xref: /openbmc/qemu/include/hw/misc/nrf51_rng.h (revision ba632924)
1 /*
2  * nRF51 Random Number Generator
3  *
4  * QEMU interface:
5  * + Property "period_unfiltered_us": Time between two biased values in
6  *   microseconds.
7  * + Property "period_filtered_us": Time between two unbiased values in
8  *   microseconds.
9  * + sysbus MMIO regions 0: Memory Region with tasks, events and registers
10  *   to be mapped to the peripherals instance address by the SOC.
11  * + Named GPIO output "irq": Interrupt line of the peripheral. Must be
12  *   connected to the associated peripheral interrupt line of the NVIC.
13  * + Named GPIO output "eep_valrdy": Event set when new random value is ready
14  *   to be read.
15  * + Named GPIO input "tep_start": Task that triggers start of continuous
16  *   generation of random values.
17  * + Named GPIO input "tep_stop": Task that ends continuous generation of
18  *   random values.
19  *
20  * Accuracy of the peripheral model:
21  * + Stochastic properties of different configurations of the random source
22  *   are not modeled.
23  * + Generation of unfiltered and filtered random values take at least the
24  *   average generation time stated in the production specification;
25  *   non-deterministic generation times are not modeled.
26  *
27  * Copyright 2018 Steffen Görtz <contrib@steffen-goertz.de>
28  *
29  * This code is licensed under the GPL version 2 or later.  See
30  * the COPYING file in the top-level directory.
31  *
32  */
33 #ifndef NRF51_RNG_H
34 #define NRF51_RNG_H
35 
36 #include "hw/sysbus.h"
37 #include "qemu/timer.h"
38 #define TYPE_NRF51_RNG "nrf51_soc.rng"
39 #define NRF51_RNG(obj) OBJECT_CHECK(NRF51RNGState, (obj), TYPE_NRF51_RNG)
40 
41 #define NRF51_RNG_SIZE         0x1000
42 
43 #define NRF51_RNG_TASK_START   0x000
44 #define NRF51_RNG_TASK_STOP    0x004
45 #define NRF51_RNG_EVENT_VALRDY 0x100
46 #define NRF51_RNG_REG_SHORTS   0x200
47 #define NRF51_RNG_REG_SHORTS_VALRDY_STOP 0
48 #define NRF51_RNG_REG_INTEN    0x300
49 #define NRF51_RNG_REG_INTEN_VALRDY 0
50 #define NRF51_RNG_REG_INTENSET 0x304
51 #define NRF51_RNG_REG_INTENCLR 0x308
52 #define NRF51_RNG_REG_CONFIG   0x504
53 #define NRF51_RNG_REG_CONFIG_DECEN 0
54 #define NRF51_RNG_REG_VALUE    0x508
55 
56 typedef struct {
57     SysBusDevice parent_obj;
58 
59     MemoryRegion mmio;
60     qemu_irq irq;
61 
62     /* Event End Points */
63     qemu_irq eep_valrdy;
64 
65     QEMUTimer timer;
66 
67     /* Time between generation of successive unfiltered values in us */
68     uint16_t period_unfiltered_us;
69     /* Time between generation of successive filtered values in us */
70     uint16_t period_filtered_us;
71 
72     uint8_t value;
73 
74     uint32_t active;
75     uint32_t event_valrdy;
76     uint32_t shortcut_stop_on_valrdy;
77     uint32_t interrupt_enabled;
78     uint32_t filter_enabled;
79 
80 } NRF51RNGState;
81 
82 
83 #endif /* NRF51_RNG_H_ */
84