xref: /openbmc/linux/drivers/clk/sunxi-ng/ccu_gate.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2016 Maxime Ripard
4  * Maxime Ripard <maxime.ripard@free-electrons.com>
5  */
6 
7 #include <linux/clk-provider.h>
8 #include <linux/io.h>
9 
10 #include "ccu_gate.h"
11 
12 void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
13 {
14 	unsigned long flags;
15 	u32 reg;
16 
17 	if (!gate)
18 		return;
19 
20 	spin_lock_irqsave(common->lock, flags);
21 
22 	reg = readl(common->base + common->reg);
23 	writel(reg & ~gate, common->base + common->reg);
24 
25 	spin_unlock_irqrestore(common->lock, flags);
26 }
27 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_disable, SUNXI_CCU);
28 
29 static void ccu_gate_disable(struct clk_hw *hw)
30 {
31 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
32 
33 	return ccu_gate_helper_disable(&cg->common, cg->enable);
34 }
35 
36 int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
37 {
38 	unsigned long flags;
39 	u32 reg;
40 
41 	if (!gate)
42 		return 0;
43 
44 	spin_lock_irqsave(common->lock, flags);
45 
46 	reg = readl(common->base + common->reg);
47 	writel(reg | gate, common->base + common->reg);
48 
49 	spin_unlock_irqrestore(common->lock, flags);
50 
51 	return 0;
52 }
53 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_enable, SUNXI_CCU);
54 
55 static int ccu_gate_enable(struct clk_hw *hw)
56 {
57 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
58 
59 	return ccu_gate_helper_enable(&cg->common, cg->enable);
60 }
61 
62 int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
63 {
64 	if (!gate)
65 		return 1;
66 
67 	return readl(common->base + common->reg) & gate;
68 }
69 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_is_enabled, SUNXI_CCU);
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 EXPORT_SYMBOL_NS_GPL(ccu_gate_ops, SUNXI_CCU);
131