xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision 6a0acfff)
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 
25 #include "qemu/osdep.h"
26 #include "hw/sysbus.h"
27 #include "sysemu/reset.h"
28 #include "sysemu/sysemu.h"
29 #include "qemu/module.h"
30 #include "qemu/timer.h"
31 #include "hw/irq.h"
32 #include "hw/ptimer.h"
33 
34 #define D(x)
35 
36 #define RW_TMR0_DIV   0x00
37 #define R_TMR0_DATA   0x04
38 #define RW_TMR0_CTRL  0x08
39 #define RW_TMR1_DIV   0x10
40 #define R_TMR1_DATA   0x14
41 #define RW_TMR1_CTRL  0x18
42 #define R_TIME        0x38
43 #define RW_WD_CTRL    0x40
44 #define R_WD_STAT     0x44
45 #define RW_INTR_MASK  0x48
46 #define RW_ACK_INTR   0x4c
47 #define R_INTR        0x50
48 #define R_MASKED_INTR 0x54
49 
50 #define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
51 #define ETRAX_TIMER(obj) \
52     OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
53 
54 typedef struct ETRAXTimerState {
55     SysBusDevice parent_obj;
56 
57     MemoryRegion mmio;
58     qemu_irq irq;
59     qemu_irq nmi;
60 
61     QEMUBH *bh_t0;
62     QEMUBH *bh_t1;
63     QEMUBH *bh_wd;
64     ptimer_state *ptimer_t0;
65     ptimer_state *ptimer_t1;
66     ptimer_state *ptimer_wd;
67 
68     int wd_hits;
69 
70     /* Control registers.  */
71     uint32_t rw_tmr0_div;
72     uint32_t r_tmr0_data;
73     uint32_t rw_tmr0_ctrl;
74 
75     uint32_t rw_tmr1_div;
76     uint32_t r_tmr1_data;
77     uint32_t rw_tmr1_ctrl;
78 
79     uint32_t rw_wd_ctrl;
80 
81     uint32_t rw_intr_mask;
82     uint32_t rw_ack_intr;
83     uint32_t r_intr;
84     uint32_t r_masked_intr;
85 } ETRAXTimerState;
86 
87 static uint64_t
88 timer_read(void *opaque, hwaddr addr, unsigned int size)
89 {
90     ETRAXTimerState *t = opaque;
91     uint32_t r = 0;
92 
93     switch (addr) {
94     case R_TMR0_DATA:
95         r = ptimer_get_count(t->ptimer_t0);
96         break;
97     case R_TMR1_DATA:
98         r = ptimer_get_count(t->ptimer_t1);
99         break;
100     case R_TIME:
101         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
102         break;
103     case RW_INTR_MASK:
104         r = t->rw_intr_mask;
105         break;
106     case R_MASKED_INTR:
107         r = t->r_intr & t->rw_intr_mask;
108         break;
109     default:
110         D(printf ("%s %x\n", __func__, addr));
111         break;
112     }
113     return r;
114 }
115 
116 static void update_ctrl(ETRAXTimerState *t, int tnum)
117 {
118     unsigned int op;
119     unsigned int freq;
120     unsigned int freq_hz;
121     unsigned int div;
122     uint32_t ctrl;
123 
124     ptimer_state *timer;
125 
126     if (tnum == 0) {
127         ctrl = t->rw_tmr0_ctrl;
128         div = t->rw_tmr0_div;
129         timer = t->ptimer_t0;
130     } else {
131         ctrl = t->rw_tmr1_ctrl;
132         div = t->rw_tmr1_div;
133         timer = t->ptimer_t1;
134     }
135 
136 
137     op = ctrl & 3;
138     freq = ctrl >> 2;
139     freq_hz = 32000000;
140 
141     switch (freq)
142     {
143     case 0:
144     case 1:
145         D(printf ("extern or disabled timer clock?\n"));
146         break;
147     case 4: freq_hz =  29493000; break;
148     case 5: freq_hz =  32000000; break;
149     case 6: freq_hz =  32768000; break;
150     case 7: freq_hz = 100000000; break;
151     default:
152         abort();
153         break;
154     }
155 
156     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
157     ptimer_set_freq(timer, freq_hz);
158     ptimer_set_limit(timer, div, 0);
159 
160     switch (op)
161     {
162         case 0:
163             /* Load.  */
164             ptimer_set_limit(timer, div, 1);
165             break;
166         case 1:
167             /* Hold.  */
168             ptimer_stop(timer);
169             break;
170         case 2:
171             /* Run.  */
172             ptimer_run(timer, 0);
173             break;
174         default:
175             abort();
176             break;
177     }
178 }
179 
180 static void timer_update_irq(ETRAXTimerState *t)
181 {
182     t->r_intr &= ~(t->rw_ack_intr);
183     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
184 
185     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
186     qemu_set_irq(t->irq, !!t->r_masked_intr);
187 }
188 
189 static void timer0_hit(void *opaque)
190 {
191     ETRAXTimerState *t = opaque;
192     t->r_intr |= 1;
193     timer_update_irq(t);
194 }
195 
196 static void timer1_hit(void *opaque)
197 {
198     ETRAXTimerState *t = opaque;
199     t->r_intr |= 2;
200     timer_update_irq(t);
201 }
202 
203 static void watchdog_hit(void *opaque)
204 {
205     ETRAXTimerState *t = opaque;
206     if (t->wd_hits == 0) {
207         /* real hw gives a single tick before reseting but we are
208            a bit friendlier to compensate for our slower execution.  */
209         ptimer_set_count(t->ptimer_wd, 10);
210         ptimer_run(t->ptimer_wd, 1);
211         qemu_irq_raise(t->nmi);
212     }
213     else
214         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
215 
216     t->wd_hits++;
217 }
218 
219 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
220 {
221     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
222     unsigned int wd_key = t->rw_wd_ctrl >> 9;
223     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
224     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
225     unsigned int new_cmd = (value >> 8) & 1;
226 
227     /* If the watchdog is enabled, they written key must match the
228        complement of the previous.  */
229     wd_key = ~wd_key & ((1 << 7) - 1);
230 
231     if (wd_en && wd_key != new_key)
232         return;
233 
234     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
235          wd_en, new_key, wd_key, new_cmd, wd_cnt));
236 
237     if (t->wd_hits)
238         qemu_irq_lower(t->nmi);
239 
240     t->wd_hits = 0;
241 
242     ptimer_set_freq(t->ptimer_wd, 760);
243     if (wd_cnt == 0)
244         wd_cnt = 256;
245     ptimer_set_count(t->ptimer_wd, wd_cnt);
246     if (new_cmd)
247         ptimer_run(t->ptimer_wd, 1);
248     else
249         ptimer_stop(t->ptimer_wd);
250 
251     t->rw_wd_ctrl = value;
252 }
253 
254 static void
255 timer_write(void *opaque, hwaddr addr,
256             uint64_t val64, unsigned int size)
257 {
258     ETRAXTimerState *t = opaque;
259     uint32_t value = val64;
260 
261     switch (addr)
262     {
263         case RW_TMR0_DIV:
264             t->rw_tmr0_div = value;
265             break;
266         case RW_TMR0_CTRL:
267             D(printf ("RW_TMR0_CTRL=%x\n", value));
268             t->rw_tmr0_ctrl = value;
269             update_ctrl(t, 0);
270             break;
271         case RW_TMR1_DIV:
272             t->rw_tmr1_div = value;
273             break;
274         case RW_TMR1_CTRL:
275             D(printf ("RW_TMR1_CTRL=%x\n", value));
276             t->rw_tmr1_ctrl = value;
277             update_ctrl(t, 1);
278             break;
279         case RW_INTR_MASK:
280             D(printf ("RW_INTR_MASK=%x\n", value));
281             t->rw_intr_mask = value;
282             timer_update_irq(t);
283             break;
284         case RW_WD_CTRL:
285             timer_watchdog_update(t, value);
286             break;
287         case RW_ACK_INTR:
288             t->rw_ack_intr = value;
289             timer_update_irq(t);
290             t->rw_ack_intr = 0;
291             break;
292         default:
293             printf ("%s " TARGET_FMT_plx " %x\n",
294                 __func__, addr, value);
295             break;
296     }
297 }
298 
299 static const MemoryRegionOps timer_ops = {
300     .read = timer_read,
301     .write = timer_write,
302     .endianness = DEVICE_LITTLE_ENDIAN,
303     .valid = {
304         .min_access_size = 4,
305         .max_access_size = 4
306     }
307 };
308 
309 static void etraxfs_timer_reset(void *opaque)
310 {
311     ETRAXTimerState *t = opaque;
312 
313     ptimer_stop(t->ptimer_t0);
314     ptimer_stop(t->ptimer_t1);
315     ptimer_stop(t->ptimer_wd);
316     t->rw_wd_ctrl = 0;
317     t->r_intr = 0;
318     t->rw_intr_mask = 0;
319     qemu_irq_lower(t->irq);
320 }
321 
322 static void etraxfs_timer_realize(DeviceState *dev, Error **errp)
323 {
324     ETRAXTimerState *t = ETRAX_TIMER(dev);
325     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
326 
327     t->bh_t0 = qemu_bh_new(timer0_hit, t);
328     t->bh_t1 = qemu_bh_new(timer1_hit, t);
329     t->bh_wd = qemu_bh_new(watchdog_hit, t);
330     t->ptimer_t0 = ptimer_init(t->bh_t0, PTIMER_POLICY_DEFAULT);
331     t->ptimer_t1 = ptimer_init(t->bh_t1, PTIMER_POLICY_DEFAULT);
332     t->ptimer_wd = ptimer_init(t->bh_wd, PTIMER_POLICY_DEFAULT);
333 
334     sysbus_init_irq(sbd, &t->irq);
335     sysbus_init_irq(sbd, &t->nmi);
336 
337     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
338                           "etraxfs-timer", 0x5c);
339     sysbus_init_mmio(sbd, &t->mmio);
340     qemu_register_reset(etraxfs_timer_reset, t);
341 }
342 
343 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
344 {
345     DeviceClass *dc = DEVICE_CLASS(klass);
346 
347     dc->realize = etraxfs_timer_realize;
348 }
349 
350 static const TypeInfo etraxfs_timer_info = {
351     .name          = TYPE_ETRAX_FS_TIMER,
352     .parent        = TYPE_SYS_BUS_DEVICE,
353     .instance_size = sizeof(ETRAXTimerState),
354     .class_init    = etraxfs_timer_class_init,
355 };
356 
357 static void etraxfs_timer_register_types(void)
358 {
359     type_register_static(&etraxfs_timer_info);
360 }
361 
362 type_init(etraxfs_timer_register_types)
363