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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/m68k/hp300/time.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/m68k/hp300/time.c')
-rw-r--r-- | arch/m68k/hp300/time.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/m68k/hp300/time.c b/arch/m68k/hp300/time.c new file mode 100644 index 000000000..1d1b7b3b5 --- /dev/null +++ b/arch/m68k/hp300/time.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/arch/m68k/hp300/time.c + * + * Copyright (C) 1998 Philip Blundell <philb@gnu.org> + * + * This file contains the HP300-specific time handling code. + */ + +#include <asm/ptrace.h> +#include <linux/clocksource.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/kernel_stat.h> +#include <linux/interrupt.h> +#include <asm/machdep.h> +#include <asm/irq.h> +#include <asm/io.h> +#include <asm/traps.h> +#include <asm/blinken.h> + +static u64 hp300_read_clk(struct clocksource *cs); + +static struct clocksource hp300_clk = { + .name = "timer", + .rating = 250, + .read = hp300_read_clk, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u32 clk_total, clk_offset; + +/* Clock hardware definitions */ + +#define CLOCKBASE 0xf05f8000 + +#define CLKCR1 0x1 +#define CLKCR2 0x3 +#define CLKCR3 CLKCR1 +#define CLKSR CLKCR2 +#define CLKMSB1 0x5 +#define CLKLSB1 0x7 +#define CLKMSB2 0x9 +#define CLKMSB3 0xD + +#define CLKSR_INT1 BIT(0) + +/* This is for machines which generate the exact clock. */ + +#define HP300_TIMER_CLOCK_FREQ 250000 +#define HP300_TIMER_CYCLES (HP300_TIMER_CLOCK_FREQ / HZ) +#define INTVAL (HP300_TIMER_CYCLES - 1) + +static irqreturn_t hp300_tick(int irq, void *dev_id) +{ + unsigned long flags; + unsigned long tmp; + + local_irq_save(flags); + in_8(CLOCKBASE + CLKSR); + asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE)); + clk_total += INTVAL; + clk_offset = 0; + legacy_timer_tick(1); + timer_heartbeat(); + local_irq_restore(flags); + + /* Turn off the network and SCSI leds */ + blinken_leds(0, 0xe0); + return IRQ_HANDLED; +} + +static u64 hp300_read_clk(struct clocksource *cs) +{ + unsigned long flags; + unsigned char lsb, msb, msb_new; + u32 ticks; + + local_irq_save(flags); + /* Read current timer 1 value */ + msb = in_8(CLOCKBASE + CLKMSB1); +again: + if ((in_8(CLOCKBASE + CLKSR) & CLKSR_INT1) && msb > 0) + clk_offset = INTVAL; + lsb = in_8(CLOCKBASE + CLKLSB1); + msb_new = in_8(CLOCKBASE + CLKMSB1); + if (msb_new != msb) { + msb = msb_new; + goto again; + } + + ticks = INTVAL - ((msb << 8) | lsb); + ticks += clk_offset + clk_total; + local_irq_restore(flags); + + return ticks; +} + +void __init hp300_sched_init(void) +{ + out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */ + out_8(CLOCKBASE + CLKCR1, 0x1); /* reset */ + + asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE)); + + if (request_irq(IRQ_AUTO_6, hp300_tick, IRQF_TIMER, "timer tick", NULL)) + pr_err("Couldn't register timer interrupt\n"); + + out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */ + out_8(CLOCKBASE + CLKCR1, 0x40); /* enable irq */ + + clocksource_register_hz(&hp300_clk, HP300_TIMER_CLOCK_FREQ); +} |