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/*
* Copyright 2016 IBM Corporation
*
* 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.
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/clkdev.h>
static void __init aspeed_of_uart_clk_init(struct device_node *node)
{
struct clk *clk;
void __iomem *base;
int reg, rate;
const char *name = node->name;
of_property_read_string(node, "clock-output-names", &name);
base = of_iomap(node, 0);
if (!base) {
pr_err("%s: of_iomap failed\n", node->full_name);
return;
}
reg = readl(base);
iounmap(base);
/*
* The documentation does not indicate where this 24MHz clock is
* derived from.
*/
rate = 24000000;
if (reg & BIT(12))
rate /= 13;
clk = clk_register_fixed_rate(NULL, name, NULL, 0, rate);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock\n", node->full_name);
return;
}
clk_register_clkdev(clk, NULL, name);
of_clk_add_provider(node, of_clk_src_simple_get, clk);
}
CLK_OF_DECLARE(aspeed_uart_clock, "aspeed,uart-clock",
aspeed_of_uart_clk_init);
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