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
33struct 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)
41static 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
52static 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
63static 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, index: 0);
74 if (!io)
75 return;
76 val = readl(addr: io);
77 iounmap(addr: io);
78
79 get_clkinfo(val, &info);
80
81 of_property_read_string(np: node, propname: "clock-output-names", out_string: &clk_name);
82 parent_name = of_clk_get_parent_name(np: node, index: 0);
83
84 hw = clk_hw_register_fixed_factor(NULL, name: clk_name, parent_name, flags: 0,
85 mult: 1, div: info.base_ahb_ratio);
86 if (!IS_ERR(ptr: hw))
87 of_clk_add_hw_provider(np: node, get: of_clk_hw_simple_get, data: hw);
88}
89
90static void __init nspire_ahbdiv_setup_cx(struct device_node *node)
91{
92 nspire_ahbdiv_setup(node, get_clkinfo: nspire_clkinfo_cx);
93}
94
95static void __init nspire_ahbdiv_setup_classic(struct device_node *node)
96{
97 nspire_ahbdiv_setup(node, get_clkinfo: nspire_clkinfo_classic);
98}
99
100CLK_OF_DECLARE(nspire_ahbdiv_cx, "lsi,nspire-cx-ahb-divider",
101 nspire_ahbdiv_setup_cx);
102CLK_OF_DECLARE(nspire_ahbdiv_classic, "lsi,nspire-classic-ahb-divider",
103 nspire_ahbdiv_setup_classic);
104
105static 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, index: 0);
115 if (!io)
116 return;
117 val = readl(addr: io);
118 iounmap(addr: io);
119
120 get_clkinfo(val, &info);
121
122 of_property_read_string(np: node, propname: "clock-output-names", out_string: &clk_name);
123
124 hw = clk_hw_register_fixed_rate(NULL, clk_name, NULL, 0,
125 info.base_clock);
126 if (!IS_ERR(ptr: hw))
127 of_clk_add_hw_provider(np: node, get: of_clk_hw_simple_get, data: 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
137static void __init nspire_clk_setup_cx(struct device_node *node)
138{
139 nspire_clk_setup(node, get_clkinfo: nspire_clkinfo_cx);
140}
141
142static void __init nspire_clk_setup_classic(struct device_node *node)
143{
144 nspire_clk_setup(node, get_clkinfo: nspire_clkinfo_classic);
145}
146
147CLK_OF_DECLARE(nspire_clk_cx, "lsi,nspire-cx-clock", nspire_clk_setup_cx);
148CLK_OF_DECLARE(nspire_clk_classic, "lsi,nspire-classic-clock",
149 nspire_clk_setup_classic);
150

source code of linux/drivers/clk/clk-nspire.c