xref: /openbmc/qemu/hw/rtc/xlnx-zynqmp-rtc.c (revision effd60c8) 
1 /*
2  * QEMU model of the Xilinx ZynqMP Real Time Clock (RTC).
3  *
4  * Copyright (c) 2017 Xilinx Inc.
5  *
6  * Written-by: Alistair Francis <alistair.francis@xilinx.com>
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #include "qemu/osdep.h"
28 #include "hw/sysbus.h"
29 #include "hw/register.h"
30 #include "qemu/bitops.h"
31 #include "qemu/log.h"
32 #include "qemu/module.h"
33 #include "hw/irq.h"
34 #include "qemu/cutils.h"
35 #include "sysemu/sysemu.h"
36 #include "sysemu/rtc.h"
37 #include "trace.h"
38 #include "hw/rtc/xlnx-zynqmp-rtc.h"
39 #include "migration/vmstate.h"
40 
41 #ifndef XLNX_ZYNQMP_RTC_ERR_DEBUG
42 #define XLNX_ZYNQMP_RTC_ERR_DEBUG 0
43 #endif
44 
45 static void rtc_int_update_irq(XlnxZynqMPRTC *s)
46 {
47     bool pending = s->regs[R_RTC_INT_STATUS] & ~s->regs[R_RTC_INT_MASK];
48     qemu_set_irq(s->irq_rtc_int, pending);
49 }
50 
51 static void addr_error_int_update_irq(XlnxZynqMPRTC *s)
52 {
53     bool pending = s->regs[R_ADDR_ERROR] & ~s->regs[R_ADDR_ERROR_INT_MASK];
54     qemu_set_irq(s->irq_addr_error_int, pending);
55 }
56 
57 static uint32_t rtc_get_count(XlnxZynqMPRTC *s)
58 {
59     int64_t now = qemu_clock_get_ns(rtc_clock);
60     return s->tick_offset + now / NANOSECONDS_PER_SECOND;
61 }
62 
63 static uint64_t current_time_postr(RegisterInfo *reg, uint64_t val64)
64 {
65     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
66 
67     return rtc_get_count(s);
68 }
69 
70 static void rtc_int_status_postw(RegisterInfo *reg, uint64_t val64)
71 {
72     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
73     rtc_int_update_irq(s);
74 }
75 
76 static uint64_t rtc_int_en_prew(RegisterInfo *reg, uint64_t val64)
77 {
78     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
79 
80     s->regs[R_RTC_INT_MASK] &= (uint32_t) ~val64;
81     rtc_int_update_irq(s);
82     return 0;
83 }
84 
85 static uint64_t rtc_int_dis_prew(RegisterInfo *reg, uint64_t val64)
86 {
87     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
88 
89     s->regs[R_RTC_INT_MASK] |= (uint32_t) val64;
90     rtc_int_update_irq(s);
91     return 0;
92 }
93 
94 static void addr_error_postw(RegisterInfo *reg, uint64_t val64)
95 {
96     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
97     addr_error_int_update_irq(s);
98 }
99 
100 static uint64_t addr_error_int_en_prew(RegisterInfo *reg, uint64_t val64)
101 {
102     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
103 
104     s->regs[R_ADDR_ERROR_INT_MASK] &= (uint32_t) ~val64;
105     addr_error_int_update_irq(s);
106     return 0;
107 }
108 
109 static uint64_t addr_error_int_dis_prew(RegisterInfo *reg, uint64_t val64)
110 {
111     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
112 
113     s->regs[R_ADDR_ERROR_INT_MASK] |= (uint32_t) val64;
114     addr_error_int_update_irq(s);
115     return 0;
116 }
117 
118 static const RegisterAccessInfo rtc_regs_info[] = {
119     {   .name = "SET_TIME_WRITE",  .addr = A_SET_TIME_WRITE,
120         .unimp = MAKE_64BIT_MASK(0, 32),
121     },{ .name = "SET_TIME_READ",  .addr = A_SET_TIME_READ,
122         .ro = 0xffffffff,
123         .post_read = current_time_postr,
124     },{ .name = "CALIB_WRITE",  .addr = A_CALIB_WRITE,
125         .unimp = MAKE_64BIT_MASK(0, 32),
126     },{ .name = "CALIB_READ",  .addr = A_CALIB_READ,
127         .ro = 0x1fffff,
128     },{ .name = "CURRENT_TIME",  .addr = A_CURRENT_TIME,
129         .ro = 0xffffffff,
130         .post_read = current_time_postr,
131     },{ .name = "CURRENT_TICK",  .addr = A_CURRENT_TICK,
132         .ro = 0xffff,
133     },{ .name = "ALARM",  .addr = A_ALARM,
134     },{ .name = "RTC_INT_STATUS",  .addr = A_RTC_INT_STATUS,
135         .w1c = 0x3,
136         .post_write = rtc_int_status_postw,
137     },{ .name = "RTC_INT_MASK",  .addr = A_RTC_INT_MASK,
138         .reset = 0x3,
139         .ro = 0x3,
140     },{ .name = "RTC_INT_EN",  .addr = A_RTC_INT_EN,
141         .pre_write = rtc_int_en_prew,
142     },{ .name = "RTC_INT_DIS",  .addr = A_RTC_INT_DIS,
143         .pre_write = rtc_int_dis_prew,
144     },{ .name = "ADDR_ERROR",  .addr = A_ADDR_ERROR,
145         .w1c = 0x1,
146         .post_write = addr_error_postw,
147     },{ .name = "ADDR_ERROR_INT_MASK",  .addr = A_ADDR_ERROR_INT_MASK,
148         .reset = 0x1,
149         .ro = 0x1,
150     },{ .name = "ADDR_ERROR_INT_EN",  .addr = A_ADDR_ERROR_INT_EN,
151         .pre_write = addr_error_int_en_prew,
152     },{ .name = "ADDR_ERROR_INT_DIS",  .addr = A_ADDR_ERROR_INT_DIS,
153         .pre_write = addr_error_int_dis_prew,
154     },{ .name = "CONTROL",  .addr = A_CONTROL,
155         .reset = 0x1000000,
156         .rsvd = 0x70fffffe,
157     },{ .name = "SAFETY_CHK",  .addr = A_SAFETY_CHK,
158     }
159 };
160 
161 static void rtc_reset(DeviceState *dev)
162 {
163     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(dev);
164     unsigned int i;
165 
166     for (i = 0; i < ARRAY_SIZE(s->regs_info); ++i) {
167         register_reset(&s->regs_info[i]);
168     }
169 
170     rtc_int_update_irq(s);
171     addr_error_int_update_irq(s);
172 }
173 
174 static const MemoryRegionOps rtc_ops = {
175     .read = register_read_memory,
176     .write = register_write_memory,
177     .endianness = DEVICE_LITTLE_ENDIAN,
178     .valid = {
179         .min_access_size = 4,
180         .max_access_size = 4,
181     },
182 };
183 
184 static void rtc_init(Object *obj)
185 {
186     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(obj);
187     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
188     RegisterInfoArray *reg_array;
189     struct tm current_tm;
190 
191     memory_region_init(&s->iomem, obj, TYPE_XLNX_ZYNQMP_RTC,
192                        XLNX_ZYNQMP_RTC_R_MAX * 4);
193     reg_array =
194         register_init_block32(DEVICE(obj), rtc_regs_info,
195                               ARRAY_SIZE(rtc_regs_info),
196                               s->regs_info, s->regs,
197                               &rtc_ops,
198                               XLNX_ZYNQMP_RTC_ERR_DEBUG,
199                               XLNX_ZYNQMP_RTC_R_MAX * 4);
200     memory_region_add_subregion(&s->iomem,
201                                 0x0,
202                                 &reg_array->mem);
203     sysbus_init_mmio(sbd, &s->iomem);
204     sysbus_init_irq(sbd, &s->irq_rtc_int);
205     sysbus_init_irq(sbd, &s->irq_addr_error_int);
206 
207     qemu_get_timedate(&current_tm, 0);
208     s->tick_offset = mktimegm(&current_tm) -
209         qemu_clock_get_ns(rtc_clock) / NANOSECONDS_PER_SECOND;
210 
211     trace_xlnx_zynqmp_rtc_gettime(current_tm.tm_year, current_tm.tm_mon,
212                                   current_tm.tm_mday, current_tm.tm_hour,
213                                   current_tm.tm_min, current_tm.tm_sec);
214 }
215 
216 static int rtc_pre_save(void *opaque)
217 {
218     XlnxZynqMPRTC *s = opaque;
219     int64_t now = qemu_clock_get_ns(rtc_clock) / NANOSECONDS_PER_SECOND;
220 
221     /* Add the time at migration */
222     s->tick_offset = s->tick_offset + now;
223 
224     return 0;
225 }
226 
227 static int rtc_post_load(void *opaque, int version_id)
228 {
229     XlnxZynqMPRTC *s = opaque;
230     int64_t now = qemu_clock_get_ns(rtc_clock) / NANOSECONDS_PER_SECOND;
231 
232     /* Subtract the time after migration. This combined with the pre_save
233      * action results in us having subtracted the time that the guest was
234      * stopped to the offset.
235      */
236     s->tick_offset = s->tick_offset - now;
237 
238     return 0;
239 }
240 
241 static const VMStateDescription vmstate_rtc = {
242     .name = TYPE_XLNX_ZYNQMP_RTC,
243     .version_id = 1,
244     .minimum_version_id = 1,
245     .pre_save = rtc_pre_save,
246     .post_load = rtc_post_load,
247     .fields = (const VMStateField[]) {
248         VMSTATE_UINT32_ARRAY(regs, XlnxZynqMPRTC, XLNX_ZYNQMP_RTC_R_MAX),
249         VMSTATE_UINT32(tick_offset, XlnxZynqMPRTC),
250         VMSTATE_END_OF_LIST(),
251     }
252 };
253 
254 static void rtc_class_init(ObjectClass *klass, void *data)
255 {
256     DeviceClass *dc = DEVICE_CLASS(klass);
257 
258     dc->reset = rtc_reset;
259     dc->vmsd = &vmstate_rtc;
260 }
261 
262 static const TypeInfo rtc_info = {
263     .name          = TYPE_XLNX_ZYNQMP_RTC,
264     .parent        = TYPE_SYS_BUS_DEVICE,
265     .instance_size = sizeof(XlnxZynqMPRTC),
266     .class_init    = rtc_class_init,
267     .instance_init = rtc_init,
268 };
269 
270 static void rtc_register_types(void)
271 {
272     type_register_static(&rtc_info);
273 }
274 
275 type_init(rtc_register_types)
276