1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/io.h>
8 
9 #include "clk.h"
10 
11 static inline struct tegra_clk_periph_fixed *
12 to_tegra_clk_periph_fixed(struct clk_hw *hw)
13 {
14 	return container_of(hw, struct tegra_clk_periph_fixed, hw);
15 }
16 
17 static int tegra_clk_periph_fixed_is_enabled(struct clk_hw *hw)
18 {
19 	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
20 	u32 mask = 1 << (fixed->num % 32), value;
21 
22 	value = readl(fixed->base + fixed->regs->enb_reg);
23 	if (value & mask) {
24 		value = readl(fixed->base + fixed->regs->rst_reg);
25 		if ((value & mask) == 0)
26 			return 1;
27 	}
28 
29 	return 0;
30 }
31 
32 static int tegra_clk_periph_fixed_enable(struct clk_hw *hw)
33 {
34 	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
35 	u32 mask = 1 << (fixed->num % 32);
36 
37 	writel(mask, fixed->base + fixed->regs->enb_set_reg);
38 
39 	return 0;
40 }
41 
42 static void tegra_clk_periph_fixed_disable(struct clk_hw *hw)
43 {
44 	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
45 	u32 mask = 1 << (fixed->num % 32);
46 
47 	writel(mask, fixed->base + fixed->regs->enb_clr_reg);
48 }
49 
50 static unsigned long
51 tegra_clk_periph_fixed_recalc_rate(struct clk_hw *hw,
52 				   unsigned long parent_rate)
53 {
54 	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
55 	unsigned long long rate;
56 
57 	rate = (unsigned long long)parent_rate * fixed->mul;
58 	do_div(rate, fixed->div);
59 
60 	return (unsigned long)rate;
61 }
62 
63 static const struct clk_ops tegra_clk_periph_fixed_ops = {
64 	.is_enabled = tegra_clk_periph_fixed_is_enabled,
65 	.enable = tegra_clk_periph_fixed_enable,
66 	.disable = tegra_clk_periph_fixed_disable,
67 	.recalc_rate = tegra_clk_periph_fixed_recalc_rate,
68 };
69 
70 struct clk *tegra_clk_register_periph_fixed(const char *name,
71 					    const char *parent,
72 					    unsigned long flags,
73 					    void __iomem *base,
74 					    unsigned int mul,
75 					    unsigned int div,
76 					    unsigned int num)
77 {
78 	const struct tegra_clk_periph_regs *regs;
79 	struct tegra_clk_periph_fixed *fixed;
80 	struct clk_init_data init;
81 	struct clk *clk;
82 
83 	regs = get_reg_bank(num);
84 	if (!regs)
85 		return ERR_PTR(-EINVAL);
86 
87 	fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
88 	if (!fixed)
89 		return ERR_PTR(-ENOMEM);
90 
91 	init.name = name;
92 	init.flags = flags;
93 	init.parent_names = parent ? &parent : NULL;
94 	init.num_parents = parent ? 1 : 0;
95 	init.ops = &tegra_clk_periph_fixed_ops;
96 
97 	fixed->base = base;
98 	fixed->regs = regs;
99 	fixed->mul = mul;
100 	fixed->div = div;
101 	fixed->num = num;
102 
103 	fixed->hw.init = &init;
104 
105 	clk = clk_register(NULL, &fixed->hw);
106 	if (IS_ERR(clk))
107 		kfree(fixed);
108 
109 	return clk;
110 }
111