xref: /openbmc/linux/drivers/clk/mxs/clk-div.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2012 Freescale Semiconductor, Inc.
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/err.h>
8 #include <linux/slab.h>
9 #include "clk.h"
10 
11 /**
12  * struct clk_div - mxs integer divider clock
13  * @divider: the parent class
14  * @ops: pointer to clk_ops of parent class
15  * @reg: register address
16  * @busy: busy bit shift
17  *
18  * The mxs divider clock is a subclass of basic clk_divider with an
19  * addtional busy bit.
20  */
21 struct clk_div {
22 	struct clk_divider divider;
23 	const struct clk_ops *ops;
24 	void __iomem *reg;
25 	u8 busy;
26 };
27 
28 static inline struct clk_div *to_clk_div(struct clk_hw *hw)
29 {
30 	struct clk_divider *divider = to_clk_divider(hw);
31 
32 	return container_of(divider, struct clk_div, divider);
33 }
34 
35 static unsigned long clk_div_recalc_rate(struct clk_hw *hw,
36 					 unsigned long parent_rate)
37 {
38 	struct clk_div *div = to_clk_div(hw);
39 
40 	return div->ops->recalc_rate(&div->divider.hw, parent_rate);
41 }
42 
43 static long clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
44 			       unsigned long *prate)
45 {
46 	struct clk_div *div = to_clk_div(hw);
47 
48 	return div->ops->round_rate(&div->divider.hw, rate, prate);
49 }
50 
51 static int clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
52 			    unsigned long parent_rate)
53 {
54 	struct clk_div *div = to_clk_div(hw);
55 	int ret;
56 
57 	ret = div->ops->set_rate(&div->divider.hw, rate, parent_rate);
58 	if (!ret)
59 		ret = mxs_clk_wait(div->reg, div->busy);
60 
61 	return ret;
62 }
63 
64 static const struct clk_ops clk_div_ops = {
65 	.recalc_rate = clk_div_recalc_rate,
66 	.round_rate = clk_div_round_rate,
67 	.set_rate = clk_div_set_rate,
68 };
69 
70 struct clk *mxs_clk_div(const char *name, const char *parent_name,
71 			void __iomem *reg, u8 shift, u8 width, u8 busy)
72 {
73 	struct clk_div *div;
74 	struct clk *clk;
75 	struct clk_init_data init;
76 
77 	div = kzalloc(sizeof(*div), GFP_KERNEL);
78 	if (!div)
79 		return ERR_PTR(-ENOMEM);
80 
81 	init.name = name;
82 	init.ops = &clk_div_ops;
83 	init.flags = CLK_SET_RATE_PARENT;
84 	init.parent_names = (parent_name ? &parent_name: NULL);
85 	init.num_parents = (parent_name ? 1 : 0);
86 
87 	div->reg = reg;
88 	div->busy = busy;
89 
90 	div->divider.reg = reg;
91 	div->divider.shift = shift;
92 	div->divider.width = width;
93 	div->divider.flags = CLK_DIVIDER_ONE_BASED;
94 	div->divider.lock = &mxs_lock;
95 	div->divider.hw.init = &init;
96 	div->ops = &clk_divider_ops;
97 
98 	clk = clk_register(NULL, &div->divider.hw);
99 	if (IS_ERR(clk))
100 		kfree(div);
101 
102 	return clk;
103 }
104