xref: /openbmc/qemu/hw/timer/xilinx_timer.c (revision 2038f8c8)
1 /*
2  * QEMU model of the Xilinx timer block.
3  *
4  * Copyright (c) 2009 Edgar E. Iglesias.
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 "hw/irq.h"
28 #include "hw/ptimer.h"
29 #include "hw/qdev-properties.h"
30 #include "qemu/log.h"
31 #include "qemu/main-loop.h"
32 #include "qemu/module.h"
33 
34 #define D(x)
35 
36 #define R_TCSR     0
37 #define R_TLR      1
38 #define R_TCR      2
39 #define R_MAX      4
40 
41 #define TCSR_MDT        (1<<0)
42 #define TCSR_UDT        (1<<1)
43 #define TCSR_GENT       (1<<2)
44 #define TCSR_CAPT       (1<<3)
45 #define TCSR_ARHT       (1<<4)
46 #define TCSR_LOAD       (1<<5)
47 #define TCSR_ENIT       (1<<6)
48 #define TCSR_ENT        (1<<7)
49 #define TCSR_TINT       (1<<8)
50 #define TCSR_PWMA       (1<<9)
51 #define TCSR_ENALL      (1<<10)
52 
53 struct xlx_timer
54 {
55     QEMUBH *bh;
56     ptimer_state *ptimer;
57     void *parent;
58     int nr; /* for debug.  */
59 
60     unsigned long timer_div;
61 
62     uint32_t regs[R_MAX];
63 };
64 
65 #define TYPE_XILINX_TIMER "xlnx.xps-timer"
66 #define XILINX_TIMER(obj) \
67     OBJECT_CHECK(struct timerblock, (obj), TYPE_XILINX_TIMER)
68 
69 struct timerblock
70 {
71     SysBusDevice parent_obj;
72 
73     MemoryRegion mmio;
74     qemu_irq irq;
75     uint8_t one_timer_only;
76     uint32_t freq_hz;
77     struct xlx_timer *timers;
78 };
79 
80 static inline unsigned int num_timers(struct timerblock *t)
81 {
82     return 2 - t->one_timer_only;
83 }
84 
85 static inline unsigned int timer_from_addr(hwaddr addr)
86 {
87     /* Timers get a 4x32bit control reg area each.  */
88     return addr >> 2;
89 }
90 
91 static void timer_update_irq(struct timerblock *t)
92 {
93     unsigned int i, irq = 0;
94     uint32_t csr;
95 
96     for (i = 0; i < num_timers(t); i++) {
97         csr = t->timers[i].regs[R_TCSR];
98         irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);
99     }
100 
101     /* All timers within the same slave share a single IRQ line.  */
102     qemu_set_irq(t->irq, !!irq);
103 }
104 
105 static uint64_t
106 timer_read(void *opaque, hwaddr addr, unsigned int size)
107 {
108     struct timerblock *t = opaque;
109     struct xlx_timer *xt;
110     uint32_t r = 0;
111     unsigned int timer;
112 
113     addr >>= 2;
114     timer = timer_from_addr(addr);
115     xt = &t->timers[timer];
116     /* Further decoding to address a specific timers reg.  */
117     addr &= 0x3;
118     switch (addr)
119     {
120         case R_TCR:
121                 r = ptimer_get_count(xt->ptimer);
122                 if (!(xt->regs[R_TCSR] & TCSR_UDT))
123                     r = ~r;
124                 D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",
125                          timer, r, xt->regs[R_TCSR] & TCSR_UDT));
126             break;
127         default:
128             if (addr < ARRAY_SIZE(xt->regs))
129                 r = xt->regs[addr];
130             break;
131 
132     }
133     D(fprintf(stderr, "%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
134     return r;
135 }
136 
137 static void timer_enable(struct xlx_timer *xt)
138 {
139     uint64_t count;
140 
141     D(fprintf(stderr, "%s timer=%d down=%d\n", __func__,
142               xt->nr, xt->regs[R_TCSR] & TCSR_UDT));
143 
144     ptimer_stop(xt->ptimer);
145 
146     if (xt->regs[R_TCSR] & TCSR_UDT)
147         count = xt->regs[R_TLR];
148     else
149         count = ~0 - xt->regs[R_TLR];
150     ptimer_set_limit(xt->ptimer, count, 1);
151     ptimer_run(xt->ptimer, 1);
152 }
153 
154 static void
155 timer_write(void *opaque, hwaddr addr,
156             uint64_t val64, unsigned int size)
157 {
158     struct timerblock *t = opaque;
159     struct xlx_timer *xt;
160     unsigned int timer;
161     uint32_t value = val64;
162 
163     addr >>= 2;
164     timer = timer_from_addr(addr);
165     xt = &t->timers[timer];
166     D(fprintf(stderr, "%s addr=%x val=%x (timer=%d off=%d)\n",
167              __func__, addr * 4, value, timer, addr & 3));
168     /* Further decoding to address a specific timers reg.  */
169     addr &= 3;
170     switch (addr)
171     {
172         case R_TCSR:
173             if (value & TCSR_TINT)
174                 value &= ~TCSR_TINT;
175 
176             xt->regs[addr] = value & 0x7ff;
177             if (value & TCSR_ENT)
178                 timer_enable(xt);
179             break;
180 
181         default:
182             if (addr < ARRAY_SIZE(xt->regs))
183                 xt->regs[addr] = value;
184             break;
185     }
186     timer_update_irq(t);
187 }
188 
189 static const MemoryRegionOps timer_ops = {
190     .read = timer_read,
191     .write = timer_write,
192     .endianness = DEVICE_NATIVE_ENDIAN,
193     .valid = {
194         .min_access_size = 4,
195         .max_access_size = 4
196     }
197 };
198 
199 static void timer_hit(void *opaque)
200 {
201     struct xlx_timer *xt = opaque;
202     struct timerblock *t = xt->parent;
203     D(fprintf(stderr, "%s %d\n", __func__, xt->nr));
204     xt->regs[R_TCSR] |= TCSR_TINT;
205 
206     if (xt->regs[R_TCSR] & TCSR_ARHT)
207         timer_enable(xt);
208     timer_update_irq(t);
209 }
210 
211 static void xilinx_timer_realize(DeviceState *dev, Error **errp)
212 {
213     struct timerblock *t = XILINX_TIMER(dev);
214     unsigned int i;
215 
216     /* Init all the ptimers.  */
217     t->timers = g_malloc0(sizeof t->timers[0] * num_timers(t));
218     for (i = 0; i < num_timers(t); i++) {
219         struct xlx_timer *xt = &t->timers[i];
220 
221         xt->parent = t;
222         xt->nr = i;
223         xt->bh = qemu_bh_new(timer_hit, xt);
224         xt->ptimer = ptimer_init(xt->bh, PTIMER_POLICY_DEFAULT);
225         ptimer_set_freq(xt->ptimer, t->freq_hz);
226     }
227 
228     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, "xlnx.xps-timer",
229                           R_MAX * 4 * num_timers(t));
230     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &t->mmio);
231 }
232 
233 static void xilinx_timer_init(Object *obj)
234 {
235     struct timerblock *t = XILINX_TIMER(obj);
236 
237     /* All timers share a single irq line.  */
238     sysbus_init_irq(SYS_BUS_DEVICE(obj), &t->irq);
239 }
240 
241 static Property xilinx_timer_properties[] = {
242     DEFINE_PROP_UINT32("clock-frequency", struct timerblock, freq_hz,
243                                                                 62 * 1000000),
244     DEFINE_PROP_UINT8("one-timer-only", struct timerblock, one_timer_only, 0),
245     DEFINE_PROP_END_OF_LIST(),
246 };
247 
248 static void xilinx_timer_class_init(ObjectClass *klass, void *data)
249 {
250     DeviceClass *dc = DEVICE_CLASS(klass);
251 
252     dc->realize = xilinx_timer_realize;
253     dc->props = xilinx_timer_properties;
254 }
255 
256 static const TypeInfo xilinx_timer_info = {
257     .name          = TYPE_XILINX_TIMER,
258     .parent        = TYPE_SYS_BUS_DEVICE,
259     .instance_size = sizeof(struct timerblock),
260     .instance_init = xilinx_timer_init,
261     .class_init    = xilinx_timer_class_init,
262 };
263 
264 static void xilinx_timer_register_types(void)
265 {
266     type_register_static(&xilinx_timer_info);
267 }
268 
269 type_init(xilinx_timer_register_types)
270