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
18 struct r8a7740_cpg {
19 struct clk_onecell_data data;
20 spinlock_t lock;
21 };
22
23 #define CPG_FRQCRA 0x00
24 #define CPG_FRQCRB 0x04
25 #define CPG_PLLC2CR 0x2c
26 #define CPG_USBCKCR 0x8c
27 #define CPG_FRQCRC 0xe0
28
29 #define CLK_ENABLE_ON_INIT BIT(0)
30
31 struct div4_clk {
32 const char *name;
33 unsigned int reg;
34 unsigned int shift;
35 int flags;
36 };
37
38 static struct div4_clk div4_clks[] = {
39 { "i", CPG_FRQCRA, 20, CLK_ENABLE_ON_INIT },
40 { "zg", CPG_FRQCRA, 16, CLK_ENABLE_ON_INIT },
41 { "b", CPG_FRQCRA, 8, CLK_ENABLE_ON_INIT },
42 { "m1", CPG_FRQCRA, 4, CLK_ENABLE_ON_INIT },
43 { "hp", CPG_FRQCRB, 4, 0 },
44 { "hpp", CPG_FRQCRC, 20, 0 },
45 { "usbp", CPG_FRQCRC, 16, 0 },
46 { "s", CPG_FRQCRC, 12, 0 },
47 { "zb", CPG_FRQCRC, 8, 0 },
48 { "m3", CPG_FRQCRC, 4, 0 },
49 { "cp", CPG_FRQCRC, 0, 0 },
50 { NULL, 0, 0, 0 },
51 };
52
53 static const struct clk_div_table div4_div_table[] = {
54 { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
55 { 6, 16 }, { 7, 18 }, { 8, 24 }, { 9, 32 }, { 10, 36 }, { 11, 48 },
56 { 13, 72 }, { 14, 96 }, { 0, 0 }
57 };
58
59 static u32 cpg_mode __initdata;
60
61 static struct clk * __init
r8a7740_cpg_register_clock(struct device_node * np,struct r8a7740_cpg * cpg,void __iomem * base,const char * name)62 r8a7740_cpg_register_clock(struct device_node *np, struct r8a7740_cpg *cpg,
63 void __iomem *base, const char *name)
64 {
65 const struct clk_div_table *table = NULL;
66 const char *parent_name;
67 unsigned int shift, reg;
68 unsigned int mult = 1;
69 unsigned int div = 1;
70
71 if (!strcmp(name, "r")) {
72 switch (cpg_mode & (BIT(2) | BIT(1))) {
73 case BIT(1) | BIT(2):
74 /* extal1 */
75 parent_name = of_clk_get_parent_name(np, 0);
76 div = 2048;
77 break;
78 case BIT(2):
79 /* extal1 */
80 parent_name = of_clk_get_parent_name(np, 0);
81 div = 1024;
82 break;
83 default:
84 /* extalr */
85 parent_name = of_clk_get_parent_name(np, 2);
86 break;
87 }
88 } else if (!strcmp(name, "system")) {
89 parent_name = of_clk_get_parent_name(np, 0);
90 if (cpg_mode & BIT(1))
91 div = 2;
92 } else if (!strcmp(name, "pllc0")) {
93 /* PLLC0/1 are configurable multiplier clocks. Register them as
94 * fixed factor clocks for now as there's no generic multiplier
95 * clock implementation and we currently have no need to change
96 * the multiplier value.
97 */
98 u32 value = readl(base + CPG_FRQCRC);
99 parent_name = "system";
100 mult = ((value >> 24) & 0x7f) + 1;
101 } else if (!strcmp(name, "pllc1")) {
102 u32 value = readl(base + CPG_FRQCRA);
103 parent_name = "system";
104 mult = ((value >> 24) & 0x7f) + 1;
105 div = 2;
106 } else if (!strcmp(name, "pllc2")) {
107 u32 value = readl(base + CPG_PLLC2CR);
108 parent_name = "system";
109 mult = ((value >> 24) & 0x3f) + 1;
110 } else if (!strcmp(name, "usb24s")) {
111 u32 value = readl(base + CPG_USBCKCR);
112 if (value & BIT(7))
113 /* extal2 */
114 parent_name = of_clk_get_parent_name(np, 1);
115 else
116 parent_name = "system";
117 if (!(value & BIT(6)))
118 div = 2;
119 } else {
120 struct div4_clk *c;
121 for (c = div4_clks; c->name; c++) {
122 if (!strcmp(name, c->name)) {
123 parent_name = "pllc1";
124 table = div4_div_table;
125 reg = c->reg;
126 shift = c->shift;
127 break;
128 }
129 }
130 if (!c->name)
131 return ERR_PTR(-EINVAL);
132 }
133
134 if (!table) {
135 return clk_register_fixed_factor(NULL, name, parent_name, 0,
136 mult, div);
137 } else {
138 return clk_register_divider_table(NULL, name, parent_name, 0,
139 base + reg, shift, 4, 0,
140 table, &cpg->lock);
141 }
142 }
143
r8a7740_cpg_clocks_init(struct device_node * np)144 static void __init r8a7740_cpg_clocks_init(struct device_node *np)
145 {
146 struct r8a7740_cpg *cpg;
147 void __iomem *base;
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 base = of_iomap(np, 0);
176 if (WARN_ON(base == 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, base, 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 }
196 CLK_OF_DECLARE(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
197 r8a7740_cpg_clocks_init);
198