1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2014 Lucas Stach <l.stach@pengutronix.de>, Pengutronix |
4 | */ |
5 | |
6 | #include <linux/clk.h> |
7 | #include <linux/clk-provider.h> |
8 | #include <linux/export.h> |
9 | #include <linux/slab.h> |
10 | #include "clk.h" |
11 | |
12 | struct clk_cpu { |
13 | struct clk_hw hw; |
14 | struct clk *div; |
15 | struct clk *mux; |
16 | struct clk *pll; |
17 | struct clk *step; |
18 | }; |
19 | |
20 | static inline struct clk_cpu *to_clk_cpu(struct clk_hw *hw) |
21 | { |
22 | return container_of(hw, struct clk_cpu, hw); |
23 | } |
24 | |
25 | static unsigned long clk_cpu_recalc_rate(struct clk_hw *hw, |
26 | unsigned long parent_rate) |
27 | { |
28 | struct clk_cpu *cpu = to_clk_cpu(hw); |
29 | |
30 | return clk_get_rate(clk: cpu->div); |
31 | } |
32 | |
33 | static long clk_cpu_round_rate(struct clk_hw *hw, unsigned long rate, |
34 | unsigned long *prate) |
35 | { |
36 | struct clk_cpu *cpu = to_clk_cpu(hw); |
37 | |
38 | return clk_round_rate(clk: cpu->pll, rate); |
39 | } |
40 | |
41 | static int clk_cpu_set_rate(struct clk_hw *hw, unsigned long rate, |
42 | unsigned long parent_rate) |
43 | { |
44 | struct clk_cpu *cpu = to_clk_cpu(hw); |
45 | int ret; |
46 | |
47 | /* switch to PLL bypass clock */ |
48 | ret = clk_set_parent(clk: cpu->mux, parent: cpu->step); |
49 | if (ret) |
50 | return ret; |
51 | |
52 | /* reprogram PLL */ |
53 | ret = clk_set_rate(clk: cpu->pll, rate); |
54 | if (ret) { |
55 | clk_set_parent(clk: cpu->mux, parent: cpu->pll); |
56 | return ret; |
57 | } |
58 | /* switch back to PLL clock */ |
59 | clk_set_parent(clk: cpu->mux, parent: cpu->pll); |
60 | |
61 | /* Ensure the divider is what we expect */ |
62 | clk_set_rate(clk: cpu->div, rate); |
63 | |
64 | return 0; |
65 | } |
66 | |
67 | static const struct clk_ops clk_cpu_ops = { |
68 | .recalc_rate = clk_cpu_recalc_rate, |
69 | .round_rate = clk_cpu_round_rate, |
70 | .set_rate = clk_cpu_set_rate, |
71 | }; |
72 | |
73 | struct clk_hw *imx_clk_hw_cpu(const char *name, const char *parent_name, |
74 | struct clk *div, struct clk *mux, struct clk *pll, |
75 | struct clk *step) |
76 | { |
77 | struct clk_cpu *cpu; |
78 | struct clk_hw *hw; |
79 | struct clk_init_data init; |
80 | int ret; |
81 | |
82 | cpu = kzalloc(size: sizeof(*cpu), GFP_KERNEL); |
83 | if (!cpu) |
84 | return ERR_PTR(error: -ENOMEM); |
85 | |
86 | cpu->div = div; |
87 | cpu->mux = mux; |
88 | cpu->pll = pll; |
89 | cpu->step = step; |
90 | |
91 | init.name = name; |
92 | init.ops = &clk_cpu_ops; |
93 | init.flags = CLK_IS_CRITICAL; |
94 | init.parent_names = &parent_name; |
95 | init.num_parents = 1; |
96 | |
97 | cpu->hw.init = &init; |
98 | hw = &cpu->hw; |
99 | |
100 | ret = clk_hw_register(NULL, hw); |
101 | if (ret) { |
102 | kfree(objp: cpu); |
103 | return ERR_PTR(error: ret); |
104 | } |
105 | |
106 | return hw; |
107 | } |
108 | EXPORT_SYMBOL_GPL(imx_clk_hw_cpu); |
109 | |