xref: /openbmc/linux/drivers/clk/sprd/gate.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Spreadtrum gate clock driver
4 //
5 // Copyright (C) 2017 Spreadtrum, Inc.
6 // Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
7 
8 #include <linux/clk-provider.h>
9 #include <linux/regmap.h>
10 
11 #include "gate.h"
12 
13 static void clk_gate_toggle(const struct sprd_gate *sg, bool en)
14 {
15 	const struct sprd_clk_common *common = &sg->common;
16 	unsigned int reg;
17 	bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? true : false;
18 
19 	set ^= en;
20 
21 	regmap_read(common->regmap, common->reg, &reg);
22 
23 	if (set)
24 		reg |= sg->enable_mask;
25 	else
26 		reg &= ~sg->enable_mask;
27 
28 	regmap_write(common->regmap, common->reg, reg);
29 }
30 
31 static void clk_sc_gate_toggle(const struct sprd_gate *sg, bool en)
32 {
33 	const struct sprd_clk_common *common = &sg->common;
34 	bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
35 	unsigned int offset;
36 
37 	set ^= en;
38 
39 	/*
40 	 * Each set/clear gate clock has three registers:
41 	 * common->reg			- base register
42 	 * common->reg + offset		- set register
43 	 * common->reg + 2 * offset	- clear register
44 	 */
45 	offset = set ? sg->sc_offset : sg->sc_offset * 2;
46 
47 	regmap_write(common->regmap, common->reg + offset,
48 			  sg->enable_mask);
49 }
50 
51 static void sprd_gate_disable(struct clk_hw *hw)
52 {
53 	struct sprd_gate *sg = hw_to_sprd_gate(hw);
54 
55 	clk_gate_toggle(sg, false);
56 }
57 
58 static int sprd_gate_enable(struct clk_hw *hw)
59 {
60 	struct sprd_gate *sg = hw_to_sprd_gate(hw);
61 
62 	clk_gate_toggle(sg, true);
63 
64 	return 0;
65 }
66 
67 static void sprd_sc_gate_disable(struct clk_hw *hw)
68 {
69 	struct sprd_gate *sg = hw_to_sprd_gate(hw);
70 
71 	clk_sc_gate_toggle(sg, false);
72 }
73 
74 static int sprd_sc_gate_enable(struct clk_hw *hw)
75 {
76 	struct sprd_gate *sg = hw_to_sprd_gate(hw);
77 
78 	clk_sc_gate_toggle(sg, true);
79 
80 	return 0;
81 }
82 
83 static int sprd_pll_sc_gate_prepare(struct clk_hw *hw)
84 {
85 	struct sprd_gate *sg = hw_to_sprd_gate(hw);
86 
87 	clk_sc_gate_toggle(sg, true);
88 	udelay(sg->udelay);
89 
90 	return 0;
91 }
92 
93 static int sprd_gate_is_enabled(struct clk_hw *hw)
94 {
95 	struct sprd_gate *sg = hw_to_sprd_gate(hw);
96 	struct sprd_clk_common *common = &sg->common;
97 	struct clk_hw *parent;
98 	unsigned int reg;
99 
100 	if (sg->flags & SPRD_GATE_NON_AON) {
101 		parent = clk_hw_get_parent(hw);
102 		if (!parent || !clk_hw_is_enabled(parent))
103 			return 0;
104 	}
105 
106 	regmap_read(common->regmap, common->reg, &reg);
107 
108 	if (sg->flags & CLK_GATE_SET_TO_DISABLE)
109 		reg ^= sg->enable_mask;
110 
111 	reg &= sg->enable_mask;
112 
113 	return reg ? 1 : 0;
114 }
115 
116 const struct clk_ops sprd_gate_ops = {
117 	.disable	= sprd_gate_disable,
118 	.enable		= sprd_gate_enable,
119 	.is_enabled	= sprd_gate_is_enabled,
120 };
121 EXPORT_SYMBOL_GPL(sprd_gate_ops);
122 
123 const struct clk_ops sprd_sc_gate_ops = {
124 	.disable	= sprd_sc_gate_disable,
125 	.enable		= sprd_sc_gate_enable,
126 	.is_enabled	= sprd_gate_is_enabled,
127 };
128 EXPORT_SYMBOL_GPL(sprd_sc_gate_ops);
129 
130 const struct clk_ops sprd_pll_sc_gate_ops = {
131 	.unprepare	= sprd_sc_gate_disable,
132 	.prepare	= sprd_pll_sc_gate_prepare,
133 	.is_enabled	= sprd_gate_is_enabled,
134 };
135 EXPORT_SYMBOL_GPL(sprd_pll_sc_gate_ops);
136