summaryrefslogtreecommitdiff
path: root/drivers/clk/mmp/clk-pll.c
blob: 7077be293871193c94b780f73949f065d0002754 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * MMP PLL clock rate calculation
 *
 * Copyright (C) 2020 Lubomir Rintel <lkundrak@v3.sk>
 */

#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>

#include "clk.h"

#define to_clk_mmp_pll(hw)	container_of(hw, struct mmp_clk_pll, hw)

struct mmp_clk_pll {
	struct clk_hw hw;
	unsigned long default_rate;
	void __iomem *enable_reg;
	u32 enable;
	void __iomem *reg;
	u8 shift;

	unsigned long input_rate;
	void __iomem *postdiv_reg;
	u8 postdiv_shift;
};

static int mmp_clk_pll_is_enabled(struct clk_hw *hw)
{
	struct mmp_clk_pll *pll = to_clk_mmp_pll(hw);
	u32 val;

	val = readl_relaxed(pll->enable_reg);
	if ((val & pll->enable) == pll->enable)
		return 1;

	/* Some PLLs, if not software controlled, output default clock. */
	if (pll->default_rate > 0)
		return 1;

	return 0;
}

static unsigned long mmp_clk_pll_recalc_rate(struct clk_hw *hw,
					unsigned long parent_rate)
{
	struct mmp_clk_pll *pll = to_clk_mmp_pll(hw);
	u32 fbdiv, refdiv, postdiv;
	u64 rate;
	u32 val;

	val = readl_relaxed(pll->enable_reg);
	if ((val & pll->enable) != pll->enable)
		return pll->default_rate;

	if (pll->reg) {
		val = readl_relaxed(pll->reg);
		fbdiv = (val >> pll->shift) & 0x1ff;
		refdiv = (val >> (pll->shift + 9)) & 0x1f;
	} else {
		fbdiv = 2;
		refdiv = 1;
	}

	if (pll->postdiv_reg) {
		/* MMP3 clock rate calculation */
		static const u8 postdivs[] = {2, 3, 4, 5, 6, 8, 10, 12, 16};

		val = readl_relaxed(pll->postdiv_reg);
		postdiv = (val >> pll->postdiv_shift) & 0x7;

		rate = pll->input_rate;
		rate *= 2 * fbdiv;
		do_div(rate, refdiv);
		do_div(rate, postdivs[postdiv]);
	} else {
		/* MMP2 clock rate calculation */
		if (refdiv == 3) {
			rate = 19200000;
		} else if (refdiv == 4) {
			rate = 26000000;
		} else {
			pr_err("bad refdiv: %d (0x%08x)\n", refdiv, val);
			return 0;
		}

		rate *= fbdiv + 2;
		do_div(rate, refdiv + 2);
	}

	return (unsigned long)rate;
}

static const struct clk_ops mmp_clk_pll_ops = {
	.is_enabled = mmp_clk_pll_is_enabled,
	.recalc_rate = mmp_clk_pll_recalc_rate,
};

struct clk *mmp_clk_register_pll(char *name,
			unsigned long default_rate,
			void __iomem *enable_reg, u32 enable,
			void __iomem *reg, u8 shift,
			unsigned long input_rate,
			void __iomem *postdiv_reg, u8 postdiv_shift)
{
	struct mmp_clk_pll *pll;
	struct clk *clk;
	struct clk_init_data init;

	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
	if (!pll)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &mmp_clk_pll_ops;
	init.flags = 0;
	init.parent_names = NULL;
	init.num_parents = 0;

	pll->default_rate = default_rate;
	pll->enable_reg = enable_reg;
	pll->enable = enable;
	pll->reg = reg;
	pll->shift = shift;

	pll->input_rate = input_rate;
	pll->postdiv_reg = postdiv_reg;
	pll->postdiv_shift = postdiv_shift;

	pll->hw.init = &init;

	clk = clk_register(NULL, &pll->hw);

	if (IS_ERR(clk))
		kfree(pll);

	return clk;
}