drivers/clk/sunxi-ng/ccu_frac.c

   1 /*
   2  * Copyright (C) 2016 Maxime Ripard
   3  * Maxime Ripard <maxime.ripard@free-electrons.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or (at your option) any later version.
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/spinlock.h>
  13
  14 #include "ccu_frac.h"
  15
  16 bool ccu_frac_helper_is_enabled(struct ccu_common *common,
  17                                 struct _ccu_frac *cf)
  18 {
  19         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  20                 return false;
  21
  22         return !(readl(common->base + common->reg) & cf->enable);
  23 }
  24
  25 void ccu_frac_helper_enable(struct ccu_common *common,
  26                             struct _ccu_frac *cf)
  27 {
  28         unsigned long flags;
  29         u32 reg;
  30
  31         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  32                 return;
  33
  34         spin_lock_irqsave(common->lock, flags);
  35         reg = readl(common->base + common->reg);
  36         writel(reg & ~cf->enable, common->base + common->reg);
  37         spin_unlock_irqrestore(common->lock, flags);
  38 }
  39
  40 void ccu_frac_helper_disable(struct ccu_common *common,
  41                              struct _ccu_frac *cf)
  42 {
  43         unsigned long flags;
  44         u32 reg;
  45
  46         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  47                 return;
  48
  49         spin_lock_irqsave(common->lock, flags);
  50         reg = readl(common->base + common->reg);
  51         writel(reg | cf->enable, common->base + common->reg);
  52         spin_unlock_irqrestore(common->lock, flags);
  53 }
  54
  55 bool ccu_frac_helper_has_rate(struct ccu_common *common,
  56                               struct _ccu_frac *cf,
  57                               unsigned long rate)
  58 {
  59         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  60                 return false;
  61
  62         return (cf->rates[0] == rate) || (cf->rates[1] == rate);
  63 }
  64
  65 unsigned long ccu_frac_helper_read_rate(struct ccu_common *common,
  66                                         struct _ccu_frac *cf)
  67 {
  68         u32 reg;
  69
  70         printk("%s: Read fractional\n", clk_hw_get_name(&common->hw));
  71
  72         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  73                 return 0;
  74
  75         printk("%s: clock is fractional (rates %lu and %lu)\n",
  76                clk_hw_get_name(&common->hw), cf->rates[0], cf->rates[1]);
  77
  78         reg = readl(common->base + common->reg);
  79
  80         printk("%s: clock reg is 0x%x (select is 0x%x)\n",
  81                clk_hw_get_name(&common->hw), reg, cf->select);
  82
  83         return (reg & cf->select) ? cf->rates[1] : cf->rates[0];
  84 }
  85
  86 int ccu_frac_helper_set_rate(struct ccu_common *common,
  87                              struct _ccu_frac *cf,
  88                              unsigned long rate)
  89 {
  90         unsigned long flags;
  91         u32 reg, sel;
  92
  93         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  94                 return -EINVAL;
  95
  96         if (cf->rates[0] == rate)
  97                 sel = 0;
  98         else if (cf->rates[1] == rate)
  99                 sel = cf->select;
 100         else
 101                 return -EINVAL;
 102
 103         spin_lock_irqsave(common->lock, flags);
 104         reg = readl(common->base + common->reg);
 105         reg &= ~cf->select;
 106         writel(reg | sel, common->base + common->reg);
 107         spin_unlock_irqrestore(common->lock, flags);
 108
 109         return 0;
 110 }