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 *
61 mtk_clk_register_cpumux(const struct mtk_composite *mux,
62 			struct regmap *regmap)
63 {
64 	struct mtk_clk_cpumux *cpumux;
65 	struct clk *clk;
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 	clk = clk_register(NULL, &cpumux->hw);
85 	if (IS_ERR(clk))
86 		kfree(cpumux);
87 
88 	return clk;
89 }
90 
91 static void mtk_clk_unregister_cpumux(struct clk *clk)
92 {
93 	struct mtk_clk_cpumux *cpumux;
94 	struct clk_hw *hw;
95 
96 	hw = __clk_get_hw(clk);
97 	if (!hw)
98 		return;
99 
100 	cpumux = to_mtk_clk_cpumux(hw);
101 
102 	clk_unregister(clk);
103 	kfree(cpumux);
104 }
105 
106 int mtk_clk_register_cpumuxes(struct device_node *node,
107 			      const struct mtk_composite *clks, int num,
108 			      struct clk_onecell_data *clk_data)
109 {
110 	int i;
111 	struct clk *clk;
112 	struct regmap *regmap;
113 
114 	regmap = device_node_to_regmap(node);
115 	if (IS_ERR(regmap)) {
116 		pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
117 		return PTR_ERR(regmap);
118 	}
119 
120 	for (i = 0; i < num; i++) {
121 		const struct mtk_composite *mux = &clks[i];
122 
123 		if (!IS_ERR_OR_NULL(clk_data->clks[mux->id])) {
124 			pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
125 				node, mux->id);
126 			continue;
127 		}
128 
129 		clk = mtk_clk_register_cpumux(mux, regmap);
130 		if (IS_ERR(clk)) {
131 			pr_err("Failed to register clk %s: %pe\n", mux->name, clk);
132 			goto err;
133 		}
134 
135 		clk_data->clks[mux->id] = clk;
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->clks[mux->id]))
145 			continue;
146 
147 		mtk_clk_unregister_cpumux(clk_data->clks[mux->id]);
148 		clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
149 	}
150 
151 	return PTR_ERR(clk);
152 }
153 
154 void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
155 				 struct clk_onecell_data *clk_data)
156 {
157 	int i;
158 
159 	for (i = num; i > 0; i--) {
160 		const struct mtk_composite *mux = &clks[i - 1];
161 
162 		if (IS_ERR_OR_NULL(clk_data->clks[mux->id]))
163 			continue;
164 
165 		mtk_clk_unregister_cpumux(clk_data->clks[mux->id]);
166 		clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
167 	}
168 }
169 
170 MODULE_LICENSE("GPL");
171