alistair23-linux/arch/mips/ralink/clk.c
Jonas Gorski a18097b767 MIPS: ralink: allow NULL clock for clk_get_rate
Make the behaviour of clk_get_rate consistent with common clk's
clk_get_rate by accepting NULL clocks as parameter. Some device
drivers rely on this, and will cause an OOPS otherwise.

Fixes: 3f0a06b036 ("MIPS: ralink: adds clkdev code")
Reported-by: Mathias Kresin <dev@kresin.me>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Cc: John Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16778/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-09-06 12:37:45 +02:00

90 lines
1.6 KiB
C

/*
* 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.
*
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2013 John Crispin <john@phrozen.org>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/clkdev.h>
#include <linux/clk.h>
#include <asm/time.h>
#include "common.h"
struct clk {
struct clk_lookup cl;
unsigned long rate;
};
void ralink_clk_add(const char *dev, unsigned long rate)
{
struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
if (!clk)
panic("failed to add clock");
clk->cl.dev_id = dev;
clk->cl.clk = clk;
clk->rate = rate;
clkdev_add(&clk->cl);
}
/*
* Linux clock API
*/
int clk_enable(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL_GPL(clk_enable);
void clk_disable(struct clk *clk)
{
}
EXPORT_SYMBOL_GPL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
if (!clk)
return 0;
return clk->rate;
}
EXPORT_SYMBOL_GPL(clk_get_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
return -1;
}
EXPORT_SYMBOL_GPL(clk_set_rate);
long clk_round_rate(struct clk *clk, unsigned long rate)
{
return -1;
}
EXPORT_SYMBOL_GPL(clk_round_rate);
void __init plat_time_init(void)
{
struct clk *clk;
ralink_of_remap();
ralink_clk_init();
clk = clk_get_sys("cpu", NULL);
if (IS_ERR(clk))
panic("unable to get CPU clock, err=%ld", PTR_ERR(clk));
pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
mips_hpt_frequency = clk_get_rate(clk) / 2;
clk_put(clk);
timer_probe();
}