1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * Copyright (c) 2018, Linaro Limited 4 */ 5 6 #ifndef __KERNEL_PM_H 7 #define __KERNEL_PM_H 8 9 #include <stdbool.h> 10 #include <stdint.h> 11 #include <tee_api_types.h> 12 13 /* 14 * Platform hints on targeted power state. Hints are stored in a 32bit 15 * unsigned value. Lower bits defines generic resource bit flags. Higher 16 * bits stores a platform specific value specific platform driver may 17 * understand. Registered callbacks may choose to use or ignore these hints. 18 * 19 * PM_HINT_CLOCK_STATE - When set clock shall be suspended/restored 20 * PM_HINT_POWER_STATE - When set device power shall be suspended/restored 21 * PM_HINT_IO_STATE - When set IO pins shall be suspended/restored 22 * PM_HINT_CONTEXT_STATE - When set the full context be suspended/restored 23 * PM_HINT_PLATFORM_STATE_MASK - Bit mask reserved for platform specific hints 24 * PM_HINT_PLATFORM_STATE_SHIFT - LSBit position of platform specific hints mask 25 */ 26 #define PM_HINT_CLOCK_STATE BIT(0) 27 #define PM_HINT_POWER_STATE BIT(1) 28 #define PM_HINT_IO_STATE BIT(2) 29 #define PM_HINT_CONTEXT_STATE BIT(3) 30 #define PM_HINT_PLATFORM_STATE_MASK GENMASK_32(31, 16) 31 #define PM_HINT_PLATFORM_STATE_SHIFT 16 32 33 /* 34 * PM_OP_SUSPEND: platform is suspending to a target low power state 35 * PM_OP_RESUME: platform is resuming from low power state 36 */ 37 enum pm_op { 38 PM_OP_SUSPEND = 0, 39 PM_OP_RESUME = 1, 40 }; 41 42 /* 43 * Registered callbacks are called the ordering directives specified 44 * by the PM_CB_ORDER_* value. Driver ordered callbacks at suspended 45 * first/resumed last. Core service ordered callbacks are suspended 46 * last/resumed first. 47 */ 48 enum pm_callback_order { 49 PM_CB_ORDER_DRIVER = 0, 50 PM_CB_ORDER_CORE_SERVICE, 51 PM_CB_ORDER_MAX 52 }; 53 54 #define PM_CALLBACK_HANDLE_INITIALIZER(_callback, _handle, _order) \ 55 (struct pm_callback_handle){ \ 56 .callback = (_callback), \ 57 .handle = (_handle), \ 58 .order = (_order), \ 59 } 60 61 #define PM_CALLBACK_GET_HANDLE(pm_handle) ((pm_handle)->handle) 62 63 struct pm_callback_handle; 64 typedef TEE_Result (*pm_callback)(enum pm_op op, uint32_t pm_hint, 65 const struct pm_callback_handle *pm_handle); 66 67 /* 68 * Drivers and services can register a callback function for the platform 69 * suspend and resume sequences. A private address handle can be registered 70 * with the callback and retrieved from the callback. Callback can be 71 * registered with a specific call order as defined per PM_CB_ORDER_*. 72 * 73 * Callback shall return an error if failing to complete target transition. 74 * This information may be used by the platform to resume a platform on 75 * non-fatal failure to suspend. 76 * 77 * Callback implementations should ensure their functions belong to unpaged 78 * memory sections (see KEEP_PAGER()) since the callback is likely to be 79 * called from an unpaged execution context. 80 * 81 * Power Mamagement callback functions API: 82 * 83 * TEE_Result (*callback)(enum pm_op op, 84 * unsigned int pm_hint, 85 * const struct pm_callback_handle *pm_handle); 86 * 87 * @op - Target operation: either PM_SUSPEND or PM_RESUME 88 * @pm_hint - Hints on power state platform suspends to /resumes from. 89 * PM_STATE_HINT_* defines the supported values. 90 * @pm_handle - Reference to the struct pm_callback_handle related to to 91 * registered callback. Callback can retrieve the registered 92 * private handle with PM_CALLBACK_GET_HANDLE(). 93 * 94 * Return a TEE_Result compliant return code 95 */ 96 /* 97 * struct pm_callback_handle store the callback registration directives. 98 * 99 * @callback - Registered callback function 100 * @handle - Registered private handler for the callback 101 * @order - Registered callback call order priority (PM_CB_ORDER_*) 102 */ 103 struct pm_callback_handle { 104 /* Set by the caller when registering a callback */ 105 pm_callback callback; 106 void *handle; 107 uint8_t order; 108 /* Set by the system according to execution context */ 109 uint8_t flags; 110 }; 111 112 /* 113 * Register a callback for suspend/resume sequence 114 * Refer to struct pm_callback_handle for description of the callbacks 115 * API and the registration directives. 116 * 117 * @pm_handle: Reference callback registration directives 118 */ 119 void register_pm_cb(struct pm_callback_handle *pm_handle); 120 121 /* 122 * Register a driver callback for generic suspend/resume. 123 * Refer to struct pm_callback_handle for description of the callbacks 124 * API. 125 * 126 * @callback: Registered callback function 127 * @handle: Registered private handle argument for the callback 128 */ 129 static inline void register_pm_driver_cb(pm_callback callback, void *handle) 130 { 131 register_pm_cb(&PM_CALLBACK_HANDLE_INITIALIZER(callback, handle, 132 PM_CB_ORDER_DRIVER)); 133 } 134 135 /* 136 * Register a core service callback for generic suspend/resume. 137 * Refer to struct pm_callback_handle for description of the callbacks 138 * API. 139 * 140 * @callback: Registered callback function 141 * @handle: Registered private handle argument for the callback 142 */ 143 static inline void register_pm_core_service_cb(pm_callback callback, 144 void *handle) 145 { 146 register_pm_cb(&PM_CALLBACK_HANDLE_INITIALIZER(callback, handle, 147 PM_CB_ORDER_CORE_SERVICE)); 148 } 149 150 /* 151 * Request call to registered PM callbacks 152 * 153 * @op: Either PM_OP_SUSPEND or PM_OP_RESUME 154 * @pm_hint: Hint (PM_HINT_*) on state the platform suspends to/resumes from. 155 * 156 * Return a TEE_Result compliant status 157 */ 158 TEE_Result pm_change_state(enum pm_op op, uint32_t pm_hint); 159 160 #endif /*__KERNEL_PM_H*/ 161