Quelle  ccu_frac.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Maxime Ripard
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/spinlock.h>

#include "ccu_frac.h"

bool ccu_frac_helper_is_enabled(struct ccu_common *common,
    struct ccu_frac_internal *cf)
{
 if (!(common->features & CCU_FEATURE_FRACTIONAL))
  return false;

 return !(readl(common->base + common->reg) & cf->enable);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_is_enabled, "SUNXI_CCU");

void ccu_frac_helper_enable(struct ccu_common *common,
       struct ccu_frac_internal *cf)
{
 unsigned long flags;
 u32 reg;

 if (!(common->features & CCU_FEATURE_FRACTIONAL))
  return;

 spin_lock_irqsave(common->lock, flags);
 reg = readl(common->base + common->reg);
 writel(reg & ~cf->enable, common->base + common->reg);
 spin_unlock_irqrestore(common->lock, flags);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_enable, "SUNXI_CCU");

void ccu_frac_helper_disable(struct ccu_common *common,
        struct ccu_frac_internal *cf)
{
 unsigned long flags;
 u32 reg;

 if (!(common->features & CCU_FEATURE_FRACTIONAL))
  return;

 spin_lock_irqsave(common->lock, flags);
 reg = readl(common->base + common->reg);
 writel(reg | cf->enable, common->base + common->reg);
 spin_unlock_irqrestore(common->lock, flags);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_disable, "SUNXI_CCU");

bool ccu_frac_helper_has_rate(struct ccu_common *common,
         struct ccu_frac_internal *cf,
         unsigned long rate)
{
 if (!(common->features & CCU_FEATURE_FRACTIONAL))
  return false;

 return (cf->rates[0] == rate) || (cf->rates[1] == rate);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_has_rate, "SUNXI_CCU");

unsigned long ccu_frac_helper_read_rate(struct ccu_common *common,
     struct ccu_frac_internal *cf)
{
 u32 reg;

 pr_debug("%s: Read fractional\n", clk_hw_get_name(&common->hw));

 if (!(common->features & CCU_FEATURE_FRACTIONAL))
  return 0;

 pr_debug("%s: clock is fractional (rates %lu and %lu)\n",
   clk_hw_get_name(&common->hw), cf->rates[0], cf->rates[1]);

 reg = readl(common->base + common->reg);

 pr_debug("%s: clock reg is 0x%x (select is 0x%x)\n",
   clk_hw_get_name(&common->hw), reg, cf->select);

 return (reg & cf->select) ? cf->rates[1] : cf->rates[0];
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_read_rate, "SUNXI_CCU");

int ccu_frac_helper_set_rate(struct ccu_common *common,
        struct ccu_frac_internal *cf,
        unsigned long rate, u32 lock)
{
 unsigned long flags;
 u32 reg, sel;

 if (!(common->features & CCU_FEATURE_FRACTIONAL))
  return -EINVAL;

 if (cf->rates[0] == rate)
  sel = 0;
 else if (cf->rates[1] == rate)
  sel = cf->select;
 else
  return -EINVAL;

 spin_lock_irqsave(common->lock, flags);
 reg = readl(common->base + common->reg);
 reg &= ~cf->select;
 writel(reg | sel, common->base + common->reg);
 spin_unlock_irqrestore(common->lock, flags);

 ccu_helper_wait_for_lock(common, lock);

 return 0;
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_set_rate, "SUNXI_CCU");