drivers/clk/versatile/clk-vexpress.c

   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/amba/sp810.h>
  15 #include <linux/clkdev.h>
  16 #include <linux/clk-provider.h>
  17 #include <linux/err.h>
  18 #include <linux/vexpress.h>
  19
  20 static struct clk *vexpress_sp810_timerclken[4];
  21 static DEFINE_SPINLOCK(vexpress_sp810_lock);
  22
  23 static void __init vexpress_sp810_init(void __iomem *base)
  24 {
  25         int i;
  26
  27         if (WARN_ON(!base))
  28                 return;
  29
  30         for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++) {
  31                 char name[12];
  32                 const char *parents[] = {
  33                         "v2m:refclk32khz", /* REFCLK */
  34                         "v2m:refclk1mhz" /* TIMCLK */
  35                 };
  36
  37                 snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
  38
  39                 vexpress_sp810_timerclken[i] = clk_register_mux(NULL, name,
  40                                 parents, 2, CLK_SET_RATE_NO_REPARENT,
  41                                 base + SCCTRL, SCCTRL_TIMERENnSEL_SHIFT(i), 1,
  42                                 0, &vexpress_sp810_lock);
  43
  44                 if (WARN_ON(IS_ERR(vexpress_sp810_timerclken[i])))
  45                         break;
  46         }
  47 }
  48
  49
  50 static const char * const vexpress_clk_24mhz_periphs[] __initconst = {
  51         "mb:uart0", "mb:uart1", "mb:uart2", "mb:uart3",
  52         "mb:mmci", "mb:kmi0", "mb:kmi1"
  53 };
  54
  55 void __init vexpress_clk_init(void __iomem *sp810_base)
  56 {
  57         struct clk *clk;
  58         int i;
  59
  60         clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
  61                         CLK_IS_ROOT, 0);
  62         WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));
  63
  64         clk = clk_register_fixed_rate(NULL, "v2m:clk_24mhz", NULL,
  65                         CLK_IS_ROOT, 24000000);
  66         for (i = 0; i < ARRAY_SIZE(vexpress_clk_24mhz_periphs); i++)
  67                 WARN_ON(clk_register_clkdev(clk, NULL,
  68                                 vexpress_clk_24mhz_periphs[i]));
  69
  70         clk = clk_register_fixed_rate(NULL, "v2m:refclk32khz", NULL,
  71                         CLK_IS_ROOT, 32768);
  72         WARN_ON(clk_register_clkdev(clk, NULL, "v2m:wdt"));
  73
  74         clk = clk_register_fixed_rate(NULL, "v2m:refclk1mhz", NULL,
  75                         CLK_IS_ROOT, 1000000);
  76
  77         vexpress_sp810_init(sp810_base);
  78
  79         for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
  80                 WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], clk));
  81
  82         WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
  83                                 "v2m-timer0", "sp804"));
  84         WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
  85                                 "v2m-timer1", "sp804"));
  86 }