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);