xref: /openbmc/qemu/include/hw/watchdog/wdt_imx2.h (revision a81df1b6)
1 /*
2  * Copyright (c) 2017, Impinj, Inc.
3  *
4  * i.MX2 Watchdog IP block
5  *
6  * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or later.
9  * See the COPYING file in the top-level directory.
10  */
11 
12 #ifndef IMX2_WDT_H
13 #define IMX2_WDT_H
14 
15 #include "qemu/bitops.h"
16 #include "hw/sysbus.h"
17 #include "hw/irq.h"
18 #include "hw/ptimer.h"
19 
20 #define TYPE_IMX2_WDT "imx2.wdt"
21 #define IMX2_WDT(obj) OBJECT_CHECK(IMX2WdtState, (obj), TYPE_IMX2_WDT)
22 
23 enum IMX2WdtRegisters {
24     IMX2_WDT_WCR  = 0x0000, /* Control Register */
25     IMX2_WDT_WSR  = 0x0002, /* Service Register */
26     IMX2_WDT_WRSR = 0x0004, /* Reset Status Register */
27     IMX2_WDT_WICR = 0x0006, /* Interrupt Control Register */
28     IMX2_WDT_WMCR = 0x0008, /* Misc Register */
29 };
30 
31 #define IMX2_WDT_MMIO_SIZE 0x000a
32 
33 /* Control Register definitions */
34 #define IMX2_WDT_WCR_WT         (0xFF << 8) /* Watchdog Timeout Field */
35 #define IMX2_WDT_WCR_WDW        BIT(7)      /* WDOG Disable for Wait */
36 #define IMX2_WDT_WCR_WDA        BIT(5)      /* WDOG Assertion */
37 #define IMX2_WDT_WCR_SRS        BIT(4)      /* Software Reset Signal */
38 #define IMX2_WDT_WCR_WDT        BIT(3)      /* WDOG Timeout Assertion */
39 #define IMX2_WDT_WCR_WDE        BIT(2)      /* Watchdog Enable */
40 #define IMX2_WDT_WCR_WDBG       BIT(1)      /* Watchdog Debug Enable */
41 #define IMX2_WDT_WCR_WDZST      BIT(0)      /* Watchdog Timer Suspend */
42 
43 #define IMX2_WDT_WCR_LOCK_MASK  (IMX2_WDT_WCR_WDZST | IMX2_WDT_WCR_WDBG \
44                                  | IMX2_WDT_WCR_WDW)
45 
46 /* Service Register definitions */
47 #define IMX2_WDT_SEQ1           0x5555      /* service sequence 1 */
48 #define IMX2_WDT_SEQ2           0xAAAA      /* service sequence 2 */
49 
50 /* Reset Status Register definitions */
51 #define IMX2_WDT_WRSR_TOUT      BIT(1)      /* Reset due to Timeout */
52 #define IMX2_WDT_WRSR_SFTW      BIT(0)      /* Reset due to software reset */
53 
54 /* Interrupt Control Register definitions */
55 #define IMX2_WDT_WICR_WIE       BIT(15)     /* Interrupt Enable */
56 #define IMX2_WDT_WICR_WTIS      BIT(14)     /* Interrupt Status */
57 #define IMX2_WDT_WICR_WICT      0xff        /* Interrupt Timeout */
58 #define IMX2_WDT_WICR_WICT_DEF  0x04        /* Default interrupt timeout (2s) */
59 
60 #define IMX2_WDT_WICR_LOCK_MASK (IMX2_WDT_WICR_WIE | IMX2_WDT_WICR_WICT)
61 
62 /* Misc Control Register definitions */
63 #define IMX2_WDT_WMCR_PDE       BIT(0)      /* Power-Down Enable */
64 
65 typedef struct IMX2WdtState {
66     /* <private> */
67     SysBusDevice parent_obj;
68 
69     /*< public >*/
70     MemoryRegion mmio;
71     qemu_irq irq;
72 
73     struct ptimer_state *timer;
74     struct ptimer_state *itimer;
75 
76     bool pretimeout_support;
77     bool wicr_locked;
78 
79     uint16_t wcr;
80     uint16_t wsr;
81     uint16_t wrsr;
82     uint16_t wicr;
83     uint16_t wmcr;
84 
85     bool wcr_locked;            /* affects WDZST, WDBG, and WDW */
86     bool wcr_wde_locked;        /* affects WDE */
87     bool wcr_wdt_locked;        /* affects WDT (never cleared) */
88 } IMX2WdtState;
89 
90 #endif /* IMX2_WDT_H */
91