diff options
Diffstat (limited to 'arch/mips/kernel/csrc-sb1250.c')
-rw-r--r-- | arch/mips/kernel/csrc-sb1250.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/mips/kernel/csrc-sb1250.c b/arch/mips/kernel/csrc-sb1250.c new file mode 100644 index 000000000..b07b7310d --- /dev/null +++ b/arch/mips/kernel/csrc-sb1250.c @@ -0,0 +1,80 @@ +/* + * Copyright (C) 2000, 2001 Broadcom Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/clocksource.h> +#include <linux/sched_clock.h> + +#include <asm/addrspace.h> +#include <asm/io.h> +#include <asm/time.h> + +#include <asm/sibyte/sb1250.h> +#include <asm/sibyte/sb1250_regs.h> +#include <asm/sibyte/sb1250_int.h> +#include <asm/sibyte/sb1250_scd.h> + +#define SB1250_HPT_NUM 3 +#define SB1250_HPT_VALUE M_SCD_TIMER_CNT /* max value */ + +/* + * The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over + * again. + */ +static inline u64 sb1250_hpt_get_cycles(void) +{ + unsigned int count; + void __iomem *addr; + + addr = IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT)); + count = G_SCD_TIMER_CNT(__raw_readq(addr)); + + return SB1250_HPT_VALUE - count; +} + +static u64 sb1250_hpt_read(struct clocksource *cs) +{ + return sb1250_hpt_get_cycles(); +} + +struct clocksource bcm1250_clocksource = { + .name = "bcm1250-counter-3", + .rating = 200, + .read = sb1250_hpt_read, + .mask = CLOCKSOURCE_MASK(23), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u64 notrace sb1250_read_sched_clock(void) +{ + return sb1250_hpt_get_cycles(); +} + +void __init sb1250_clocksource_init(void) +{ + struct clocksource *cs = &bcm1250_clocksource; + + /* Setup hpt using timer #3 but do not enable irq for it */ + __raw_writeq(0, + IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, + R_SCD_TIMER_CFG))); + __raw_writeq(SB1250_HPT_VALUE, + IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, + R_SCD_TIMER_INIT))); + __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, + IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, + R_SCD_TIMER_CFG))); + + clocksource_register_hz(cs, V_SCD_TIMER_FREQ); + + sched_clock_register(sb1250_read_sched_clock, 23, V_SCD_TIMER_FREQ); +} |