1 /*
2  * r8a7779 Core CPG Clocks
3  *
4  * Copyright (C) 2013, 2014 Horms Solutions Ltd.
5  *
6  * Contact: Simon Horman <horms@verge.net.au>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  */
12 
13 #include <linux/clk-provider.h>
14 #include <linux/clk/renesas.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 
22 #include <dt-bindings/clock/r8a7779-clock.h>
23 
24 #define CPG_NUM_CLOCKS			(R8A7779_CLK_OUT + 1)
25 
26 struct r8a7779_cpg {
27 	struct clk_onecell_data data;
28 	spinlock_t lock;
29 	void __iomem *reg;
30 };
31 
32 /* -----------------------------------------------------------------------------
33  * CPG Clock Data
34  */
35 
36 /*
37  *		MD1 = 1			MD1 = 0
38  *		(PLLA = 1500)		(PLLA = 1600)
39  *		(MHz)			(MHz)
40  *------------------------------------------------+--------------------
41  * clkz		1000   (2/3)		800   (1/2)
42  * clkzs	 250   (1/6)		200   (1/8)
43  * clki		 750   (1/2)		800   (1/2)
44  * clks		 250   (1/6)		200   (1/8)
45  * clks1	 125   (1/12)		100   (1/16)
46  * clks3	 187.5 (1/8)		200   (1/8)
47  * clks4	  93.7 (1/16)		100   (1/16)
48  * clkp		  62.5 (1/24)		 50   (1/32)
49  * clkg		  62.5 (1/24)		 66.6 (1/24)
50  * clkb, CLKOUT
51  * (MD2 = 0)	  62.5 (1/24)		 66.6 (1/24)
52  * (MD2 = 1)	  41.6 (1/36)		 50   (1/32)
53  */
54 
55 #define CPG_CLK_CONFIG_INDEX(md)	(((md) & (BIT(2)|BIT(1))) >> 1)
56 
57 struct cpg_clk_config {
58 	unsigned int z_mult;
59 	unsigned int z_div;
60 	unsigned int zs_and_s_div;
61 	unsigned int s1_div;
62 	unsigned int p_div;
63 	unsigned int b_and_out_div;
64 };
65 
66 static const struct cpg_clk_config cpg_clk_configs[4] __initconst = {
67 	{ 1, 2, 8, 16, 32, 24 },
68 	{ 2, 3, 6, 12, 24, 24 },
69 	{ 1, 2, 8, 16, 32, 32 },
70 	{ 2, 3, 6, 12, 24, 36 },
71 };
72 
73 /*
74  *   MD		PLLA Ratio
75  * 12 11
76  *------------------------
77  * 0  0		x42
78  * 0  1		x48
79  * 1  0		x56
80  * 1  1		x64
81  */
82 
83 #define CPG_PLLA_MULT_INDEX(md)	(((md) & (BIT(12)|BIT(11))) >> 11)
84 
85 static const unsigned int cpg_plla_mult[4] __initconst = { 42, 48, 56, 64 };
86 
87 /* -----------------------------------------------------------------------------
88  * Initialization
89  */
90 
91 static u32 cpg_mode __initdata;
92 
93 static struct clk * __init
94 r8a7779_cpg_register_clock(struct device_node *np, struct r8a7779_cpg *cpg,
95 			   const struct cpg_clk_config *config,
96 			   unsigned int plla_mult, const char *name)
97 {
98 	const char *parent_name = "plla";
99 	unsigned int mult = 1;
100 	unsigned int div = 1;
101 
102 	if (!strcmp(name, "plla")) {
103 		parent_name = of_clk_get_parent_name(np, 0);
104 		mult = plla_mult;
105 	} else if (!strcmp(name, "z")) {
106 		div = config->z_div;
107 		mult = config->z_mult;
108 	} else if (!strcmp(name, "zs") || !strcmp(name, "s")) {
109 		div = config->zs_and_s_div;
110 	} else if (!strcmp(name, "s1")) {
111 		div = config->s1_div;
112 	} else if (!strcmp(name, "p")) {
113 		div = config->p_div;
114 	} else if (!strcmp(name, "b") || !strcmp(name, "out")) {
115 		div = config->b_and_out_div;
116 	} else {
117 		return ERR_PTR(-EINVAL);
118 	}
119 
120 	return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, div);
121 }
122 
123 static void __init r8a7779_cpg_clocks_init(struct device_node *np)
124 {
125 	const struct cpg_clk_config *config;
126 	struct r8a7779_cpg *cpg;
127 	struct clk **clks;
128 	unsigned int i, plla_mult;
129 	int num_clks;
130 
131 	num_clks = of_property_count_strings(np, "clock-output-names");
132 	if (num_clks < 0) {
133 		pr_err("%s: failed to count clocks\n", __func__);
134 		return;
135 	}
136 
137 	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
138 	clks = kzalloc(CPG_NUM_CLOCKS * sizeof(*clks), GFP_KERNEL);
139 	if (cpg == NULL || clks == NULL) {
140 		/* We're leaking memory on purpose, there's no point in cleaning
141 		 * up as the system won't boot anyway.
142 		 */
143 		return;
144 	}
145 
146 	spin_lock_init(&cpg->lock);
147 
148 	cpg->data.clks = clks;
149 	cpg->data.clk_num = num_clks;
150 
151 	config = &cpg_clk_configs[CPG_CLK_CONFIG_INDEX(cpg_mode)];
152 	plla_mult = cpg_plla_mult[CPG_PLLA_MULT_INDEX(cpg_mode)];
153 
154 	for (i = 0; i < num_clks; ++i) {
155 		const char *name;
156 		struct clk *clk;
157 
158 		of_property_read_string_index(np, "clock-output-names", i,
159 					      &name);
160 
161 		clk = r8a7779_cpg_register_clock(np, cpg, config,
162 						 plla_mult, name);
163 		if (IS_ERR(clk))
164 			pr_err("%s: failed to register %s %s clock (%ld)\n",
165 			       __func__, np->name, name, PTR_ERR(clk));
166 		else
167 			cpg->data.clks[i] = clk;
168 	}
169 
170 	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
171 
172 	cpg_mstp_add_clk_domain(np);
173 }
174 CLK_OF_DECLARE(r8a7779_cpg_clks, "renesas,r8a7779-cpg-clocks",
175 	       r8a7779_cpg_clocks_init);
176 
177 void __init r8a7779_clocks_init(u32 mode)
178 {
179 	cpg_mode = mode;
180 
181 	of_clk_init(NULL);
182 }
183