tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2012 ARM Limited
12 */
13
14#include <linux/clkdev.h>
15#include <linux/clk-provider.h>
16#include <linux/err.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/vexpress.h>
20
21#include <asm/hardware/sp810.h>
22
23static struct clk *vexpress_sp810_timerclken[4];
24static DEFINE_SPINLOCK(vexpress_sp810_lock);
25
26static void __init vexpress_sp810_init(void __iomem *base)
27{
28 int i;
29
30 if (WARN_ON(!base))
31 return;
32
33 for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++) {
34 char name[12];
35 const char *parents[] = {
36 "v2m:refclk32khz", /* REFCLK */
37 "v2m:refclk1mhz" /* TIMCLK */
38 };
39
40 snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
41
42 vexpress_sp810_timerclken[i] = clk_register_mux(NULL, name,
43 parents, 2, 0, base + SCCTRL,
44 SCCTRL_TIMERENnSEL_SHIFT(i), 1,
45 0, &vexpress_sp810_lock);
46
47 if (WARN_ON(IS_ERR(vexpress_sp810_timerclken[i])))
48 break;
49 }
50}
51
52
53static const char * const vexpress_clk_24mhz_periphs[] __initconst = {
54 "mb:uart0", "mb:uart1", "mb:uart2", "mb:uart3",
55 "mb:mmci", "mb:kmi0", "mb:kmi1"
56};
57
58void __init vexpress_clk_init(void __iomem *sp810_base)
59{
60 struct clk *clk;
61 int i;
62
63 clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
64 CLK_IS_ROOT, 0);
65 WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));
66
67 clk = clk_register_fixed_rate(NULL, "v2m:clk_24mhz", NULL,
68 CLK_IS_ROOT, 24000000);
69 for (i = 0; i < ARRAY_SIZE(vexpress_clk_24mhz_periphs); i++)
70 WARN_ON(clk_register_clkdev(clk, NULL,
71 vexpress_clk_24mhz_periphs[i]));
72
73 clk = clk_register_fixed_rate(NULL, "v2m:refclk32khz", NULL,
74 CLK_IS_ROOT, 32768);
75 WARN_ON(clk_register_clkdev(clk, NULL, "v2m:wdt"));
76
77 clk = clk_register_fixed_rate(NULL, "v2m:refclk1mhz", NULL,
78 CLK_IS_ROOT, 1000000);
79
80 vexpress_sp810_init(sp810_base);
81
82 for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
83 WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], clk));
84
85 WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
86 "v2m-timer0", "sp804"));
87 WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
88 "v2m-timer1", "sp804"));
89}
90
91#if defined(CONFIG_OF)
92
93struct clk *vexpress_sp810_of_get(struct of_phandle_args *clkspec, void *data)
94{
95 if (WARN_ON(clkspec->args_count != 1 || clkspec->args[0] >
96 ARRAY_SIZE(vexpress_sp810_timerclken)))
97 return NULL;
98
99 return vexpress_sp810_timerclken[clkspec->args[0]];
100}
101
102static const __initconst struct of_device_id vexpress_fixed_clk_match[] = {
103 { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
104 { .compatible = "arm,vexpress-osc", .data = vexpress_osc_of_setup, },
105 {}
106};
107
108void __init vexpress_clk_of_init(void)
109{
110 struct device_node *node;
111 struct clk *clk;
112 struct clk *refclk, *timclk;
113
114 of_clk_init(vexpress_fixed_clk_match);
115
116 node = of_find_compatible_node(NULL, NULL, "arm,sp810");
117 vexpress_sp810_init(of_iomap(node, 0));
118 of_clk_add_provider(node, vexpress_sp810_of_get, NULL);
119
120 /* Select "better" (faster) parent for SP804 timers */
121 refclk = of_clk_get_by_name(node, "refclk");
122 timclk = of_clk_get_by_name(node, "timclk");
123 if (!WARN_ON(IS_ERR(refclk) || IS_ERR(timclk))) {
124 int i = 0;
125
126 if (clk_get_rate(refclk) > clk_get_rate(timclk))
127 clk = refclk;
128 else
129 clk = timclk;
130
131 for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
132 WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i],
133 clk));
134 }
135
136 WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
137 "v2m-timer0", "sp804"));
138 WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
139 "v2m-timer1", "sp804"));
140}
141
142#endif