xref: /linux/drivers/clk/sunxi-ng/ccu_gate.c (revision 22c55fb9eb92395d999b8404d73e58540d11bdd8)
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 	if (common->features & CCU_FEATURE_UPDATE_BIT)
24 		reg |= CCU_SUNXI_UPDATE_BIT;
25 	writel(reg & ~gate, common->base + common->reg);
26 
27 	spin_unlock_irqrestore(common->lock, flags);
28 }
29 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_disable, "SUNXI_CCU");
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 	if (common->features & CCU_FEATURE_UPDATE_BIT)
50 		reg |= CCU_SUNXI_UPDATE_BIT;
51 	writel(reg | gate, common->base + common->reg);
52 
53 	spin_unlock_irqrestore(common->lock, flags);
54 
55 	return 0;
56 }
57 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_enable, "SUNXI_CCU");
58 
59 static int ccu_gate_enable(struct clk_hw *hw)
60 {
61 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
62 
63 	return ccu_gate_helper_enable(&cg->common, cg->enable);
64 }
65 
66 int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
67 {
68 	if (!gate)
69 		return 1;
70 
71 	return readl(common->base + common->reg) & gate;
72 }
73 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_is_enabled, "SUNXI_CCU");
74 
75 static int ccu_gate_is_enabled(struct clk_hw *hw)
76 {
77 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
78 
79 	return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
80 }
81 
82 static unsigned long ccu_gate_recalc_rate(struct clk_hw *hw,
83 					  unsigned long parent_rate)
84 {
85 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
86 	unsigned long rate = parent_rate;
87 
88 	if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
89 		rate /= cg->common.prediv;
90 
91 	return rate;
92 }
93 
94 static int ccu_gate_determine_rate(struct clk_hw *hw,
95 				   struct clk_rate_request *req)
96 {
97 	struct ccu_gate *cg = hw_to_ccu_gate(hw);
98 	int div = 1;
99 
100 	if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
101 		div = cg->common.prediv;
102 
103 	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
104 		unsigned long best_parent = req->rate;
105 
106 		if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
107 			best_parent *= div;
108 		req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
109 	}
110 
111 	req->rate = req->best_parent_rate / div;
112 
113 	return 0;
114 }
115 
116 static int ccu_gate_set_rate(struct clk_hw *hw, unsigned long rate,
117 			     unsigned long parent_rate)
118 {
119 	/*
120 	 * We must report success but we can do so unconditionally because
121 	 * clk_factor_round_rate returns values that ensure this call is a
122 	 * nop.
123 	 */
124 
125 	return 0;
126 }
127 
128 const struct clk_ops ccu_gate_ops = {
129 	.disable	= ccu_gate_disable,
130 	.enable		= ccu_gate_enable,
131 	.is_enabled	= ccu_gate_is_enabled,
132 	.determine_rate = ccu_gate_determine_rate,
133 	.set_rate	= ccu_gate_set_rate,
134 	.recalc_rate	= ccu_gate_recalc_rate,
135 };
136 EXPORT_SYMBOL_NS_GPL(ccu_gate_ops, "SUNXI_CCU");
137