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 	.determine_rate = clk_hw_determine_rate_no_reparent,
57 	.get_parent = clk_cpumux_get_parent,
58 	.set_parent = clk_cpumux_set_parent,
59 };
60 
61 static struct clk_hw *
62 mtk_clk_register_cpumux(struct device *dev, const struct mtk_composite *mux,
63 			struct regmap *regmap)
64 {
65 	struct mtk_clk_cpumux *cpumux;
66 	int ret;
67 	struct clk_init_data init;
68 
69 	cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
70 	if (!cpumux)
71 		return ERR_PTR(-ENOMEM);
72 
73 	init.name = mux->name;
74 	init.ops = &clk_cpumux_ops;
75 	init.parent_names = mux->parent_names;
76 	init.num_parents = mux->num_parents;
77 	init.flags = mux->flags;
78 
79 	cpumux->reg = mux->mux_reg;
80 	cpumux->shift = mux->mux_shift;
81 	cpumux->mask = BIT(mux->mux_width) - 1;
82 	cpumux->regmap = regmap;
83 	cpumux->hw.init = &init;
84 
85 	ret = clk_hw_register(dev, &cpumux->hw);
86 	if (ret) {
87 		kfree(cpumux);
88 		return ERR_PTR(ret);
89 	}
90 
91 	return &cpumux->hw;
92 }
93 
94 static void mtk_clk_unregister_cpumux(struct clk_hw *hw)
95 {
96 	struct mtk_clk_cpumux *cpumux;
97 	if (!hw)
98 		return;
99 
100 	cpumux = to_mtk_clk_cpumux(hw);
101 
102 	clk_hw_unregister(hw);
103 	kfree(cpumux);
104 }
105 
106 int mtk_clk_register_cpumuxes(struct device *dev, struct device_node *node,
107 			      const struct mtk_composite *clks, int num,
108 			      struct clk_hw_onecell_data *clk_data)
109 {
110 	int i;
111 	struct clk_hw *hw;
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->hws[mux->id])) {
124 			pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
125 				node, mux->id);
126 			continue;
127 		}
128 
129 		hw = mtk_clk_register_cpumux(dev, mux, regmap);
130 		if (IS_ERR(hw)) {
131 			pr_err("Failed to register clk %s: %pe\n", mux->name,
132 			       hw);
133 			goto err;
134 		}
135 
136 		clk_data->hws[mux->id] = hw;
137 	}
138 
139 	return 0;
140 
141 err:
142 	while (--i >= 0) {
143 		const struct mtk_composite *mux = &clks[i];
144 
145 		if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
146 			continue;
147 
148 		mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
149 		clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
150 	}
151 
152 	return PTR_ERR(hw);
153 }
154 EXPORT_SYMBOL_GPL(mtk_clk_register_cpumuxes);
155 
156 void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
157 				 struct clk_hw_onecell_data *clk_data)
158 {
159 	int i;
160 
161 	for (i = num; i > 0; i--) {
162 		const struct mtk_composite *mux = &clks[i - 1];
163 
164 		if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
165 			continue;
166 
167 		mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
168 		clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
169 	}
170 }
171 EXPORT_SYMBOL_GPL(mtk_clk_unregister_cpumuxes);
172 
173 MODULE_LICENSE("GPL");
174