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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/kernel/csrc-ioasic.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/kernel/csrc-ioasic.c')
-rw-r--r-- | arch/mips/kernel/csrc-ioasic.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/mips/kernel/csrc-ioasic.c b/arch/mips/kernel/csrc-ioasic.c new file mode 100644 index 000000000..bad740ad3 --- /dev/null +++ b/arch/mips/kernel/csrc-ioasic.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * DEC I/O ASIC's counter clocksource + * + * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> + */ +#include <linux/clocksource.h> +#include <linux/sched_clock.h> +#include <linux/init.h> + +#include <asm/ds1287.h> +#include <asm/time.h> +#include <asm/dec/ioasic.h> +#include <asm/dec/ioasic_addrs.h> + +static u64 dec_ioasic_hpt_read(struct clocksource *cs) +{ + return ioasic_read(IO_REG_FCTR); +} + +static struct clocksource clocksource_dec = { + .name = "dec-ioasic", + .read = dec_ioasic_hpt_read, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u64 notrace dec_ioasic_read_sched_clock(void) +{ + return ioasic_read(IO_REG_FCTR); +} + +int __init dec_ioasic_clocksource_init(void) +{ + unsigned int freq; + u32 start, end; + int i = HZ / 8; + + ds1287_timer_state(); + while (!ds1287_timer_state()) + ; + + start = dec_ioasic_hpt_read(&clocksource_dec); + + while (i--) + while (!ds1287_timer_state()) + ; + + end = dec_ioasic_hpt_read(&clocksource_dec); + + freq = (end - start) * 8; + + /* An early revision of the I/O ASIC didn't have the counter. */ + if (!freq) + return -ENXIO; + + printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq); + + clocksource_dec.rating = 200 + freq / 10000000; + clocksource_register_hz(&clocksource_dec, freq); + + sched_clock_register(dec_ioasic_read_sched_clock, 32, freq); + + return 0; +} |