mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-16 12:26:49 +07:00
50cc4caf53
This patch adds a driver for Fixed MMIO clock. The driver reads a clock frequency value from a single 32-bit memory mapped register and registers it as a fixed rate clock. It can be enabled with COMMON_CLK_FIXED_MMIO Kconfig option. Signed-off-by: Jan Kotas <jank@cadence.com> [sboyd@kernel.org: Make of_fixed_mmio_clk_setup() static, use clk_hw based APIs] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
102 lines
2.3 KiB
C
102 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
/*
|
|
* Memory Mapped IO Fixed clock driver
|
|
*
|
|
* Copyright (C) 2018 Cadence Design Systems, Inc.
|
|
*
|
|
* Authors:
|
|
* Jan Kotas <jank@cadence.com>
|
|
*/
|
|
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
static struct clk_hw *fixed_mmio_clk_setup(struct device_node *node)
|
|
{
|
|
struct clk_hw *clk;
|
|
const char *clk_name = node->name;
|
|
void __iomem *base;
|
|
u32 freq;
|
|
int ret;
|
|
|
|
base = of_iomap(node, 0);
|
|
if (!base) {
|
|
pr_err("%pOFn: failed to map address\n", node);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
freq = readl(base);
|
|
iounmap(base);
|
|
of_property_read_string(node, "clock-output-names", &clk_name);
|
|
|
|
clk = clk_hw_register_fixed_rate(NULL, clk_name, NULL, 0, freq);
|
|
if (IS_ERR(clk)) {
|
|
pr_err("%pOFn: failed to register fixed rate clock\n", node);
|
|
return clk;
|
|
}
|
|
|
|
ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, clk);
|
|
if (ret) {
|
|
pr_err("%pOFn: failed to add clock provider\n", node);
|
|
clk_hw_unregister(clk);
|
|
clk = ERR_PTR(ret);
|
|
}
|
|
|
|
return clk;
|
|
}
|
|
|
|
static void __init of_fixed_mmio_clk_setup(struct device_node *node)
|
|
{
|
|
fixed_mmio_clk_setup(node);
|
|
}
|
|
CLK_OF_DECLARE(fixed_mmio_clk, "fixed-mmio-clock", of_fixed_mmio_clk_setup);
|
|
|
|
/**
|
|
* This is not executed when of_fixed_mmio_clk_setup succeeded.
|
|
*/
|
|
static int of_fixed_mmio_clk_probe(struct platform_device *pdev)
|
|
{
|
|
struct clk_hw *clk;
|
|
|
|
clk = fixed_mmio_clk_setup(pdev->dev.of_node);
|
|
if (IS_ERR(clk))
|
|
return PTR_ERR(clk);
|
|
|
|
platform_set_drvdata(pdev, clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int of_fixed_mmio_clk_remove(struct platform_device *pdev)
|
|
{
|
|
struct clk_hw *clk = platform_get_drvdata(pdev);
|
|
|
|
of_clk_del_provider(pdev->dev.of_node);
|
|
clk_hw_unregister_fixed_rate(clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id of_fixed_mmio_clk_ids[] = {
|
|
{ .compatible = "fixed-mmio-clock" },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, of_fixed_mmio_clk_ids);
|
|
|
|
static struct platform_driver of_fixed_mmio_clk_driver = {
|
|
.driver = {
|
|
.name = "of_fixed_mmio_clk",
|
|
.of_match_table = of_fixed_mmio_clk_ids,
|
|
},
|
|
.probe = of_fixed_mmio_clk_probe,
|
|
.remove = of_fixed_mmio_clk_remove,
|
|
};
|
|
module_platform_driver(of_fixed_mmio_clk_driver);
|
|
|
|
MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
|
|
MODULE_DESCRIPTION("Memory Mapped IO Fixed clock driver");
|
|
MODULE_LICENSE("GPL v2");
|