141 строка
2.8 KiB
C
141 строка
2.8 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) 2010 Thomas Langer <thomas.langer@lantiq.com>
|
|
* Copyright (C) 2010 John Crispin <blogic@openwrt.org>
|
|
*/
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/err.h>
|
|
#include <linux/list.h>
|
|
|
|
#include <asm/time.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/div64.h>
|
|
|
|
#include <lantiq_soc.h>
|
|
|
|
#include "clk.h"
|
|
|
|
struct clk {
|
|
const char *name;
|
|
unsigned long rate;
|
|
unsigned long (*get_rate) (void);
|
|
};
|
|
|
|
static struct clk *cpu_clk;
|
|
static int cpu_clk_cnt;
|
|
|
|
/* lantiq socs have 3 static clocks */
|
|
static struct clk cpu_clk_generic[] = {
|
|
{
|
|
.name = "cpu",
|
|
.get_rate = ltq_get_cpu_hz,
|
|
}, {
|
|
.name = "fpi",
|
|
.get_rate = ltq_get_fpi_hz,
|
|
}, {
|
|
.name = "io",
|
|
.get_rate = ltq_get_io_region_clock,
|
|
},
|
|
};
|
|
|
|
static struct resource ltq_cgu_resource = {
|
|
.name = "cgu",
|
|
.start = LTQ_CGU_BASE_ADDR,
|
|
.end = LTQ_CGU_BASE_ADDR + LTQ_CGU_SIZE - 1,
|
|
.flags = IORESOURCE_MEM,
|
|
};
|
|
|
|
/* remapped clock register range */
|
|
void __iomem *ltq_cgu_membase;
|
|
|
|
void clk_init(void)
|
|
{
|
|
cpu_clk = cpu_clk_generic;
|
|
cpu_clk_cnt = ARRAY_SIZE(cpu_clk_generic);
|
|
}
|
|
|
|
static inline int clk_good(struct clk *clk)
|
|
{
|
|
return clk && !IS_ERR(clk);
|
|
}
|
|
|
|
unsigned long clk_get_rate(struct clk *clk)
|
|
{
|
|
if (unlikely(!clk_good(clk)))
|
|
return 0;
|
|
|
|
if (clk->rate != 0)
|
|
return clk->rate;
|
|
|
|
if (clk->get_rate != NULL)
|
|
return clk->get_rate();
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(clk_get_rate);
|
|
|
|
struct clk *clk_get(struct device *dev, const char *id)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < cpu_clk_cnt; i++)
|
|
if (!strcmp(id, cpu_clk[i].name))
|
|
return &cpu_clk[i];
|
|
BUG();
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
EXPORT_SYMBOL(clk_get);
|
|
|
|
void clk_put(struct clk *clk)
|
|
{
|
|
/* not used */
|
|
}
|
|
EXPORT_SYMBOL(clk_put);
|
|
|
|
static inline u32 ltq_get_counter_resolution(void)
|
|
{
|
|
u32 res;
|
|
|
|
__asm__ __volatile__(
|
|
".set push\n"
|
|
".set mips32r2\n"
|
|
"rdhwr %0, $3\n"
|
|
".set pop\n"
|
|
: "=&r" (res)
|
|
: /* no input */
|
|
: "memory");
|
|
|
|
return res;
|
|
}
|
|
|
|
void __init plat_time_init(void)
|
|
{
|
|
struct clk *clk;
|
|
|
|
if (insert_resource(&iomem_resource, <q_cgu_resource) < 0)
|
|
panic("Failed to insert cgu memory\n");
|
|
|
|
if (request_mem_region(ltq_cgu_resource.start,
|
|
resource_size(<q_cgu_resource), "cgu") < 0)
|
|
panic("Failed to request cgu memory\n");
|
|
|
|
ltq_cgu_membase = ioremap_nocache(ltq_cgu_resource.start,
|
|
resource_size(<q_cgu_resource));
|
|
if (!ltq_cgu_membase) {
|
|
pr_err("Failed to remap cgu memory\n");
|
|
unreachable();
|
|
}
|
|
clk = clk_get(0, "cpu");
|
|
mips_hpt_frequency = clk_get_rate(clk) / ltq_get_counter_resolution();
|
|
write_c0_compare(read_c0_count());
|
|
clk_put(clk);
|
|
}
|