clk: sunxi-ng: Add gate clock support

Some clocks in the Allwinner SoCs clocks unit are just simple gates. Add
support for those clocks.

Since it's a feature that can also be found in more complex clocks, provide
a bunch of helpers that can be reused later on.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-5-maxime.ripard@free-electrons.com
This commit is contained in:
Maxime Ripard 2016-06-29 21:05:25 +02:00 committed by Michael Turquette
parent 89a3dfb787
commit 1a7e7c388d
4 changed files with 138 additions and 0 deletions

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@ -9,4 +9,7 @@ if SUNXI_CCU
config SUNXI_CCU_FRAC
bool
config SUNXI_CCU_GATE
bool
endif

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@ -4,3 +4,4 @@ obj-$(CONFIG_SUNXI_CCU) += ccu_reset.o
# Base clock types
obj-$(CONFIG_SUNXI_CCU_FRAC) += ccu_frac.o
obj-$(CONFIG_SUNXI_CCU_GATE) += ccu_gate.o

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@ -0,0 +1,82 @@
/*
* 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 "ccu_gate.h"
void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
{
unsigned long flags;
u32 reg;
if (!gate)
return;
spin_lock_irqsave(common->lock, flags);
reg = readl(common->base + common->reg);
writel(reg & ~gate, common->base + common->reg);
spin_unlock_irqrestore(common->lock, flags);
}
static void ccu_gate_disable(struct clk_hw *hw)
{
struct ccu_gate *cg = hw_to_ccu_gate(hw);
return ccu_gate_helper_disable(&cg->common, cg->enable);
}
int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
{
unsigned long flags;
u32 reg;
if (!gate)
return 0;
spin_lock_irqsave(common->lock, flags);
reg = readl(common->base + common->reg);
writel(reg | gate, common->base + common->reg);
spin_unlock_irqrestore(common->lock, flags);
return 0;
}
static int ccu_gate_enable(struct clk_hw *hw)
{
struct ccu_gate *cg = hw_to_ccu_gate(hw);
return ccu_gate_helper_enable(&cg->common, cg->enable);
}
int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
{
if (!gate)
return 1;
return readl(common->base + common->reg) & gate;
}
static int ccu_gate_is_enabled(struct clk_hw *hw)
{
struct ccu_gate *cg = hw_to_ccu_gate(hw);
return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
}
const struct clk_ops ccu_gate_ops = {
.disable = ccu_gate_disable,
.enable = ccu_gate_enable,
.is_enabled = ccu_gate_is_enabled,
};

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@ -0,0 +1,52 @@
/*
* Copyright (c) 2016 Maxime Ripard. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _CCU_GATE_H_
#define _CCU_GATE_H_
#include <linux/clk-provider.h>
#include "ccu_common.h"
struct ccu_gate {
u32 enable;
struct ccu_common common;
};
#define SUNXI_CCU_GATE(_struct, _name, _parent, _reg, _gate, _flags) \
struct ccu_gate _struct = { \
.enable = _gate, \
.common = { \
.reg = _reg, \
.hw.init = CLK_HW_INIT(_name, \
_parent, \
&ccu_gate_ops, \
_flags), \
} \
}
static inline struct ccu_gate *hw_to_ccu_gate(struct clk_hw *hw)
{
struct ccu_common *common = hw_to_ccu_common(hw);
return container_of(common, struct ccu_gate, common);
}
void ccu_gate_helper_disable(struct ccu_common *common, u32 gate);
int ccu_gate_helper_enable(struct ccu_common *common, u32 gate);
int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate);
extern const struct clk_ops ccu_gate_ops;
#endif /* _CCU_GATE_H_ */