summaryrefslogtreecommitdiffstats
path: root/drivers/clk/shmobile/clk-r8a73a4.c
blob: 29b9a0b0012ad3260d882be6d5dbb40f3fabaf0d (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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*
 * r8a73a4 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/clkdev.h>
#include <linux/clk/shmobile.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/spinlock.h>

struct r8a73a4_cpg {
	struct clk_onecell_data data;
	spinlock_t lock;
	void __iomem *reg;
};

#define CPG_CKSCR	0xc0
#define CPG_FRQCRA	0x00
#define CPG_FRQCRB	0x04
#define CPG_FRQCRC	0xe0
#define CPG_PLL0CR	0xd8
#define CPG_PLL1CR	0x28
#define CPG_PLL2CR	0x2c
#define CPG_PLL2HCR	0xe4
#define CPG_PLL2SCR	0xf4

#define CLK_ENABLE_ON_INIT BIT(0)

struct div4_clk {
	const char *name;
	unsigned int reg;
	unsigned int shift;
};

static struct div4_clk div4_clks[] = {
	{ "i",	CPG_FRQCRA, 20 },
	{ "m3", CPG_FRQCRA, 12 },
	{ "b",	CPG_FRQCRA,  8 },
	{ "m1", CPG_FRQCRA,  4 },
	{ "m2", CPG_FRQCRA,  0 },
	{ "zx", CPG_FRQCRB, 12 },
	{ "zs", CPG_FRQCRB,  8 },
	{ "hp", CPG_FRQCRB,  4 },
	{ NULL, 0, 0 },
};

static const struct clk_div_table div4_div_table[] = {
	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
	{ 12, 10 }, { 0, 0 }
};

static struct clk * __init
r8a73a4_cpg_register_clock(struct device_node *np, struct r8a73a4_cpg *cpg,
			     const char *name)
{
	const struct clk_div_table *table = NULL;
	const char *parent_name;
	unsigned int shift, reg;
	unsigned int mult = 1;
	unsigned int div = 1;


	if (!strcmp(name, "main")) {
		u32 ckscr = clk_readl(cpg->reg + CPG_CKSCR);

		switch ((ckscr >> 28) & 3) {
		case 0:	/* extal1 */
			parent_name = of_clk_get_parent_name(np, 0);
			break;
		case 1:	/* extal1 / 2 */
			parent_name = of_clk_get_parent_name(np, 0);
			div = 2;
			break;
		case 2: /* extal2 */
			parent_name = of_clk_get_parent_name(np, 1);
			break;
		case 3: /* extal2 / 2 */
			parent_name = of_clk_get_parent_name(np, 1);
			div = 2;
			break;
		}
	} else if (!strcmp(name, "pll0")) {
		/* PLL0/1 are configurable multiplier clocks. Register them as
		 * fixed factor clocks for now as there's no generic multiplier
		 * clock implementation and we currently have no need to change
		 * the multiplier value.
		 */
		u32 value = clk_readl(cpg->reg + CPG_PLL0CR);

		parent_name = "main";
		mult = ((value >> 24) & 0x7f) + 1;
		if (value & BIT(20))
			div = 2;
	} else if (!strcmp(name, "pll1")) {
		u32 value = clk_readl(cpg->reg + CPG_PLL1CR);

		parent_name = "main";
		/* XXX: enable bit? */
		mult = ((value >> 24) & 0x7f) + 1;
		if (value & BIT(7))
			div = 2;
	} else if (!strncmp(name, "pll2", 4)) {
		u32 value, cr;

		switch (name[4]) {
		case 0:
			cr = CPG_PLL2CR;
			break;
		case 's':
			cr = CPG_PLL2SCR;
			break;
		case 'h':
			cr = CPG_PLL2HCR;
			break;
		default:
			return ERR_PTR(-EINVAL);
		}
		value = clk_readl(cpg->reg + cr);
		switch ((value >> 5) & 7) {
		case 0:
			parent_name = "main";
			div = 2;
			break;
		case 1:
			parent_name = "extal2";
			div = 2;
			break;
		case 3:
			parent_name = "extal2";
			div = 4;
			break;
		case 4:
			parent_name = "main";
			break;
		case 5:
			parent_name = "extal2";
			break;
		default:
			pr_warn("%s: unexpected parent of %s\n", __func__,
				name);
			return ERR_PTR(-EINVAL);
		}
		/* XXX: enable bit? */
		mult = ((value >> 24) & 0x7f) + 1;
	} else if (!strcmp(name, "z") || !strcmp(name, "z2")) {
		u32 shift = 8;

		parent_name = "pll0";
		if (name[1] == '2') {
			div = 2;
			shift = 0;
		}
		div *= 32;
		mult = 0x20 - ((clk_readl(cpg->reg + CPG_FRQCRC) >> shift)
		       & 0x1f);
	} else {
		struct div4_clk *c;

		for (c = div4_clks; c->name; c++) {
			if (!strcmp(name, c->name))
				break;
		}
		if (!c->name)
			return ERR_PTR(-EINVAL);

		parent_name = "pll1";
		table = div4_div_table;
		reg = c->reg;
		shift = c->shift;
	}

	if (!table) {
		return clk_register_fixed_factor(NULL, name, parent_name, 0,
						 mult, div);
	} else {
		return clk_register_divider_table(NULL, name, parent_name, 0,
						  cpg->reg + reg, shift, 4, 0,
						  table, &cpg->lock);
	}
}

static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
{
	struct r8a73a4_cpg *cpg;
	struct clk **clks;
	unsigned int i;
	int num_clks;

	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 = r8a73a4_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);
}
CLK_OF_DECLARE(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
	       r8a73a4_cpg_clocks_init);