1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
5 */
6
7 #include <linux/clk-provider.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12
13 #define MHZ (1000 * 1000)
14
15 #define BASE_CPU_SHIFT 1
16 #define BASE_CPU_MASK 0x7F
17
18 #define CPU_AHB_SHIFT 12
19 #define CPU_AHB_MASK 0x07
20
21 #define FIXED_BASE_SHIFT 8
22 #define FIXED_BASE_MASK 0x01
23
24 #define CLASSIC_BASE_SHIFT 16
25 #define CLASSIC_BASE_MASK 0x1F
26
27 #define CX_BASE_SHIFT 15
28 #define CX_BASE_MASK 0x3F
29
30 #define CX_UNKNOWN_SHIFT 21
31 #define CX_UNKNOWN_MASK 0x03
32
33 struct nspire_clk_info {
34 u32 base_clock;
35 u16 base_cpu_ratio;
36 u16 base_ahb_ratio;
37 };
38
39
40 #define EXTRACT(var, prop) (((var)>>prop##_SHIFT) & prop##_MASK)
nspire_clkinfo_cx(u32 val,struct nspire_clk_info * clk)41 static void nspire_clkinfo_cx(u32 val, struct nspire_clk_info *clk)
42 {
43 if (EXTRACT(val, FIXED_BASE))
44 clk->base_clock = 48 * MHZ;
45 else
46 clk->base_clock = 6 * EXTRACT(val, CX_BASE) * MHZ;
47
48 clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * EXTRACT(val, CX_UNKNOWN);
49 clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1);
50 }
51
nspire_clkinfo_classic(u32 val,struct nspire_clk_info * clk)52 static void nspire_clkinfo_classic(u32 val, struct nspire_clk_info *clk)
53 {
54 if (EXTRACT(val, FIXED_BASE))
55 clk->base_clock = 27 * MHZ;
56 else
57 clk->base_clock = (300 - 6 * EXTRACT(val, CLASSIC_BASE)) * MHZ;
58
59 clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * 2;
60 clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1);
61 }
62
nspire_ahbdiv_setup(struct device_node * node,void (* get_clkinfo)(u32,struct nspire_clk_info *))63 static void __init nspire_ahbdiv_setup(struct device_node *node,
64 void (*get_clkinfo)(u32, struct nspire_clk_info *))
65 {
66 u32 val;
67 void __iomem *io;
68 struct clk_hw *hw;
69 const char *clk_name = node->name;
70 const char *parent_name;
71 struct nspire_clk_info info;
72
73 io = of_iomap(node, 0);
74 if (!io)
75 return;
76 val = readl(io);
77 iounmap(io);
78
79 get_clkinfo(val, &info);
80
81 of_property_read_string(node, "clock-output-names", &clk_name);
82 parent_name = of_clk_get_parent_name(node, 0);
83
84 hw = clk_hw_register_fixed_factor(NULL, clk_name, parent_name, 0,
85 1, info.base_ahb_ratio);
86 if (!IS_ERR(hw))
87 of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
88 }
89
nspire_ahbdiv_setup_cx(struct device_node * node)90 static void __init nspire_ahbdiv_setup_cx(struct device_node *node)
91 {
92 nspire_ahbdiv_setup(node, nspire_clkinfo_cx);
93 }
94
nspire_ahbdiv_setup_classic(struct device_node * node)95 static void __init nspire_ahbdiv_setup_classic(struct device_node *node)
96 {
97 nspire_ahbdiv_setup(node, nspire_clkinfo_classic);
98 }
99
100 CLK_OF_DECLARE(nspire_ahbdiv_cx, "lsi,nspire-cx-ahb-divider",
101 nspire_ahbdiv_setup_cx);
102 CLK_OF_DECLARE(nspire_ahbdiv_classic, "lsi,nspire-classic-ahb-divider",
103 nspire_ahbdiv_setup_classic);
104
nspire_clk_setup(struct device_node * node,void (* get_clkinfo)(u32,struct nspire_clk_info *))105 static void __init nspire_clk_setup(struct device_node *node,
106 void (*get_clkinfo)(u32, struct nspire_clk_info *))
107 {
108 u32 val;
109 void __iomem *io;
110 struct clk_hw *hw;
111 const char *clk_name = node->name;
112 struct nspire_clk_info info;
113
114 io = of_iomap(node, 0);
115 if (!io)
116 return;
117 val = readl(io);
118 iounmap(io);
119
120 get_clkinfo(val, &info);
121
122 of_property_read_string(node, "clock-output-names", &clk_name);
123
124 hw = clk_hw_register_fixed_rate(NULL, clk_name, NULL, 0,
125 info.base_clock);
126 if (!IS_ERR(hw))
127 of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
128 else
129 return;
130
131 pr_info("TI-NSPIRE Base: %uMHz CPU: %uMHz AHB: %uMHz\n",
132 info.base_clock / MHZ,
133 info.base_clock / info.base_cpu_ratio / MHZ,
134 info.base_clock / info.base_ahb_ratio / MHZ);
135 }
136
nspire_clk_setup_cx(struct device_node * node)137 static void __init nspire_clk_setup_cx(struct device_node *node)
138 {
139 nspire_clk_setup(node, nspire_clkinfo_cx);
140 }
141
nspire_clk_setup_classic(struct device_node * node)142 static void __init nspire_clk_setup_classic(struct device_node *node)
143 {
144 nspire_clk_setup(node, nspire_clkinfo_classic);
145 }
146
147 CLK_OF_DECLARE(nspire_clk_cx, "lsi,nspire-cx-clock", nspire_clk_setup_cx);
148 CLK_OF_DECLARE(nspire_clk_classic, "lsi,nspire-classic-clock",
149 nspire_clk_setup_classic);
150