Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> */ #include <linux/clk-provider.h> #include <linux/clkdev.h> #include <linux/clk/at91_pmc.h> #include <linux/of.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> #include "pmc.h" #define SYSTEM_MAX_ID 31 #define SYSTEM_MAX_NAME_SZ 32 #define to_clk_system(hw) container_of(hw, struct clk_system, hw) struct clk_system { struct clk_hw hw; struct regmap *regmap; struct at91_clk_pms pms; u8 id; }; static inline int is_pck(int id) { return (id >= 8) && (id <= 15); } static inline bool clk_system_ready(struct regmap *regmap, int id) { unsigned int status; regmap_read(regmap, AT91_PMC_SR, &status); return !!(status & (1 << id)); } static int clk_system_prepare(struct clk_hw *hw) { struct clk_system *sys = to_clk_system(hw); regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id); if (!is_pck(sys->id)) return 0; while (!clk_system_ready(sys->regmap, sys->id)) cpu_relax(); return 0; } static void clk_system_unprepare(struct clk_hw *hw) { struct clk_system *sys = to_clk_system(hw); regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id); } static int clk_system_is_prepared(struct clk_hw *hw) { struct clk_system *sys = to_clk_system(hw); unsigned int status; regmap_read(sys->regmap, AT91_PMC_SCSR, &status); if (!(status & (1 << sys->id))) return 0; if (!is_pck(sys->id)) return 1; regmap_read(sys->regmap, AT91_PMC_SR, &status); return !!(status & (1 << sys->id)); } static int clk_system_save_context(struct clk_hw *hw) { struct clk_system *sys = to_clk_system(hw); sys->pms.status = clk_system_is_prepared(hw); return 0; } static void clk_system_restore_context(struct clk_hw *hw) { struct clk_system *sys = to_clk_system(hw); if (sys->pms.status) clk_system_prepare(&sys->hw); } static const struct clk_ops system_ops = { .prepare = clk_system_prepare, .unprepare = clk_system_unprepare, .is_prepared = clk_system_is_prepared, .save_context = clk_system_save_context, .restore_context = clk_system_restore_context, }; struct clk_hw * __init at91_clk_register_system(struct regmap *regmap, const char *name, const char *parent_name, struct clk_hw *parent_hw, u8 id, unsigned long flags) { struct clk_system *sys; struct clk_hw *hw; struct clk_init_data init = {}; int ret; if (!(parent_name || parent_hw) || id > SYSTEM_MAX_ID) return ERR_PTR(-EINVAL); sys = kzalloc(sizeof(*sys), GFP_KERNEL); if (!sys) return ERR_PTR(-ENOMEM); init.name = name; init.ops = &system_ops; if (parent_hw) init.parent_hws = (const struct clk_hw **)&parent_hw; else init.parent_names = &parent_name; init.num_parents = 1; init.flags = CLK_SET_RATE_PARENT | flags; sys->id = id; sys->hw.init = &init; sys->regmap = regmap; hw = &sys->hw; ret = clk_hw_register(NULL, &sys->hw); if (ret) { kfree(sys); hw = ERR_PTR(ret); } return hw; } |