xref: /openbmc/linux/drivers/clk/sunxi-ng/ccu_gate.c (revision 68198dca)
1 /*
2  * Copyright (C) 2016 Maxime Ripard
3  * Maxime Ripard <maxime.ripard@free-electrons.com>
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation; either version 2 of
8  * the License, or (at your option) any later version.
9  */
10 
11 #include <linux/clk-provider.h>
12 
13 #include "ccu_gate.h"
14 
15 void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
16 {
17 	unsigned long flags;
18 	u32 reg;
19 
20 	if (!gate)
21 		return;
22 
23 	spin_lock_irqsave(common->lock, flags);
24 
25 	reg = readl(common->base + common->reg);
26 	writel(reg & ~gate, common->base + common->reg);
27 
28 	spin_unlock_irqrestore(common->lock, flags);
29 }
30 
31 static void ccu_gate_disable(struct clk_hw *hw)
32 {
33 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
34 
35 	return ccu_gate_helper_disable(&cg->common, cg->enable);
36 }
37 
38 int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
39 {
40 	unsigned long flags;
41 	u32 reg;
42 
43 	if (!gate)
44 		return 0;
45 
46 	spin_lock_irqsave(common->lock, flags);
47 
48 	reg = readl(common->base + common->reg);
49 	writel(reg | gate, common->base + common->reg);
50 
51 	spin_unlock_irqrestore(common->lock, flags);
52 
53 	return 0;
54 }
55 
56 static int ccu_gate_enable(struct clk_hw *hw)
57 {
58 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
59 
60 	return ccu_gate_helper_enable(&cg->common, cg->enable);
61 }
62 
63 int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
64 {
65 	if (!gate)
66 		return 1;
67 
68 	return readl(common->base + common->reg) & gate;
69 }
70 
71 static int ccu_gate_is_enabled(struct clk_hw *hw)
72 {
73 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
74 
75 	return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
76 }
77 
78 static unsigned long ccu_gate_recalc_rate(struct clk_hw *hw,
79 					  unsigned long parent_rate)
80 {
81 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
82 	unsigned long rate = parent_rate;
83 
84 	if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
85 		rate /= cg->common.prediv;
86 
87 	return rate;
88 }
89 
90 static long ccu_gate_round_rate(struct clk_hw *hw, unsigned long rate,
91 				unsigned long *prate)
92 {
93 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
94 	int div = 1;
95 
96 	if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
97 		div = cg->common.prediv;
98 
99 	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
100 		unsigned long best_parent = rate;
101 
102 		if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
103 			best_parent *= div;
104 		*prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
105 	}
106 
107 	return *prate / div;
108 }
109 
110 static int ccu_gate_set_rate(struct clk_hw *hw, unsigned long rate,
111 			     unsigned long parent_rate)
112 {
113 	/*
114 	 * We must report success but we can do so unconditionally because
115 	 * clk_factor_round_rate returns values that ensure this call is a
116 	 * nop.
117 	 */
118 
119 	return 0;
120 }
121 
122 const struct clk_ops ccu_gate_ops = {
123 	.disable	= ccu_gate_disable,
124 	.enable		= ccu_gate_enable,
125 	.is_enabled	= ccu_gate_is_enabled,
126 	.round_rate	= ccu_gate_round_rate,
127 	.set_rate	= ccu_gate_set_rate,
128 	.recalc_rate	= ccu_gate_recalc_rate,
129 };
130