| Michael Walle | f606c9a | 2021-11-15 23:45:43 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Watchdog driver for the sl28cpld |
| 4 | * |
| 5 | * Copyright (c) 2021 Michael Walle <michael@walle.cc> |
| 6 | */ |
| 7 | |
| 8 | #include <common.h> |
| 9 | #include <dm.h> |
| 10 | #include <wdt.h> |
| 11 | #include <sl28cpld.h> |
| 12 | #include <div64.h> |
| 13 | |
| 14 | #define SL28CPLD_WDT_CTRL 0x00 |
| 15 | #define WDT_CTRL_EN0 BIT(0) |
| 16 | #define WDT_CTRL_EN1 BIT(1) |
| 17 | #define WDT_CTRL_EN_MASK GENMASK(1, 0) |
| 18 | #define WDT_CTRL_LOCK BIT(2) |
| 19 | #define WDT_CTRL_ASSERT_SYS_RESET BIT(6) |
| 20 | #define WDT_CTRL_ASSERT_WDT_TIMEOUT BIT(7) |
| 21 | #define SL28CPLD_WDT_TIMEOUT 0x01 |
| 22 | #define SL28CPLD_WDT_KICK 0x02 |
| 23 | #define WDT_KICK_VALUE 0x6b |
| 24 | |
| 25 | static int sl28cpld_wdt_reset(struct udevice *dev) |
| 26 | { |
| 27 | return sl28cpld_write(dev, SL28CPLD_WDT_KICK, WDT_KICK_VALUE); |
| 28 | } |
| 29 | |
| 30 | static int sl28cpld_wdt_start(struct udevice *dev, u64 timeout, ulong flags) |
| 31 | { |
| 32 | int ret, val; |
| 33 | |
| 34 | val = sl28cpld_read(dev, SL28CPLD_WDT_CTRL); |
| 35 | if (val < 0) |
| 36 | return val; |
| 37 | |
| 38 | /* (1) disable watchdog */ |
| 39 | val &= ~WDT_CTRL_EN_MASK; |
| 40 | ret = sl28cpld_write(dev, SL28CPLD_WDT_CTRL, val); |
| 41 | if (ret) |
| 42 | return ret; |
| 43 | |
| 44 | /* (2) set timeout */ |
| 45 | ret = sl28cpld_write(dev, SL28CPLD_WDT_TIMEOUT, lldiv(timeout, 1000)); |
| 46 | if (ret) |
| 47 | return ret; |
| 48 | |
| 49 | /* (3) kick it, will reset timer to the timeout value */ |
| 50 | ret = sl28cpld_wdt_reset(dev); |
| 51 | if (ret) |
| 52 | return ret; |
| 53 | |
| 54 | /* (4) enable either recovery or normal one */ |
| 55 | if (flags & BIT(0)) |
| 56 | val |= WDT_CTRL_EN1; |
| 57 | else |
| 58 | val |= WDT_CTRL_EN0; |
| 59 | |
| 60 | if (flags & BIT(1)) |
| 61 | val |= WDT_CTRL_LOCK; |
| 62 | |
| 63 | if (flags & BIT(2)) |
| 64 | val &= ~WDT_CTRL_ASSERT_SYS_RESET; |
| 65 | else |
| 66 | val |= WDT_CTRL_ASSERT_SYS_RESET; |
| 67 | |
| 68 | if (flags & BIT(3)) |
| 69 | val |= WDT_CTRL_ASSERT_WDT_TIMEOUT; |
| 70 | else |
| 71 | val &= ~WDT_CTRL_ASSERT_WDT_TIMEOUT; |
| 72 | |
| 73 | return sl28cpld_write(dev, SL28CPLD_WDT_CTRL, val); |
| 74 | } |
| 75 | |
| 76 | static int sl28cpld_wdt_stop(struct udevice *dev) |
| 77 | { |
| 78 | int val; |
| 79 | |
| 80 | val = sl28cpld_read(dev, SL28CPLD_WDT_CTRL); |
| 81 | if (val < 0) |
| 82 | return val; |
| 83 | |
| 84 | return sl28cpld_write(dev, SL28CPLD_WDT_CTRL, val & ~WDT_CTRL_EN_MASK); |
| 85 | } |
| 86 | |
| 87 | static int sl28cpld_wdt_expire_now(struct udevice *dev, ulong flags) |
| 88 | { |
| 89 | return sl28cpld_wdt_start(dev, 0, flags); |
| 90 | } |
| 91 | |
| 92 | static const struct wdt_ops sl28cpld_wdt_ops = { |
| 93 | .start = sl28cpld_wdt_start, |
| 94 | .reset = sl28cpld_wdt_reset, |
| 95 | .stop = sl28cpld_wdt_stop, |
| 96 | .expire_now = sl28cpld_wdt_expire_now, |
| 97 | }; |
| 98 | |
| 99 | static const struct udevice_id sl28cpld_wdt_ids[] = { |
| 100 | { .compatible = "kontron,sl28cpld-wdt", }, |
| 101 | {} |
| 102 | }; |
| 103 | |
| 104 | U_BOOT_DRIVER(sl28cpld_wdt) = { |
| 105 | .name = "sl28cpld-wdt", |
| 106 | .id = UCLASS_WDT, |
| 107 | .of_match = sl28cpld_wdt_ids, |
| 108 | .ops = &sl28cpld_wdt_ops, |
| 109 | }; |