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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* Copyright (C) 2012 ARM Limited
*/
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/vexpress.h>
struct vexpress_osc {
struct regmap *reg;
struct clk_hw hw;
unsigned long rate_min;
unsigned long rate_max;
};
#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct vexpress_osc *osc = to_vexpress_osc(hw);
u32 rate;
regmap_read(osc->reg, 0, &rate);
return rate;
}
static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct vexpress_osc *osc = to_vexpress_osc(hw);
if (WARN_ON(osc->rate_min && rate < osc->rate_min))
rate = osc->rate_min;
if (WARN_ON(osc->rate_max && rate > osc->rate_max))
rate = osc->rate_max;
return rate;
}
static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct vexpress_osc *osc = to_vexpress_osc(hw);
return regmap_write(osc->reg, 0, rate);
}
static struct clk_ops vexpress_osc_ops = {
.recalc_rate = vexpress_osc_recalc_rate,
.round_rate = vexpress_osc_round_rate,
.set_rate = vexpress_osc_set_rate,
};
static int vexpress_osc_probe(struct platform_device *pdev)
{
struct clk_init_data init;
struct vexpress_osc *osc;
struct clk *clk;
u32 range[2];
osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
if (!osc)
return -ENOMEM;
osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
if (IS_ERR(osc->reg))
return PTR_ERR(osc->reg);
if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
ARRAY_SIZE(range)) == 0) {
osc->rate_min = range[0];
osc->rate_max = range[1];
}
if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
&init.name) != 0)
init.name = dev_name(&pdev->dev);
init.ops = &vexpress_osc_ops;
init.flags = CLK_IS_ROOT;
init.num_parents = 0;
osc->hw.init = &init;
clk = clk_register(NULL, &osc->hw);
if (IS_ERR(clk))
return PTR_ERR(clk);
of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk);
dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
return 0;
}
static const struct of_device_id vexpress_osc_of_match[] = {
{ .compatible = "arm,vexpress-osc", },
{}
};
static struct platform_driver vexpress_osc_driver = {
.driver = {
.name = "vexpress-osc",
.of_match_table = vexpress_osc_of_match,
},
.probe = vexpress_osc_probe,
};
static int __init vexpress_osc_init(void)
{
return platform_driver_register(&vexpress_osc_driver);
}
core_initcall(vexpress_osc_init);
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