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 	int num_parents = clk_hw_get_num_parents(hw);
31 	unsigned int val;
32 
33 	regmap_read(mux->regmap, mux->reg, &val);
34 
35 	val >>= mux->shift;
36 	val &= mux->mask;
37 
38 	if (val >= num_parents)
39 		return -EINVAL;
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 __init *
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 int __init mtk_clk_register_cpumuxes(struct device_node *node,
92 				     const struct mtk_composite *clks, int num,
93 				     struct clk_onecell_data *clk_data)
94 {
95 	int i;
96 	struct clk *clk;
97 	struct regmap *regmap;
98 
99 	regmap = syscon_node_to_regmap(node);
100 	if (IS_ERR(regmap)) {
101 		pr_err("Cannot find regmap for %s: %ld\n", node->full_name,
102 		       PTR_ERR(regmap));
103 		return PTR_ERR(regmap);
104 	}
105 
106 	for (i = 0; i < num; i++) {
107 		const struct mtk_composite *mux = &clks[i];
108 
109 		clk = mtk_clk_register_cpumux(mux, regmap);
110 		if (IS_ERR(clk)) {
111 			pr_err("Failed to register clk %s: %ld\n",
112 			       mux->name, PTR_ERR(clk));
113 			continue;
114 		}
115 
116 		clk_data->clks[mux->id] = clk;
117 	}
118 
119 	return 0;
120 }
121