linux/drivers/clk/sunxi-ng/ccu_frac.c

113 lines
2.8 KiB
C

/*
* Copyright (C) 2016 Maxime Ripard
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
#include <linux/clk-provider.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);
}
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);
}
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);
}
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);
}
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];
}
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;
}