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