xref: /openbmc/linux/drivers/clk/sunxi-ng/ccu_mult.c (revision 8730046c)
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 #include "ccu_mult.h"
15 
16 struct _ccu_mult {
17 	unsigned long	mult, min, max;
18 };
19 
20 static void ccu_mult_find_best(unsigned long parent, unsigned long rate,
21 			       struct _ccu_mult *mult)
22 {
23 	int _mult;
24 
25 	_mult = rate / parent;
26 	if (_mult < mult->min)
27 		_mult = mult->min;
28 
29 	if (_mult > mult->max)
30 		_mult = mult->max;
31 
32 	mult->mult = _mult;
33 }
34 
35 static unsigned long ccu_mult_round_rate(struct ccu_mux_internal *mux,
36 					unsigned long parent_rate,
37 					unsigned long rate,
38 					void *data)
39 {
40 	struct ccu_mult *cm = data;
41 	struct _ccu_mult _cm;
42 
43 	_cm.min = 1;
44 	_cm.max = 1 << cm->mult.width;
45 	ccu_mult_find_best(parent_rate, rate, &_cm);
46 
47 	return parent_rate * _cm.mult;
48 }
49 
50 static void ccu_mult_disable(struct clk_hw *hw)
51 {
52 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
53 
54 	return ccu_gate_helper_disable(&cm->common, cm->enable);
55 }
56 
57 static int ccu_mult_enable(struct clk_hw *hw)
58 {
59 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
60 
61 	return ccu_gate_helper_enable(&cm->common, cm->enable);
62 }
63 
64 static int ccu_mult_is_enabled(struct clk_hw *hw)
65 {
66 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
67 
68 	return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
69 }
70 
71 static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
72 					unsigned long parent_rate)
73 {
74 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
75 	unsigned long val;
76 	u32 reg;
77 
78 	reg = readl(cm->common.base + cm->common.reg);
79 	val = reg >> cm->mult.shift;
80 	val &= (1 << cm->mult.width) - 1;
81 
82 	ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
83 						&parent_rate);
84 
85 	return parent_rate * (val + 1);
86 }
87 
88 static int ccu_mult_determine_rate(struct clk_hw *hw,
89 				struct clk_rate_request *req)
90 {
91 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
92 
93 	return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
94 					     req, ccu_mult_round_rate, cm);
95 }
96 
97 static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
98 			   unsigned long parent_rate)
99 {
100 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
101 	struct _ccu_mult _cm;
102 	unsigned long flags;
103 	u32 reg;
104 
105 	ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
106 						&parent_rate);
107 
108 	_cm.min = cm->mult.min;
109 	_cm.max = 1 << cm->mult.width;
110 	ccu_mult_find_best(parent_rate, rate, &_cm);
111 
112 	spin_lock_irqsave(cm->common.lock, flags);
113 
114 	reg = readl(cm->common.base + cm->common.reg);
115 	reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
116 
117 	writel(reg | ((_cm.mult - 1) << cm->mult.shift),
118 	       cm->common.base + cm->common.reg);
119 
120 	spin_unlock_irqrestore(cm->common.lock, flags);
121 
122 	return 0;
123 }
124 
125 static u8 ccu_mult_get_parent(struct clk_hw *hw)
126 {
127 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
128 
129 	return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
130 }
131 
132 static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
133 {
134 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
135 
136 	return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
137 }
138 
139 const struct clk_ops ccu_mult_ops = {
140 	.disable	= ccu_mult_disable,
141 	.enable		= ccu_mult_enable,
142 	.is_enabled	= ccu_mult_is_enabled,
143 
144 	.get_parent	= ccu_mult_get_parent,
145 	.set_parent	= ccu_mult_set_parent,
146 
147 	.determine_rate	= ccu_mult_determine_rate,
148 	.recalc_rate	= ccu_mult_recalc_rate,
149 	.set_rate	= ccu_mult_set_rate,
150 };
151