acrn-kernel/drivers/clk/clk-max-gen.c

195 lines
4.4 KiB
C

/*
* clk-max-gen.c - Generic clock driver for Maxim PMICs clocks
*
* Copyright (C) 2014 Google, Inc
*
* Copyright (C) 2012 Samsung Electornics
* Jonghwa Lee <jonghwa3.lee@samsung.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.
*
* This driver is based on clk-max77686.c
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/regmap.h>
#include <linux/platform_device.h>
#include <linux/clk-provider.h>
#include <linux/mutex.h>
#include <linux/clkdev.h>
#include <linux/of.h>
#include <linux/export.h>
#include "clk-max-gen.h"
struct max_gen_clk {
struct regmap *regmap;
u32 mask;
u32 reg;
struct clk_hw hw;
};
static struct max_gen_clk *to_max_gen_clk(struct clk_hw *hw)
{
return container_of(hw, struct max_gen_clk, hw);
}
static int max_gen_clk_prepare(struct clk_hw *hw)
{
struct max_gen_clk *max_gen = to_max_gen_clk(hw);
return regmap_update_bits(max_gen->regmap, max_gen->reg,
max_gen->mask, max_gen->mask);
}
static void max_gen_clk_unprepare(struct clk_hw *hw)
{
struct max_gen_clk *max_gen = to_max_gen_clk(hw);
regmap_update_bits(max_gen->regmap, max_gen->reg,
max_gen->mask, ~max_gen->mask);
}
static int max_gen_clk_is_prepared(struct clk_hw *hw)
{
struct max_gen_clk *max_gen = to_max_gen_clk(hw);
int ret;
u32 val;
ret = regmap_read(max_gen->regmap, max_gen->reg, &val);
if (ret < 0)
return -EINVAL;
return val & max_gen->mask;
}
static unsigned long max_gen_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
return 32768;
}
struct clk_ops max_gen_clk_ops = {
.prepare = max_gen_clk_prepare,
.unprepare = max_gen_clk_unprepare,
.is_prepared = max_gen_clk_is_prepared,
.recalc_rate = max_gen_recalc_rate,
};
EXPORT_SYMBOL_GPL(max_gen_clk_ops);
static struct clk *max_gen_clk_register(struct device *dev,
struct max_gen_clk *max_gen)
{
struct clk *clk;
struct clk_hw *hw = &max_gen->hw;
int ret;
clk = devm_clk_register(dev, hw);
if (IS_ERR(clk))
return clk;
ret = clk_register_clkdev(clk, hw->init->name, NULL);
if (ret)
return ERR_PTR(ret);
return clk;
}
int max_gen_clk_probe(struct platform_device *pdev, struct regmap *regmap,
u32 reg, struct clk_init_data *clks_init, int num_init)
{
int i, ret;
struct max_gen_clk *max_gen_clks;
struct clk **clocks;
struct device *dev = pdev->dev.parent;
const char *clk_name;
struct clk_init_data *init;
clocks = devm_kzalloc(dev, sizeof(struct clk *) * num_init, GFP_KERNEL);
if (!clocks)
return -ENOMEM;
max_gen_clks = devm_kzalloc(dev, sizeof(struct max_gen_clk)
* num_init, GFP_KERNEL);
if (!max_gen_clks)
return -ENOMEM;
for (i = 0; i < num_init; i++) {
max_gen_clks[i].regmap = regmap;
max_gen_clks[i].mask = 1 << i;
max_gen_clks[i].reg = reg;
init = devm_kzalloc(dev, sizeof(*init), GFP_KERNEL);
if (!init)
return -ENOMEM;
if (dev->of_node &&
!of_property_read_string_index(dev->of_node,
"clock-output-names",
i, &clk_name))
init->name = clk_name;
else
init->name = clks_init[i].name;
init->ops = clks_init[i].ops;
init->flags = clks_init[i].flags;
max_gen_clks[i].hw.init = init;
clocks[i] = max_gen_clk_register(dev, &max_gen_clks[i]);
if (IS_ERR(clocks[i])) {
ret = PTR_ERR(clocks[i]);
dev_err(dev, "failed to register %s\n",
max_gen_clks[i].hw.init->name);
return ret;
}
}
platform_set_drvdata(pdev, clocks);
if (dev->of_node) {
struct clk_onecell_data *of_data;
of_data = devm_kzalloc(dev, sizeof(*of_data), GFP_KERNEL);
if (!of_data)
return -ENOMEM;
of_data->clks = clocks;
of_data->clk_num = num_init;
ret = of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
of_data);
if (ret) {
dev_err(dev, "failed to register OF clock provider\n");
return ret;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(max_gen_clk_probe);
int max_gen_clk_remove(struct platform_device *pdev, int num_init)
{
struct device *dev = pdev->dev.parent;
if (dev->of_node)
of_clk_del_provider(dev->of_node);
return 0;
}
EXPORT_SYMBOL_GPL(max_gen_clk_remove);