linux/drivers/clk/mvebu/armada-37xx-xtal.c

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/*
* Marvell Armada 37xx SoC xtal clocks
*
* Copyright (C) 2016 Marvell
*
* Gregory CLEMENT <gregory.clement@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define NB_GPIO1_LATCH 0xC
#define XTAL_MODE BIT(31)
static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const char *xtal_name = "xtal";
struct device_node *parent;
struct regmap *regmap;
struct clk_hw *xtal_hw;
unsigned int rate;
u32 reg;
int ret;
xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
if (!xtal_hw)
return -ENOMEM;
platform_set_drvdata(pdev, xtal_hw);
parent = np->parent;
if (!parent) {
dev_err(&pdev->dev, "no parent\n");
return -ENODEV;
}
regmap = syscon_node_to_regmap(parent);
if (IS_ERR(regmap)) {
dev_err(&pdev->dev, "cannot get regmap\n");
return PTR_ERR(regmap);
}
ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
if (ret) {
dev_err(&pdev->dev, "cannot read from regmap\n");
return ret;
}
if (reg & XTAL_MODE)
rate = 40000000;
else
rate = 25000000;
of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
if (IS_ERR(xtal_hw))
return PTR_ERR(xtal_hw);
ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
return ret;
}
static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
{
of_clk_del_provider(pdev->dev.of_node);
return 0;
}
static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
{ .compatible = "marvell,armada-3700-xtal-clock", },
{ }
};
static struct platform_driver armada_3700_xtal_clock_driver = {
.probe = armada_3700_xtal_clock_probe,
.remove = armada_3700_xtal_clock_remove,
.driver = {
.name = "marvell-armada-3700-xtal-clock",
.of_match_table = armada_3700_xtal_clock_of_match,
},
};
builtin_platform_driver(armada_3700_xtal_clock_driver);