linux-sg2042/drivers/clk/uniphier/clk-uniphier-gate.c

98 lines
2.6 KiB
C

/*
* Copyright (C) 2016 Socionext Inc.
* Author: Masahiro Yamada <yamada.masahiro@socionext.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.
*
* 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.
*/
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/regmap.h>
#include "clk-uniphier.h"
struct uniphier_clk_gate {
struct clk_hw hw;
struct regmap *regmap;
unsigned int reg;
unsigned int bit;
};
#define to_uniphier_clk_gate(_hw) \
container_of(_hw, struct uniphier_clk_gate, hw)
static int uniphier_clk_gate_endisable(struct clk_hw *hw, int enable)
{
struct uniphier_clk_gate *gate = to_uniphier_clk_gate(hw);
return regmap_write_bits(gate->regmap, gate->reg, BIT(gate->bit),
enable ? BIT(gate->bit) : 0);
}
static int uniphier_clk_gate_enable(struct clk_hw *hw)
{
return uniphier_clk_gate_endisable(hw, 1);
}
static void uniphier_clk_gate_disable(struct clk_hw *hw)
{
if (uniphier_clk_gate_endisable(hw, 0) < 0)
pr_warn("failed to disable clk\n");
}
static int uniphier_clk_gate_is_enabled(struct clk_hw *hw)
{
struct uniphier_clk_gate *gate = to_uniphier_clk_gate(hw);
unsigned int val;
if (regmap_read(gate->regmap, gate->reg, &val) < 0)
pr_warn("is_enabled() may return wrong result\n");
return !!(val & BIT(gate->bit));
}
static const struct clk_ops uniphier_clk_gate_ops = {
.enable = uniphier_clk_gate_enable,
.disable = uniphier_clk_gate_disable,
.is_enabled = uniphier_clk_gate_is_enabled,
};
struct clk_hw *uniphier_clk_register_gate(struct device *dev,
struct regmap *regmap,
const char *name,
const struct uniphier_clk_gate_data *data)
{
struct uniphier_clk_gate *gate;
struct clk_init_data init;
int ret;
gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
if (!gate)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &uniphier_clk_gate_ops;
init.flags = data->parent_name ? CLK_SET_RATE_PARENT : 0;
init.parent_names = data->parent_name ? &data->parent_name : NULL;
init.num_parents = data->parent_name ? 1 : 0;
gate->regmap = regmap;
gate->reg = data->reg;
gate->bit = data->bit;
gate->hw.init = &init;
ret = devm_clk_hw_register(dev, &gate->hw);
if (ret)
return ERR_PTR(ret);
return &gate->hw;
}