1// SPDX-License-Identifier: GPL-2.0
2/*
3 * r8a7740 Core CPG Clocks
4 *
5 * Copyright (C) 2014  Ulrich Hecht
6 */
7
8#include <linux/clk-provider.h>
9#include <linux/clk/renesas.h>
10#include <linux/init.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/of.h>
15#include <linux/of_address.h>
16#include <linux/spinlock.h>
17
18struct r8a7740_cpg {
19	struct clk_onecell_data data;
20	spinlock_t lock;
21	void __iomem *reg;
22};
23
24#define CPG_FRQCRA	0x00
25#define CPG_FRQCRB	0x04
26#define CPG_PLLC2CR	0x2c
27#define CPG_USBCKCR	0x8c
28#define CPG_FRQCRC	0xe0
29
30#define CLK_ENABLE_ON_INIT BIT(0)
31
32struct div4_clk {
33	const char *name;
34	unsigned int reg;
35	unsigned int shift;
36	int flags;
37};
38
39static struct div4_clk div4_clks[] = {
40	{ "i", CPG_FRQCRA, 20, CLK_ENABLE_ON_INIT },
41	{ "zg", CPG_FRQCRA, 16, CLK_ENABLE_ON_INIT },
42	{ "b", CPG_FRQCRA,  8, CLK_ENABLE_ON_INIT },
43	{ "m1", CPG_FRQCRA,  4, CLK_ENABLE_ON_INIT },
44	{ "hp", CPG_FRQCRB,  4, 0 },
45	{ "hpp", CPG_FRQCRC, 20, 0 },
46	{ "usbp", CPG_FRQCRC, 16, 0 },
47	{ "s", CPG_FRQCRC, 12, 0 },
48	{ "zb", CPG_FRQCRC,  8, 0 },
49	{ "m3", CPG_FRQCRC,  4, 0 },
50	{ "cp", CPG_FRQCRC,  0, 0 },
51	{ NULL, 0, 0, 0 },
52};
53
54static const struct clk_div_table div4_div_table[] = {
55	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
56	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 9, 32 }, { 10, 36 }, { 11, 48 },
57	{ 13, 72 }, { 14, 96 }, { 0, 0 }
58};
59
60static u32 cpg_mode __initdata;
61
62static struct clk * __init
63r8a7740_cpg_register_clock(struct device_node *np, struct r8a7740_cpg *cpg,
64			     const char *name)
65{
66	const struct clk_div_table *table = NULL;
67	const char *parent_name;
68	unsigned int shift, reg;
69	unsigned int mult = 1;
70	unsigned int div = 1;
71
72	if (!strcmp(name, "r")) {
73		switch (cpg_mode & (BIT(2) | BIT(1))) {
74		case BIT(1) | BIT(2):
75			/* extal1 */
76			parent_name = of_clk_get_parent_name(np, 0);
77			div = 2048;
78			break;
79		case BIT(2):
80			/* extal1 */
81			parent_name = of_clk_get_parent_name(np, 0);
82			div = 1024;
83			break;
84		default:
85			/* extalr */
86			parent_name = of_clk_get_parent_name(np, 2);
87			break;
88		}
89	} else if (!strcmp(name, "system")) {
90		parent_name = of_clk_get_parent_name(np, 0);
91		if (cpg_mode & BIT(1))
92			div = 2;
93	} else if (!strcmp(name, "pllc0")) {
94		/* PLLC0/1 are configurable multiplier clocks. Register them as
95		 * fixed factor clocks for now as there's no generic multiplier
96		 * clock implementation and we currently have no need to change
97		 * the multiplier value.
98		 */
99		u32 value = readl(cpg->reg + CPG_FRQCRC);
100		parent_name = "system";
101		mult = ((value >> 24) & 0x7f) + 1;
102	} else if (!strcmp(name, "pllc1")) {
103		u32 value = readl(cpg->reg + CPG_FRQCRA);
104		parent_name = "system";
105		mult = ((value >> 24) & 0x7f) + 1;
106		div = 2;
107	} else if (!strcmp(name, "pllc2")) {
108		u32 value = readl(cpg->reg + CPG_PLLC2CR);
109		parent_name = "system";
110		mult = ((value >> 24) & 0x3f) + 1;
111	} else if (!strcmp(name, "usb24s")) {
112		u32 value = readl(cpg->reg + CPG_USBCKCR);
113		if (value & BIT(7))
114			/* extal2 */
115			parent_name = of_clk_get_parent_name(np, 1);
116		else
117			parent_name = "system";
118		if (!(value & BIT(6)))
119			div = 2;
120	} else {
121		struct div4_clk *c;
122		for (c = div4_clks; c->name; c++) {
123			if (!strcmp(name, c->name)) {
124				parent_name = "pllc1";
125				table = div4_div_table;
126				reg = c->reg;
127				shift = c->shift;
128				break;
129			}
130		}
131		if (!c->name)
132			return ERR_PTR(-EINVAL);
133	}
134
135	if (!table) {
136		return clk_register_fixed_factor(NULL, name, parent_name, 0,
137						 mult, div);
138	} else {
139		return clk_register_divider_table(NULL, name, parent_name, 0,
140						  cpg->reg + reg, shift, 4, 0,
141						  table, &cpg->lock);
142	}
143}
144
145static void __init r8a7740_cpg_clocks_init(struct device_node *np)
146{
147	struct r8a7740_cpg *cpg;
148	struct clk **clks;
149	unsigned int i;
150	int num_clks;
151
152	if (of_property_read_u32(np, "renesas,mode", &cpg_mode))
153		pr_warn("%s: missing renesas,mode property\n", __func__);
154
155	num_clks = of_property_count_strings(np, "clock-output-names");
156	if (num_clks < 0) {
157		pr_err("%s: failed to count clocks\n", __func__);
158		return;
159	}
160
161	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
162	clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
163	if (cpg == NULL || clks == NULL) {
164		/* We're leaking memory on purpose, there's no point in cleaning
165		 * up as the system won't boot anyway.
166		 */
167		return;
168	}
169
170	spin_lock_init(&cpg->lock);
171
172	cpg->data.clks = clks;
173	cpg->data.clk_num = num_clks;
174
175	cpg->reg = of_iomap(np, 0);
176	if (WARN_ON(cpg->reg == NULL))
177		return;
178
179	for (i = 0; i < num_clks; ++i) {
180		const char *name;
181		struct clk *clk;
182
183		of_property_read_string_index(np, "clock-output-names", i,
184					      &name);
185
186		clk = r8a7740_cpg_register_clock(np, cpg, name);
187		if (IS_ERR(clk))
188			pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
189			       __func__, np, name, PTR_ERR(clk));
190		else
191			cpg->data.clks[i] = clk;
192	}
193
194	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
195}
196CLK_OF_DECLARE(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
197	       r8a7740_cpg_clocks_init);
198