1 /*
2  * Copyright (c) 2015 Linaro Ltd.
3  * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/clk-provider.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/slab.h>
18 
19 #include "clk-mtk.h"
20 #include "clk-cpumux.h"
21 
22 static inline struct mtk_clk_cpumux *to_mtk_clk_cpumux(struct clk_hw *_hw)
23 {
24 	return container_of(_hw, struct mtk_clk_cpumux, hw);
25 }
26 
27 static u8 clk_cpumux_get_parent(struct clk_hw *hw)
28 {
29 	struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
30 	unsigned int val;
31 
32 	regmap_read(mux->regmap, mux->reg, &val);
33 
34 	val >>= mux->shift;
35 	val &= mux->mask;
36 
37 	return val;
38 }
39 
40 static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
41 {
42 	struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
43 	u32 mask, val;
44 
45 	val = index << mux->shift;
46 	mask = mux->mask << mux->shift;
47 
48 	return regmap_update_bits(mux->regmap, mux->reg, mask, val);
49 }
50 
51 static const struct clk_ops clk_cpumux_ops = {
52 	.get_parent = clk_cpumux_get_parent,
53 	.set_parent = clk_cpumux_set_parent,
54 };
55 
56 static struct clk *
57 mtk_clk_register_cpumux(const struct mtk_composite *mux,
58 			struct regmap *regmap)
59 {
60 	struct mtk_clk_cpumux *cpumux;
61 	struct clk *clk;
62 	struct clk_init_data init;
63 
64 	cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
65 	if (!cpumux)
66 		return ERR_PTR(-ENOMEM);
67 
68 	init.name = mux->name;
69 	init.ops = &clk_cpumux_ops;
70 	init.parent_names = mux->parent_names;
71 	init.num_parents = mux->num_parents;
72 	init.flags = mux->flags;
73 
74 	cpumux->reg = mux->mux_reg;
75 	cpumux->shift = mux->mux_shift;
76 	cpumux->mask = BIT(mux->mux_width) - 1;
77 	cpumux->regmap = regmap;
78 	cpumux->hw.init = &init;
79 
80 	clk = clk_register(NULL, &cpumux->hw);
81 	if (IS_ERR(clk))
82 		kfree(cpumux);
83 
84 	return clk;
85 }
86 
87 int mtk_clk_register_cpumuxes(struct device_node *node,
88 			      const struct mtk_composite *clks, int num,
89 			      struct clk_onecell_data *clk_data)
90 {
91 	int i;
92 	struct clk *clk;
93 	struct regmap *regmap;
94 
95 	regmap = syscon_node_to_regmap(node);
96 	if (IS_ERR(regmap)) {
97 		pr_err("Cannot find regmap for %pOF: %ld\n", node,
98 		       PTR_ERR(regmap));
99 		return PTR_ERR(regmap);
100 	}
101 
102 	for (i = 0; i < num; i++) {
103 		const struct mtk_composite *mux = &clks[i];
104 
105 		clk = mtk_clk_register_cpumux(mux, regmap);
106 		if (IS_ERR(clk)) {
107 			pr_err("Failed to register clk %s: %ld\n",
108 			       mux->name, PTR_ERR(clk));
109 			continue;
110 		}
111 
112 		clk_data->clks[mux->id] = clk;
113 	}
114 
115 	return 0;
116 }
117