xref: /openbmc/linux/drivers/clk/sunxi-ng/ccu_mult.c (revision e2c75e76)
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 					 struct clk_hw *parent,
37 					 unsigned long *parent_rate,
38 					 unsigned long rate,
39 					 void *data)
40 {
41 	struct ccu_mult *cm = data;
42 	struct _ccu_mult _cm;
43 
44 	_cm.min = cm->mult.min;
45 
46 	if (cm->mult.max)
47 		_cm.max = cm->mult.max;
48 	else
49 		_cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;
50 
51 	ccu_mult_find_best(*parent_rate, rate, &_cm);
52 
53 	return *parent_rate * _cm.mult;
54 }
55 
56 static void ccu_mult_disable(struct clk_hw *hw)
57 {
58 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
59 
60 	return ccu_gate_helper_disable(&cm->common, cm->enable);
61 }
62 
63 static int ccu_mult_enable(struct clk_hw *hw)
64 {
65 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
66 
67 	return ccu_gate_helper_enable(&cm->common, cm->enable);
68 }
69 
70 static int ccu_mult_is_enabled(struct clk_hw *hw)
71 {
72 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
73 
74 	return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
75 }
76 
77 static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
78 					unsigned long parent_rate)
79 {
80 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
81 	unsigned long val;
82 	u32 reg;
83 
84 	if (ccu_frac_helper_is_enabled(&cm->common, &cm->frac))
85 		return ccu_frac_helper_read_rate(&cm->common, &cm->frac);
86 
87 	reg = readl(cm->common.base + cm->common.reg);
88 	val = reg >> cm->mult.shift;
89 	val &= (1 << cm->mult.width) - 1;
90 
91 	parent_rate = ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
92 						  parent_rate);
93 
94 	return parent_rate * (val + cm->mult.offset);
95 }
96 
97 static int ccu_mult_determine_rate(struct clk_hw *hw,
98 				struct clk_rate_request *req)
99 {
100 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
101 
102 	return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
103 					     req, ccu_mult_round_rate, cm);
104 }
105 
106 static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
107 			   unsigned long parent_rate)
108 {
109 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
110 	struct _ccu_mult _cm;
111 	unsigned long flags;
112 	u32 reg;
113 
114 	if (ccu_frac_helper_has_rate(&cm->common, &cm->frac, rate)) {
115 		ccu_frac_helper_enable(&cm->common, &cm->frac);
116 
117 		return ccu_frac_helper_set_rate(&cm->common, &cm->frac,
118 						rate, cm->lock);
119 	} else {
120 		ccu_frac_helper_disable(&cm->common, &cm->frac);
121 	}
122 
123 	parent_rate = ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
124 						  parent_rate);
125 
126 	_cm.min = cm->mult.min;
127 
128 	if (cm->mult.max)
129 		_cm.max = cm->mult.max;
130 	else
131 		_cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;
132 
133 	ccu_mult_find_best(parent_rate, rate, &_cm);
134 
135 	spin_lock_irqsave(cm->common.lock, flags);
136 
137 	reg = readl(cm->common.base + cm->common.reg);
138 	reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
139 	reg |= ((_cm.mult - cm->mult.offset) << cm->mult.shift);
140 
141 	writel(reg, cm->common.base + cm->common.reg);
142 
143 	spin_unlock_irqrestore(cm->common.lock, flags);
144 
145 	ccu_helper_wait_for_lock(&cm->common, cm->lock);
146 
147 	return 0;
148 }
149 
150 static u8 ccu_mult_get_parent(struct clk_hw *hw)
151 {
152 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
153 
154 	return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
155 }
156 
157 static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
158 {
159 	struct ccu_mult *cm = hw_to_ccu_mult(hw);
160 
161 	return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
162 }
163 
164 const struct clk_ops ccu_mult_ops = {
165 	.disable	= ccu_mult_disable,
166 	.enable		= ccu_mult_enable,
167 	.is_enabled	= ccu_mult_is_enabled,
168 
169 	.get_parent	= ccu_mult_get_parent,
170 	.set_parent	= ccu_mult_set_parent,
171 
172 	.determine_rate	= ccu_mult_determine_rate,
173 	.recalc_rate	= ccu_mult_recalc_rate,
174 	.set_rate	= ccu_mult_set_rate,
175 };
176