1/*
2 * Copyright (c) 2014 Lucas Stach <l.stach@pengutronix.de>, Pengutronix
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * http://www.opensource.org/licenses/gpl-license.html
9 * http://www.gnu.org/copyleft/gpl.html
10 */
11
12#include <linux/clk.h>
13#include <linux/clk-provider.h>
14#include <linux/slab.h>
15
16struct clk_cpu {
17	struct clk_hw	hw;
18	struct clk	*div;
19	struct clk	*mux;
20	struct clk	*pll;
21	struct clk	*step;
22};
23
24static inline struct clk_cpu *to_clk_cpu(struct clk_hw *hw)
25{
26	return container_of(hw, struct clk_cpu, hw);
27}
28
29static unsigned long clk_cpu_recalc_rate(struct clk_hw *hw,
30					 unsigned long parent_rate)
31{
32	struct clk_cpu *cpu = to_clk_cpu(hw);
33
34	return clk_get_rate(cpu->div);
35}
36
37static long clk_cpu_round_rate(struct clk_hw *hw, unsigned long rate,
38			       unsigned long *prate)
39{
40	struct clk_cpu *cpu = to_clk_cpu(hw);
41
42	return clk_round_rate(cpu->pll, rate);
43}
44
45static int clk_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
46			    unsigned long parent_rate)
47{
48	struct clk_cpu *cpu = to_clk_cpu(hw);
49	int ret;
50
51	/* switch to PLL bypass clock */
52	ret = clk_set_parent(cpu->mux, cpu->step);
53	if (ret)
54		return ret;
55
56	/* reprogram PLL */
57	ret = clk_set_rate(cpu->pll, rate);
58	if (ret) {
59		clk_set_parent(cpu->mux, cpu->pll);
60		return ret;
61	}
62	/* switch back to PLL clock */
63	clk_set_parent(cpu->mux, cpu->pll);
64
65	/* Ensure the divider is what we expect */
66	clk_set_rate(cpu->div, rate);
67
68	return 0;
69}
70
71static const struct clk_ops clk_cpu_ops = {
72	.recalc_rate	= clk_cpu_recalc_rate,
73	.round_rate	= clk_cpu_round_rate,
74	.set_rate	= clk_cpu_set_rate,
75};
76
77struct clk *imx_clk_cpu(const char *name, const char *parent_name,
78		struct clk *div, struct clk *mux, struct clk *pll,
79		struct clk *step)
80{
81	struct clk_cpu *cpu;
82	struct clk *clk;
83	struct clk_init_data init;
84
85	cpu = kzalloc(sizeof(*cpu), GFP_KERNEL);
86	if (!cpu)
87		return ERR_PTR(-ENOMEM);
88
89	cpu->div = div;
90	cpu->mux = mux;
91	cpu->pll = pll;
92	cpu->step = step;
93
94	init.name = name;
95	init.ops = &clk_cpu_ops;
96	init.flags = 0;
97	init.parent_names = &parent_name;
98	init.num_parents = 1;
99
100	cpu->hw.init = &init;
101
102	clk = clk_register(NULL, &cpu->hw);
103	if (IS_ERR(clk))
104		kfree(cpu);
105
106	return clk;
107}
108