1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright 2012 Freescale Semiconductor, Inc. |
4 | * Copyright 2012 Linaro Ltd. |
5 | */ |
6 | |
7 | #include <linux/clk-provider.h> |
8 | #include <linux/export.h> |
9 | #include <linux/io.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/err.h> |
12 | #include "clk.h" |
13 | |
14 | /** |
15 | * struct clk_pfd - IMX PFD clock |
16 | * @hw: clock source |
17 | * @reg: PFD register address |
18 | * @idx: the index of PFD encoded in the register |
19 | * |
20 | * PFD clock found on i.MX6 series. Each register for PFD has 4 clk_pfd |
21 | * data encoded, and member idx is used to specify the one. And each |
22 | * register has SET, CLR and TOG registers at offset 0x4 0x8 and 0xc. |
23 | */ |
24 | struct clk_pfd { |
25 | struct clk_hw hw; |
26 | void __iomem *reg; |
27 | u8 idx; |
28 | }; |
29 | |
30 | #define to_clk_pfd(_hw) container_of(_hw, struct clk_pfd, hw) |
31 | |
32 | #define SET 0x4 |
33 | #define CLR 0x8 |
34 | #define OTG 0xc |
35 | |
36 | static int clk_pfd_enable(struct clk_hw *hw) |
37 | { |
38 | struct clk_pfd *pfd = to_clk_pfd(hw); |
39 | |
40 | writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + CLR); |
41 | |
42 | return 0; |
43 | } |
44 | |
45 | static void clk_pfd_disable(struct clk_hw *hw) |
46 | { |
47 | struct clk_pfd *pfd = to_clk_pfd(hw); |
48 | |
49 | writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + SET); |
50 | } |
51 | |
52 | static unsigned long clk_pfd_recalc_rate(struct clk_hw *hw, |
53 | unsigned long parent_rate) |
54 | { |
55 | struct clk_pfd *pfd = to_clk_pfd(hw); |
56 | u64 tmp = parent_rate; |
57 | u8 frac = (readl_relaxed(pfd->reg) >> (pfd->idx * 8)) & 0x3f; |
58 | |
59 | tmp *= 18; |
60 | do_div(tmp, frac); |
61 | |
62 | return tmp; |
63 | } |
64 | |
65 | static long clk_pfd_round_rate(struct clk_hw *hw, unsigned long rate, |
66 | unsigned long *prate) |
67 | { |
68 | u64 tmp = *prate; |
69 | u8 frac; |
70 | |
71 | tmp = tmp * 18 + rate / 2; |
72 | do_div(tmp, rate); |
73 | frac = tmp; |
74 | if (frac < 12) |
75 | frac = 12; |
76 | else if (frac > 35) |
77 | frac = 35; |
78 | tmp = *prate; |
79 | tmp *= 18; |
80 | do_div(tmp, frac); |
81 | |
82 | return tmp; |
83 | } |
84 | |
85 | static int clk_pfd_set_rate(struct clk_hw *hw, unsigned long rate, |
86 | unsigned long parent_rate) |
87 | { |
88 | struct clk_pfd *pfd = to_clk_pfd(hw); |
89 | u64 tmp = parent_rate; |
90 | u8 frac; |
91 | |
92 | tmp = tmp * 18 + rate / 2; |
93 | do_div(tmp, rate); |
94 | frac = tmp; |
95 | if (frac < 12) |
96 | frac = 12; |
97 | else if (frac > 35) |
98 | frac = 35; |
99 | |
100 | writel_relaxed(0x3f << (pfd->idx * 8), pfd->reg + CLR); |
101 | writel_relaxed(frac << (pfd->idx * 8), pfd->reg + SET); |
102 | |
103 | return 0; |
104 | } |
105 | |
106 | static int clk_pfd_is_enabled(struct clk_hw *hw) |
107 | { |
108 | struct clk_pfd *pfd = to_clk_pfd(hw); |
109 | |
110 | if (readl_relaxed(pfd->reg) & (1 << ((pfd->idx + 1) * 8 - 1))) |
111 | return 0; |
112 | |
113 | return 1; |
114 | } |
115 | |
116 | static const struct clk_ops clk_pfd_ops = { |
117 | .enable = clk_pfd_enable, |
118 | .disable = clk_pfd_disable, |
119 | .recalc_rate = clk_pfd_recalc_rate, |
120 | .round_rate = clk_pfd_round_rate, |
121 | .set_rate = clk_pfd_set_rate, |
122 | .is_enabled = clk_pfd_is_enabled, |
123 | }; |
124 | |
125 | struct clk_hw *imx_clk_hw_pfd(const char *name, const char *parent_name, |
126 | void __iomem *reg, u8 idx) |
127 | { |
128 | struct clk_pfd *pfd; |
129 | struct clk_hw *hw; |
130 | struct clk_init_data init; |
131 | int ret; |
132 | |
133 | pfd = kzalloc(size: sizeof(*pfd), GFP_KERNEL); |
134 | if (!pfd) |
135 | return ERR_PTR(error: -ENOMEM); |
136 | |
137 | pfd->reg = reg; |
138 | pfd->idx = idx; |
139 | |
140 | init.name = name; |
141 | init.ops = &clk_pfd_ops; |
142 | init.flags = 0; |
143 | init.parent_names = &parent_name; |
144 | init.num_parents = 1; |
145 | |
146 | pfd->hw.init = &init; |
147 | hw = &pfd->hw; |
148 | |
149 | ret = clk_hw_register(NULL, hw); |
150 | if (ret) { |
151 | kfree(objp: pfd); |
152 | return ERR_PTR(error: ret); |
153 | } |
154 | |
155 | return hw; |
156 | } |
157 | EXPORT_SYMBOL_GPL(imx_clk_hw_pfd); |
158 | |