drivers/clk/sunxi-ng/ccu_frac.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016 Maxime Ripard
   4  * Maxime Ripard <maxime.ripard@free-electrons.com>
   5  */
   6
   7 #include <linux/clk-provider.h>
   8 #include <linux/io.h>
   9 #include <linux/spinlock.h>
  10
  11 #include "ccu_frac.h"
  12
  13 bool ccu_frac_helper_is_enabled(struct ccu_common *common,
  14                                 struct ccu_frac_internal *cf)
  15 {
  16         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  17                 return false;
  18
  19         return !(readl(common->base + common->reg) & cf->enable);
  20 }
  21 EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_is_enabled, SUNXI_CCU);
  22
  23 void ccu_frac_helper_enable(struct ccu_common *common,
  24                             struct ccu_frac_internal *cf)
  25 {
  26         unsigned long flags;
  27         u32 reg;
  28
  29         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  30                 return;
  31
  32         spin_lock_irqsave(common->lock, flags);
  33         reg = readl(common->base + common->reg);
  34         writel(reg & ~cf->enable, common->base + common->reg);
  35         spin_unlock_irqrestore(common->lock, flags);
  36 }
  37 EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_enable, SUNXI_CCU);
  38
  39 void ccu_frac_helper_disable(struct ccu_common *common,
  40                              struct ccu_frac_internal *cf)
  41 {
  42         unsigned long flags;
  43         u32 reg;
  44
  45         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  46                 return;
  47
  48         spin_lock_irqsave(common->lock, flags);
  49         reg = readl(common->base + common->reg);
  50         writel(reg | cf->enable, common->base + common->reg);
  51         spin_unlock_irqrestore(common->lock, flags);
  52 }
  53 EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_disable, SUNXI_CCU);
  54
  55 bool ccu_frac_helper_has_rate(struct ccu_common *common,
  56                               struct ccu_frac_internal *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 EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_has_rate, SUNXI_CCU);
  65
  66 unsigned long ccu_frac_helper_read_rate(struct ccu_common *common,
  67                                         struct ccu_frac_internal *cf)
  68 {
  69         u32 reg;
  70
  71         pr_debug("%s: Read fractional\n", clk_hw_get_name(&common->hw));
  72
  73         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  74                 return 0;
  75
  76         pr_debug("%s: clock is fractional (rates %lu and %lu)\n",
  77                  clk_hw_get_name(&common->hw), cf->rates[0], cf->rates[1]);
  78
  79         reg = readl(common->base + common->reg);
  80
  81         pr_debug("%s: clock reg is 0x%x (select is 0x%x)\n",
  82                  clk_hw_get_name(&common->hw), reg, cf->select);
  83
  84         return (reg & cf->select) ? cf->rates[1] : cf->rates[0];
  85 }
  86 EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_read_rate, SUNXI_CCU);
  87
  88 int ccu_frac_helper_set_rate(struct ccu_common *common,
  89                              struct ccu_frac_internal *cf,
  90                              unsigned long rate, u32 lock)
  91 {
  92         unsigned long flags;
  93         u32 reg, sel;
  94
  95         if (!(common->features & CCU_FEATURE_FRACTIONAL))
  96                 return -EINVAL;
  97
  98         if (cf->rates[0] == rate)
  99                 sel = 0;
 100         else if (cf->rates[1] == rate)
 101                 sel = cf->select;
 102         else
 103                 return -EINVAL;
 104
 105         spin_lock_irqsave(common->lock, flags);
 106         reg = readl(common->base + common->reg);
 107         reg &= ~cf->select;
 108         writel(reg | sel, common->base + common->reg);
 109         spin_unlock_irqrestore(common->lock, flags);
 110
 111         ccu_helper_wait_for_lock(common, lock);
 112
 113         return 0;
 114 }
 115 EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_set_rate, SUNXI_CCU);