xref: /openbmc/linux/drivers/clk/sunxi-ng/ccu_mult.c (revision 2891f2d5)
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 = cm->mult.min;
44 
45 	if (cm->mult.max)
46 		_cm.max = cm->mult.max;
47 	else
48 		_cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;
49 
50 	ccu_mult_find_best(parent_rate, rate, &_cm);
51 
52 	return parent_rate * _cm.mult;
53 }
54 
55 static void ccu_mult_disable(struct clk_hw *hw)
56 {
57 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
58 
59 	return ccu_gate_helper_disable(&cm->common, cm->enable);
60 }
61 
62 static int ccu_mult_enable(struct clk_hw *hw)
63 {
64 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
65 
66 	return ccu_gate_helper_enable(&cm->common, cm->enable);
67 }
68 
69 static int ccu_mult_is_enabled(struct clk_hw *hw)
70 {
71 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
72 
73 	return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
74 }
75 
76 static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
77 					unsigned long parent_rate)
78 {
79 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
80 	unsigned long val;
81 	u32 reg;
82 
83 	if (ccu_frac_helper_is_enabled(&cm->common, &cm->frac))
84 		return ccu_frac_helper_read_rate(&cm->common, &cm->frac);
85 
86 	reg = readl(cm->common.base + cm->common.reg);
87 	val = reg >> cm->mult.shift;
88 	val &= (1 << cm->mult.width) - 1;
89 
90 	ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
91 						&parent_rate);
92 
93 	return parent_rate * (val + cm->mult.offset);
94 }
95 
96 static int ccu_mult_determine_rate(struct clk_hw *hw,
97 				struct clk_rate_request *req)
98 {
99 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
100 
101 	return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
102 					     req, ccu_mult_round_rate, cm);
103 }
104 
105 static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
106 			   unsigned long parent_rate)
107 {
108 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
109 	struct _ccu_mult _cm;
110 	unsigned long flags;
111 	u32 reg;
112 
113 	if (ccu_frac_helper_has_rate(&cm->common, &cm->frac, rate))
114 		return ccu_frac_helper_set_rate(&cm->common, &cm->frac, rate);
115 	else
116 		ccu_frac_helper_disable(&cm->common, &cm->frac);
117 
118 	ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
119 						&parent_rate);
120 
121 	_cm.min = cm->mult.min;
122 
123 	if (cm->mult.max)
124 		_cm.max = cm->mult.max;
125 	else
126 		_cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;
127 
128 	ccu_mult_find_best(parent_rate, rate, &_cm);
129 
130 	spin_lock_irqsave(cm->common.lock, flags);
131 
132 	reg = readl(cm->common.base + cm->common.reg);
133 	reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
134 	reg |= ((_cm.mult - cm->mult.offset) << cm->mult.shift);
135 
136 	writel(reg, cm->common.base + cm->common.reg);
137 
138 	spin_unlock_irqrestore(cm->common.lock, flags);
139 
140 	return 0;
141 }
142 
143 static u8 ccu_mult_get_parent(struct clk_hw *hw)
144 {
145 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
146 
147 	return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
148 }
149 
150 static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
151 {
152 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
153 
154 	return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
155 }
156 
157 const struct clk_ops ccu_mult_ops = {
158 	.disable	= ccu_mult_disable,
159 	.enable		= ccu_mult_enable,
160 	.is_enabled	= ccu_mult_is_enabled,
161 
162 	.get_parent	= ccu_mult_get_parent,
163 	.set_parent	= ccu_mult_set_parent,
164 
165 	.determine_rate	= ccu_mult_determine_rate,
166 	.recalc_rate	= ccu_mult_recalc_rate,
167 	.set_rate	= ccu_mult_set_rate,
168 };
169