xref: /linux/drivers/clk/mediatek/clk-cpumux.c (revision 90e0d94d369d342e735a75174439482119b6c393)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015 Linaro Ltd.
4  * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
5  */
6 
7 #include <linux/clk-provider.h>
8 #include <linux/container_of.h>
9 #include <linux/err.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/regmap.h>
13 #include <linux/slab.h>
14 
15 #include "clk-mtk.h"
16 #include "clk-cpumux.h"
17 
18 struct mtk_clk_cpumux {
19 	struct clk_hw	hw;
20 	struct regmap	*regmap;
21 	u32		reg;
22 	u32		mask;
23 	u8		shift;
24 };
25 
26 static inline struct mtk_clk_cpumux *to_mtk_clk_cpumux(struct clk_hw *_hw)
27 {
28 	return container_of(_hw, struct mtk_clk_cpumux, hw);
29 }
30 
31 static u8 clk_cpumux_get_parent(struct clk_hw *hw)
32 {
33 	struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
34 	unsigned int val;
35 
36 	regmap_read(mux->regmap, mux->reg, &val);
37 
38 	val >>= mux->shift;
39 	val &= mux->mask;
40 
41 	return val;
42 }
43 
44 static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
45 {
46 	struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
47 	u32 mask, val;
48 
49 	val = index << mux->shift;
50 	mask = mux->mask << mux->shift;
51 
52 	return regmap_update_bits(mux->regmap, mux->reg, mask, val);
53 }
54 
55 static const struct clk_ops clk_cpumux_ops = {
56 	.get_parent = clk_cpumux_get_parent,
57 	.set_parent = clk_cpumux_set_parent,
58 };
59 
60 static struct clk_hw *
61 mtk_clk_register_cpumux(const struct mtk_composite *mux,
62 			struct regmap *regmap)
63 {
64 	struct mtk_clk_cpumux *cpumux;
65 	int ret;
66 	struct clk_init_data init;
67 
68 	cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
69 	if (!cpumux)
70 		return ERR_PTR(-ENOMEM);
71 
72 	init.name = mux->name;
73 	init.ops = &clk_cpumux_ops;
74 	init.parent_names = mux->parent_names;
75 	init.num_parents = mux->num_parents;
76 	init.flags = mux->flags;
77 
78 	cpumux->reg = mux->mux_reg;
79 	cpumux->shift = mux->mux_shift;
80 	cpumux->mask = BIT(mux->mux_width) - 1;
81 	cpumux->regmap = regmap;
82 	cpumux->hw.init = &init;
83 
84 	ret = clk_hw_register(NULL, &cpumux->hw);
85 	if (ret) {
86 		kfree(cpumux);
87 		return ERR_PTR(ret);
88 	}
89 
90 	return &cpumux->hw;
91 }
92 
93 static void mtk_clk_unregister_cpumux(struct clk_hw *hw)
94 {
95 	struct mtk_clk_cpumux *cpumux;
96 	if (!hw)
97 		return;
98 
99 	cpumux = to_mtk_clk_cpumux(hw);
100 
101 	clk_hw_unregister(hw);
102 	kfree(cpumux);
103 }
104 
105 int mtk_clk_register_cpumuxes(struct device_node *node,
106 			      const struct mtk_composite *clks, int num,
107 			      struct clk_hw_onecell_data *clk_data)
108 {
109 	int i;
110 	struct clk_hw *hw;
111 	struct regmap *regmap;
112 
113 	regmap = device_node_to_regmap(node);
114 	if (IS_ERR(regmap)) {
115 		pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
116 		return PTR_ERR(regmap);
117 	}
118 
119 	for (i = 0; i < num; i++) {
120 		const struct mtk_composite *mux = &clks[i];
121 
122 		if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
123 			pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
124 				node, mux->id);
125 			continue;
126 		}
127 
128 		hw = mtk_clk_register_cpumux(mux, regmap);
129 		if (IS_ERR(hw)) {
130 			pr_err("Failed to register clk %s: %pe\n", mux->name,
131 			       hw);
132 			goto err;
133 		}
134 
135 		clk_data->hws[mux->id] = hw;
136 	}
137 
138 	return 0;
139 
140 err:
141 	while (--i >= 0) {
142 		const struct mtk_composite *mux = &clks[i];
143 
144 		if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
145 			continue;
146 
147 		mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
148 		clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
149 	}
150 
151 	return PTR_ERR(hw);
152 }
153 EXPORT_SYMBOL_GPL(mtk_clk_register_cpumuxes);
154 
155 void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
156 				 struct clk_hw_onecell_data *clk_data)
157 {
158 	int i;
159 
160 	for (i = num; i > 0; i--) {
161 		const struct mtk_composite *mux = &clks[i - 1];
162 
163 		if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
164 			continue;
165 
166 		mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
167 		clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
168 	}
169 }
170 EXPORT_SYMBOL_GPL(mtk_clk_unregister_cpumuxes);
171 
172 MODULE_LICENSE("GPL");
173