1 /* 2 * Copyright (c) 2016-2017 ARM Limited 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /** 18 * \file arm_watchdog_drv.h 19 * \brief Generic driver for ARM watchdogs. 20 */ 21 22 #ifndef __ARM_WATCHDOG_DRV_H__ 23 #define __ARM_WATCHDOG_DRV_H__ 24 25 #include <stdint.h> 26 27 #ifdef __cplusplus 28 extern "C" { 29 #endif 30 31 enum arm_watchdog_error_t { 32 ARM_WATCHDOG_ERR_NONE = 0, /*!< No error */ 33 ARM_WATCHDOG_ERR_NOT_INIT, /*!< Watchdog is not initialized */ 34 ARM_WATCHDOG_ERR_NOT_ENAB, /*!< Watchdog is not enabled */ 35 ARM_WATCHDOG_ERR_LOCKED /*!< Watchdog is locked */ 36 }; 37 38 /* ARM watchdog device configuration structure */ 39 struct arm_watchdog_dev_cfg_t { 40 const uint32_t base; /*!< Watchdog base address */ 41 }; 42 43 /* ARM watchdog device data structure */ 44 struct arm_watchdog_dev_data_t { 45 uint32_t state; /*!< Indicates if the watchdog 46 is initialized and enabled */ 47 uint32_t timeout; /*!< Timeout to reset in cycles */ 48 }; 49 50 /* ARM watchdog device structure */ 51 struct arm_watchdog_dev_t { 52 const struct arm_watchdog_dev_cfg_t* const cfg; /*!< Watchdog 53 configuration */ 54 struct arm_watchdog_dev_data_t* const data; /*!< Watchdog data */ 55 }; 56 57 /** 58 * \brief Initializes a watchdog hardware. 59 * 60 * \param[in] dev Watchdog to be initialized \ref arm_watchdog_dev_t 61 * \param[in] timeout Timeout in cycles - 0 assings timeout to max value. 62 * 63 * \note This function doesn't check if dev is NULL. 64 * This function leaves the watchdog locked. Before any further 65 * operations, it needs to be unlocked and locked again. 66 */ 67 void arm_watchdog_init(struct arm_watchdog_dev_t* dev, uint32_t timeout); 68 69 /** 70 * \brief Feeds the watchdog to not cause a reset. 71 * 72 * \param[in] dev Watchdog to be fed \ref arm_watchdog_dev_t 73 * 74 * \return Returns error code as specified in \ref arm_watchdog_error_t 75 * 76 * \note This function doesn't check if dev is NULL. 77 */ 78 enum arm_watchdog_error_t arm_watchdog_feed(struct arm_watchdog_dev_t* dev); 79 80 /** 81 * \brief Clear the interrupt and load timeout value to the load register. 82 * 83 * \param[in] dev Watchdog to be fed \ref arm_watchdog_dev_t 84 * 85 * \return Returns error code as specified in \ref arm_watchdog_error_t 86 * 87 * \note This function doesn't check if dev is NULL. 88 */ 89 enum arm_watchdog_error_t 90 arm_watchdog_clear_interrupt_and_refresh_counter( 91 struct arm_watchdog_dev_t* dev); 92 93 /** 94 * \brief Enables the watchdog. 95 * 96 * \param[in] dev Watchdog to be enabled \ref arm_watchdog_dev_t 97 * 98 * \return Returns error code as specified in \ref arm_watchdog_error_t 99 * 100 * \note This function doesn't check if dev is NULL. 101 */ 102 enum arm_watchdog_error_t arm_watchdog_enable(struct arm_watchdog_dev_t* dev); 103 104 /** 105 * \brief Checks if the watchdog is enabled 106 * 107 * \param[in] dev Watchdog to be checked \ref arm_watchdog_dev_t 108 * 109 * \return 1 if watchdog is enabled, 0 otherwise. 110 * 111 * \note This function doesn't check if dev is NULL. 112 */ 113 uint32_t arm_watchdog_is_enabled(struct arm_watchdog_dev_t* dev); 114 115 /** 116 * \brief Disables the watchdog. 117 * 118 * \param[in] dev Watchdog to be disabled \ref arm_watchdog_dev_t 119 * 120 * \return 1 if watchdog is enabled, 0 otherwise. 121 * 122 * \note This function doesn't check if dev is NULL. 123 */ 124 enum arm_watchdog_error_t arm_watchdog_disable(struct arm_watchdog_dev_t* dev); 125 126 /** 127 * \brief Locks the registers to not be written again. 128 * 129 * \param[in] dev Watchdog to be locked \ref arm_watchdog_dev_t 130 * 131 * \note This function doesn't check if dev is NULL. 132 */ 133 void arm_watchdog_lock(struct arm_watchdog_dev_t* dev); 134 135 /** 136 * \brief Checks if the watchdog registers are locked 137 * 138 * \param[in] dev Watchdog to be checked \ref arm_watchdog_dev_t 139 * 140 * \return 1 if the registers are locked, 0 otherwise 141 * 142 * \note This function doesn't check if dev is NULL. 143 */ 144 uint32_t arm_watchdog_is_locked(struct arm_watchdog_dev_t* dev); 145 146 /** 147 * \brief Unlocks the registers to configure the watchdog again. 148 * 149 * \param[in] dev Watchdog to be unlocked \ref arm_watchdog_dev_t 150 * 151 * \note This function doesn't check if dev is NULL. 152 */ 153 void arm_watchdog_unlock(struct arm_watchdog_dev_t* dev); 154 155 /** 156 * \brief Provides watchdog remaining time before reset. 157 * 158 * \param[in] dev Watchdog to get the remaining time \ref arm_watchdog_dev_t 159 * 160 * \return 0 if watchdog is disabled. 161 * 162 * \note This function doesn't check if dev is NULL. 163 */ 164 uint32_t arm_watchdog_get_remaining_time(struct arm_watchdog_dev_t* dev); 165 166 #ifdef __cplusplus 167 } 168 #endif 169 #endif /* __ARM_WATCHDOG_DRV_H__ */ 170
