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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/rb532/time.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/mips/rb532/time.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/mips/rb532/time.c b/arch/mips/rb532/time.c new file mode 100644 index 000000000..68713dd32 --- /dev/null +++ b/arch/mips/rb532/time.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Carsten Langgaard, carstenl@mips.com + * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. + * + * Setting up the clock on the MIPS boards. + */ + +#include <linux/init.h> +#include <linux/kernel_stat.h> +#include <linux/ptrace.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/mc146818rtc.h> +#include <linux/irq.h> +#include <linux/timex.h> + +#include <asm/mipsregs.h> +#include <asm/time.h> +#include <asm/mach-rc32434/rc32434.h> + +extern unsigned int idt_cpu_freq; + +/* + * Figure out the r4k offset, the amount to increment the compare + * register for each time tick. There is no RTC available. + * + * The RC32434 counts at half the CPU *core* speed. + */ +static unsigned long __init cal_r4koff(void) +{ + mips_hpt_frequency = idt_cpu_freq * IDT_CLOCK_MULT / 2; + + return mips_hpt_frequency / HZ; +} + +void __init plat_time_init(void) +{ + unsigned int est_freq; + unsigned long flags, r4k_offset; + + local_irq_save(flags); + + printk(KERN_INFO "calculating r4koff... "); + r4k_offset = cal_r4koff(); + printk("%08lx(%d)\n", r4k_offset, (int) r4k_offset); + + est_freq = 2 * r4k_offset * HZ; + est_freq += 5000; /* round */ + est_freq -= est_freq % 10000; + printk(KERN_INFO "CPU frequency %d.%02d MHz\n", est_freq / 1000000, + (est_freq % 1000000) * 100 / 1000000); + local_irq_restore(flags); +} |