blob: a378db7b23822a9cb6da0bd52fc3c47fa3206260 [file] [log] [blame]
Daniel Tang7d1818f2013-05-31 19:27:33 +10001/*
2 *
3 * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2, as
7 * published by the Free Software Foundation.
8 *
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/of.h>
15#include <linux/of_address.h>
16
17#define MHZ (1000 * 1000)
18
19#define BASE_CPU_SHIFT 1
20#define BASE_CPU_MASK 0x7F
21
22#define CPU_AHB_SHIFT 12
23#define CPU_AHB_MASK 0x07
24
25#define FIXED_BASE_SHIFT 8
26#define FIXED_BASE_MASK 0x01
27
28#define CLASSIC_BASE_SHIFT 16
29#define CLASSIC_BASE_MASK 0x1F
30
31#define CX_BASE_SHIFT 15
32#define CX_BASE_MASK 0x3F
33
34#define CX_UNKNOWN_SHIFT 21
35#define CX_UNKNOWN_MASK 0x03
36
37struct nspire_clk_info {
38 u32 base_clock;
39 u16 base_cpu_ratio;
40 u16 base_ahb_ratio;
41};
42
43
44#define EXTRACT(var, prop) (((var)>>prop##_SHIFT) & prop##_MASK)
45static void nspire_clkinfo_cx(u32 val, struct nspire_clk_info *clk)
46{
47 if (EXTRACT(val, FIXED_BASE))
48 clk->base_clock = 48 * MHZ;
49 else
50 clk->base_clock = 6 * EXTRACT(val, CX_BASE) * MHZ;
51
52 clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * EXTRACT(val, CX_UNKNOWN);
53 clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1);
54}
55
56static void nspire_clkinfo_classic(u32 val, struct nspire_clk_info *clk)
57{
58 if (EXTRACT(val, FIXED_BASE))
59 clk->base_clock = 27 * MHZ;
60 else
61 clk->base_clock = (300 - 6 * EXTRACT(val, CLASSIC_BASE)) * MHZ;
62
63 clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * 2;
64 clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1);
65}
66
67static void __init nspire_ahbdiv_setup(struct device_node *node,
68 void (*get_clkinfo)(u32, struct nspire_clk_info *))
69{
70 u32 val;
71 void __iomem *io;
72 struct clk *clk;
73 const char *clk_name = node->name;
74 const char *parent_name;
75 struct nspire_clk_info info;
76
77 io = of_iomap(node, 0);
78 if (!io)
79 return;
80 val = readl(io);
81 iounmap(io);
82
83 get_clkinfo(val, &info);
84
85 of_property_read_string(node, "clock-output-names", &clk_name);
86 parent_name = of_clk_get_parent_name(node, 0);
87
88 clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
89 1, info.base_ahb_ratio);
90 if (!IS_ERR(clk))
91 of_clk_add_provider(node, of_clk_src_simple_get, clk);
92}
93
94static void __init nspire_ahbdiv_setup_cx(struct device_node *node)
95{
96 nspire_ahbdiv_setup(node, nspire_clkinfo_cx);
97}
98
99static void __init nspire_ahbdiv_setup_classic(struct device_node *node)
100{
101 nspire_ahbdiv_setup(node, nspire_clkinfo_classic);
102}
103
104CLK_OF_DECLARE(nspire_ahbdiv_cx, "lsi,nspire-cx-ahb-divider",
105 nspire_ahbdiv_setup_cx);
106CLK_OF_DECLARE(nspire_ahbdiv_classic, "lsi,nspire-classic-ahb-divider",
107 nspire_ahbdiv_setup_classic);
108
109static void __init nspire_clk_setup(struct device_node *node,
110 void (*get_clkinfo)(u32, struct nspire_clk_info *))
111{
112 u32 val;
113 void __iomem *io;
114 struct clk *clk;
115 const char *clk_name = node->name;
116 struct nspire_clk_info info;
117
118 io = of_iomap(node, 0);
119 if (!io)
120 return;
121 val = readl(io);
122 iounmap(io);
123
124 get_clkinfo(val, &info);
125
126 of_property_read_string(node, "clock-output-names", &clk_name);
127
128 clk = clk_register_fixed_rate(NULL, clk_name, NULL, CLK_IS_ROOT,
129 info.base_clock);
130 if (!IS_ERR(clk))
131 of_clk_add_provider(node, of_clk_src_simple_get, clk);
132 else
133 return;
134
135 pr_info("TI-NSPIRE Base: %uMHz CPU: %uMHz AHB: %uMHz\n",
136 info.base_clock / MHZ,
137 info.base_clock / info.base_cpu_ratio / MHZ,
138 info.base_clock / info.base_ahb_ratio / MHZ);
139}
140
141static void __init nspire_clk_setup_cx(struct device_node *node)
142{
143 nspire_clk_setup(node, nspire_clkinfo_cx);
144}
145
146static void __init nspire_clk_setup_classic(struct device_node *node)
147{
148 nspire_clk_setup(node, nspire_clkinfo_classic);
149}
150
151CLK_OF_DECLARE(nspire_clk_cx, "lsi,nspire-cx-clock", nspire_clk_setup_cx);
152CLK_OF_DECLARE(nspire_clk_classic, "lsi,nspire-classic-clock",
153 nspire_clk_setup_classic);