xref: /openbmc/linux/drivers/clk/mediatek/clk-gate.c (revision be709d48)
1 /*
2  * Copyright (c) 2014 MediaTek Inc.
3  * Author: James Liao <jamesjj.liao@mediatek.com>
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/of.h>
16 #include <linux/of_address.h>
17 
18 #include <linux/io.h>
19 #include <linux/slab.h>
20 #include <linux/delay.h>
21 #include <linux/clkdev.h>
22 
23 #include "clk-mtk.h"
24 #include "clk-gate.h"
25 
26 static int mtk_cg_bit_is_cleared(struct clk_hw *hw)
27 {
28 	struct mtk_clk_gate *cg = to_mtk_clk_gate(hw);
29 	u32 val;
30 
31 	regmap_read(cg->regmap, cg->sta_ofs, &val);
32 
33 	val &= BIT(cg->bit);
34 
35 	return val == 0;
36 }
37 
38 static int mtk_cg_bit_is_set(struct clk_hw *hw)
39 {
40 	struct mtk_clk_gate *cg = to_mtk_clk_gate(hw);
41 	u32 val;
42 
43 	regmap_read(cg->regmap, cg->sta_ofs, &val);
44 
45 	val &= BIT(cg->bit);
46 
47 	return val != 0;
48 }
49 
50 static void mtk_cg_set_bit(struct clk_hw *hw)
51 {
52 	struct mtk_clk_gate *cg = to_mtk_clk_gate(hw);
53 
54 	regmap_write(cg->regmap, cg->set_ofs, BIT(cg->bit));
55 }
56 
57 static void mtk_cg_clr_bit(struct clk_hw *hw)
58 {
59 	struct mtk_clk_gate *cg = to_mtk_clk_gate(hw);
60 
61 	regmap_write(cg->regmap, cg->clr_ofs, BIT(cg->bit));
62 }
63 
64 static void mtk_cg_set_bit_no_setclr(struct clk_hw *hw)
65 {
66 	struct mtk_clk_gate *cg = to_mtk_clk_gate(hw);
67 	u32 cgbit = BIT(cg->bit);
68 
69 	regmap_update_bits(cg->regmap, cg->sta_ofs, cgbit, cgbit);
70 }
71 
72 static void mtk_cg_clr_bit_no_setclr(struct clk_hw *hw)
73 {
74 	struct mtk_clk_gate *cg = to_mtk_clk_gate(hw);
75 	u32 cgbit = BIT(cg->bit);
76 
77 	regmap_update_bits(cg->regmap, cg->sta_ofs, cgbit, 0);
78 }
79 
80 static int mtk_cg_enable(struct clk_hw *hw)
81 {
82 	mtk_cg_clr_bit(hw);
83 
84 	return 0;
85 }
86 
87 static void mtk_cg_disable(struct clk_hw *hw)
88 {
89 	mtk_cg_set_bit(hw);
90 }
91 
92 static int mtk_cg_enable_inv(struct clk_hw *hw)
93 {
94 	mtk_cg_set_bit(hw);
95 
96 	return 0;
97 }
98 
99 static void mtk_cg_disable_inv(struct clk_hw *hw)
100 {
101 	mtk_cg_clr_bit(hw);
102 }
103 
104 static int mtk_cg_enable_no_setclr(struct clk_hw *hw)
105 {
106 	mtk_cg_clr_bit_no_setclr(hw);
107 
108 	return 0;
109 }
110 
111 static void mtk_cg_disable_no_setclr(struct clk_hw *hw)
112 {
113 	mtk_cg_set_bit_no_setclr(hw);
114 }
115 
116 static int mtk_cg_enable_inv_no_setclr(struct clk_hw *hw)
117 {
118 	mtk_cg_set_bit_no_setclr(hw);
119 
120 	return 0;
121 }
122 
123 static void mtk_cg_disable_inv_no_setclr(struct clk_hw *hw)
124 {
125 	mtk_cg_clr_bit_no_setclr(hw);
126 }
127 
128 const struct clk_ops mtk_clk_gate_ops_setclr = {
129 	.is_enabled	= mtk_cg_bit_is_cleared,
130 	.enable		= mtk_cg_enable,
131 	.disable	= mtk_cg_disable,
132 };
133 
134 const struct clk_ops mtk_clk_gate_ops_setclr_inv = {
135 	.is_enabled	= mtk_cg_bit_is_set,
136 	.enable		= mtk_cg_enable_inv,
137 	.disable	= mtk_cg_disable_inv,
138 };
139 
140 const struct clk_ops mtk_clk_gate_ops_no_setclr = {
141 	.is_enabled	= mtk_cg_bit_is_cleared,
142 	.enable		= mtk_cg_enable_no_setclr,
143 	.disable	= mtk_cg_disable_no_setclr,
144 };
145 
146 const struct clk_ops mtk_clk_gate_ops_no_setclr_inv = {
147 	.is_enabled	= mtk_cg_bit_is_set,
148 	.enable		= mtk_cg_enable_inv_no_setclr,
149 	.disable	= mtk_cg_disable_inv_no_setclr,
150 };
151 
152 struct clk *mtk_clk_register_gate(
153 		const char *name,
154 		const char *parent_name,
155 		struct regmap *regmap,
156 		int set_ofs,
157 		int clr_ofs,
158 		int sta_ofs,
159 		u8 bit,
160 		const struct clk_ops *ops,
161 		unsigned long flags)
162 {
163 	struct mtk_clk_gate *cg;
164 	struct clk *clk;
165 	struct clk_init_data init = {};
166 
167 	cg = kzalloc(sizeof(*cg), GFP_KERNEL);
168 	if (!cg)
169 		return ERR_PTR(-ENOMEM);
170 
171 	init.name = name;
172 	init.flags = CLK_SET_RATE_PARENT;
173 	init.parent_names = parent_name ? &parent_name : NULL;
174 	init.num_parents = parent_name ? 1 : 0;
175 	init.ops = ops;
176 	init.flags = flags;
177 
178 	cg->regmap = regmap;
179 	cg->set_ofs = set_ofs;
180 	cg->clr_ofs = clr_ofs;
181 	cg->sta_ofs = sta_ofs;
182 	cg->bit = bit;
183 
184 	cg->hw.init = &init;
185 
186 	clk = clk_register(NULL, &cg->hw);
187 	if (IS_ERR(clk))
188 		kfree(cg);
189 
190 	return clk;
191 }
192