xref: /openbmc/qemu/include/hw/misc/nrf51_rng.h (revision d9cb4336)
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 
34 #ifndef NRF51_RNG_H
35 #define NRF51_RNG_H
36 
37 #include "hw/sysbus.h"
38 #include "qemu/timer.h"
39 #define TYPE_NRF51_RNG "nrf51_soc.rng"
40 #define NRF51_RNG(obj) OBJECT_CHECK(NRF51RNGState, (obj), TYPE_NRF51_RNG)
41 
42 #define NRF51_RNG_SIZE         0x1000
43 
44 #define NRF51_RNG_TASK_START   0x000
45 #define NRF51_RNG_TASK_STOP    0x004
46 #define NRF51_RNG_EVENT_VALRDY 0x100
47 #define NRF51_RNG_REG_SHORTS   0x200
48 #define NRF51_RNG_REG_SHORTS_VALRDY_STOP 0
49 #define NRF51_RNG_REG_INTEN    0x300
50 #define NRF51_RNG_REG_INTEN_VALRDY 0
51 #define NRF51_RNG_REG_INTENSET 0x304
52 #define NRF51_RNG_REG_INTENCLR 0x308
53 #define NRF51_RNG_REG_CONFIG   0x504
54 #define NRF51_RNG_REG_CONFIG_DECEN 0
55 #define NRF51_RNG_REG_VALUE    0x508
56 
57 typedef struct {
58     SysBusDevice parent_obj;
59 
60     MemoryRegion mmio;
61     qemu_irq irq;
62 
63     /* Event End Points */
64     qemu_irq eep_valrdy;
65 
66     QEMUTimer timer;
67 
68     /* Time between generation of successive unfiltered values in us */
69     uint16_t period_unfiltered_us;
70     /* Time between generation of successive filtered values in us */
71     uint16_t period_filtered_us;
72 
73     uint8_t value;
74 
75     uint32_t active;
76     uint32_t event_valrdy;
77     uint32_t shortcut_stop_on_valrdy;
78     uint32_t interrupt_enabled;
79     uint32_t filter_enabled;
80 
81 } NRF51RNGState;
82 
83 
84 #endif /* NRF51_RNG_H */
85