xref: /openbmc/linux/drivers/clk/mediatek/clk-mux.c (revision c6acb1e7)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018 MediaTek Inc.
4  * Author: Owen Chen <owen.chen@mediatek.com>
5  */
6 
7 #include <linux/of.h>
8 #include <linux/of_address.h>
9 #include <linux/slab.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 
13 #include "clk-mtk.h"
14 #include "clk-mux.h"
15 
16 static inline struct mtk_clk_mux *to_mtk_clk_mux(struct clk_hw *hw)
17 {
18 	return container_of(hw, struct mtk_clk_mux, hw);
19 }
20 
21 static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
22 {
23 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
24 	unsigned long flags = 0;
25 
26 	if (mux->lock)
27 		spin_lock_irqsave(mux->lock, flags);
28 	else
29 		__acquire(mux->lock);
30 
31 	regmap_write(mux->regmap, mux->data->clr_ofs,
32 		     BIT(mux->data->gate_shift));
33 
34 	/*
35 	 * If the parent has been changed when the clock was disabled, it will
36 	 * not be effective yet. Set the update bit to ensure the mux gets
37 	 * updated.
38 	 */
39 	if (mux->reparent && mux->data->upd_shift >= 0) {
40 		regmap_write(mux->regmap, mux->data->upd_ofs,
41 			     BIT(mux->data->upd_shift));
42 		mux->reparent = false;
43 	}
44 
45 	if (mux->lock)
46 		spin_unlock_irqrestore(mux->lock, flags);
47 	else
48 		__release(mux->lock);
49 
50 	return 0;
51 }
52 
53 static void mtk_clk_mux_disable_setclr(struct clk_hw *hw)
54 {
55 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
56 
57 	regmap_write(mux->regmap, mux->data->set_ofs,
58 			BIT(mux->data->gate_shift));
59 }
60 
61 static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
62 {
63 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
64 	u32 val;
65 
66 	regmap_read(mux->regmap, mux->data->mux_ofs, &val);
67 
68 	return (val & BIT(mux->data->gate_shift)) == 0;
69 }
70 
71 static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
72 {
73 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
74 	u32 mask = GENMASK(mux->data->mux_width - 1, 0);
75 	u32 val;
76 
77 	regmap_read(mux->regmap, mux->data->mux_ofs, &val);
78 	val = (val >> mux->data->mux_shift) & mask;
79 
80 	return val;
81 }
82 
83 static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
84 {
85 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
86 	u32 mask = GENMASK(mux->data->mux_width - 1, 0);
87 	u32 val, orig;
88 	unsigned long flags = 0;
89 
90 	if (mux->lock)
91 		spin_lock_irqsave(mux->lock, flags);
92 	else
93 		__acquire(mux->lock);
94 
95 	regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
96 	val = (orig & ~(mask << mux->data->mux_shift))
97 			| (index << mux->data->mux_shift);
98 
99 	if (val != orig) {
100 		regmap_write(mux->regmap, mux->data->clr_ofs,
101 				mask << mux->data->mux_shift);
102 		regmap_write(mux->regmap, mux->data->set_ofs,
103 				index << mux->data->mux_shift);
104 
105 		if (mux->data->upd_shift >= 0) {
106 			regmap_write(mux->regmap, mux->data->upd_ofs,
107 					BIT(mux->data->upd_shift));
108 			mux->reparent = true;
109 		}
110 	}
111 
112 	if (mux->lock)
113 		spin_unlock_irqrestore(mux->lock, flags);
114 	else
115 		__release(mux->lock);
116 
117 	return 0;
118 }
119 
120 const struct clk_ops mtk_mux_clr_set_upd_ops = {
121 	.get_parent = mtk_clk_mux_get_parent,
122 	.set_parent = mtk_clk_mux_set_parent_setclr_lock,
123 };
124 EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops);
125 
126 const struct clk_ops mtk_mux_gate_clr_set_upd_ops  = {
127 	.enable = mtk_clk_mux_enable_setclr,
128 	.disable = mtk_clk_mux_disable_setclr,
129 	.is_enabled = mtk_clk_mux_is_enabled,
130 	.get_parent = mtk_clk_mux_get_parent,
131 	.set_parent = mtk_clk_mux_set_parent_setclr_lock,
132 };
133 EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);
134 
135 static struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
136 				 struct regmap *regmap,
137 				 spinlock_t *lock)
138 {
139 	struct mtk_clk_mux *clk_mux;
140 	struct clk_init_data init = {};
141 	struct clk *clk;
142 
143 	clk_mux = kzalloc(sizeof(*clk_mux), GFP_KERNEL);
144 	if (!clk_mux)
145 		return ERR_PTR(-ENOMEM);
146 
147 	init.name = mux->name;
148 	init.flags = mux->flags | CLK_SET_RATE_PARENT;
149 	init.parent_names = mux->parent_names;
150 	init.num_parents = mux->num_parents;
151 	init.ops = mux->ops;
152 
153 	clk_mux->regmap = regmap;
154 	clk_mux->data = mux;
155 	clk_mux->lock = lock;
156 	clk_mux->hw.init = &init;
157 
158 	clk = clk_register(NULL, &clk_mux->hw);
159 	if (IS_ERR(clk)) {
160 		kfree(clk_mux);
161 		return clk;
162 	}
163 
164 	return clk;
165 }
166 
167 int mtk_clk_register_muxes(const struct mtk_mux *muxes,
168 			   int num, struct device_node *node,
169 			   spinlock_t *lock,
170 			   struct clk_onecell_data *clk_data)
171 {
172 	struct regmap *regmap;
173 	struct clk *clk;
174 	int i;
175 
176 	regmap = device_node_to_regmap(node);
177 	if (IS_ERR(regmap)) {
178 		pr_err("Cannot find regmap for %pOF: %ld\n", node,
179 		       PTR_ERR(regmap));
180 		return PTR_ERR(regmap);
181 	}
182 
183 	for (i = 0; i < num; i++) {
184 		const struct mtk_mux *mux = &muxes[i];
185 
186 		if (IS_ERR_OR_NULL(clk_data->clks[mux->id])) {
187 			clk = mtk_clk_register_mux(mux, regmap, lock);
188 
189 			if (IS_ERR(clk)) {
190 				pr_err("Failed to register clk %s: %ld\n",
191 				       mux->name, PTR_ERR(clk));
192 				continue;
193 			}
194 
195 			clk_data->clks[mux->id] = clk;
196 		}
197 	}
198 
199 	return 0;
200 }
201 EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
202 
203 MODULE_LICENSE("GPL");
204