ramips: implement clock API for RT305X
[openwrt/svn-archive/archive.git] / target / linux / ramips / files / arch / mips / ralink / rt305x / clock.c
1 /*
2 * Ralink RT305X clock API
3 *
4 * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/err.h>
15 #include <linux/clk.h>
16
17 #include <asm/mach-ralink/common.h>
18 #include <asm/mach-ralink/rt305x.h>
19 #include <asm/mach-ralink/rt305x_regs.h>
20 #include "common.h"
21
22 struct clk {
23 unsigned long rate;
24 };
25
26 static struct clk rt305x_cpu_clk;
27 static struct clk rt305x_sys_clk;
28 static struct clk rt305x_wdt_clk;
29 static struct clk rt305x_uart_clk;
30
31 void __init rt305x_clocks_init(void)
32 {
33 u32 t;
34
35 t = rt305x_sysc_rr(SYSC_REG_SYSTEM_CONFIG);
36 t = ((t >> SYSTEM_CONFIG_CPUCLK_SHIFT) & SYSTEM_CONFIG_CPUCLK_MASK);
37
38 switch (t) {
39 case SYSTEM_CONFIG_CPUCLK_320:
40 rt305x_cpu_clk.rate = 320000000;
41 break;
42 case SYSTEM_CONFIG_CPUCLK_384:
43 rt305x_cpu_clk.rate = 384000000;
44 break;
45 }
46
47 rt305x_sys_clk.rate = rt305x_cpu_clk.rate / 3;
48 rt305x_uart_clk.rate = rt305x_sys_clk.rate;
49 rt305x_wdt_clk.rate = rt305x_sys_clk.rate;
50 }
51
52 /*
53 * Linux clock API
54 */
55 struct clk *clk_get(struct device *dev, const char *id)
56 {
57 if (!strcmp(id, "sys"))
58 return &rt305x_sys_clk;
59
60 if (!strcmp(id, "cpu"))
61 return &rt305x_cpu_clk;
62
63 if (!strcmp(id, "wdt"))
64 return &rt305x_wdt_clk;
65
66 if (!strcmp(id, "uart"))
67 return &rt305x_uart_clk;
68
69 return ERR_PTR(-ENOENT);
70 }
71 EXPORT_SYMBOL(clk_get);
72
73 int clk_enable(struct clk *clk)
74 {
75 return 0;
76 }
77 EXPORT_SYMBOL(clk_enable);
78
79 void clk_disable(struct clk *clk)
80 {
81 }
82 EXPORT_SYMBOL(clk_disable);
83
84 unsigned long clk_get_rate(struct clk *clk)
85 {
86 return clk->rate;
87 }
88 EXPORT_SYMBOL(clk_get_rate);
89
90 void clk_put(struct clk *clk)
91 {
92 }
93 EXPORT_SYMBOL(clk_put);