xref: /openbmc/linux/drivers/clk/mxs/clk-pll.c (revision fb574682)
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/delay.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/slab.h>
11 #include "clk.h"
12 
13 /**
14  * struct clk_pll - mxs pll clock
15  * @hw: clk_hw for the pll
16  * @base: base address of the pll
17  * @power: the shift of power bit
18  * @rate: the clock rate of the pll
19  *
20  * The mxs pll is a fixed rate clock with power and gate control,
21  * and the shift of gate bit is always 31.
22  */
23 struct clk_pll {
24 	struct clk_hw hw;
25 	void __iomem *base;
26 	u8 power;
27 	unsigned long rate;
28 };
29 
30 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
31 
32 static int clk_pll_prepare(struct clk_hw *hw)
33 {
34 	struct clk_pll *pll = to_clk_pll(hw);
35 
36 	writel_relaxed(1 << pll->power, pll->base + SET);
37 
38 	udelay(10);
39 
40 	return 0;
41 }
42 
43 static void clk_pll_unprepare(struct clk_hw *hw)
44 {
45 	struct clk_pll *pll = to_clk_pll(hw);
46 
47 	writel_relaxed(1 << pll->power, pll->base + CLR);
48 }
49 
50 static int clk_pll_enable(struct clk_hw *hw)
51 {
52 	struct clk_pll *pll = to_clk_pll(hw);
53 
54 	writel_relaxed(1 << 31, pll->base + CLR);
55 
56 	return 0;
57 }
58 
59 static void clk_pll_disable(struct clk_hw *hw)
60 {
61 	struct clk_pll *pll = to_clk_pll(hw);
62 
63 	writel_relaxed(1 << 31, pll->base + SET);
64 }
65 
66 static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
67 					 unsigned long parent_rate)
68 {
69 	struct clk_pll *pll = to_clk_pll(hw);
70 
71 	return pll->rate;
72 }
73 
74 static const struct clk_ops clk_pll_ops = {
75 	.prepare = clk_pll_prepare,
76 	.unprepare = clk_pll_unprepare,
77 	.enable = clk_pll_enable,
78 	.disable = clk_pll_disable,
79 	.recalc_rate = clk_pll_recalc_rate,
80 };
81 
82 struct clk *mxs_clk_pll(const char *name, const char *parent_name,
83 			void __iomem *base, u8 power, unsigned long rate)
84 {
85 	struct clk_pll *pll;
86 	struct clk *clk;
87 	struct clk_init_data init;
88 
89 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
90 	if (!pll)
91 		return ERR_PTR(-ENOMEM);
92 
93 	init.name = name;
94 	init.ops = &clk_pll_ops;
95 	init.flags = 0;
96 	init.parent_names = (parent_name ? &parent_name: NULL);
97 	init.num_parents = (parent_name ? 1 : 0);
98 
99 	pll->base = base;
100 	pll->rate = rate;
101 	pll->power = power;
102 	pll->hw.init = &init;
103 
104 	clk = clk_register(NULL, &pll->hw);
105 	if (IS_ERR(clk))
106 		kfree(pll);
107 
108 	return clk;
109 }
110