     return 0;
337 }
338 
339 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
340 {
341     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
342 
343     sdc->init = etraxfs_timer_init;
344 }
345 
346 static const TypeInfo etraxfs_timer_info = {
347     .name          = TYPE_ETRAX_FS_TIMER,
348     .parent        = TYPE_SYS_BUS_DEVICE,
349     .instance_size = sizeof(ETRAXTimerState),
350     .class_init    = etraxfs_timer_class_init,
351 };
352 
353 static void etraxfs_timer_register_types(void)
354 {
355     type_register_static(&etraxfs_timer_info);
356 }
357 
358 type_init(etraxfs_timer_register_types)
359