1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * Copyright (c) 2021, Bootlin 4 */ 5 6 #ifndef __DRIVERS_CLK_H 7 #define __DRIVERS_CLK_H 8 9 #include <kernel/refcount.h> 10 #include <stdint.h> 11 #include <tee_api_types.h> 12 13 /* Flags for clock */ 14 #define CLK_SET_RATE_GATE BIT(0) /* must be gated across rate change */ 15 #define CLK_SET_PARENT_GATE BIT(1) /* must be gated across re-parent */ 16 17 /** 18 * struct clk - Clock structure 19 * 20 * @name: Clock name 21 * @priv: Private data for the clock provider 22 * @ops: Clock operations 23 * @parent: Current parent 24 * @rate: Current clock rate (cached after init or rate change) 25 * @flags: Specific clock flags 26 * @enabled_count: Enable/disable reference counter 27 * @num_parents: Number of parents 28 * @parents: Array of possible parents of the clock 29 */ 30 struct clk { 31 const char *name; 32 void *priv; 33 const struct clk_ops *ops; 34 struct clk *parent; 35 unsigned long rate; 36 unsigned int flags; 37 struct refcount enabled_count; 38 size_t num_parents; 39 struct clk *parents[]; 40 }; 41 42 /** 43 * struct clk_ops 44 * 45 * @enable: Enable the clock 46 * @disable: Disable the clock 47 * @set_parent: Set the clock parent based on index 48 * @get_parent: Get the current parent index of the clock 49 * @set_rate: Set the clock rate 50 * @get_rate: Get the clock rate 51 */ 52 struct clk_ops { 53 TEE_Result (*enable)(struct clk *clk); 54 void (*disable)(struct clk *clk); 55 TEE_Result (*set_parent)(struct clk *clk, size_t index); 56 size_t (*get_parent)(struct clk *clk); 57 TEE_Result (*set_rate)(struct clk *clk, unsigned long rate, 58 unsigned long parent_rate); 59 unsigned long (*get_rate)(struct clk *clk, 60 unsigned long parent_rate); 61 }; 62 63 /** 64 * Return the clock name 65 * 66 * @clk: Clock for which the name is needed 67 * Return a const char * pointing to the clock name 68 */ 69 static inline const char *clk_get_name(struct clk *clk) 70 { 71 return clk->name; 72 } 73 74 /** 75 * clk_alloc - Allocate a clock structure 76 * 77 * @name: Clock name 78 * @ops: Clock operations 79 * @parent_clks: Parents of the clock 80 * @parent_count: Number of parents of the clock 81 * 82 * Return a clock struct properly initialized or NULL if allocation failed 83 */ 84 struct clk *clk_alloc(const char *name, const struct clk_ops *ops, 85 struct clk **parent_clks, size_t parent_count); 86 87 /** 88 * clk_free - Free a clock structure 89 * 90 * @clk: Clock to be freed or NULL 91 */ 92 void clk_free(struct clk *clk); 93 94 /** 95 * clk_register - Register a clock within the clock framework 96 * 97 * @clk: Clock struct to be registered 98 * Return a TEE_Result compliant value 99 */ 100 TEE_Result clk_register(struct clk *clk); 101 102 /** 103 * clk_get_rate - Get clock rate 104 * 105 * @clk: Clock for which the rate is needed 106 * Return the clock rate in Hz 107 */ 108 unsigned long clk_get_rate(struct clk *clk); 109 110 /** 111 * clk_set_rate - Set a clock rate 112 * 113 * @clk: Clock to be set with the rate 114 * @rate: Rate to set in Hz 115 * Return a TEE_Result compliant value 116 */ 117 TEE_Result clk_set_rate(struct clk *clk, unsigned long rate); 118 119 /** 120 * clk_enable - Enable a clock and its ascendance 121 * 122 * @clk: Clock to be enabled 123 * Return a TEE_Result compliant value 124 */ 125 TEE_Result clk_enable(struct clk *clk); 126 127 /** 128 * clk_disable - Disable a clock 129 * 130 * @clk: Clock to be disabled 131 */ 132 void clk_disable(struct clk *clk); 133 134 /** 135 * clk_is_enabled - Informative state on the clock 136 * 137 * This function is useful during specific system sequences where core 138 * executes atomically (primary core boot, some low power sequences). 139 * 140 * @clk: Clock refernece 141 */ 142 bool clk_is_enabled(struct clk *clk); 143 144 /** 145 * clk_get_parent - Get the current clock parent 146 * 147 * @clk: Clock for which the parent is needed 148 * Return the clock parent or NULL if there is no parent 149 */ 150 struct clk *clk_get_parent(struct clk *clk); 151 152 /** 153 * clk_get_num_parents - Get the number of parents for a clock 154 * 155 * @clk: Clock for which the number of parents is needed 156 * Return the number of parents 157 */ 158 static inline size_t clk_get_num_parents(struct clk *clk) 159 { 160 return clk->num_parents; 161 } 162 163 /** 164 * Get a clock parent by its index 165 * 166 * @clk: Clock for which the parent is needed 167 * @pidx: Parent index for the clock 168 * Return the clock parent at index @pidx or NULL if out of bound 169 */ 170 struct clk *clk_get_parent_by_index(struct clk *clk, size_t pidx); 171 172 /** 173 * clk_set_parent - Set the current clock parent 174 * 175 * @clk: Clock for which the parent should be set 176 * @parent: Parent clock to set 177 * Return a TEE_Result compliant value 178 */ 179 TEE_Result clk_set_parent(struct clk *clk, struct clk *parent); 180 181 #endif /* __DRIVERS_CLK_H */ 182