xref: /openbmc/qemu/include/hw/i2c/microbit_i2c.h (revision a68694cd)
1 /*
2  * Microbit stub for Nordic Semiconductor nRF51 SoC Two-Wire Interface
3  * http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.1.pdf
4  *
5  * Copyright 2019 Red Hat, Inc.
6  *
7  * This code is licensed under the GPL version 2 or later.  See
8  * the COPYING file in the top-level directory.
9  */
10 
11 #ifndef MICROBIT_I2C_H
12 #define MICROBIT_I2C_H
13 
14 #include "hw/sysbus.h"
15 #include "hw/arm/nrf51.h"
16 #include "qom/object.h"
17 
18 #define NRF51_TWI_TASK_STARTRX 0x000
19 #define NRF51_TWI_TASK_STARTTX 0x008
20 #define NRF51_TWI_TASK_STOP 0x014
21 #define NRF51_TWI_EVENT_STOPPED 0x104
22 #define NRF51_TWI_EVENT_RXDREADY 0x108
23 #define NRF51_TWI_EVENT_TXDSENT 0x11c
24 #define NRF51_TWI_REG_ENABLE 0x500
25 #define NRF51_TWI_REG_RXD 0x518
26 #define NRF51_TWI_REG_TXD 0x51c
27 #define NRF51_TWI_REG_ADDRESS 0x588
28 
29 #define TYPE_MICROBIT_I2C "microbit.i2c"
30 typedef struct MicrobitI2CState MicrobitI2CState;
31 DECLARE_INSTANCE_CHECKER(MicrobitI2CState, MICROBIT_I2C,
32                          TYPE_MICROBIT_I2C)
33 
34 #define MICROBIT_I2C_NREGS (NRF51_PERIPHERAL_SIZE / sizeof(uint32_t))
35 
36 struct MicrobitI2CState {
37     SysBusDevice parent_obj;
38 
39     MemoryRegion iomem;
40     uint32_t regs[MICROBIT_I2C_NREGS];
41     uint32_t read_idx;
42 };
43 
44 #endif /* MICROBIT_I2C_H */
45