xref: /openbmc/qemu/hw/timer/xilinx_timer.c (revision fc8c745d)
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/module.h"
32 #include "qom/object.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     ptimer_state *ptimer;
56     void *parent;
57     int nr; /* for debug.  */
58 
59     unsigned long timer_div;
60 
61     uint32_t regs[R_MAX];
62 };
63 
64 #define TYPE_XILINX_TIMER "xlnx.xps-timer"
65 DECLARE_INSTANCE_CHECKER(struct timerblock, XILINX_TIMER,
66                          TYPE_XILINX_TIMER)
67 
68 struct timerblock
69 {
70     SysBusDevice parent_obj;
71 
72     MemoryRegion mmio;
73     qemu_irq irq;
74     uint8_t one_timer_only;
75     uint32_t freq_hz;
76     struct xlx_timer *timers;
77 };
78 
79 static inline unsigned int num_timers(struct timerblock *t)
80 {
81     return 2 - t->one_timer_only;
82 }
83 
84 static inline unsigned int timer_from_addr(hwaddr addr)
85 {
86     /* Timers get a 4x32bit control reg area each.  */
87     return addr >> 2;
88 }
89 
90 static void timer_update_irq(struct timerblock *t)
91 {
92     unsigned int i, irq = 0;
93     uint32_t csr;
94 
95     for (i = 0; i < num_timers(t); i++) {
96         csr = t->timers[i].regs[R_TCSR];
97         irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);
98     }
99 
100     /* All timers within the same slave share a single IRQ line.  */
101     qemu_set_irq(t->irq, !!irq);
102 }
103 
104 static uint64_t
105 timer_read(void *opaque, hwaddr addr, unsigned int size)
106 {
107     struct timerblock *t = opaque;
108     struct xlx_timer *xt;
109     uint32_t r = 0;
110     unsigned int timer;
111 
112     addr >>= 2;
113     timer = timer_from_addr(addr);
114     xt = &t->timers[timer];
115     /* Further decoding to address a specific timers reg.  */
116     addr &= 0x3;
117     switch (addr)
118     {
119         case R_TCR:
120                 r = ptimer_get_count(xt->ptimer);
121                 if (!(xt->regs[R_TCSR] & TCSR_UDT))
122                     r = ~r;
123                 D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",
124                          timer, r, xt->regs[R_TCSR] & TCSR_UDT));
125             break;
126         default:
127             if (addr < ARRAY_SIZE(xt->regs))
128                 r = xt->regs[addr];
129             break;
130 
131     }
132     D(fprintf(stderr, "%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
133     return r;
134 }
135 
136 /* Must be called inside ptimer transaction block */
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                 ptimer_transaction_begin(xt->ptimer);
179                 timer_enable(xt);
180                 ptimer_transaction_commit(xt->ptimer);
181             }
182             break;
183 
184         default:
185             if (addr < ARRAY_SIZE(xt->regs))
186                 xt->regs[addr] = value;
187             break;
188     }
189     timer_update_irq(t);
190 }
191 
192 static const MemoryRegionOps timer_ops = {
193     .read = timer_read,
194     .write = timer_write,
195     .endianness = DEVICE_NATIVE_ENDIAN,
196     .valid = {
197         .min_access_size = 4,
198         .max_access_size = 4
199     }
200 };
201 
202 static void timer_hit(void *opaque)
203 {
204     struct xlx_timer *xt = opaque;
205     struct timerblock *t = xt->parent;
206     D(fprintf(stderr, "%s %d\n", __func__, xt->nr));
207     xt->regs[R_TCSR] |= TCSR_TINT;
208 
209     if (xt->regs[R_TCSR] & TCSR_ARHT)
210         timer_enable(xt);
211     timer_update_irq(t);
212 }
213 
214 static void xilinx_timer_realize(DeviceState *dev, Error **errp)
215 {
216     struct timerblock *t = XILINX_TIMER(dev);
217     unsigned int i;
218 
219     /* Init all the ptimers.  */
220     t->timers = g_malloc0(sizeof t->timers[0] * num_timers(t));
221     for (i = 0; i < num_timers(t); i++) {
222         struct xlx_timer *xt = &t->timers[i];
223 
224         xt->parent = t;
225         xt->nr = i;
226         xt->ptimer = ptimer_init(timer_hit, xt, PTIMER_POLICY_DEFAULT);
227         ptimer_transaction_begin(xt->ptimer);
228         ptimer_set_freq(xt->ptimer, t->freq_hz);
229         ptimer_transaction_commit(xt->ptimer);
230     }
231 
232     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, "xlnx.xps-timer",
233                           R_MAX * 4 * num_timers(t));
234     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &t->mmio);
235 }
236 
237 static void xilinx_timer_init(Object *obj)
238 {
239     struct timerblock *t = XILINX_TIMER(obj);
240 
241     /* All timers share a single irq line.  */
242     sysbus_init_irq(SYS_BUS_DEVICE(obj), &t->irq);
243 }
244 
245 static Property xilinx_timer_properties[] = {
246     DEFINE_PROP_UINT32("clock-frequency", struct timerblock, freq_hz,
247                                                                 62 * 1000000),
248     DEFINE_PROP_UINT8("one-timer-only", struct timerblock, one_timer_only, 0),
249     DEFINE_PROP_END_OF_LIST(),
250 };
251 
252 static void xilinx_timer_class_init(ObjectClass *klass, void *data)
253 {
254     DeviceClass *dc = DEVICE_CLASS(klass);
255 
256     dc->realize = xilinx_timer_realize;
257     device_class_set_props(dc, xilinx_timer_properties);
258 }
259 
260 static const TypeInfo xilinx_timer_info = {
261     .name          = TYPE_XILINX_TIMER,
262     .parent        = TYPE_SYS_BUS_DEVICE,
263     .instance_size = sizeof(struct timerblock),
264     .instance_init = xilinx_timer_init,
265     .class_init    = xilinx_timer_class_init,
266 };
267 
268 static void xilinx_timer_register_types(void)
269 {
270     type_register_static(&xilinx_timer_info);
271 }
272 
273 type_init(xilinx_timer_register_types)
274