xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision a42e9c41)
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 "hw/sysbus.h"
25 #include "sysemu/sysemu.h"
26 #include "qemu/timer.h"
27 #include "hw/ptimer.h"
28 
29 #define D(x)
30 
31 #define RW_TMR0_DIV   0x00
32 #define R_TMR0_DATA   0x04
33 #define RW_TMR0_CTRL  0x08
34 #define RW_TMR1_DIV   0x10
35 #define R_TMR1_DATA   0x14
36 #define RW_TMR1_CTRL  0x18
37 #define R_TIME        0x38
38 #define RW_WD_CTRL    0x40
39 #define R_WD_STAT     0x44
40 #define RW_INTR_MASK  0x48
41 #define RW_ACK_INTR   0x4c
42 #define R_INTR        0x50
43 #define R_MASKED_INTR 0x54
44 
45 #define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
46 #define ETRAX_TIMER(obj) \
47     OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
48 
49 typedef struct ETRAXTimerState {
50     SysBusDevice parent_obj;
51 
52     MemoryRegion mmio;
53     qemu_irq irq;
54     qemu_irq nmi;
55 
56     QEMUBH *bh_t0;
57     QEMUBH *bh_t1;
58     QEMUBH *bh_wd;
59     ptimer_state *ptimer_t0;
60     ptimer_state *ptimer_t1;
61     ptimer_state *ptimer_wd;
62 
63     int wd_hits;
64 
65     /* Control registers.  */
66     uint32_t rw_tmr0_div;
67     uint32_t r_tmr0_data;
68     uint32_t rw_tmr0_ctrl;
69 
70     uint32_t rw_tmr1_div;
71     uint32_t r_tmr1_data;
72     uint32_t rw_tmr1_ctrl;
73 
74     uint32_t rw_wd_ctrl;
75 
76     uint32_t rw_intr_mask;
77     uint32_t rw_ack_intr;
78     uint32_t r_intr;
79     uint32_t r_masked_intr;
80 } ETRAXTimerState;
81 
82 static uint64_t
83 timer_read(void *opaque, hwaddr addr, unsigned int size)
84 {
85     ETRAXTimerState *t = opaque;
86     uint32_t r = 0;
87 
88     switch (addr) {
89     case R_TMR0_DATA:
90         r = ptimer_get_count(t->ptimer_t0);
91         break;
92     case R_TMR1_DATA:
93         r = ptimer_get_count(t->ptimer_t1);
94         break;
95     case R_TIME:
96         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
97         break;
98     case RW_INTR_MASK:
99         r = t->rw_intr_mask;
100         break;
101     case R_MASKED_INTR:
102         r = t->r_intr & t->rw_intr_mask;
103         break;
104     default:
105         D(printf ("%s %x\n", __func__, addr));
106         break;
107     }
108     return r;
109 }
110 
111 static void update_ctrl(ETRAXTimerState *t, int tnum)
112 {
113     unsigned int op;
114     unsigned int freq;
115     unsigned int freq_hz;
116     unsigned int div;
117     uint32_t ctrl;
118 
119     ptimer_state *timer;
120 
121     if (tnum == 0) {
122         ctrl = t->rw_tmr0_ctrl;
123         div = t->rw_tmr0_div;
124         timer = t->ptimer_t0;
125     } else {
126         ctrl = t->rw_tmr1_ctrl;
127         div = t->rw_tmr1_div;
128         timer = t->ptimer_t1;
129     }
130 
131 
132     op = ctrl & 3;
133     freq = ctrl >> 2;
134     freq_hz = 32000000;
135 
136     switch (freq)
137     {
138     case 0:
139     case 1:
140         D(printf ("extern or disabled timer clock?\n"));
141         break;
142     case 4: freq_hz =  29493000; break;
143     case 5: freq_hz =  32000000; break;
144     case 6: freq_hz =  32768000; break;
145     case 7: freq_hz = 100000000; break;
146     default:
147         abort();
148         break;
149     }
150 
151     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
152     ptimer_set_freq(timer, freq_hz);
153     ptimer_set_limit(timer, div, 0);
154 
155     switch (op)
156     {
157         case 0:
158             /* Load.  */
159             ptimer_set_limit(timer, div, 1);
160             break;
161         case 1:
162             /* Hold.  */
163             ptimer_stop(timer);
164             break;
165         case 2:
166             /* Run.  */
167             ptimer_run(timer, 0);
168             break;
169         default:
170             abort();
171             break;
172     }
173 }
174 
175 static void timer_update_irq(ETRAXTimerState *t)
176 {
177     t->r_intr &= ~(t->rw_ack_intr);
178     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
179 
180     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
181     qemu_set_irq(t->irq, !!t->r_masked_intr);
182 }
183 
184 static void timer0_hit(void *opaque)
185 {
186     ETRAXTimerState *t = opaque;
187     t->r_intr |= 1;
188     timer_update_irq(t);
189 }
190 
191 static void timer1_hit(void *opaque)
192 {
193     ETRAXTimerState *t = opaque;
194     t->r_intr |= 2;
195     timer_update_irq(t);
196 }
197 
198 static void watchdog_hit(void *opaque)
199 {
200     ETRAXTimerState *t = opaque;
201     if (t->wd_hits == 0) {
202         /* real hw gives a single tick before reseting but we are
203            a bit friendlier to compensate for our slower execution.  */
204         ptimer_set_count(t->ptimer_wd, 10);
205         ptimer_run(t->ptimer_wd, 1);
206         qemu_irq_raise(t->nmi);
207     }
208     else
209         qemu_system_reset_request();
210 
211     t->wd_hits++;
212 }
213 
214 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
215 {
216     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
217     unsigned int wd_key = t->rw_wd_ctrl >> 9;
218     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
219     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
220     unsigned int new_cmd = (value >> 8) & 1;
221 
222     /* If the watchdog is enabled, they written key must match the
223        complement of the previous.  */
224     wd_key = ~wd_key & ((1 << 7) - 1);
225 
226     if (wd_en && wd_key != new_key)
227         return;
228 
229     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
230          wd_en, new_key, wd_key, new_cmd, wd_cnt));
231 
232     if (t->wd_hits)
233         qemu_irq_lower(t->nmi);
234 
235     t->wd_hits = 0;
236 
237     ptimer_set_freq(t->ptimer_wd, 760);
238     if (wd_cnt == 0)
239         wd_cnt = 256;
240     ptimer_set_count(t->ptimer_wd, wd_cnt);
241     if (new_cmd)
242         ptimer_run(t->ptimer_wd, 1);
243     else
244         ptimer_stop(t->ptimer_wd);
245 
246     t->rw_wd_ctrl = value;
247 }
248 
249 static void
250 timer_write(void *opaque, hwaddr addr,
251             uint64_t val64, unsigned int size)
252 {
253     ETRAXTimerState *t = opaque;
254     uint32_t value = val64;
255 
256     switch (addr)
257     {
258         case RW_TMR0_DIV:
259             t->rw_tmr0_div = value;
260             break;
261         case RW_TMR0_CTRL:
262             D(printf ("RW_TMR0_CTRL=%x\n", value));
263             t->rw_tmr0_ctrl = value;
264             update_ctrl(t, 0);
265             break;
266         case RW_TMR1_DIV:
267             t->rw_tmr1_div = value;
268             break;
269         case RW_TMR1_CTRL:
270             D(printf ("RW_TMR1_CTRL=%x\n", value));
271             t->rw_tmr1_ctrl = value;
272             update_ctrl(t, 1);
273             break;
274         case RW_INTR_MASK:
275             D(printf ("RW_INTR_MASK=%x\n", value));
276             t->rw_intr_mask = value;
277             timer_update_irq(t);
278             break;
279         case RW_WD_CTRL:
280             timer_watchdog_update(t, value);
281             break;
282         case RW_ACK_INTR:
283             t->rw_ack_intr = value;
284             timer_update_irq(t);
285             t->rw_ack_intr = 0;
286             break;
287         default:
288             printf ("%s " TARGET_FMT_plx " %x\n",
289                 __func__, addr, value);
290             break;
291     }
292 }
293 
294 static const MemoryRegionOps timer_ops = {
295     .read = timer_read,
296     .write = timer_write,
297     .endianness = DEVICE_LITTLE_ENDIAN,
298     .valid = {
299         .min_access_size = 4,
300         .max_access_size = 4
301     }
302 };
303 
304 static void etraxfs_timer_reset(void *opaque)
305 {
306     ETRAXTimerState *t = opaque;
307 
308     ptimer_stop(t->ptimer_t0);
309     ptimer_stop(t->ptimer_t1);
310     ptimer_stop(t->ptimer_wd);
311     t->rw_wd_ctrl = 0;
312     t->r_intr = 0;
313     t->rw_intr_mask = 0;
314     qemu_irq_lower(t->irq);
315 }
316 
317 static int etraxfs_timer_init(SysBusDevice *dev)
318 {
319     ETRAXTimerState *t = ETRAX_TIMER(dev);
320 
321     t->bh_t0 = qemu_bh_new(timer0_hit, t);
322     t->bh_t1 = qemu_bh_new(timer1_hit, t);
323     t->bh_wd = qemu_bh_new(watchdog_hit, t);
324     t->ptimer_t0 = ptimer_init(t->bh_t0);
325     t->ptimer_t1 = ptimer_init(t->bh_t1);
326     t->ptimer_wd = ptimer_init(t->bh_wd);
327 
328     sysbus_init_irq(dev, &t->irq);
329     sysbus_init_irq(dev, &t->nmi);
330 
331     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
332                           "etraxfs-timer", 0x5c);
333     sysbus_init_mmio(dev, &t->mmio);
334     qemu_register_reset(etraxfs_timer_reset, t);
335     return 0;
336 }
337 
338 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
339 {
340     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
341 
342     sdc->init = etraxfs_timer_init;
343 }
344 
345 static const TypeInfo etraxfs_timer_info = {
346     .name          = TYPE_ETRAX_FS_TIMER,
347     .parent        = TYPE_SYS_BUS_DEVICE,
348     .instance_size = sizeof(ETRAXTimerState),
349     .class_init    = etraxfs_timer_class_init,
350 };
351 
352 static void etraxfs_timer_register_types(void)
353 {
354     type_register_static(&etraxfs_timer_info);
355 }
356 
357 type_init(etraxfs_timer_register_types)
358