xref: /openbmc/qemu/hw/rtc/xlnx-zynqmp-rtc.c (revision 8035f85ef3ef4bc7ad4e181b9ebfe3f620cf614b)
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 "qemu-common.h"
29 #include "hw/sysbus.h"
30 #include "hw/register.h"
31 #include "qemu/bitops.h"
32 #include "qemu/log.h"
33 #include "qemu/module.h"
34 #include "hw/irq.h"
35 #include "hw/ptimer.h"
36 #include "qemu/cutils.h"
37 #include "sysemu/sysemu.h"
38 #include "trace.h"
39 #include "hw/rtc/xlnx-zynqmp-rtc.h"
40 #include "migration/vmstate.h"
41 
42 #ifndef XLNX_ZYNQMP_RTC_ERR_DEBUG
43 #define XLNX_ZYNQMP_RTC_ERR_DEBUG 0
44 #endif
45 
46 static void rtc_int_update_irq(XlnxZynqMPRTC *s)
47 {
48     bool pending = s->regs[R_RTC_INT_STATUS] & ~s->regs[R_RTC_INT_MASK];
49     qemu_set_irq(s->irq_rtc_int, pending);
50 }
51 
52 static void addr_error_int_update_irq(XlnxZynqMPRTC *s)
53 {
54     bool pending = s->regs[R_ADDR_ERROR] & ~s->regs[R_ADDR_ERROR_INT_MASK];
55     qemu_set_irq(s->irq_addr_error_int, pending);
56 }
57 
58 static uint32_t rtc_get_count(XlnxZynqMPRTC *s)
59 {
60     int64_t now = qemu_clock_get_ns(rtc_clock);
61     return s->tick_offset + now / NANOSECONDS_PER_SECOND;
62 }
63 
64 static uint64_t current_time_postr(RegisterInfo *reg, uint64_t val64)
65 {
66     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
67 
68     return rtc_get_count(s);
69 }
70 
71 static void rtc_int_status_postw(RegisterInfo *reg, uint64_t val64)
72 {
73     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
74     rtc_int_update_irq(s);
75 }
76 
77 static uint64_t rtc_int_en_prew(RegisterInfo *reg, uint64_t val64)
78 {
79     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
80 
81     s->regs[R_RTC_INT_MASK] &= (uint32_t) ~val64;
82     rtc_int_update_irq(s);
83     return 0;
84 }
85 
86 static uint64_t rtc_int_dis_prew(RegisterInfo *reg, uint64_t val64)
87 {
88     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
89 
90     s->regs[R_RTC_INT_MASK] |= (uint32_t) val64;
91     rtc_int_update_irq(s);
92     return 0;
93 }
94 
95 static void addr_error_postw(RegisterInfo *reg, uint64_t val64)
96 {
97     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
98     addr_error_int_update_irq(s);
99 }
100 
101 static uint64_t addr_error_int_en_prew(RegisterInfo *reg, uint64_t val64)
102 {
103     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
104 
105     s->regs[R_ADDR_ERROR_INT_MASK] &= (uint32_t) ~val64;
106     addr_error_int_update_irq(s);
107     return 0;
108 }
109 
110 static uint64_t addr_error_int_dis_prew(RegisterInfo *reg, uint64_t val64)
111 {
112     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
113 
114     s->regs[R_ADDR_ERROR_INT_MASK] |= (uint32_t) val64;
115     addr_error_int_update_irq(s);
116     return 0;
117 }
118 
119 static const RegisterAccessInfo rtc_regs_info[] = {
120     {   .name = "SET_TIME_WRITE",  .addr = A_SET_TIME_WRITE,
121         .unimp = MAKE_64BIT_MASK(0, 32),
122     },{ .name = "SET_TIME_READ",  .addr = A_SET_TIME_READ,
123         .ro = 0xffffffff,
124         .post_read = current_time_postr,
125     },{ .name = "CALIB_WRITE",  .addr = A_CALIB_WRITE,
126         .unimp = MAKE_64BIT_MASK(0, 32),
127     },{ .name = "CALIB_READ",  .addr = A_CALIB_READ,
128         .ro = 0x1fffff,
129     },{ .name = "CURRENT_TIME",  .addr = A_CURRENT_TIME,
130         .ro = 0xffffffff,
131         .post_read = current_time_postr,
132     },{ .name = "CURRENT_TICK",  .addr = A_CURRENT_TICK,
133         .ro = 0xffff,
134     },{ .name = "ALARM",  .addr = A_ALARM,
135     },{ .name = "RTC_INT_STATUS",  .addr = A_RTC_INT_STATUS,
136         .w1c = 0x3,
137         .post_write = rtc_int_status_postw,
138     },{ .name = "RTC_INT_MASK",  .addr = A_RTC_INT_MASK,
139         .reset = 0x3,
140         .ro = 0x3,
141     },{ .name = "RTC_INT_EN",  .addr = A_RTC_INT_EN,
142         .pre_write = rtc_int_en_prew,
143     },{ .name = "RTC_INT_DIS",  .addr = A_RTC_INT_DIS,
144         .pre_write = rtc_int_dis_prew,
145     },{ .name = "ADDR_ERROR",  .addr = A_ADDR_ERROR,
146         .w1c = 0x1,
147         .post_write = addr_error_postw,
148     },{ .name = "ADDR_ERROR_INT_MASK",  .addr = A_ADDR_ERROR_INT_MASK,
149         .reset = 0x1,
150         .ro = 0x1,
151     },{ .name = "ADDR_ERROR_INT_EN",  .addr = A_ADDR_ERROR_INT_EN,
152         .pre_write = addr_error_int_en_prew,
153     },{ .name = "ADDR_ERROR_INT_DIS",  .addr = A_ADDR_ERROR_INT_DIS,
154         .pre_write = addr_error_int_dis_prew,
155     },{ .name = "CONTROL",  .addr = A_CONTROL,
156         .reset = 0x1000000,
157         .rsvd = 0x70fffffe,
158     },{ .name = "SAFETY_CHK",  .addr = A_SAFETY_CHK,
159     }
160 };
161 
162 static void rtc_reset(DeviceState *dev)
163 {
164     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(dev);
165     unsigned int i;
166 
167     for (i = 0; i < ARRAY_SIZE(s->regs_info); ++i) {
168         register_reset(&s->regs_info[i]);
169     }
170 
171     rtc_int_update_irq(s);
172     addr_error_int_update_irq(s);
173 }
174 
175 static const MemoryRegionOps rtc_ops = {
176     .read = register_read_memory,
177     .write = register_write_memory,
178     .endianness = DEVICE_LITTLE_ENDIAN,
179     .valid = {
180         .min_access_size = 4,
181         .max_access_size = 4,
182     },
183 };
184 
185 static void rtc_init(Object *obj)
186 {
187     XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(obj);
188     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
189     RegisterInfoArray *reg_array;
190     struct tm current_tm;
191 
192     memory_region_init(&s->iomem, obj, TYPE_XLNX_ZYNQMP_RTC,
193                        XLNX_ZYNQMP_RTC_R_MAX * 4);
194     reg_array =
195         register_init_block32(DEVICE(obj), rtc_regs_info,
196                               ARRAY_SIZE(rtc_regs_info),
197                               s->regs_info, s->regs,
198                               &rtc_ops,
199                               XLNX_ZYNQMP_RTC_ERR_DEBUG,
200                               XLNX_ZYNQMP_RTC_R_MAX * 4);
201     memory_region_add_subregion(&s->iomem,
202                                 0x0,
203                                 &reg_array->mem);
204     sysbus_init_mmio(sbd, &s->iomem);
205     sysbus_init_irq(sbd, &s->irq_rtc_int);
206     sysbus_init_irq(sbd, &s->irq_addr_error_int);
207 
208     qemu_get_timedate(&current_tm, 0);
209     s->tick_offset = mktimegm(&current_tm) -
210         qemu_clock_get_ns(rtc_clock) / NANOSECONDS_PER_SECOND;
211 
212     trace_xlnx_zynqmp_rtc_gettime(current_tm.tm_year, current_tm.tm_mon,
213                                   current_tm.tm_mday, current_tm.tm_hour,
214                                   current_tm.tm_min, current_tm.tm_sec);
215 }
216 
217 static int rtc_pre_save(void *opaque)
218 {
219     XlnxZynqMPRTC *s = opaque;
220     int64_t now = qemu_clock_get_ns(rtc_clock) / NANOSECONDS_PER_SECOND;
221 
222     /* Add the time at migration */
223     s->tick_offset = s->tick_offset + now;
224 
225     return 0;
226 }
227 
228 static int rtc_post_load(void *opaque, int version_id)
229 {
230     XlnxZynqMPRTC *s = opaque;
231     int64_t now = qemu_clock_get_ns(rtc_clock) / NANOSECONDS_PER_SECOND;
232 
233     /* Subtract the time after migration. This combined with the pre_save
234      * action results in us having subtracted the time that the guest was
235      * stopped to the offset.
236      */
237     s->tick_offset = s->tick_offset - now;
238 
239     return 0;
240 }
241 
242 static const VMStateDescription vmstate_rtc = {
243     .name = TYPE_XLNX_ZYNQMP_RTC,
244     .version_id = 1,
245     .minimum_version_id = 1,
246     .pre_save = rtc_pre_save,
247     .post_load = rtc_post_load,
248     .fields = (VMStateField[]) {
249         VMSTATE_UINT32_ARRAY(regs, XlnxZynqMPRTC, XLNX_ZYNQMP_RTC_R_MAX),
250         VMSTATE_UINT32(tick_offset, XlnxZynqMPRTC),
251         VMSTATE_END_OF_LIST(),
252     }
253 };
254 
255 static void rtc_class_init(ObjectClass *klass, void *data)
256 {
257     DeviceClass *dc = DEVICE_CLASS(klass);
258 
259     dc->reset = rtc_reset;
260     dc->vmsd = &vmstate_rtc;
261 }
262 
263 static const TypeInfo rtc_info = {
264     .name          = TYPE_XLNX_ZYNQMP_RTC,
265     .parent        = TYPE_SYS_BUS_DEVICE,
266     .instance_size = sizeof(XlnxZynqMPRTC),
267     .class_init    = rtc_class_init,
268     .instance_init = rtc_init,
269 };
270 
271 static void rtc_register_types(void)
272 {
273     type_register_static(&rtc_info);
274 }
275 
276 type_init(rtc_register_types)
277