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
r8a7779_cpg_register_clock(struct device_node * np,struct r8a7779_cpg * cpg,const struct cpg_clk_config * config,unsigned int plla_mult,const char * name)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
r8a7779_cpg_clocks_init(struct device_node * np)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
r8a7779_clocks_init(u32 mode)177 void __init r8a7779_clocks_init(u32 mode)
178 {
179 cpg_mode = mode;
180
181 of_clk_init(NULL);
182 }
183