xref: /linux/drivers/clk/sunxi-ng/ccu_div.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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_div.h"
15 
16 static unsigned long ccu_div_round_rate(struct ccu_mux_internal *mux,
17 					unsigned long parent_rate,
18 					unsigned long rate,
19 					void *data)
20 {
21 	struct ccu_div *cd = data;
22 	unsigned long val;
23 
24 	/*
25 	 * We can't use divider_round_rate that assumes that there's
26 	 * several parents, while we might be called to evaluate
27 	 * several different parents.
28 	 */
29 	val = divider_get_val(rate, parent_rate, cd->div.table, cd->div.width,
30 			      cd->div.flags);
31 
32 	return divider_recalc_rate(&cd->common.hw, parent_rate, val,
33 				   cd->div.table, cd->div.flags);
34 }
35 
36 static void ccu_div_disable(struct clk_hw *hw)
37 {
38 	struct ccu_div *cd = hw_to_ccu_div(hw);
39 
40 	return ccu_gate_helper_disable(&cd->common, cd->enable);
41 }
42 
43 static int ccu_div_enable(struct clk_hw *hw)
44 {
45 	struct ccu_div *cd = hw_to_ccu_div(hw);
46 
47 	return ccu_gate_helper_enable(&cd->common, cd->enable);
48 }
49 
50 static int ccu_div_is_enabled(struct clk_hw *hw)
51 {
52 	struct ccu_div *cd = hw_to_ccu_div(hw);
53 
54 	return ccu_gate_helper_is_enabled(&cd->common, cd->enable);
55 }
56 
57 static unsigned long ccu_div_recalc_rate(struct clk_hw *hw,
58 					unsigned long parent_rate)
59 {
60 	struct ccu_div *cd = hw_to_ccu_div(hw);
61 	unsigned long val;
62 	u32 reg;
63 
64 	reg = readl(cd->common.base + cd->common.reg);
65 	val = reg >> cd->div.shift;
66 	val &= (1 << cd->div.width) - 1;
67 
68 	ccu_mux_helper_adjust_parent_for_prediv(&cd->common, &cd->mux, -1,
69 						&parent_rate);
70 
71 	return divider_recalc_rate(hw, parent_rate, val, cd->div.table,
72 				   cd->div.flags);
73 }
74 
75 static int ccu_div_determine_rate(struct clk_hw *hw,
76 				struct clk_rate_request *req)
77 {
78 	struct ccu_div *cd = hw_to_ccu_div(hw);
79 
80 	if (clk_hw_get_num_parents(hw) == 1) {
81 		req->rate = divider_round_rate(hw, req->rate,
82 					       &req->best_parent_rate,
83 					       cd->div.table,
84 					       cd->div.width,
85 					       cd->div.flags);
86 
87 		req->best_parent_hw = clk_hw_get_parent(hw);
88 
89 		return 0;
90 	}
91 
92 	return ccu_mux_helper_determine_rate(&cd->common, &cd->mux,
93 					     req, ccu_div_round_rate, cd);
94 }
95 
96 static int ccu_div_set_rate(struct clk_hw *hw, unsigned long rate,
97 			   unsigned long parent_rate)
98 {
99 	struct ccu_div *cd = hw_to_ccu_div(hw);
100 	unsigned long flags;
101 	unsigned long val;
102 	u32 reg;
103 
104 	ccu_mux_helper_adjust_parent_for_prediv(&cd->common, &cd->mux, -1,
105 						&parent_rate);
106 
107 	val = divider_get_val(rate, parent_rate, cd->div.table, cd->div.width,
108 			      cd->div.flags);
109 
110 	spin_lock_irqsave(cd->common.lock, flags);
111 
112 	reg = readl(cd->common.base + cd->common.reg);
113 	reg &= ~GENMASK(cd->div.width + cd->div.shift - 1, cd->div.shift);
114 
115 	writel(reg | (val << cd->div.shift),
116 	       cd->common.base + cd->common.reg);
117 
118 	spin_unlock_irqrestore(cd->common.lock, flags);
119 
120 	return 0;
121 }
122 
123 static u8 ccu_div_get_parent(struct clk_hw *hw)
124 {
125 	struct ccu_div *cd = hw_to_ccu_div(hw);
126 
127 	return ccu_mux_helper_get_parent(&cd->common, &cd->mux);
128 }
129 
130 static int ccu_div_set_parent(struct clk_hw *hw, u8 index)
131 {
132 	struct ccu_div *cd = hw_to_ccu_div(hw);
133 
134 	return ccu_mux_helper_set_parent(&cd->common, &cd->mux, index);
135 }
136 
137 const struct clk_ops ccu_div_ops = {
138 	.disable	= ccu_div_disable,
139 	.enable		= ccu_div_enable,
140 	.is_enabled	= ccu_div_is_enabled,
141 
142 	.get_parent	= ccu_div_get_parent,
143 	.set_parent	= ccu_div_set_parent,
144 
145 	.determine_rate	= ccu_div_determine_rate,
146 	.recalc_rate	= ccu_div_recalc_rate,
147 	.set_rate	= ccu_div_set_rate,
148 };
149