1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2016 Socionext Inc. 4 * Author: Masahiro Yamada <yamada.masahiro@socionext.com> 5 */ 6 7 #include <linux/clk-provider.h> 8 #include <linux/device.h> 9 #include <linux/regmap.h> 10 11 #include "clk-uniphier.h" 12 13 #define UNIPHIER_CLK_CPUGEAR_STAT 0 /* status */ 14 #define UNIPHIER_CLK_CPUGEAR_SET 4 /* set */ 15 #define UNIPHIER_CLK_CPUGEAR_UPD 8 /* update */ 16 #define UNIPHIER_CLK_CPUGEAR_UPD_BIT BIT(0) 17 18 struct uniphier_clk_cpugear { 19 struct clk_hw hw; 20 struct regmap *regmap; 21 unsigned int regbase; 22 unsigned int mask; 23 }; 24 25 #define to_uniphier_clk_cpugear(_hw) \ 26 container_of(_hw, struct uniphier_clk_cpugear, hw) 27 28 static int uniphier_clk_cpugear_set_parent(struct clk_hw *hw, u8 index) 29 { 30 struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw); 31 int ret; 32 unsigned int val; 33 34 ret = regmap_write_bits(gear->regmap, 35 gear->regbase + UNIPHIER_CLK_CPUGEAR_SET, 36 gear->mask, index); 37 if (ret) 38 return ret; 39 40 ret = regmap_write_bits(gear->regmap, 41 gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD, 42 UNIPHIER_CLK_CPUGEAR_UPD_BIT, 43 UNIPHIER_CLK_CPUGEAR_UPD_BIT); 44 if (ret) 45 return ret; 46 47 return regmap_read_poll_timeout(gear->regmap, 48 gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD, 49 val, !(val & UNIPHIER_CLK_CPUGEAR_UPD_BIT), 50 0, 1); 51 } 52 53 static u8 uniphier_clk_cpugear_get_parent(struct clk_hw *hw) 54 { 55 struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw); 56 int num_parents = clk_hw_get_num_parents(hw); 57 int ret; 58 unsigned int val; 59 60 ret = regmap_read(gear->regmap, 61 gear->regbase + UNIPHIER_CLK_CPUGEAR_STAT, &val); 62 if (ret) 63 return ret; 64 65 val &= gear->mask; 66 67 return val < num_parents ? val : -EINVAL; 68 } 69 70 static const struct clk_ops uniphier_clk_cpugear_ops = { 71 .determine_rate = __clk_mux_determine_rate, 72 .set_parent = uniphier_clk_cpugear_set_parent, 73 .get_parent = uniphier_clk_cpugear_get_parent, 74 }; 75 76 struct clk_hw *uniphier_clk_register_cpugear(struct device *dev, 77 struct regmap *regmap, 78 const char *name, 79 const struct uniphier_clk_cpugear_data *data) 80 { 81 struct uniphier_clk_cpugear *gear; 82 struct clk_init_data init; 83 int ret; 84 85 gear = devm_kzalloc(dev, sizeof(*gear), GFP_KERNEL); 86 if (!gear) 87 return ERR_PTR(-ENOMEM); 88 89 init.name = name; 90 init.ops = &uniphier_clk_cpugear_ops; 91 init.flags = CLK_SET_RATE_PARENT; 92 init.parent_names = data->parent_names; 93 init.num_parents = data->num_parents; 94 95 gear->regmap = regmap; 96 gear->regbase = data->regbase; 97 gear->mask = data->mask; 98 gear->hw.init = &init; 99 100 ret = devm_clk_hw_register(dev, &gear->hw); 101 if (ret) 102 return ERR_PTR(ret); 103 104 return &gear->hw; 105 } 106