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
to_clk_cpu(struct clk_hw * hw)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
clk_cpu_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)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(cpu->div);
31 }
32
clk_cpu_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)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(cpu->pll, rate);
39 }
40
clk_cpu_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)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(cpu->mux, cpu->step);
49 if (ret)
50 return ret;
51
52 /* reprogram PLL */
53 ret = clk_set_rate(cpu->pll, rate);
54 if (ret) {
55 clk_set_parent(cpu->mux, cpu->pll);
56 return ret;
57 }
58 /* switch back to PLL clock */
59 clk_set_parent(cpu->mux, cpu->pll);
60
61 /* Ensure the divider is what we expect */
62 clk_set_rate(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
imx_clk_hw_cpu(const char * name,const char * parent_name,struct clk * div,struct clk * mux,struct clk * pll,struct clk * step)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(sizeof(*cpu), GFP_KERNEL);
83 if (!cpu)
84 return ERR_PTR(-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(cpu);
103 return ERR_PTR(ret);
104 }
105
106 return hw;
107 }
108 EXPORT_SYMBOL_GPL(imx_clk_hw_cpu);
109