xref: /openbmc/qemu/hw/timer/sh_timer.c (revision ad9e5aa2)
1 /*
2  * SuperH Timer modules.
3  *
4  * Copyright (c) 2007 Magnus Damm
5  * Based on arm_timer.c by Paul Brook
6  * Copyright (c) 2005-2006 CodeSourcery.
7  *
8  * This code is licensed under the GPL.
9  */
10 
11 #include "qemu/osdep.h"
12 #include "exec/memory.h"
13 #include "hw/hw.h"
14 #include "hw/irq.h"
15 #include "hw/sh4/sh.h"
16 #include "hw/timer/tmu012.h"
17 #include "hw/ptimer.h"
18 
19 //#define DEBUG_TIMER
20 
21 #define TIMER_TCR_TPSC          (7 << 0)
22 #define TIMER_TCR_CKEG          (3 << 3)
23 #define TIMER_TCR_UNIE          (1 << 5)
24 #define TIMER_TCR_ICPE          (3 << 6)
25 #define TIMER_TCR_UNF           (1 << 8)
26 #define TIMER_TCR_ICPF          (1 << 9)
27 #define TIMER_TCR_RESERVED      (0x3f << 10)
28 
29 #define TIMER_FEAT_CAPT   (1 << 0)
30 #define TIMER_FEAT_EXTCLK (1 << 1)
31 
32 #define OFFSET_TCOR   0
33 #define OFFSET_TCNT   1
34 #define OFFSET_TCR    2
35 #define OFFSET_TCPR   3
36 
37 typedef struct {
38     ptimer_state *timer;
39     uint32_t tcnt;
40     uint32_t tcor;
41     uint32_t tcr;
42     uint32_t tcpr;
43     int freq;
44     int int_level;
45     int old_level;
46     int feat;
47     int enabled;
48     qemu_irq irq;
49 } sh_timer_state;
50 
51 /* Check all active timers, and schedule the next timer interrupt. */
52 
53 static void sh_timer_update(sh_timer_state *s)
54 {
55     int new_level = s->int_level && (s->tcr & TIMER_TCR_UNIE);
56 
57     if (new_level != s->old_level)
58       qemu_set_irq (s->irq, new_level);
59 
60     s->old_level = s->int_level;
61     s->int_level = new_level;
62 }
63 
64 static uint32_t sh_timer_read(void *opaque, hwaddr offset)
65 {
66     sh_timer_state *s = (sh_timer_state *)opaque;
67 
68     switch (offset >> 2) {
69     case OFFSET_TCOR:
70         return s->tcor;
71     case OFFSET_TCNT:
72         return ptimer_get_count(s->timer);
73     case OFFSET_TCR:
74         return s->tcr | (s->int_level ? TIMER_TCR_UNF : 0);
75     case OFFSET_TCPR:
76         if (s->feat & TIMER_FEAT_CAPT)
77             return s->tcpr;
78         /* fall through */
79     default:
80         hw_error("sh_timer_read: Bad offset %x\n", (int)offset);
81         return 0;
82     }
83 }
84 
85 static void sh_timer_write(void *opaque, hwaddr offset,
86                             uint32_t value)
87 {
88     sh_timer_state *s = (sh_timer_state *)opaque;
89     int freq;
90 
91     switch (offset >> 2) {
92     case OFFSET_TCOR:
93         s->tcor = value;
94         ptimer_transaction_begin(s->timer);
95         ptimer_set_limit(s->timer, s->tcor, 0);
96         ptimer_transaction_commit(s->timer);
97         break;
98     case OFFSET_TCNT:
99         s->tcnt = value;
100         ptimer_transaction_begin(s->timer);
101         ptimer_set_count(s->timer, s->tcnt);
102         ptimer_transaction_commit(s->timer);
103         break;
104     case OFFSET_TCR:
105         ptimer_transaction_begin(s->timer);
106         if (s->enabled) {
107             /* Pause the timer if it is running.  This may cause some
108                inaccuracy dure to rounding, but avoids a whole lot of other
109                messyness.  */
110             ptimer_stop(s->timer);
111         }
112         freq = s->freq;
113         /* ??? Need to recalculate expiry time after changing divisor.  */
114         switch (value & TIMER_TCR_TPSC) {
115         case 0: freq >>= 2; break;
116         case 1: freq >>= 4; break;
117         case 2: freq >>= 6; break;
118         case 3: freq >>= 8; break;
119         case 4: freq >>= 10; break;
120 	case 6:
121 	case 7: if (s->feat & TIMER_FEAT_EXTCLK) break;
122 	default: hw_error("sh_timer_write: Reserved TPSC value\n"); break;
123         }
124         switch ((value & TIMER_TCR_CKEG) >> 3) {
125 	case 0: break;
126         case 1:
127         case 2:
128         case 3: if (s->feat & TIMER_FEAT_EXTCLK) break;
129 	default: hw_error("sh_timer_write: Reserved CKEG value\n"); break;
130         }
131         switch ((value & TIMER_TCR_ICPE) >> 6) {
132 	case 0: break;
133         case 2:
134         case 3: if (s->feat & TIMER_FEAT_CAPT) break;
135 	default: hw_error("sh_timer_write: Reserved ICPE value\n"); break;
136         }
137 	if ((value & TIMER_TCR_UNF) == 0)
138             s->int_level = 0;
139 
140 	value &= ~TIMER_TCR_UNF;
141 
142 	if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT)))
143             hw_error("sh_timer_write: Reserved ICPF value\n");
144 
145 	value &= ~TIMER_TCR_ICPF; /* capture not supported */
146 
147 	if (value & TIMER_TCR_RESERVED)
148             hw_error("sh_timer_write: Reserved TCR bits set\n");
149         s->tcr = value;
150         ptimer_set_limit(s->timer, s->tcor, 0);
151         ptimer_set_freq(s->timer, freq);
152         if (s->enabled) {
153             /* Restart the timer if still enabled.  */
154             ptimer_run(s->timer, 0);
155         }
156         ptimer_transaction_commit(s->timer);
157         break;
158     case OFFSET_TCPR:
159         if (s->feat & TIMER_FEAT_CAPT) {
160             s->tcpr = value;
161 	    break;
162 	}
163     default:
164         hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
165     }
166     sh_timer_update(s);
167 }
168 
169 static void sh_timer_start_stop(void *opaque, int enable)
170 {
171     sh_timer_state *s = (sh_timer_state *)opaque;
172 
173 #ifdef DEBUG_TIMER
174     printf("sh_timer_start_stop %d (%d)\n", enable, s->enabled);
175 #endif
176 
177     ptimer_transaction_begin(s->timer);
178     if (s->enabled && !enable) {
179         ptimer_stop(s->timer);
180     }
181     if (!s->enabled && enable) {
182         ptimer_run(s->timer, 0);
183     }
184     ptimer_transaction_commit(s->timer);
185     s->enabled = !!enable;
186 
187 #ifdef DEBUG_TIMER
188     printf("sh_timer_start_stop done %d\n", s->enabled);
189 #endif
190 }
191 
192 static void sh_timer_tick(void *opaque)
193 {
194     sh_timer_state *s = (sh_timer_state *)opaque;
195     s->int_level = s->enabled;
196     sh_timer_update(s);
197 }
198 
199 static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
200 {
201     sh_timer_state *s;
202 
203     s = (sh_timer_state *)g_malloc0(sizeof(sh_timer_state));
204     s->freq = freq;
205     s->feat = feat;
206     s->tcor = 0xffffffff;
207     s->tcnt = 0xffffffff;
208     s->tcpr = 0xdeadbeef;
209     s->tcr = 0;
210     s->enabled = 0;
211     s->irq = irq;
212 
213     s->timer = ptimer_init(sh_timer_tick, s, PTIMER_POLICY_DEFAULT);
214 
215     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
216     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
217     sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
218     sh_timer_write(s, OFFSET_TCR  >> 2, s->tcpr);
219     /* ??? Save/restore.  */
220     return s;
221 }
222 
223 typedef struct {
224     MemoryRegion iomem;
225     MemoryRegion iomem_p4;
226     MemoryRegion iomem_a7;
227     void *timer[3];
228     int level[3];
229     uint32_t tocr;
230     uint32_t tstr;
231     int feat;
232 } tmu012_state;
233 
234 static uint64_t tmu012_read(void *opaque, hwaddr offset,
235                             unsigned size)
236 {
237     tmu012_state *s = (tmu012_state *)opaque;
238 
239 #ifdef DEBUG_TIMER
240     printf("tmu012_read 0x%lx\n", (unsigned long) offset);
241 #endif
242 
243     if (offset >= 0x20) {
244         if (!(s->feat & TMU012_FEAT_3CHAN))
245 	    hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
246         return sh_timer_read(s->timer[2], offset - 0x20);
247     }
248 
249     if (offset >= 0x14)
250         return sh_timer_read(s->timer[1], offset - 0x14);
251 
252     if (offset >= 0x08)
253         return sh_timer_read(s->timer[0], offset - 0x08);
254 
255     if (offset == 4)
256         return s->tstr;
257 
258     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0)
259         return s->tocr;
260 
261     hw_error("tmu012_write: Bad offset %x\n", (int)offset);
262     return 0;
263 }
264 
265 static void tmu012_write(void *opaque, hwaddr offset,
266                         uint64_t value, unsigned size)
267 {
268     tmu012_state *s = (tmu012_state *)opaque;
269 
270 #ifdef DEBUG_TIMER
271     printf("tmu012_write 0x%lx 0x%08x\n", (unsigned long) offset, value);
272 #endif
273 
274     if (offset >= 0x20) {
275         if (!(s->feat & TMU012_FEAT_3CHAN))
276 	    hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
277         sh_timer_write(s->timer[2], offset - 0x20, value);
278 	return;
279     }
280 
281     if (offset >= 0x14) {
282         sh_timer_write(s->timer[1], offset - 0x14, value);
283 	return;
284     }
285 
286     if (offset >= 0x08) {
287         sh_timer_write(s->timer[0], offset - 0x08, value);
288 	return;
289     }
290 
291     if (offset == 4) {
292         sh_timer_start_stop(s->timer[0], value & (1 << 0));
293         sh_timer_start_stop(s->timer[1], value & (1 << 1));
294         if (s->feat & TMU012_FEAT_3CHAN)
295             sh_timer_start_stop(s->timer[2], value & (1 << 2));
296 	else
297             if (value & (1 << 2))
298                 hw_error("tmu012_write: Bad channel\n");
299 
300 	s->tstr = value;
301 	return;
302     }
303 
304     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
305         s->tocr = value & (1 << 0);
306     }
307 }
308 
309 static const MemoryRegionOps tmu012_ops = {
310     .read = tmu012_read,
311     .write = tmu012_write,
312     .endianness = DEVICE_NATIVE_ENDIAN,
313 };
314 
315 void tmu012_init(MemoryRegion *sysmem, hwaddr base,
316                  int feat, uint32_t freq,
317 		 qemu_irq ch0_irq, qemu_irq ch1_irq,
318 		 qemu_irq ch2_irq0, qemu_irq ch2_irq1)
319 {
320     tmu012_state *s;
321     int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
322 
323     s = (tmu012_state *)g_malloc0(sizeof(tmu012_state));
324     s->feat = feat;
325     s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
326     s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
327     if (feat & TMU012_FEAT_3CHAN)
328         s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
329 				    ch2_irq0); /* ch2_irq1 not supported */
330 
331     memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s,
332                           "timer", 0x100000000ULL);
333 
334     memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
335                              &s->iomem, 0, 0x1000);
336     memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
337 
338     memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
339                              &s->iomem, 0, 0x1000);
340     memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
341     /* ??? Save/restore.  */
342 }
343