xref: /openbmc/linux/drivers/clk/mediatek/clk-mux.c (revision 0ad53fe3)
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 
12 #include "clk-mtk.h"
13 #include "clk-mux.h"
14 
15 static inline struct mtk_clk_mux *to_mtk_clk_mux(struct clk_hw *hw)
16 {
17 	return container_of(hw, struct mtk_clk_mux, hw);
18 }
19 
20 static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
21 {
22 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
23 	unsigned long flags = 0;
24 
25 	if (mux->lock)
26 		spin_lock_irqsave(mux->lock, flags);
27 	else
28 		__acquire(mux->lock);
29 
30 	regmap_write(mux->regmap, mux->data->clr_ofs,
31 		     BIT(mux->data->gate_shift));
32 
33 	/*
34 	 * If the parent has been changed when the clock was disabled, it will
35 	 * not be effective yet. Set the update bit to ensure the mux gets
36 	 * updated.
37 	 */
38 	if (mux->reparent && mux->data->upd_shift >= 0) {
39 		regmap_write(mux->regmap, mux->data->upd_ofs,
40 			     BIT(mux->data->upd_shift));
41 		mux->reparent = false;
42 	}
43 
44 	if (mux->lock)
45 		spin_unlock_irqrestore(mux->lock, flags);
46 	else
47 		__release(mux->lock);
48 
49 	return 0;
50 }
51 
52 static void mtk_clk_mux_disable_setclr(struct clk_hw *hw)
53 {
54 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
55 
56 	regmap_write(mux->regmap, mux->data->set_ofs,
57 			BIT(mux->data->gate_shift));
58 }
59 
60 static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
61 {
62 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
63 	u32 val;
64 
65 	regmap_read(mux->regmap, mux->data->mux_ofs, &val);
66 
67 	return (val & BIT(mux->data->gate_shift)) == 0;
68 }
69 
70 static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
71 {
72 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
73 	u32 mask = GENMASK(mux->data->mux_width - 1, 0);
74 	u32 val;
75 
76 	regmap_read(mux->regmap, mux->data->mux_ofs, &val);
77 	val = (val >> mux->data->mux_shift) & mask;
78 
79 	return val;
80 }
81 
82 static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
83 {
84 	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
85 	u32 mask = GENMASK(mux->data->mux_width - 1, 0);
86 	u32 val, orig;
87 	unsigned long flags = 0;
88 
89 	if (mux->lock)
90 		spin_lock_irqsave(mux->lock, flags);
91 	else
92 		__acquire(mux->lock);
93 
94 	regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
95 	val = (orig & ~(mask << mux->data->mux_shift))
96 			| (index << mux->data->mux_shift);
97 
98 	if (val != orig) {
99 		regmap_write(mux->regmap, mux->data->clr_ofs,
100 				mask << mux->data->mux_shift);
101 		regmap_write(mux->regmap, mux->data->set_ofs,
102 				index << mux->data->mux_shift);
103 
104 		if (mux->data->upd_shift >= 0) {
105 			regmap_write(mux->regmap, mux->data->upd_ofs,
106 					BIT(mux->data->upd_shift));
107 			mux->reparent = true;
108 		}
109 	}
110 
111 	if (mux->lock)
112 		spin_unlock_irqrestore(mux->lock, flags);
113 	else
114 		__release(mux->lock);
115 
116 	return 0;
117 }
118 
119 const struct clk_ops mtk_mux_clr_set_upd_ops = {
120 	.get_parent = mtk_clk_mux_get_parent,
121 	.set_parent = mtk_clk_mux_set_parent_setclr_lock,
122 };
123 
124 const struct clk_ops mtk_mux_gate_clr_set_upd_ops  = {
125 	.enable = mtk_clk_mux_enable_setclr,
126 	.disable = mtk_clk_mux_disable_setclr,
127 	.is_enabled = mtk_clk_mux_is_enabled,
128 	.get_parent = mtk_clk_mux_get_parent,
129 	.set_parent = mtk_clk_mux_set_parent_setclr_lock,
130 };
131 
132 static struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
133 				 struct regmap *regmap,
134 				 spinlock_t *lock)
135 {
136 	struct mtk_clk_mux *clk_mux;
137 	struct clk_init_data init = {};
138 	struct clk *clk;
139 
140 	clk_mux = kzalloc(sizeof(*clk_mux), GFP_KERNEL);
141 	if (!clk_mux)
142 		return ERR_PTR(-ENOMEM);
143 
144 	init.name = mux->name;
145 	init.flags = mux->flags | CLK_SET_RATE_PARENT;
146 	init.parent_names = mux->parent_names;
147 	init.num_parents = mux->num_parents;
148 	init.ops = mux->ops;
149 
150 	clk_mux->regmap = regmap;
151 	clk_mux->data = mux;
152 	clk_mux->lock = lock;
153 	clk_mux->hw.init = &init;
154 
155 	clk = clk_register(NULL, &clk_mux->hw);
156 	if (IS_ERR(clk)) {
157 		kfree(clk_mux);
158 		return clk;
159 	}
160 
161 	return clk;
162 }
163 
164 int mtk_clk_register_muxes(const struct mtk_mux *muxes,
165 			   int num, struct device_node *node,
166 			   spinlock_t *lock,
167 			   struct clk_onecell_data *clk_data)
168 {
169 	struct regmap *regmap;
170 	struct clk *clk;
171 	int i;
172 
173 	regmap = device_node_to_regmap(node);
174 	if (IS_ERR(regmap)) {
175 		pr_err("Cannot find regmap for %pOF: %ld\n", node,
176 		       PTR_ERR(regmap));
177 		return PTR_ERR(regmap);
178 	}
179 
180 	for (i = 0; i < num; i++) {
181 		const struct mtk_mux *mux = &muxes[i];
182 
183 		if (IS_ERR_OR_NULL(clk_data->clks[mux->id])) {
184 			clk = mtk_clk_register_mux(mux, regmap, lock);
185 
186 			if (IS_ERR(clk)) {
187 				pr_err("Failed to register clk %s: %ld\n",
188 				       mux->name, PTR_ERR(clk));
189 				continue;
190 			}
191 
192 			clk_data->clks[mux->id] = clk;
193 		}
194 	}
195 
196 	return 0;
197 }
198