summaryrefslogtreecommitdiffstats
path: root/drivers/clk/renesas/clk-r8a7778.c
blob: 886a8380e91247a199f2852177b9fda5cff8f0ad (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
140
141
142
143
144
145
/*
 * r8a7778 Core CPG Clocks
 *
 * Copyright (C) 2014  Ulrich Hecht
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 */

#include <linux/clk-provider.h>
#include <linux/clk/renesas.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/soc/renesas/rcar-rst.h>

struct r8a7778_cpg {
	struct clk_onecell_data data;
	spinlock_t lock;
	void __iomem *reg;
};

/* PLL multipliers per bits 11, 12, and 18 of MODEMR */
static const struct {
	unsigned long plla_mult;
	unsigned long pllb_mult;
} r8a7778_rates[] __initconst = {
	[0] = { 21, 21 },
	[1] = { 24, 24 },
	[2] = { 28, 28 },
	[3] = { 32, 32 },
	[5] = { 24, 21 },
	[6] = { 28, 21 },
	[7] = { 32, 24 },
};

/* Clock dividers per bits 1 and 2 of MODEMR */
static const struct {
	const char *name;
	unsigned int div[4];
} r8a7778_divs[6] __initconst = {
	{ "b",   { 12, 12, 16, 18 } },
	{ "out", { 12, 12, 16, 18 } },
	{ "p",   { 16, 12, 16, 12 } },
	{ "s",   { 4,  3,  4,  3  } },
	{ "s1",  { 8,  6,  8,  6  } },
};

static u32 cpg_mode_rates __initdata;
static u32 cpg_mode_divs __initdata;

static struct clk * __init
r8a7778_cpg_register_clock(struct device_node *np, struct r8a7778_cpg *cpg,
			     const char *name)
{
	if (!strcmp(name, "plla")) {
		return clk_register_fixed_factor(NULL, "plla",
			of_clk_get_parent_name(np, 0), 0,
			r8a7778_rates[cpg_mode_rates].plla_mult, 1);
	} else if (!strcmp(name, "pllb")) {
		return clk_register_fixed_factor(NULL, "pllb",
			of_clk_get_parent_name(np, 0), 0,
			r8a7778_rates[cpg_mode_rates].pllb_mult, 1);
	} else {
		unsigned int i;

		for (i = 0; i < ARRAY_SIZE(r8a7778_divs); i++) {
			if (!strcmp(name, r8a7778_divs[i].name)) {
				return clk_register_fixed_factor(NULL,
					r8a7778_divs[i].name,
					"plla", 0, 1,
					r8a7778_divs[i].div[cpg_mode_divs]);
			}
		}
	}

	return ERR_PTR(-EINVAL);
}


static void __init r8a7778_cpg_clocks_init(struct device_node *np)
{
	struct r8a7778_cpg *cpg;
	struct clk **clks;
	unsigned int i;
	int num_clks;
	u32 mode;

	if (rcar_rst_read_mode_pins(&mode))
		return;

	BUG_ON(!(mode & BIT(19)));

	cpg_mode_rates = (!!(mode & BIT(18)) << 2) |
			 (!!(mode & BIT(12)) << 1) |
			 (!!(mode & BIT(11)));
	cpg_mode_divs = (!!(mode & BIT(2)) << 1) |
			(!!(mode & BIT(1)));

	num_clks = of_property_count_strings(np, "clock-output-names");
	if (num_clks < 0) {
		pr_err("%s: failed to count clocks\n", __func__);
		return;
	}

	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
	clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
	if (cpg == NULL || clks == NULL) {
		/* We're leaking memory on purpose, there's no point in cleaning
		 * up as the system won't boot anyway.
		 */
		return;
	}

	spin_lock_init(&cpg->lock);

	cpg->data.clks = clks;
	cpg->data.clk_num = num_clks;

	cpg->reg = of_iomap(np, 0);
	if (WARN_ON(cpg->reg == NULL))
		return;

	for (i = 0; i < num_clks; ++i) {
		const char *name;
		struct clk *clk;

		of_property_read_string_index(np, "clock-output-names", i,
					      &name);

		clk = r8a7778_cpg_register_clock(np, cpg, name);
		if (IS_ERR(clk))
			pr_err("%s: failed to register %s %s clock (%ld)\n",
			       __func__, np->name, name, PTR_ERR(clk));
		else
			cpg->data.clks[i] = clk;
	}

	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);

	cpg_mstp_add_clk_domain(np);
}

CLK_OF_DECLARE(r8a7778_cpg_clks, "renesas,r8a7778-cpg-clocks",
	       r8a7778_cpg_clocks_init);
OpenPOWER on IntegriCloud